Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 01/30/07


AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
AFDLWX 935 PM EST MON JAN 29 2007

.EVENING UPDATE...

NO UPDATES NECESSARY TO THE GOING FCST. FCST MIN TEMPS IN AGREEMENT WITH LATEST GDNC... OBS AND 00Z DULLES SOUNDING. A SMALL CHANCE OF SNOW STILL LOOKS RSNBL FOR LATE TUESDAY GIVEN A CLIPPER SYSTEM DROPPING ESE FROM THE GRT LKS. THE BEST CHC FOR SNOW LOOKS TO BE IN OUR NORTHERN CWFA...SUCH AS NORTH-CENTRAL MARYLAND CLOSER TO THE BETTER LAPSE RATES PRODUCED BY UPPER TROUGH. MARINE WINDS ABOUT 10 KT OR LESS FOR THE REMAINDER OF THE NIGHT.

JB

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...

WATER VAPOR LOOP SHOWS A TROUGH MOVING INTO THE ATLANTIC...AS THE NEXT UPPER LOW DROPS SOUTH INTO THE UPPER MIDWEST. ACARS 400-250MB WIND OBSERVATIONS REVEAL A NORTHWESTERLY 120-160KT JET FROM THE PLAINS THROUGH THE SOUTHEAST CONUS. 11Z SURFACE ANALYSIS PLACED THE ARCTIC BOUNDARY FROM A 1000MB OCCLUDED CYCLONE IN NORTHERN MINNESOTA EAST THROUGH THE UPPER GREAT LAKES AND NEW ENGLAND. A 1028MB ANTICYCLONE DOMINATED THE GULF STATES. A TROUGH WAS LOCATED IN LEE OF THE APPALACHIANS.

WARM ADVECTION WILL BE INCREASING WITHIN THE MID LEVELS OVERNIGHT AS THE NEXT WAVE ROTATES EAST FROM THE UPPER MIDWEST. THIS WILL BRING PERIODS OF MID LEVEL CLOUDS OVERNIGHT ON NEARLY ZONAL FLOW ALOFT. THERE WILL BE SEVERAL HOURS OF CLEAR SKY DURING THE EVENING...ALLOWING TEMPERATURES TO FALL EFFICIENTLY WITH DECOUPLING IN THE DRY AIRMASS. EXPECT TEMPERATURES TO RISE IN THE HIGHER TERRAIN AS SOUTHWEST WINDS BRING IN WARMER AIRMASS ALOFT OVERNIGHT.

THE NEXT WAVE WILL BE SHEARING INTO THE REGION THROUGH THE DAY TUESDAY. THIS WILL ALLOW CLOUDS TO THICKEN ACROSS THE REGION...AND THEREFORE WENT A FEW DEGREES BELOW MOS GUIDANCE FOR HIGH TEMPERATURES. EXPECT WESTERLY FLOW TO INDUCE SOME UPSLOPE PRECIPITATION ACROSS THE MOUNTAINS BY THE END OF THE DAY. 12Z NAM/GFS BUFKIT FORECAST SOUNDINGS INDICATE STEEPENING MID LEVEL LAPSE RATES WITHIN THE CLOUD LAYER...AND HAVE INTRODUCED LOW CHANCE OF SNOW SHOWERS AS FAR SOUTH AS WASHINGTON DC...AND FLURRIES INTO CENTRAL VIRGINIA DURING THE LATE AFTERNOON.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...

12Z GFS MODEL COMING MORE IN LINE WITH EUROPEAN MODEL IN RESPECT TO TIMING AND TRACK OF COASTAL LOW EXPECTED TO IMPACT THE AREA ON THU-THU NIGHT. LATEST ENSEMBLE PLOT ALSO SHOWS GOOD CLUSTERING WITH THIS LOW INCREASING CONFIDENCE ON A WINTER PRECIP EVENT ACROSS THE AREA THU-THU NIGHT. THIS IS ABOUT 24 HRS FASTER THAN RUNS FROM 24 HRS AGO. TREND IN THE MODELS IS ALSO FOR A FURTHER EAST TRACK AND TO HOLD THE COLD AIR AT THE SFC LONGER RESULTING IN A MOSTLY FROZEN PRECIP EVENT. WILL CONTINUE TO USE GENERIC RAIN/SNOW WORDING AS THIS EVENT IS STILL MORE THAN 72 HRS AWAY AND THERE IS STILL PRECIP TYPE ISSUES. LOW IS WELL OFFSHORE BY 12Z FRI.

REST OF THE EXTENDED...CONTINUED COLD PATTERN AND MAINLY DRY AS SVRL SURGES OF ARCTIC AIR MOVE SOUTH FROM CANADA.

&&

.AVIATION /20Z-18Z/...

WARM ADVECTION WILL ALLOW MID LEVEL CLOUDS TO STREAM IN FOR PERIODS OF THE OVERNIGHT AS WINDS DECOUPLE. WINDS WILL BECOME SW TUESDAY WITH MIXING.

&&

.MARINE...

SMALL CRAFT ADVISORY IN EFFECT...WINDS EXPECTED TO DECOUPLE THIS EVENING.

12Z ETA/MAV MOS AT THOMAS POINT INDICATE SUSTAINED WINDS FALL BELOW 10KT THIS EVENING...AND INCREASE TO 15KT TUESDAY AFTERNOON. 12Z NAM/GFS PROXIMITY BUFKIT FORECAST SOUNDINGS SHOW ADDITIONAL MOMENTUM TRANSFER OF UP TO 25KT TUESDAY AFTERNOON.

WATER LEVELS ARE CURRENTLY ABOUT A HALF FOOT TO A FOOT BELOW ASTRONOMIC PREDICTIONS. THE LUNAR CYCLE IS WAXING TOWARD A FULL MOON IN EARLY FEBRUARY.

THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM AND THE NOAA EXTRATROPICAL STORM SURGE MODEL BOTH SUGGEST TIDAL DEPARTURES GRADUALLY RETURN TO ASTRONOMIC PREDICTIONS LATE TONIGHT AND TOMORROW MORNING.

&&

.LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE... SMALL CRAFT ADVISORY FROM 12 PM TUESDAY TO 12 PM EST WEDNESDAY FOR ANZ530>537.

&&

$$

SHORT TERM...ROGOWSKI LONG TERM...ROSA AVIATION...ROGOWSKI MARINE...ROGOWSKI


AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
AFDLWX 244 PM EST SUN JAN 28 2007

.SHORT TERM /TONIGHT THROUGH MONDAY/... ...SIGNIFICANT UPSLOPE SNOW EVENT EXPECTED ACROSS THE MOUNTAINS... ...POSSIBLE LIGHT ACCUMULATIONS ACROSS THE METRO AREAS THIS EVENING AND EARLY TONIGHT...

WATER VAPOR LOOP SHOWS A SHORT WAVE MOVING EAST THROUGH THE CAROLINAS...WITH A SHEAR AXIS ACROSS THE FORECAST AREA. THE NEXT AND MORE VIGOROUS WAVE IS DROPPING SOUTHEAST THROUGH THE MIDWEST. ACARS 400-250MB WIND OBSERVATIONS REVEAL A 100-120KT SOUTHWESTERLY JET FROM THE MIDWEST INTO NEW ENGLAND...AND A 130-150KT SOUTHWESTERLY JET FROM THE NORTHERN GULF OF MEXICO THROUGH THE CAROLINAS. 11Z SURFACE ANALYSIS PLACED A COLD FRONT FROM THE WESTERN GULF OF MEXICO TO NEAR CHARLOTTESVILLE...THEN EAST ACROSS THE DELMARVA. A 1029MB ANTICYCLONE WAS LOCATED ACROSS THE CENTRAL CONUS...WITH THE ARCTIC COLD FRONT STRETCHED FROM THE UPPER MIDWEST EAST ACROSS THE GREAT LAKES AND NORTH INTO NEW ENGLAND.

A SIGNIFICANT UPSLOPE SNOW EVENT IS UNDERWAY ACROSS THE WESTERN MOUNTAINS. BAYARD AND MOUNT STORM CHECKED IN WITH 1-1.5" ALREADY EARLY THIS MORNING. THE NAM HAS BEEN VERY CONSISTENT WITH INDICATING ABOUT A HALF INCH OF LIQUID EQUIVALENT THROUGH 12Z MONDAY...AND THE SHORT RANGE ENSEMBLES ALSO HAVE BEEN CLUSTERED BETWEEN 0.5-0.7" FOR THE PAST FEW RUNS AT KEKN. THE DENDRITIC SNOW GROWTH LAYER IS ALSO WITHIN THE VERTICAL MOTION FORCED BY THE TERRAIN. WITH REPORTS OF HEAVY SNOW AND THE ARRIVAL OF UNSTABLE AIR LATE THIS AFTERNOON...HAVE A WINTER STORM WARNING ACROSS THE FAR NORTHWEST 3 COUNTIES...AND A SNOW ADVISORY ACROSS HIGHLAND AND PENDLETON COUNTIES.

THIS EVENING AND EARLY TONIGHT APPEAR INTERESTING WITH THE ARRIVAL OF A VIGOROUS SHORT WAVE. INSTABILITY IS VERY APPARENT WITH 7-9C/KM LAPSE RATES FROM THE SURFACE TO ABOVE 700MB. EXPECT SNOW SHOWERS TO ARRIVE FROM THE NORTH AND WEST THIS EVENING WITH THE INSTABILITY. MODEL GUIDANCE AND MOS DO NOT PRESENT MUCH QPF OR PROBABILITY OF PRECIPITATION...HOWEVER THIS IS A CASE FOR GOING WELL ABOVE GUIDANCE. IT DOES NOT TAKE MUCH MOISTURE TO DEVELOP PRECIPITATION WITHIN AN UNSTABLE AIRMASS ALONG A VIGOROUS SHORT WAVE. IT COULD SNOW HEAVILY FOR A BIT IN SOME PLACES AS THE DENDRITIC SNOW GROWTH LAYER IS WITHIN THE UNSTABLE 900-700MB LAYER.

APPEARS BEST CHANCES FOR ACCUMULATION ARE ALONG AND EAST OF INTERSTATE 95...WHERE THE INCOMING INSTABILITY WILL INTERSECT REMAINING SHEAR AXIS ALOFT. TO NARROW IT DOWN FURTHER...THE BALTIMORE METRO AREA HAS THE BEST CHANCES OF AN INCH OR GREATER. FOR NOW HAVE MENTIONED AN INCH OF SNOW...BUT EVENING SHIFT WILL HAVE TO MONITOR RADAR TRENDS FOR A POSSIBLE SNOW ADVISORY AS INSTABILITY COMES IN TO SEE HOW MUCH OF A PLAYER THE SHEAR AXIS IS FOR FOCUSING SNOW SHOWERS. HAVE ISSUED A SPECIAL WEATHER STATEMENT AS STRONG INSTABILITY SHOULD PROVIDE FOR HIGH IMPACT SUB ADVISORY CONDITIONS WITH BRIEF REDUCTION IN VISIBILITIES BELOW A HALF MILE.

WINDS INCREASE OVERNIGHT AS A CYCLONE QUICKLY DEVELOPS WELL OFFSHORE AND THE GRADIENT STRENGTHENS WITHIN STRONG COLD ADVECTION REGIME.

BUILDING HEIGHTS WILL ALLOW ANTICYCLONIC FLOW TO BUILD IN...CAUSING UPSLOPE SNOW SHOWERS TO DISSIPATE MONDAY. DOWNSLOPE FLOW...ALBEIT WEAKENING THROUGH THE DAY...SHOULD BE ENOUGH TO ERODE LOW LEVEL MOISTURE FROM THE SHENANDOAH VALLEY EASTWARD DURING THE DAY. WENT BELOW MOS GUIDANCE FOR HIGH TEMPERATURES WITH PRESENCE OF STRONG COLD ADVECTION AND SOME AREAS OF ANTICIPATED LIGHT SNOW ACCUMULATION OVERNIGHT.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... RELATIVELY QUIET EXTENDED...UNTIL THE END OF THE WORK-WEEK.

ZONAL FLOW IN THE MID LEVELS AT THE BEGINNING OF THE PERIOD. THIS PRETTY MUCH WILL BE STATUS QUO UNTIL THURSDAY. SEVERAL PIECES OF SHORTWAVE ENERGY TRAVEL EAST WITHIN THE FLOW...WITH TWO NOTABLE SHORTWAVES...ONE LATE TUESDAY/WEDNESDAY AND THE OTHER ON THURSDAY. THE ZONAL FLOW WILL TURN MORE SOUTHWEST LATER THURSDAY AS A TROUGH DIGS OVER THE WEST-CENTRAL PART OF THE COUNTRY. THE LONGWAVE TROUGH WILL MOVE EAST THROUGH FRIDAY BEFORE SETTING UP ALONG THE EAST COAST ON SATURDAY.

HIGH PRESSURE WILL BE BUILDING IN MONDAY EVENING. A FRONTAL BOUNDARY COMES TROUGH ON TUESDAY...BUT PRECIP REMAINS CONFINED TO WEST OF THE BLUE RIDGE. UPSLOPE SNOW SHOWERS WILL CONTINUE THROUGH LATE TUESDAY/EARLY WEDNESDAY. MOISTURE BEGINS TO INCREASE ON THURSDAY AHEAD OF THE NEXT FRONTAL BOUNDARY AND A DEVELOPING COASTAL LOW PRESSURE SYSTEM. THE COASTAL LOW IS EXPECTED TO MOVE UP THE EAST COAST ON FRIDAY. HIGH PRESSURE BUILDS IN FOR THE WEEKEND.

DID NOT REALLY DEVIATE FROM GUIDANCE FOR MOST OF THE EXTENDED...JUST MADE SOME MINOR TWEAKS. THERE ARE SOME INDICATIONS OF A WINTRY MIX ON FRIDAY W OF THE BLUE RIDGE...AND WILL HAVE RN/SN MIX FOR NOW.

&&

.AVIATION... STRONG MID LEVEL INSTABILITY WILL ENTER THE REGION FROM THE NORTH AND WEST THIS EVENING...ALLOWING CONVECTIVE SNOW SHOWERS TO DEVELOP THROUGH THE FIRST PORTION OF THE NIGHT. LIFR VISIBILITIES AND MVFR CEILINGS WILL BE POSSIBLE WITHIN THE HEAVIER SNOW SHOWERS...WHICH WILL BE ENDING FROM WEST TO EAST BEHIND THE SHORT WAVE BEGINNING AROUND MIDNIGHT. STRONG COLD ADVECTION WILL MAINTAIN STRONG NORTHWEST WIND GUSTS THROUGH THE NIGHT...UNTIL THE GRADIENT RELAXES MONDAY MORNING.

&&

.MARINE... SMALL CRAFT ADVISORY IN EFFECT. OBSERVED WIND GUSTS ALONG AND WEST OF THE BLUE RIDGE ARE 20KTS.

12Z ETA/MAV MOS AT THOMAS POINT INDICATE SUSTAINED WINDS INCREASE TO 20KT LATE TONIGHT AND MONDAY. 12Z NAM/GFS PROXIMITY BUFKIT FORECAST SOUNDINGS SHOW ADDITIONAL MOMENTUM TRANSFER INCREASE TO JUST OVER 30KT LATE TONIGHT. WITH STRENGTHENING GRADIENT AS A CYCLONE QUICKLY DEVELOPS OFF THE COAST THIS EVENING AND STRONG DYNAMICS PASSING OVERHEAD...WILL GO SLIGHTLY MORE PESSIMISTIC THAN GUIDANCE AND RAISE A GALE WARNING FOR 35KT WIND GUSTS THROUGH 10AM.

SMALL CRAFT CONDITIONS ARE STILL POSSIBLE TUESDAY INTO WEDNESDAY BEHIND THE FRONTAL BOUNDARY. HAVE INCREASED WINDS TO AROUND 15 KTS OVER THE WATERS...SOME 20KT MAY SHOW UP IN THE BAY.

AS THE COASTAL LOW TRAVELS UP THE EASTERN SEABOARD ON FRIDAY/SATURDAY WINDS MAY ONCE AGAIN INCREASE TO SMALL CRAFT ADVISORY LEVELS.

&&

.TIDES... WATER LEVELS ARE CURRENTLY ABOUT A HALF FOOT ABOVE ASTRONOMIC PREDICTIONS. THE LUNAR CYCLE IS WAXING TOWARD A FULL MOON IN EARLY FEBRUARY (79% FULL).

THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM AND THE NOAA EXTRATROPICAL STORM SURGE MODEL BOTH SUGGEST TIDAL DEPARTURES REMAIN AT CURRENT DEPARTURES OR GRADUALLY RETURN TO ASTRONOMIC PREDICTIONS THROUGH TONIGHT.

&&

.LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MDZ501.

WIND CHILL ADVISORY FROM 10 PM THIS EVENING TO 10 AM EST MONDAY FOR MDZ501.

VA...WIND CHILL ADVISORY FROM 10 PM THIS EVENING TO 10 AM EST MONDAY FOR VAZ021.

SNOW ADVISORY UNTIL 7 AM EST MONDAY FOR VAZ021.

WV...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR WVZ501-503.

WIND CHILL ADVISORY FROM 10 PM THIS EVENING TO 10 AM EST MONDAY FOR WVZ054-501-503.

SNOW ADVISORY UNTIL 7 AM EST MONDAY FOR WVZ054.

MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ530>537.

SMALL CRAFT ADVISORY FROM 9 AM TO 6 PM EST MONDAY FOR ANZ530>537.

GALE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EST MONDAY FOR ANZ530>537.

&&

$$

SHORT TERM/AVIATION/TIDES...ROGOWSKI LONG TERM...LISTEMAA MARINE...ROGOWSKI/LISTEMAA


AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
AFDLWX 1040 AM EST SUN JAN 28 2007

.SHORT TERM... ...SIGNIFICANT UPSLOPE SNOW EVENT EXPECTED ACROSS THE MOUNTAINS... ...POSSIBLE LIGHT ACCUMULATIONS ACROSS THE METRO AREAS THIS EVENING AND EARLY TONIGHT...

WATER VAPOR LOOP SHOWS A SHORT WAVE MOVING EAST THROUGH THE CAROLINAS...WITH A SHEAR AXIS ACROSS THE FORECAST AREA. THE NEXT AND MORE VIGOROUS WAVE IS DROPPING SOUTHEAST THROUGH THE MIDWEST. ACARS 400-250MB WIND OBSERVATIONS REVEAL A 100-120KT SOUTHWESTERLY JET FROM THE MIDWEST INTO NEW ENGLAND...AND A 130-150KT SOUTHWESTERLY JET FROM THE NORTHERN GULF OF MEXICO THROUGH THE CAROLINAS. 11Z SURFACE ANALYSIS PLACED A COLD FRONT FROM THE WESTERN GULF OF MEXICO TO NEAR CHARLOTTESVILLE...THEN EAST ACROSS THE DELMARVA. A 1029MB ANTICYCLONE WAS LOCATED ACROSS THE CENTRAL CONUS...WITH THE ARCTIC COLD FRONT STRETCHED FROM THE UPPER MIDWEST EAST ACROSS THE GREAT LAKES AND NORTH INTO NEW ENGLAND.

RAIN HAS DEVELOPED ON THE UPPER LEVEL SHEAR AXIS ACROSS THE CENTRAL FORECAST AREA...WHICH WILL CONTINUE TO PIVOT SOUTH AND EAST AFFECTING MAINLY LOWER SOUTHERN MARYLAND THIS AFTERNOON. A FEW HUNDREDTHS OF AN INCH OF RAIN WERE RECORDED THIS MORNING ACROSS THE WASHINGTON AND BALTIMORE METRO AREAS...WITH SIMILAR AMOUNTS EXPECTED FURTHER SOUTH.

A SIGNIFICANT UPSLOPE SNOW EVENT IS UNDERWAY ACROSS THE WESTERN MOUNTAINS. BAYARD AND MOUNT STORM CHECKED IN WITH 1-1.5" ALREADY EARLY THIS MORNING...WITH LIQUID EQUIVALENT AT MOUNT STORM OF 0.07" (20 TO 1 SNOW RATIO). THE NAM HAS BEEN VERY CONSISTENT WITH INDICATING ABOUT A HALF INCH OF LIQUID EQUIVALENT THROUGH 12Z MONDAY...AND THE SHORT RANGE ENSEMBLES ALSO HAVE BEEN CLUSTERED BETWEEN 0.5-0.7" FOR THE PAST FEW RUNS AT KEKN. THE DENDRITIC SNOW GROWTH LAYER IS ALSO WITHIN THE VERTICAL MOTION FORCED BY THE TERRAIN. WITH REPORTS OF HEAVY SNOW AND THE ARRIVAL OF UNSTABLE AIR LATE THIS AFTERNOON...HAVE UPGRADED TO A WINTER STORM WARNING ACROSS THE FAR NORTHWEST 3 COUNTIES...AND ISSUED A SNOW ADVISORY ACROSS HIGHLAND AND PENDLETON COUNTIES.

IN BETWEEN THE UPSLOPE SNOW AND SHEAR AXIS RAIN...NOT SEEING MUCH FORCING SO HAVE REMOVED POPS THIS AFTERNOON.

THIS EVENING AND EARLY TONIGHT APPEAR INTERESTING WITH THE ARRIVAL OF A VIGOROUS SHORT WAVE. INSTABILITY IS VERY APPARENT WITH 7-9C/KM LAPSE RATES FROM THE SURFACE TO ABOVE 700MB. EXPECT SNOW SHOWERS TO ARRIVE FROM THE NORTH AND WEST THIS EVENING WITH THE INSTABILITY. MODEL GUIDANCE AND MOS DO NOT PRESENT MUCH QPF OR PROBABILITY OF PRECIPITATION...HOWEVER THIS IS A CASE FOR GOING WELL ABOVE GUIDANCE. IT DOES NOT TAKE MUCH MOISTURE TO DEVELOP PRECIPITATION WITHIN AN UNSTABLE AIRMASS ALONG A VIGOROUS SHORT WAVE. HAVE INCREASED POPS TO 50 PERCENT FOR NOW AND WILL LOOK AT FURTHER OBSERVATIONS FOR POSSIBLY INCREASING THEM FURTHER AND INCLUDING LIGHT ACCUMULATIONS. IT COULD SNOW HEAVILY FOR A BIT IN SOME PLACES AS THE DENDRITIC SNOW GROWTH LAYER IS WITHIN THE UNSTABLE 900-700MB LAYER.

&&

.AVIATION... WINDS BACK FROM NORTHERLY TO NORTHWEST AS LOW PRESSURE DEVELOPS WELL OFF THE EAST COAST (AND MAY BEGIN TO GUST AS THE GRADIENT INCREASES). SHEAR AXIS SUPPORTING LIGHT RAIN AND MVFR CIGS/VFR VISBY WILL TRANSLATE TO THE SOUTHEAST OF THE METRO TERMINALS BY MIDDAY. EXPECT SCT-BKN040 TO PERSIST THROUGH THE AFTERNOON.

&&

.MARINE... SMALL CRAFT ADVISORY IN EFFECT. OBSERVED WIND GUSTS IN THE MOUNTAINS ARE BETWEEN 15-20KTS. OBSERVED WINDS JUST ABOVE THE MIX LAYER ARE 20KT ON THE 12Z KIAD RAOB.

00Z ETA/06Z MAV MOS AT THOMAS POINT INDICATE SUSTAINED WINDS BETWEEN 8-12KTS TODAY. 06Z NAM/GFS PROXIMITY BUFKIT FORECAST SOUNDINGS SHOW ADDITIONAL MOMENTUM TRANSFER OF 15-20KTS. WITH STRENGTHENING GRADIENT THIS EVENING...WILL MAINTAIN THE SMALL CRAFT ADVISORY DURING THE DAY TODAY WITH 20KT WIND GUSTS.

&&

.TIDES... WATER LEVELS ARE CURRENTLY LESS THAN A HALF FOOT ABOVE ASTRONOMIC PREDICTIONS. THE LUNAR CYCLE IS WAXING TOWARD A FULL MOON IN EARLY FEBRUARY.

THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM AND THE NOAA EXTRATROPICAL STORM SURGE MODEL BOTH SUGGEST TIDAL DEPARTURES REMAIN AT CURRENT DEPARTURES OR GRADUALLY RETURN TO ASTRONOMIC PREDICTIONS THROUGH THIS TONIGHT.

&&

.LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MDZ501.

VA...SNOW ADVISORY UNTIL 7 AM EST MONDAY FOR VAZ021.

WV...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR WVZ501-503.

SNOW ADVISORY UNTIL 7 AM EST MONDAY FOR WVZ054.

MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST MONDAY FOR ANZ530>537.

&&

$$

SHORT TERM/AVIATION/MARINE/TIDES...ROGOWSKI


AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
AFDMQT 940 PM EST MON JAN 29 2007

.UPDATE... RADAR INDICATED A PROMINENT LES BAND FROM THE LEELANAU PENINSULA TO SE UPPER MI. MESO-LOW CHARACTER TO THE BAND INTO THE AREA FROM KESC-KISQ WILL ENHANCE SNOWFALL RATES IN AN ENVIRONMENT ALREADY VERY FAVORABLE FOR SNOW GROWTH. 00Z AREA TAMDAR SNDGS SHOWED 850 MB TEMPS NEAR -17C WITH MOIST PROFILE OR NO INVERSION TO 700 MB(KPLN). THE 00Z NAM WAS CATCHING ON TO THIS FEATURE WHILE THE 18Z RUC13 HAD BEST GRASP OF THE LES SCENARIO. THE SHRTWV OVER NE WI IS EXPECTED TO SAG SE HELPING TO DRAG THE ASSOCIATED SFC LOW ALONG. THIS SHOULD RESULT IN A STRONG ENOUGH NRLY FLOW TO PUSH THE BAND OUT OF THE CWA BY 06Z-09Z. GIVEN POTENTIAL FOR 2-3 INCH SNOWFALL RATES WITH THE BAND(PER REPORT NEAR PT AUX BARQUES)...EXPECT LCL AMOUNTS INTO THE 4-8 INCH RANGE. SO...LES WARNING WAS POSTED FOR DELTA-SCHOOLCRAFT COUNTIES.

FARTHER NORTH...LES WAS ALSO INCREASING JUST OFFSHORE FROM MARQUETTE AND WERE MOVING INLAND AS NE WINDS GRADUALLY INCREASE. THE RUC13 ALSO SUGGESTS THAT THE BEST LOW LVL CONV WILL QUICKLY SHIFT FORM KP59-STANNARD ROCK VCNTY SOUTHWARD WITH THE POTENTIAL FOR MORE SIGNIFICANT LES INTO MARQUETTE COUNTY. HOWEVER...CONFIDENCE IN THIS SCENARIO IS MORE LIMITED...GIVEN UNORGANIZED LOOK OF THE LES ON RADAR. SO...WILL ONLY MODERATELY BOOST GOING SNOWFALL AMOUNT FCST INTO THIS AREA.

&&

JLB

.PREV DISCUSSION...ISSUED 346 PM EST MON JAN 29 2007.

...COLDEST AIR OF THE SEASON TO MOVE INTO WEST AND CENTRAL UPPER MICHIGAN ON FRI...

.SYNOPSIS...

WATER VAPOR LOOP AND UPR AIR ANALYSIS SHOWS A HIGH AMPLITUDE RDG OVER THE ERN PAC AND NW NOAM WHILE DOWNSTREAM A BROAD TROF IS NOTED MUCH OF CANADA EXTENDING INTO GREAT LAKES AND NE U.S. THIS HIGH AMPLITUDE PATTERN NOT EXPECTED TO CHANGE MUCH THIS WEEK WHICH WILL ALLOW FOR POLAR VORTEX TO WORK ITS WAY SOUTHWARD INTO THE UPR GREAT LAKES BY THE WEEKEND. IN THE SHORT TERM...A SHORTWAVE/CLIPPER SYSTEM DIVING JUST TO OUR S HAS BROUGHT LIGHT SNOW TODAY TO MUCH OF WI AND SOME FLURRIES TO SW UPR MI. WINDS COMING AROUND TO THE N-NE THIS EVENING BEHIND CLIPPER SYSTEM WILL BRING SOME LES BACK ONSHORE TONIGHT INTO TUE.

&&

.SHORT TERM (TONIGHT AND TUE)...

THE MAIN CONCERN IS LES FOR TONIGHT INTO TUE.

SFC/MARINE OBS SHOWS WINDS ALREADY STARTING TO COME AROUND TO NE OVER WRN LAKE SUPERIOR IN LINE WITH FCST OF RUC AND LOCAL MESOSCALE MODELS. MID-LAKE LES CONVERGENCE BAND OVER LAKE SUPERIOR EXPECTED TO COME ONSHORE THIS EVENING INTO WRN AND NCNTRL COUNTIES AS WINDS SHIFT TO N-NE BEHIND CLIPPER SYSTEM NOW DIVING S. EXPECT A BURST OF HEAVIER SNOW AS CONVERGENCE BAND COMES THROUGH AND THEN LOOK FOR SOME WIND-PARALLEL BANDS SETTING UP BEHIND IT INTO TUE.

WEAK ENHANCEMENT THIS EVENING FROM MID-LVL TROF PASSAGE COULD BOOST SNOW AMTS SOME...BUT SHIFTING WINDS WILL NOT FOCUS HEAVY BANDS OVER ANY ONE AREA FOR TOO LONG. BEST CONVERGENCE WITH N-NE FLOW WOULD TEND TO FAVOR MQT COUNTY WHERE MESOSCALE MODEL QPF AROUND .10-.15 INCH COULD BRING TOTAL ACCUMULATIONS UP TO 4 INCHES AT SOME HIGHER TERRAIN LOCATIONS TONIGHT INTO TUE MORNING. SOME LOCATIONS IN GOGEBIC AND ONTONAGON COUNTIES COULD SEE UP TO 3 INCHES. ELSEWHERE ACROSS THE NRN TIER COUNTY...GENERALLY EXPECT 1-2". DID BUMP POPS TO CATEGORICAL FOR WEST AND NCNTRL COUNTIES TONIGHT WITH GOOD CYCLONIC FLOW AND POTENTIAL ENHANCEMENT FROM MID-LVL TROF.

LOOKS LIKE LES SHOULD TAPER OFF OR END QUICKLY FOR MOST LOCATIONS BY MIDDAY TUE AS FLOW BECOMES ANTICYCLONIC AND BACKS MORE WRLY WITH BUILDING SFC RDG FROM THE NRN PLAINS. LEFT HIGHER POPS OVER ERN COUNTIES DUE TO LONGER FETCH ACROSS LAKE SUPERIOR IN NW TO W FLOW.

.LONG TERM (TUE NIGHT THROUGH MON)...

TUE NIGHT...MODELS SHOW A SHRTWV OVER THE NE PORTION OF NUNAVUT MOVING SSE THROUGH THE FLOW ALOFT...MOVING ACROSS NORTHERN ONTARIO DURING THIS TIME PERIOD. THE NAM BRINGS THIS SHRTWV MUCH CLOSER TO THE CWA THAN ALL THE OTHER MODELS (NEAR WAWA BY 06Z)...BUT BELIEVE THIS IS TOO CLOSE GIVEN THAT HEIGHTS ARE PROGGED TO RISE ACROSS THE UPPER MIDWEST AHEAD OF A TROUGH DIGGING INTO MONTANA. THEREFORE WILL FOLLOW THE GFS/REGIONAL CANADIAN AND OUR LOCAL WRF MODELS...WHICH KEEP THE SHRTWV FARTHER TO THE NE. BASICALLY...AS THIS SHRTWV MOVES DOWN...VERY WEAK ISENTROPIC ASCENT AND DPVA HELP TO PRODUCE A MID CLOUD DECK WHICH MOVES OVER THE CWA. AT THE LOW LEVELS...WITH A SURFACE RIDGE TRYING TO BUILD IN FROM THE WEST AND A WEAK TROUGH MOVING S ASSOCIATED WITH THE SHRTWV OVER LAKE SUPERIOR...A CONVERGENT LAKE EFFECT BAND LOOKS LIKELY...AIDED BY LAND BREEZES. RIGHT NOW THE BEST CONVERGENCE IS FOCUSED IN THE NORTHERN PART OF LUCE COUNTY AND EASTERN ALGER COUNTY...WHERE OUR LOCAL HIGH RESOLUTION WRF-ARW RUN PRINTS OUT UP TO 0.40 OF AN INCH OF QPF BETWEEN 00Z-12Z. DID NOT GO THIS HIGH...BUT GIVEN A FAVORABLE LAKE ENHANCED SETUP WITH STRONG CONVERGENCE...HAVE ADVISORY LEVEL SNOWFALL IN THE FORECAST. IN ADDITION...HAVE RAISED POPS TO LIKELY ACROSS THE KEWEENAW AND IN THE HIGH QPF AREA SINCE THESE CONTINUE TO LOOK FAVORABLE FOR SNOWFALL. FUTURE SHIFTS WILL NEED TO WATCH THIS EVENT IN CASE IT AMOUNTS TO MORE. GOING FORECAST TEMPS SEEM REASONABLE.

WED...SHRTWV TROUGH OVER MONTANA IS PROGGED TO DROP INTO NEBRASKA BY 00Z WHILE A WEAKER EXTENSION OF THIS SHRTWV EXTENDS UP INTO WESTERN LAKE SUPERIOR. THE MAIN EFFECT OF THE TROUGH WILL BE TO SWITCH THE LOW LEVEL WIND FLOW MORE WSW...THEREFORE ALLOWING THE LAKE EFFECT BAND OVER THE NE CWA TO MOVE NORTH DURING THE DAY. LAKE EFFECT SNOW WILL LIKELY AFFECT THE KEWEENAW AREA THOUGH...GIVEN THAT THE WIND FLOW IS STILL NOT TRUE SW...THEREFORE LIKELY POPS WERE MAINTAINED THROUGH THE DAY. ELSEWHERE...GIVEN THE APPROACHING SHRTWV AND STILL PLENTY OF MID LEVEL MOISTURE AROUND...FEEL IT IS STILL PRUDENT TO HAVE SOME SLIGHT CHANCE POPS IN. HOWEVER ANY SYNOPTIC SNOW RIGHT NOW DOES NOT LOOK LIKE A BIG DEAL. HIGH TEMPERATURES APPEAR THAT THEY WILL BE A LITTLE WARMER COMPARED TO TUE AS SW FLOW ALLOW 850MB TEMPS TO CLIMB TO ABOUT 3-5C HIGHER.

WED NIGHT AND THU...A MORE SIGNIFICANT SHRTWV TROUGH IS SHOWN BY THE GFS/UKMET/ECMWF TO DROP S THROUGH CANADA INTO THE NORTHERN PLAINS BY THU EVENING (MORE MENTIONED ABOUT THIS SHRTWV IN THE NEXT PERIOD DISCUSSION). THIS SHRTWV WILL CAUSE THE PREVIOUS WEAKER SHRTWV TROUGH OVER WESTERN LAKE SUPERIOR TO CROSS MUCH OF THE CWA EARLY IN THE EVENING. 850MB TEMPS ARE STILL AROUND -16C BEHIND THE SHRTWV...AND WITH A LIGHT TO NEARLY LAND-BREEZE CONVERGENT LOW LEVEL WIND FLOW...LAKE EFFECT CHANCES REMAINS FOR THE WESTERN U.P. WED NIGHT. HAVE KEPT THE REST OF THE CWA DRY...WITH SKIES BECOMING PARTLY CLOUDY AS WEAK RIDGING BUILDS IN AHEAD OF THE SHRTWV. BECAUSE OF THE CLEARING AND LIGHTER WINDS...DROPPED LOW TEMPS A FEW DEGREES. ON THU...AS THE SHRTWV TROUGH AND ASSOCIATED SURFACE LOW APPROACH THE CWA...CLOUD COVER SHOULD BEGIN TO INCREASE AGAIN. FOR NOW HAVE KEPT SOME SLIGHT CHANCE POPS FOR THE WARM ADVECTION AHEAD OF THE TROUGH...BUT AS THE POPS STATE...AM NOT VERY CONFIDENT. HAVE ALSO KEPT 30 POPS IN FOR THE SAME LAKE EFFECT AREA MENTIONED WED NIGHT...BUT WITH THE 950MB AND SURFACE WINDS TURNING TRUE SW AHEAD OF THE SURFACE LOW...THINK MUCH OF THE SNOW MAY END UP BEING IN THE MORNING. HIGH TEMPERATURES ARE EXPECTED TO BE SIMILAR TO WED GIVEN SIMILAR 850MB READINGS AND SOME PARTIAL SUN IN THE MORNING TO HELP OUT.

THU NIGHT THROUGH MON...THE WORD FOR THIS PERIOD IS COLD. OPERATIONAL MODELS CONTINUE THE THEME THAT HAS BEEN SHOWN OVER THE PAST WEEK OF SUGGESTING THAT THE POLAR VORTEX CURRENTLY SITUATED NORTH OF HUDSON BAY WILL DIVE SOUTHWARD TOWARDS UPPER MICHIGAN...DUE TO THE DEVELOPMENT OF A VERY AMPLIFIED RIDGE INTO EASTERN ALASKA AND A STRONG SHRTWV NORTH OF ALASKA RIDING DOWN THE EAST SIDE OF THE RIDGE. THIS SHRTWV MAY RESULT IN AN INTERESTING FRI FOR THE CWA AS MODELS NOW INDICATE THAT BOTH IT AND AN ASSOCIATED SURFACE LOW (THE ONE THAT MOVES INTO THE NORTHERN PLAINS AND MINNESOTA ON THU) ARE STRONGER THAN PREVIOUSLY PROGGED. DPVA AND MOISTURE AHEAD OF THE SHRTWV MAY RESULT IN SOME LIGHT SNOW SPREADING ACROSS THE CWA THU NIGHT. THEN ON FRI AS THE SURFACE LOW PASSES ACROSS UPPER MI...THE COLD AIRMASS WITH 850MB TEMPS FALLING INTO THE LOW TO MID -20S C WILL BEGIN ADVECTING INTO THE CWA ON STRONG NW WINDS...POSSIBLY EVEN GALES ON EASTERN LAKE SUPERIOR. GIVEN HOW COLD IT IS...LAKE EFFECT THAT THE DOES FORM ONCE THE COLD AIRMASS MOVES IN WILL LIKELY CONSIST OF SMALL SNOWFLAKES...AND WITH THE WIND...BLOWING SNOW WITH VERY LOW VISIBILITIES MAY BECOME A CONCERN. COLDER AIR IS PROGGED TO CONTINUE ADVECTING INTO THE CWA FRI NIGHT THROUGH SUN AS THE POLAR VORTEX HEADS TOWARDS LAKE SUPERIOR. RIGHT NOW IT APPEARS FROM THE GFS/ECMWF THAT THE VORTEX WILL REACH NORTHERN LAKE SUPERIOR SOME POINT ON SUN...WITH 850MB TEMPS FALLING TO AROUND -30C. IF WINDS CAN BACK TO THE WEST AT NIGHT IN THE INTERIOR AND DIMINISH TO LIGHT...AND SKIES CAN CLEAR...-20S F TEMPERATURES WILL OCCUR. HOWEVER...PLENTY OF UNCERTAINTY EXISTS ON ALL THREE PARAMETERS AT THIS POINT AND RESULTS IN GOING NOW LOWER THAN -15F AT THIS POINT. OTHERWISE...WIND CHILLS WILL BE THE MAIN CONCERN DURING THE WEEKEND GIVEN LOW TEMPERATURES AND BREEZY CONDITIONS...PARTICULARLY OVER THE NORTHERN U.P.. THERE IS SOME UNCERTAINTY ON HOW LONG THE VORTEX WILL STAY AROUND...WITH THE 06Z/12Z GFS MUCH QUICKER ON EXITING IT (SUN NIGHT) COMPARED TO THE 00Z ECMWF WHICH STILL HAS IT NEAR WAWA MON EVENING. PREFER TO STAY CLOSER TO THE SLOWER ECMWF...WHICH IS CLOSE TO HPC PROGS.

WILL CONTINUE TO HIGHLIGHT THE UPCOMING COLD IN THE HWO. ON A FINAL NOTE...THE 00Z/12Z ECMWF SUGGESTS THE ARCTIC AIR MIGHT HANG AROUND FOR A FEW MORE DAYS AFTER MON...RAISING SOME CONCERN ABOUT POTENTIAL FOR PIPES UNDERGROUND FREEZING. THIS IS ESPECIALLY TRUE FOR THE SOUTH CENTRAL U.P. WHERE ONLY A FEW INCHES OF SNOW EXIST ON THE GROUND. WILL WAIT AND SEE ON THIS...BUT AT A MINIMUM...EVERYONE SHOULD TRY TO MAKE SURE ANY EXPOSED PIPES ARE INSULATED.

&&

.MQT WATCHES/WARNINGS/ADVISORIES... HEAVY FREEZING SPRAY WARNING WEST 1/2 LAKE SUPERIOR. LAKE EFFECT SNOW WARNING UNTIL 10Z FOR MIZ013-014.

&&

$$

AJ


AREA FORECAST DISCUSSION
NWS GAYLORD MI
AFDAPX 1100 AM EST SUN JAN 28 2007

.UPDATE...NORTHERN MICHIGAN THIS MORNING DOMINATED BY COLD NORTH TO NORTHEAST WINDS BETWEEN MID LEVEL TROUGH AXIS PASSING BY TO THE SOUTH AND SURFACE RIDGING BUILDING INTO THE WESTERN LAKES. IMPRESSIVE OVER WATER INSTABILITY (DELTA T VALUES ON THE ORDER OF 20C) AND REMNANT MID LEVEL MOISTURE KICKING OFF NORTHEAST TO SOUTHWEST ORIENTED LAKE SNOW SHOWERS OVER AREAS ALONG AND WEST OF GRAND TRAVERSE BAY AND ALONG THE LAKE HURON SHORELINE. RECENT CALLS TO SPOTTERS IN WARNING AND ADVISORY AREAS SHOWS ABOUT 5 INCHES OF NEW SNOW OVER PARTS OF LEELANAU COUNTY WITH MUCH LESSER AMOUNTS ELSEWHERE. SOME LIGHT SYNOPTIC SNOW ASSOCIATED WITH AFOREMENTIONED SHORTWAVE OVER SOUTHERN AREAS IS STEADILY DROPPING TO THE SOUTHEAST. ATTENTION THIS MORNING REMAINS CENTERED ON LAKE EFFECT SNOWS AND ASSOCIATED LAKE SNOW HEADLINES.

REST OF TODAY...SYNOPTIC SUPPORT AND MOISTURE QUICKLY ROTATES SOUTHEAST OUT OF THE AREA AS SOUTHERN LAKE MICHIGAN SHORTWAVE RACES EAST THROUGH SOUTHERN MICHIGAN. WESTERN LAKES SURFACE RIDGING CONTINUES TO BUILD INTO THE AREA BEHIND DEPARTING SYSTEM. SOME EVIDENCE OF THIS ALREADY OCCURRING WITH LAKE SUPERIOR BANDS ONCE AGAIN BECOMING ORIENTED NORTHWEST TO SOUTHEAST AS 1000MB-850MB WINDS BACK AROUND TO NORTHWESTERLY. INVERSION HEIGHTS ALSO SHOWING INFLUENCE OF INCREASED MID LEVEL SUBSIDENCE WITH MORNING ACARS SOUNDINGS OUT OF SAWYER IN THE CENTRAL U.P AND RHINELANDER IN NORTH CENTRAL WISCONSIN SHOWING INVERSION HEIGHTS AT ONLY 850MB (ABOUT 4.5KFT). EXPECT NORTHERN MICHIGAN WINDS TO SLOWLY BACK AROUND TO NORTHWEST DURING THE AFTERNOON...DIRECTING BANDS ONCE AGAIN FARTHER INLAND. OVERALL DIMINISHING TREND EXPECTED TO CONTINUE...DESPITE EXTREME OVER WATER INSTABILITY...WITH CRASHING INVERSION HEIGHTS AND 850MB-700MB MOISTURE DROPPING TO <40 PERCENT. BASED OFF CALLS AND EXPECTED TRANSIENT AND WEAKENING NATURE OF BANDS...WILL DROP MANISTEE COUNTY (ONLY HAD ABOUT AN INCH SO FAR) AND DOWNGRADE BENZIE AND GRAND TRAVERSE TO AN ADVISORY. COULD SEE LOCALIZED WARNING CRITERIA AMOUNT JUST WEST OF THE WEST ARM OF GRAND TRAVERSE BAY WHERE BETTER BANDING HAS SET UP THIS MORNING. HOWEVER...EXTREME LOCALIZED NATURE OF EVENT DOES NOT WARRANT A WARNING. WILL LEAVE LEELANAU COUNTY AS IS WITH RECENT 5 INCH REPORT AND SEVERAL BANDS YET TO TRAVERSE THE AREA. OTHERWISE...SNOW SHOWER THREAT WILL ONCE AGAIN INCREASE ALONG AND WEST OF INTERSTATE 75 OVER THE NORTHERN LOWER LATER THIS AFTERNOON AND EVENING AS REMNANT BANDS PROPAGATE FARTHER INLAND. ANY ACCUMULATIONS IN THIS AREA WILL BE MINIMAL. LAKE HURON BANDS WILL HANG ON A COUPLE HOURS MORE UNTIL THEY MOVE OFFSHORE WITH PERHAPS AN ADDITIONAL INCH OF ACCUMULATION. ACROSS EASTERN UPPER...COLD NORTHEAST DRAINAGE FLOW HAS KEPT BANDS WELL WEST OF CHIPPEWA COUNTY. MUCH LIKE THE NORTHERN LOWER...BANDS WILL MOVE BACK IN THIS AFTERNOON IN RESPONSE TO BACKING WINDS. COULD SEE UP TO AN INCH NEAR WHITEFISH POINT WITH LONGER LAKE SUPERIOR FETCH PARTIALLY OVERCOMING OTHER NEGATIVE PARAMETERS. AS FOR TEMPERATURES...DRAINAGE FLOW HAS SPREAD AS FAR SOUTH AS NORTHERN SECTIONS OF THE NORTHERN LOWER RESULTING IN TEMPERATURES A FEW DEGREES BELOW ZERO OVER EASTERN SECTION OF EASTERN UPPER MICHIGAN AND NEAR THE TIP OF THE MIT. HENCE...HAVE LOWERED HIGHS A COUPLE DEGREES IN THESE AREAS.

UPDATED WINTER WEATHER PRODUCTS/GRIDS/ZONES/NEARSHORES OUT SHORTLY.

MSB &&

.PREV DISCUSSION...ISSUED AT 410 AM EST SUN JAN 28 2007

IR/WATER VAPOR SATELLITE IMAGERY SHOWING SHORT WAVE CENTER AND AREA OF COOLER CLOUD TOPS PROGRESSING THROUGH SOUTHWEST WISCONSIN HEADING TOWARD ILLINOIS THIS MORNING. AT THE SFC... TROUGH/BACKDOOR COLD FRONT CONTINUES TO PROGRESS SOUTHWARD THROUGH NRN LOWER MICHIGAN NOW ROUGHLY ALONG THE M-55 CORRIDOR WHILE LAST BIT OF SYNOPTIC SNOWFALL ALSO SLIDING SOUTHWARD THROUGH NRN LOWER MICHIGAN. HEAVIEST LAKE EFFECT BANDING HAS SHIFTED INTO THE GRAND TRAVERSE BAY AREA AS THE LOW LEVEL FLOW BEHIND THE TROUGH SHIFTS TO THE NORTH. BUT INTERESTING TO NOTE THE MESO-LOW FEATURE THAT HAS DEVELOPED WITHIN THE SHARP TROUGH NOW SLIDING SOUTHWARD THROUGH GRAND TRAVERSE/KALKASKA COUNTIES. SOME ADDITIONAL LAKE BANDING NOTED COMING OFF LAKE HURON INTO PRESQUE ISLE COUNTY AND INTO THE HIGHER TERRAIN.

MAIN FORECAST CONCERN REVOLVES AROUND DISPOSITION OF ONGOING WARNINGS/ADVISORIES.

TODAY...FIRST OFF...WILL CONTINUE TO CARRY HIGHER POPS OVER MUCH OF NRN LOWER MICHIGAN THIS MORNING AS LAST BIT OF SYNOPTIC SNOWFALL (AND MESO-LOW FEATURE) SLIDES SOUTH WITH THE SHARP SFC TROUGH... COUPLED WITH NNE FLOW OFF LAKE HURON PRODUCING DECENT LIGHT SNOW COVERAGE ACROSS THE CENTRAL AND EASTERN COUNTIES. HOWEVER...BELIEVE SIGNIFICANT ACCUMULATING SNOW IS DONE FOR THE SO CALLED "BIG 5 COUNTIES" AND WILL ALLOW HEADLINES TO EXPIRE WITH MORNING FORECAST ISSUANCE. MAIN STORY WILL BE THE CONTINUING LAKE EFFECT EVENT AS MEAN 1000-850 MB FLOW TURNS ROUGHLY TO THE NORTH AND COLDER AIR SETTLES INTO NRN MICHIGAN. FROM A LAKE EFFECT STANDPOINT...CONDITIONS LOOKING GOOD FOR HEAVY LAKE EFFECT SNOWFALL THROUGH MID TO LATE AFTERNOON. LAKE-850 MB DELTA T/S AROUND 20C/WEAK OR NON EXISTENT INVERSIONS/ ABUNDANT LOW LEVEL MOISTURE AROUND THROUGH MID AFTERNOON. ONLY HINDRANCE WILL BE THE MEAN FLOW WHICH CURRENT LAPS DATA SHOWS IS VEERING BEHIND THE TROUGH TO ~020/030 DEGREES ON THE MICHIGAN SIDE THIS MORNING...AND SUGGESTS LEELANAU/BENZIE COUNTIES GET THE BULK OF HEAVIEST SNOWFALL. HOWEVER...FLOW IS FORECAST TO BACK TO ~360 DEGREES EARLY IN THE AFTERNOON PULLING SNOW BANDS BACK TOWARD GRAND TRAVERS COUNTY. AT THIS POINT WILL LET ONGOING WARNINGS/ADVISORY FOR GRAND TRAVERSE/LEELANAU/BENZIE/MANISTEE COUNTIES RIDE...AND LET THE EVENT PLAY OUT FOR AWHILE. AS FAR AS ACCUMULATIONS ARE CONCERNED: BASED ON THE PARAMETERS WE CERTAINLY SHOULD SEE INCH PER HOUR TYPE SNOW SHOWERS THIS MORNING THROUGH MID AFTERNOON PRODUCING OVERALL ACCUMULATIONS IN THE 3-6 INCH RANGE IN THE MOST FAVORED AREAS (AGAIN LEELANAU/BENZIE COUNTIES) AND LOCALIZED HIGHER AMOUNTS CERTAINLY A POSSIBILITY. WILL OPEN THE RANGE A BIT MORE FOR GRAND TRAVERSE COUNTY (2-6) GIVEN THE EARLY NNE FLOW TARGETING HIGHEST ACCUMS OVER WESTERN PORTION OF THE COUNTY. FOR MID TO LATE AFTERNOON...STRONG DRYING ALOFT STILL INDICATED WITH 850-700 MEAN RH LOWERING TO <50 PERCENT AS HIGH PRESSURE/ANTICYCLONIC FLOW NOSES INTO THE NRN MICHIGAN. LOW LEVEL FLOW LOOKING TO BACK TOWARD NNW OR NW BY EARLY EVENING WHICH WILL PULL REMAINING SNOW SHOWERS BACK TOWARD THE I-75 CORRIDOR LATE IN THE DAY. HOWEVER...DESPITE THE GREAT OVER LAKE INSTABILITY...THE OTHER MENTIONED FACTORS SHOULD TEMPER SNOW SHOWER INTENSITIES BY THAT POINT. THUS DO NOT FORESEE ANY ADDITIONAL HEADLINES BEYOND THE CURRENT ONES.

LAKE HURON SIDE...AS MENTIONED ABOVE NNE FLOW WILL CONTINUE TO PRODUCE ACCUMULATING LAKE SNOW SHOWERS INTO PRESQUE ISLE AND ALPENA COUNTIES EARLY ON...BUT EVENTUALLY SHIFTING TOWARD THE COAST (OR OFFSHORE) AS WINDS BACK MORE NORTHERLY. FURTHER BACKING OF THE WIND TOWARD IN THE AFTERNOON MAY ESTABLISH A LAKE SUPERIOR CONNECTION WITH SOME DECENT SNOW SHOWERS SKIRTING ALONG THE SHORELINE STRETCH OF PRESQUE ISLE COUNTY. BUT OVERALL...WITH THE SHIFTING WIND PATTERN WILL KEEP ACCUMULATIONS ON THE LIGHTER SIDE ACROSS NE LOWER MICHIGAN.

FINALLY...EASTERN UPPER MICHIGAN. NE FLOW PRETTY MUCH KEEPING EASTERN UPPER MICHIGAN OUT OF THE ACTION EARLY THIS MORNING. BUT FLOW IS EXPECTED TO BACK TOWARD NORTH WHICH WOULD PULL SOME SNOW SHOWERS BACK TOWARD WHITEFISH POINT...AND EVENTUALLY TO NW THIS AFTERNOON. BUT...DRYING ALOFT WILL ALREADY BE OVERSPREADING LAKE SUPERIOR THIS MORNING AND SHOULD KEEP OVERALL ACCUMULATIONS AT BAY (2 OR 3 INCHES AT BEST AROUND WHITEFISH POINT).

TONIGHT...FURTHER DRYING CONTINUES WHILE LOW LEVEL RIDGING SLIDES INTO THE WESTERN GREAT LAKES...AND LOW LEVEL FLOW BACKS FROM NW IN THE EVENING AROUND TO ROUGHLY WEST BY MONDAY MORNING. INTERESTING TO NOTE HOWEVER...LAKE INDUCED TROUGHING FORECAST TO REDEVELOP FROM EASTERN LAKE SUPERIOR DOWN ACROSS NRN LAKE HURON OVERNIGHT...WHICH IS REASONABLE GIVEN THE COLD AIRMASS ACROSS THE LAKES. SO ALTHOUGH LAKE EFFECT PARAMETERS NOT NECESSARILY CONDUCIVE TO HEAVY SNOW SHOWERS PRIMARILY DUE TO THE DRY AND COLD AIRMASS...LAKE TROUGHING MIGHT BE ENOUGH TO FOCUS SOME HEAVIER SNOW SHOWERS AND AN INCH OR TWO ACROSS CHIPPEWA COUNTY ESPECIALLY THE WHITEFISH POINT AREA. FOR NRN LOWER MICHIGAN...BACKING LOW LEVEL FLOW EXPECTED TO MIGRATE SNOW SHOWERS OFF THE LAKE INLAND AND NORTHWARD DURING THE NIGHT...WITH AN INCH OR TWO TOTAL ACCUMULATION IN THE MOST FAVORED AREAS.

MONDAY...NEXT IN A SERIES OF WAVES/CLIPPER SYSTEMS TRAVERSES THROUGH THE WESTERN GREAT LAKES LATE MONDAY THROUGH MONDAY NIGHT GENERATING SOME SYNOPTIC SNOWFALL ACROSS THE REGION. AT THIS POINT...NAM/GFS DISAGREE OVER TRACK OF THIS SYSTEM WITH THE NAM MUCH FARTHER SOUTH KEEPING ANY SYNOPTIC SNOWFALL OUT OF NRN MICHIGAN ALTOGETHER. GFS AS WELL AS THE ECMWF AND UKMET (WHICH IS EVEN FURTHER NORTH) SUGGEST SOME LIGHT SNOWFALL MOVING THROUGH NRN MICHIGAN WITH THIS SYSTEM LATE MONDAY AND MONDAY NIGHT. MEANWHILE...LIGHT LAKE EFFECT SNOW SHOWERS WILL MOST CERTAINLY BE ONGOING GIVEN THE OVER LAKE INSTABILITY...AND IF FURTHER NORTH TRACK OF UPCOMING SYSTEM IS CORRECT WOULD EXPECT SOME SORT OF UP TICK IN LAKE EFFECT INTENSITIES. WILL TREND FORECAST TOWARD THIS IDEA FOR NOW IF FOR NO OTHER REASON THAN MODEL CONSENSUS BUT STILL KEEP POPS IN THE CHANCY CATEGORY GIVEN THE UNCERTAINTY.

TUESDAY THROUGH THURSDAY...SOUNDING LIKE A BROKEN RECORD...BUT NO CHANGES IN THE ONGOING COLD PATTERN THROUGH THE WEEK. BLOCKING RIDGE PATTERN IN THE EASTERN PACIFIC ONLY STRENGTHENS...WHILE DOWNSTREAM LONG WAVE TROUGHING ACROSS CENTRAL AND EASTERN NAOM DEEPENS. WITHIN THE LONG WAVE TROUGH PATTERN...SERIES OF SHORT WAVES EXPECTED TO SLIDE THROUGH THE REGION DURING THIS TIME REINFORCING THE COLD AIR OVER THE GREAT LAKES AND BRINING PERIODS OF ENHANCED SNOW/LAKE EFFECT SNOW TO THE REGION. FIRST WAVE/SFC LOW SLATED TO ARRIVE LATE MONDAY INTO EARLY TUESDAY. AS IT STANDS...THIS SYSTEM IS EXPECTED TO BRING A ROUND OF SYNOPTIC SNOWFALL (PERHAPS A COUPLE OF INCHES) PRIMARILY TO LOWER MICHIGAN FOLLOWED BY LAKE EFFECT SNOW CONCERNS TUESDAY AND TUESDAY NIGHT. A BRIEF REPRIEVE AGAIN FOR WEDNESDAY (STILL LIGHT LAKE EFFECT) AS HIGH PRESSURE AND DRIER AIR PASS THROUGH. ANOTHER WAVE LATE WEDNESDAY INTO THURSDAY WHICH WILL BRING THE SAME CONCERNS AS TUESDAY. THIS GENERAL IDEA ALREADY PORTRAYED IN THE CURRENT FORECAST WITH FINER DETAILS TO BE WORKED OUT AS WE GET CLOSER TO THE EVENTS. THUS...NO SIGNIFICANT CHANGES ANTICIPATED AT THIS TIME.

ADAM

&&

.APX WATCHES/WARNINGS/ADVISORIES...LAKE EFFECT SNOW WARNING THROUGH THIS AFTERNOON...MIZ020. LAKE EFFECT SNOW ADVISORY THROUGH THIS AFTERNOON...MIZ025-026.

&&

$$


AREA FORECAST DISCUSSION...UPDATE
NWS GRAND RAPIDS MI
AFDGRR 1004 AM EST SUN JAN 28 2007

.UPDATED... AS OF 10 AM THE PRIMARY SNOW BAND HAS MOVED OFF SHORE FOR MOST OF THE GRR CWA. THERE IS A MESO-LOW JUST OFF SHORE OF HOLLAND MOVING DUE SOUTH. TAMDAR SOUNDINGS FROM WEST MICHIGAN SHOW WINDS OUT OF THE NORTHEAST OR EVEN EAST BELOW 10000 FT. THERE IS SHARP SURFACE TROUGH DROPPING SOUTH THROUGH LOWER MICHIGAN. AT 10 AM IT WAS NEAR INTERSTATE 96. OVERALL DUE TO THE NORTH NORTHEAST WINDS BEHIND THE TROUGH THROUGH 800 MB MOST OF TODAY... THE HEAVY SNOW BAND WILL REMAIN OFF SHORE. EXTREME EASTERN VAN BUREN COUNTY MAY SEE ANOTHER PERIOD OF MODERATE TO HEAVY SNOW AS THE MESO LOW NEAR HOLLAND MOVES THROUGH THE AREA. TIMING TOOLS SHOW THIS WOULD BE BETWEEN 11 AM AND NOON. AS A RESULT OF THE PRIMARY SNOW BAND STAYING OFF SHORE AND ONLY LIGHT SNOW SHOWERS INLAND ASSOCIATED WITH THE TROUGH... I PLAN ON DROPPING MOST OF OUR HEADLINES AROUND 11 AM. I MAY LEAVE VAN BUREN IN A WARNING TILL 1 PM...ENOUGH TIME TO ALLOW THE MESO LOW FEATURE TO MOVE THROUGH.

I DO EXPECT THE LAKE CONVERGENCE BAND TO MOVE ON SHORE THIS EVENING OVER MOST OF SOUTHWEST MICHIGAN BUT BY THEN THE INVERSION HEIGHTS WILL HAVE CRASHED AND THE FEATURE WILL BE FALLING APART. SO I SEE NO HEADLINE ISSUES THERE.

&& .GRR WATCHES/WARNINGS/ADVISORIES...LAKE EFFECT SNOW WARNING IN EFFECT THROUGH SUNDAY EVENING FOR OTTAWA...ALLEGAN...VAN BUREN... KALAMAZOO AND CALHOUN COUNTIES.

LAKE EFFECT SNOW ADVISORY MASON...OCEANA...AND MUSKEGON COUNTIES THROUGH SUNDAY EVENING.

SMALL CRAFT ADVISORY FOR THE NEARSHORE WATERS THROUGH SUNDAY NIGHT.

&&

$$

WDM


AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
AFDABQ 1046 AM MST SUN JAN 28 2007

.UPDATE...IMPROVED SKY COVER MANY W AND N ZONES FOR THIS PM. KEPT MENTION OF LOW CLOUDS AND SOME FOG OVER EC AND SE ZONES THROUGH EARLY TO MID PM AND ADJUSTED TEMPS DOWN. 40

&&

.PREV DISCUSSION...300 AM MST SUN JAN 28 2007... 09Z SFC ANALYSIS SHOWS A STNRY BNDRY DRAPED ALONG THE LEE OF THE CENTRAL MTN CHAIN WITH AN EXPANSIVE AREA OF LOW CLOUDS TO THE EAST OF THE FRONT. LATEST WV IMAGERY SHOWS AN UPPER LOW CENTERED NEAR SAN FRANCISCO ELONGATING EAST TO WEST BETWEEN AN ARCTIC SYSTEM DIVING SOUTH OVER WESTERN CANADA AND A TROPICAL PLUME MOVING NORTHEAST OVER THE E PACIFIC. LATEST 400-200MB AIRCRAFT WINDS SHOWS A 80-110 KNOT JET STREAKING ACROSS THE DESERT SW IN THE BASE OF THE CALIFORNIA UPPER LOW.

00Z MREF/03Z SREF IN FAIRLY GOOD AGREEMENT WITH EVOLN OF THE H5 PATTERN THRU THE SHORT TERM. 00Z GFS/NAM/ECMWF/UKMET ALSO ON BOARD IN THE SHORT TERM THAT WEAK SHORT WAVE RIDGING WILL CONTINUE TO DEVELOP TO THE WEST OF NM THRU MON NIGHT. THIS SPELLS PERIODS OF HIGH CLOUDINESS FOR NM SUNDAY AND MONDAY AND WEAK LEE TROUGHING IN THE E PLAINS. EXPECT LOW CLOUDS TO DISSIPATE TODAY ACROSS THE EAST AS LEE TROUGHING DEVELOPS SW WINDS. TEMPS WILL RISE INTO LOW TO MID 40S IN MOST AREAS...STILL 5 TO 10 DEG BELOW NORMAL. MODELS THEN INDICATE A COLD FRONT TO SWING SW THRU THE NE PLAINS AND CONTINUE WEST INTO THE CENTRAL VALLEYS TUESDAY MORNING. EXPECTING EAST CANYON WINDS TO DEVELOP USHERING IN SLIGHTLY COOLER TEMPS FOR TUESDAY FROM CENTRAL VALLEYS EASTWARD. RAISED POPS ACROSS THE EAST BEHIND THE FRONT TO CHANCE AS LOW LEVEL EASTERLY FLOW UNDERCUTS MOISTENING 700-500MB SW WINDS THUS ENHANCING ISENTROPIC LIFT. FRONT THEN EXPECTED TO WASH OUT LATE TUES INTO WED AS AN AREA OF LOW PRESSURE DEVELOPS OVER THE PLAINS STATES.

MODELS SHOW MORE UNCERTAINTY WITH THE EVOLN OF THE STORM SYSTEM SLATED FOR WED AND THURS. TREND HAS BEEN FOR NORTHERN STREAM ENERGY TO DIVE MORE TO THE EAST OVER THE PLAINS STATES AND ALLOW THE SOUTHERN ENERGY TO DRAW MORE MOISTURE NORTH INTO NM THURS. THIS BRINGS US INTO THE NEXT PERIOD OF ENHANCED POPS WED OR THURS. UNDERCUT MET/MAV GUIDANCE SINCE UNCERTAINTY IS STILL HIGH WITH THIS SYSTEM. IF NORTHERN STREAM ENERGY PHASES WITH SOUTHERN STREAM WILL BE TALKING ABOUT ANOTHER SNOW STORM ACROSS NM HOWEVER IF NORTHERN STREAM CONTINUES TO TREND TO THE EAST WILL HAVE MORE RAIN/SNOW SHOWER ACTIVITY. IN ANY EVENT...MODELS SHOW UNSETTLED PATTERN WILL CONTINUE INTO THE WEEKEND STATEWIDE.

&&

.PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 46 22 44 23 / 0 0 0 5 GALLUP.......................... 43 15 41 19 / 0 0 0 5 GRANTS.......................... 46 14 44 19 / 0 0 0 10 GLENWOOD........................ 55 29 53 31 / 0 0 0 0 CHAMA........................... 39 0 35 7 / 5 0 0 20 LOS ALAMOS...................... 41 14 39 13 / 5 0 0 20 RED RIVER....................... 35 5 32 9 / 5 0 0 20 TAOS............................ 40 9 39 12 / 5 0 0 20 SANTA FE........................ 41 19 40 21 / 0 0 0 20 SANTA FE AIRPORT................ 41 20 38 22 / 0 0 0 20 ESPANOLA........................ 46 19 44 21 / 0 0 0 20 ALBUQUERQUE HEIGHTS............. 48 26 46 29 / 0 0 0 5 ALBUQUERQUE VALLEY.............. 50 22 48 28 / 0 0 0 10 ALBUQUERQUE FOOTHILLS........... 45 25 44 28 / 0 0 0 10 ALBUQUERQUE WEST MESA........... 47 25 47 29 / 0 0 0 10 SOCORRO......................... 52 27 51 28 / 0 0 0 0 SANDIA PARK/CEDAR CREST......... 40 20 41 22 / 0 0 0 20 MORIARTY/ESTANCIA............... 43 22 43 24 / 0 0 0 20 CARRIZOZO....................... 49 23 50 28 / 0 0 0 5 RUIDOSO......................... 46 25 45 24 / 0 0 0 10 RATON........................... 40 13 39 16 / 0 0 0 20 LAS VEGAS....................... 40 18 40 19 / 0 0 0 20 ROY............................. 42 24 39 17 / 0 0 0 20 CLAYTON......................... 40 23 36 16 / 0 0 0 20 SANTA ROSA...................... 46 27 44 25 / 0 0 0 20 TUCUMCARI....................... 44 24 41 25 / 0 0 0 20 FORT SUMNER..................... 46 24 45 24 / 0 0 0 20 CLOVIS.......................... 43 26 43 25 / 0 0 0 20 PORTALES........................ 46 25 45 24 / 5 0 0 20 ROSWELL......................... 48 27 50 29 / 5 0 0 10

&&

.ABQ WATCHES/WARNINGS/ADVISORIES... NONE.

&&

$$

GUYER


AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
AFDABQ 300 AM MST SUN JAN 28 2007

.DISCUSSION... 09Z SFC ANALYSIS SHOWS A STNRY BNDRY DRAPED ALONG THE LEE OF THE CENTRAL MTN CHAIN WITH AN EXPANSIVE AREA OF LOW CLOUDS TO THE EAST OF THE FRONT. LATEST WV IMAGERY SHOWS AN UPPER LOW CENTERED NEAR SAN FRANCISCO ELONGATING EAST TO WEST BETWEEN AN ARCTIC SYSTEM DIVING SOUTH OVER WESTERN CANADA AND A TROPICAL PLUME MOVING NORTHEAST OVER THE E PACIFIC. LATEST 400-200MB AIRCRAFT WINDS SHOWS A 80-110 KNOT JET STREAKING ACROSS THE DESERT SW IN THE BASE OF THE CALIFORNIA UPPER LOW.

00Z MREF/03Z SREF IN FAIRLY GOOD AGREEMENT WITH EVOLN OF THE H5 PATTERN THRU THE SHORT TERM. 00Z GFS/NAM/ECMWF/UKMET ALSO ON BOARD IN THE SHORT TERM THAT WEAK SHORT WAVE RIDGING WILL CONTINUE TO DEVELOP TO THE WEST OF NM THRU MON NIGHT. THIS SPELLS PERIODS OF HIGH CLOUDINESS FOR NM SUNDAY AND MONDAY AND WEAK LEE TROUGHING IN THE E PLAINS. EXPECT LOW CLOUDS TO DISSIPATE TODAY ACROSS THE EAST AS LEE TROUGHING DEVELOPS SW WINDS. TEMPS WILL RISE INTO LOW TO MID 40S IN MOST AREAS...STILL 5 TO 10 DEG BELOW NORMAL. MODELS THEN INDICATE A COLD FRONT TO SWING SW THRU THE NE PLAINS AND CONTINUE WEST INTO THE CENTRAL VALLEYS TUESDAY MORNING. EXPECTING EAST CANYON WINDS TO DEVELOP USHERING IN SLIGHTLY COOLER TEMPS FOR TUESDAY FROM CENTRAL VALLEYS EASTWARD. RAISED POPS ACROSS THE EAST BEHIND THE FRONT TO CHANCE AS LOW LEVEL EASTERLY FLOW UNDERCUTS MOISTENING 700-500MB SW WINDS THUS ENHANCING ISENTROPIC LIFT. FRONT THEN EXPECTED TO WASH OUT LATE TUES INTO WED AS AN AREA OF LOW PRESSURE DEVELOPS OVER THE PLAINS STATES.

MODELS SHOW MORE UNCERTAINTY WITH THE EVOLN OF THE STORM SYSTEM SLATED FOR WED AND THURS. TREND HAS BEEN FOR NORTHERN STREAM ENERGY TO DIVE MORE TO THE EAST OVER THE PLAINS STATES AND ALLOW THE SOUTHERN ENERGY TO DRAW MORE MOISTURE NORTH INTO NM THURS. THIS BRINGS US INTO THE NEXT PERIOD OF ENHANCED POPS WED OR THURS. UNDERCUT MET/MAV GUIDANCE SINCE UNCERTAINTY IS STILL HIGH WITH THIS SYSTEM. IF NORTHERN STREAM ENERGY PHASES WITH SOUTHERN STREAM WILL BE TALKING ABOUT ANOTHER SNOW STORM ACROSS NM HOWEVER IF NORTHERN STREAM CONTINUES TO TREND TO THE EAST WILL HAVE MORE RAIN/SNOW SHOWER ACTIVITY. IN ANY EVENT...MODELS SHOW UNSETTLED PATTERN WILL CONTINUE INTO THE WEEKEND STATEWIDE.

&&

.PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 46 22 44 23 / 0 0 0 5 GALLUP.......................... 43 15 41 19 / 0 0 0 5 GRANTS.......................... 46 14 44 19 / 0 0 0 10 GLENWOOD........................ 55 29 53 31 / 0 0 0 0 CHAMA........................... 39 0 35 7 / 5 0 0 20 LOS ALAMOS...................... 41 14 39 13 / 5 0 0 20 RED RIVER....................... 35 5 32 9 / 5 0 0 20 TAOS............................ 40 9 39 12 / 5 0 0 20 SANTA FE........................ 41 19 40 21 / 0 0 0 20 SANTA FE AIRPORT................ 41 20 38 22 / 0 0 0 20 ESPANOLA........................ 46 19 44 21 / 0 0 0 20 ALBUQUERQUE HEIGHTS............. 48 26 46 29 / 0 0 0 5 ALBUQUERQUE VALLEY.............. 50 22 48 28 / 0 0 0 10 ALBUQUERQUE FOOTHILLS........... 45 25 44 28 / 0 0 0 10 ALBUQUERQUE WEST MESA........... 47 25 47 29 / 0 0 0 10 SOCORRO......................... 52 27 51 28 / 0 0 0 0 SANDIA PARK/CEDAR CREST......... 40 20 41 22 / 0 0 0 20 MORIARTY/ESTANCIA............... 43 22 43 24 / 0 0 0 20 CARRIZOZO....................... 49 23 50 28 / 0 0 0 5 RUIDOSO......................... 46 25 45 24 / 0 0 0 10 RATON........................... 40 13 39 16 / 0 0 0 20 LAS VEGAS....................... 40 18 40 19 / 0 0 0 20 ROY............................. 42 24 39 17 / 0 0 0 20 CLAYTON......................... 40 23 36 16 / 0 0 0 20 SANTA ROSA...................... 46 27 44 25 / 0 0 0 20 TUCUMCARI....................... 44 24 41 25 / 0 0 0 20 FORT SUMNER..................... 46 24 45 24 / 0 0 0 20 CLOVIS.......................... 43 26 43 25 / 0 0 0 20 PORTALES........................ 46 25 45 24 / 5 0 0 20 ROSWELL......................... 48 27 50 29 / 5 0 0 10

&&

.ABQ WATCHES/WARNINGS/ADVISORIES... NONE.

&&

$$

GUYER


AREA FORECAST DISCUSSION
NWS DODGE CITY KS
AFDDDC 321 AM CST TUE JAN 30 2007

.DAYS 1-2...

FOCUS THIS MORNING WILL BE ON PCPN CHANCES WEDNESDAY.

MAIN DIFFERENCES IN THE NAM/GFS AT 00Z WAS THE SFC FRONT AND 85H/7H BAROCLINIC ZONE WED WITH THE NAM FURTHER NORTH THAN THE GFS. ALSO THE SFC FEATURES FROM THE GFS THIS MORNING WERE SIMILAR TO THE ECMWF/UKMET AND CANADIAN MODELS. IT IS INTERESTING TO NOTE THAT DESPITE THE FURTHER NORTH SOLUTION OF THE NAM THE I285 SFC FROM THE NAM WAS VERY SIMILAR TO THE GFS AT 18Z WED WHICH ALSO SUPPORTED THE BETTER ISENTROPIC LIFT BEING FURTHER SOUTH. GIVEN THIS WILL BE TRENDING TOWARDS A FURTHER SOUTH SOLUTION OF PCPN THIS MORNING WHICH WOULD STILL FAVOR AREAS IN OUR SE CWA SEEING 1 TO 2 INCHES OF SNOW BY 12Z THURSDAY. WILL THEREFORE CONTINUE WITH LIKELY POPS IN THESE LOCATIONS WED AFTERNOON AND EARLY WEDNESDAY NIGHT. FURTHER NORTHWEST HOWEVER WILL TAPER POPS OFF DURING THE DAY ON WEDNESDAY AS ISENTROPIC DOWNGLIDE DEVELOPS AND 85H-7H BAROCLINIC ZONES MOVES SOUTH AND SOUTHEAST OF THE AREA. TEMPERATURES ON WEDNESDAY ARE NOT EXPECTED TO VARY MUCH FROM TONIGHTS LOWS AND KEPT DIURNAL CHANGE TO 10F OR LESS.

UNTIL THEN EXPECTING ONLY INCREASING CLOUDS LATER TODAY WITH TEMPS SOME 10F COOLER THAN YESTERDAY BASED ON 85H TEMPS.

.DAYS 3-7...

THE CURRENT GRIDS FOR THE EXTENDED PERIOD STILL LOOK VERY REASONABLE...AND ONLY MINOR ADJUSTMENTS WERE PERFORMED. THE NUMERICAL MODELS ARE IN SURPRISINGLY GOOD AGREEMENT THROUGH DAY FIVE AND DEMONSTRATE FAIRLY GOOD CONSISTENCY WITH PREVIOUS RUNS. THE GFS APPEARED TO INITIALIZE WELL THIS EVENING WITH AIRCRAFT AND SATELLITE WINDS OVER THE EASTERN PACIFIC AND LARGELY WAS FOLLOWED FOR THE GRIDS.

THE CLOSED UPPER LEVEL CYCLONE OFF THE CALIFORNIA COAST APPEARS TO BE OPENING SLOWLY AS THE UPPER LEVEL TROUGH EVIDENT ON SATELLITE IMAGERY OVER OREGON DROPS SOUTHWARD AND BEGINS TO INTERACT WITH THE OLD CYCLONE. A VORTICITY MAXIMUM THAT WAS APPROACHING BAJA CALIFORNIA EARLY THIS MORNING WILL RIPPLE EASTWARD THROUGH THE SOUTHERN BRANCH OF THE WESTERLIES, BUT MOST OF THE UPPER LEVEL CYCLONE WILL NOT EJECT UNTIL WEDNESDAY NIGHT AND THURSDAY WHEN IT PHASES WITH THE NEXT UPPER LEVEL TROUGH...CURRENTLY OVER NORTHERN ALBERTA...AS IT DIGS INTO THE LONG WAVE TROUGH POSITION OVER THE CENTRAL UNITED STATES. IT STILL APPEARS THAT THE BULK OF THE UVV AND PRECIPITATION WITH THE OLD CLOSED LOW WILL BE OVER THE SOUTHERN PLAINS WITH ONLY LIGHT PRECIPITATION SPREADING INTO SOUTH CENTRAL KANSAS LATE WEDNESDAY NIGHT AND THURSDAY MORNING. LOW POPS WERE CONTINUED OVER THE SOUTHEASTERN COUNTIES INTO THURSDAY MORNING.

A VIGOROUS UPPER LEVEL TROUGH ROTATING AROUND THE POLAR VORTEX OVER HUDSON BAY WILL DIG INTO THE NORTHERN PLAINS THURSDAY NIGHT, AND A STRONG SURGE OF ARCTIC AIR WILL INVADE KANSAS. THE ARCTIC AIR WILL ENTER NORTHERN KANSAS LATE THURSDAY AFTERNOON AND INVADE MOST OF THE STATE BY FRIDAY MORNING. GUIDANCE IS TRENDING DOWNWARD ON TEMPERATURES FOR THURSDAY NIGHT AND FRIDAY BUT STILL PROBABLY IS NOT SUFFICIENTLY COLD IN THE ARCTIC AIR. THERE MAY BE SOME FLURRIES BEHIND THE ARCTIC BOUNDARY AS IT PLUNGES SOUTHWARD THURSDAY NIGHT AND EARLY FRIDAY, BUT LITTLE SNOW ACCUMULATION IS EXPECTED IN SOUTHWESTERN KANSAS.

ONCE THE ARCTIC AIR BECOMES ENTRENCHED OVER THE GLACIER IN THE CENTRAL UNITED STATES, IT WILL BE VERY SLOW TO MODIFY. A SHARP MID LEVEL BAROCLINIC ZONE WILL PERSIST OVER THE CENTRAL PLAINS THROUGH THE WEEKEND, AND ANY MINOR JET STREAK ROTATING THROUGH THE FLOW MAY SUPPORT ENOUGH AGEOSTROPHIC CIRCULATION TO GENERATE SOME LIGHT SNOW. THE BEST OPPORTUNITY FOR ANYTHING MEASURABLE WILL BE ON THE WEST SIDE OF THE ARCTIC DOME. ALTHOUGH CERTAINTY IN DETAILS IS VERY LOW FOUR OR FIVE DAYS IN THE FUTURE, THE ECMWF, GFS AND CANADIAN ALL SUGGEST THAT AN UPPER LEVEL TROUGH WILL MOVE ACROSS COLORADO INTO THE TEXAS PANHANDLE LATE FRIDAY NIGHT AND SATURDAY. LIGHT SNOW WAS INTRODUCED OVER THE SOUTHWESTERN ZONES AFTER MIDNIGHT FRIDAY INTO SATURDAY MORNING IN THE MOST FAVORED AREA OF UPWARD VERTICAL MOTION.

THE ECMWF CONTINUES ITS TREND TO MAINTAIN MORE TROUGHING OVER THE CENTRAL UNITED STATES INTO EARLY NEXT WEEK, WHILE THE CANADIAN AND GFS ARE MORE PROGRESSIVE AND BREAK MORE FLOW THROUGH THE RIDGE NEAR 140W THAN THE ECMWF. SEVERAL OF THE CANADIAN ENSEMBLE MEMBERS SUGGEST A MORE PROGRESSIVE SOLUTION. THE MODELS HAVE A TENDENCY TO ATTEMPT TO SCOUR OUT ARCTIC AIR QUICKER THAN ACTUALLY OCCURS. MINOR UPPER LEVEL TROUGHS IN THE INCREASING MID LATITUDE FLOW WILL SERVE TO SLOSH THE WEST SIDE OF THE ARCTIC AIR BACK AND FORTH AS THEY MOVE OVER THE COLD DOME, RESULTING IN CONSIDERABLE UNCERTAINTY IN DAILY TEMPERATURES THE FIRST PART OF NEXT WEEK. THE GFS ENSEMBLE MEMBERS VARY WIDELY WITH SPEED OF EROSION OF THE ARCTIC AIR. FOR EXAMPLE, AT 00Z MONDAY, GFS ENSEMBLE H8 TEMPERATURES OVER SOUTHWEST KANSAS VARY FROM -15C TO +10C. GIVEN THE LEVEL OF UNCERTAINTY, THE CURRENT FORECAST OF BELOW AVERAGE TEMPERATURES IN THE 8 TO 10 DAY PERIOD STILL SEEMS REASONABLE.

&&

.AVIATION...

WINDS WILL BEGIN TO SHIFT TO A MORE NORTHERLY DIRECTION FROM 10-15KTS TODAY ACROSS SOUTHWEST KANSAS AND THE POSSIBILITY DOES EXITS FOR STRATUS NEAR THE BAROCLINIC ZONE IN CENTRAL KANSAS. CIGS ARE EXPECTED TO STAY ABOVE 030 SO VFR CONDITIONS ARE EXPECTED.

&&

.PRELIMINARY POINT TEMPS/POPS... DDC 32 20 30 15 / 0 30 40 30 GCK 29 18 27 13 / 0 20 30 10 EHA 30 21 28 16 / 0 30 30 30 LBL 34 21 30 16 / 0 30 40 30 HYS 26 15 28 13 / 0 10 30 10 P28 32 21 31 20 / 0 30 70 60

&&

.DDC WATCHES/WARNINGS/ADVISORIES... NONE. &&

$$

FN18/01/31


AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
AFDLMK 240 AM EST TUE JAN 30 2007

.SHORT TERM (TODAY-TONIGHT)...

CLIPPER SHORT WAVE MOVING ESE THROUGH IOWA INTO IL/IN ATTM...WITH ASSOC SFC TROF/FRONT STRETCHING FROM NEAR IND TO PAH AS OF 6Z. MOISTURE POOLING ALONG THE FRONT...WITH DEWPOINTS RISING INTO THE MID 20S. SCT SHSN HAVE DEVELOPED ALONG/AHEAD OF THE SFC FRONT...WITH A FEW MOVING INTO THE LMK CWA AND AS FAR S AS NEAR LEITCHFIELD. RECENT ACARS DATA AT KSDF SHOW VERY STEEP LAPSE RATES TO 700MB... HELPING PROMOTE THIS PRECIP.

EXPECT ISLTD-SCT SHSN TO REMAIN POSSIBLE THROUGH THE MORNING HOURS...WITH HIGHEST CHCS OVER THE N 1/2 OF THE CWA...DECREASING SOUTHWARD. ANY SNOW AMTS SHOULD BE MINOR AT BEST THOUGH SOME OF THE SHSN HAVE BEEN INTENSE OVER IL/IN/OH BASED ON RADAR REFLECTIVITIES NEAR 35DBZ OR HIGHER...SO IF SOME OF THESE WERE TO AFFECT OUR CWA THERE COULD BE LOCALIZED ACCUMS OF A COUPLE TENTHS OF AN INCH IN A SHORT PERIOD OF TIME. WILL CONTINUE TO MONITOR AS WE GET CLOSER TO THE MORNING DRIVE.

BASED ON NAM/RUC...SFC FRONT WILL PASS THROUGH WRN COUNTIES AROUND 10-12Z...INTO ERN/SRN COUNTIES 12-14Z TIMEFRAME. THIS WILL BRING A ROUND OF GUSTY W/NW WINDS TODAY. BUFKIT DIAGNOSTICS INDICATE GUSTS TO 20-25KTS POSSIBLE AND THIS SEEMS REASONABLE BASED ON UPSTREAM OBSERVATIONS. THIS WILL ALSO BRING STEADY OR FALLING TEMPS (EXCEPT PERHAPS THE FAR SE COUNTIES). HAVE FOLLOWED A RUC/NAM BLEND FOR TEMPS TODAY INTO TONIGHT.

CHANCES FOR SHSN WILL CONTINUE INTO THE AFTN WITH STEEP LAPSE RATES...THOUGH FEEL THAT OVERALL THREAT WILL BE LOWER THAN IN THE MORNING DUE TO SIGNIFICANTLY DRIER AIR ADVECTING INTO THE LOWER OHIO VALLEY. DEWPOINTS WILL LIKELY FALL INTO THE SINGLE DIGITS THIS AFTN. WILL WORD AFTERNOON POPS AS CHANCE VERSUS MORNING COVERAGE WORDING.

GUSTY WINDS WILL LIGHTEN AFTER SUNSET...THOUGH BEFORE THAT OCCURS WIND CHILL VALUES THIS AFTN INTO THE EARLY EVENING WILL LIKELY DROP INTO THE SINGLE DIGITS WITH A FEW NEAR-ZERO VALUES POSSIBLE. HAVE ALLOWED SKIES TO CLEAR OVERNIGHT...THOUGH DID NOT GO WITH COMPLETE CLEARING SINCE NAM AND TO A LESSER EXTENT GFS SUGGEST AN AREA OF 3-5KFT CLOUDS SWEEPING ACROSS THE CWA BETWEEN 6-9Z/WED (OVERNIGHT).

CS

.LONG TERM (WEDNESDAY-MONDAY)...

...ACTIVE WEATHER PERIOD WITH POTENTIAL FOR ACCUMULATING SNOWS LATE WED THROUGH THURSDAY NIGHT...

WEDNESDAY THROUGH FRIDAY NIGHT...

FAIRLY ACTIVE AND CHALLENGING FORECAST PERIOD APPEARS TO BE IN STORE FOR THIS PART OF THE FORECAST PERIOD. LATE EVENING MODELS CONTINUE TO BE IN GENERAL AGREEMENT WITH SOUTHWESTERN U.S. UPPER LEVEL WAVE EJECTING EASTWARD DURING THE PERIOD. ALL THE MODELS INDUCE SFC CYCLOGENESIS ACROSS THE DEEP SOUTH AND BRING A SFC LOW EASTWARD ACROSS THE NORTHERN GULF STATES. THE PAST FEW RUNS OF THE MODELS HAVE BEEN TRENDING NORTHWARD WITH THE TRACK OF THE SFC LOW ACROSS THE SOUTHEAST U.S. WE STILL HAVE TWO CAMPS OF TRACKS TONIGHT...WITH THE CANADIAN GLOBAL AND NAM-WRF BEING THE FARTHEST NORTH WITH THE LOW COMING ACROSS THE FA...WHILE THE UKMET AND EURO ARE FURTHER SOUTH. THE 00Z OP GFS IS BETWEEN THESE TWO CAMPS AND OFFERS A PRETTY GOOD COMPROMISE.

USING A CONSENSUS OF THE MODEL DATA...WEDNESDAY WILL GENERALLY BE A DRY DAY WITH MID-HIGH LEVEL CLOUDS INCREASING FROM WEST TO EAST. ISENTROPIC UPGLIDE WILL INCREASE WEDNESDAY EVENING AS SFC LOW BEGINS ITS TREK TOWARDS THE NORTHEAST. ANTECEDENT DRY AIRMASS WILL TAKE SOME TIME TO MOISTEN UP WEDNESDAY NIGHT SO PRECIPITATION MAY NOT START UNTIL LATE WEDNESDAY NIGHT. NONETHELESS...IT DOES APPEAR PRECIPITATION WILL BE LIKELY AND THUS HAVE INCREASED POPS TO LIKELY FOR THIS PERIOD. MODEL PROFILES FROM THE GFS SUGGEST ALL SNOW AS THE PRECIPITATION TYPE FOR WEDNESDAY NIGHT.

MAIN BULK OF PRECIPITATION WILL FALL ON THURSDAY AS ISENTROPIC LIFT AND FRONTOGENETICAL FORCING WILL BE MAXIMIZED OVER KENTUCKY. BANDED PRECIPITATION WILL LIKELY LIFT NORTHWARD THROUGH THE DAY AND BE ORIENTED ALONG THE OHIO RIVER BY EVENING. HAVE GONE WITH LIKELY POPS HERE BUT PRECIPITATION TYPE WILL BE CHALLENGING. IN THE PAST SEVERAL EVENTS...WE HAVE SEEN STORMS SYSTEMS OUT IN THE LONG RANGE BEING FORECAST TO GO SOUTH...ONLY TO SEE A NORTHWARD TRACK VERIFY AS THE EVENT CAME CLOSER/UNFOLDED. IN ADDITION...THE NUMERICAL MODELS HAVE HAD A TOUGH TIME ESTIMATING THE AMOUNT OF WARM AIR ADVECTING IN ALOFT...WHICH HAS RESULTED IN MORE LIQUID PRECIPITATION OCCURRING. TONIGHT...WE ARE IN THE SAME DILEMMA.

BASED ON ALL THE AVAILABLE DATA...AND NOT COMPLETELY THROWING OUT THE NAM-WRF...AM INCLINED TO LEAVE A MIX OF RAIN/SLEET/SNOW IN ACROSS THE SOUTHERN FA SOUTH OF A LINE FROM NEAR HARTFORD TO JUST SOUTH OF RICHMOND. NORTH OF THAT LINE...FEEL THAT DOMINANT PRECIPITATION TYPE WILL BE SNOW. AS SFC LOW HEADS EAST THU NIGHT...SHOULD SEE ALL AREAS GO TO SNOW. ACCUMULATIONS OF SNOW APPEAR LIKELY AT THIS TIME WITH TWO TO FOUR INCHES ACROSS THE NORTHERN HALF OF THE FA WITH ONE TO TWO ACROSS SOUTHERN KY. HOWEVER...IF THE NORTHWARD TREND IN THE SURFACE TRACK OCCURS...LESS SNOW WILL BE LIKELY IN THE SOUTH AND THE 2-4 INCH BAND WOULD BE DISPLACED FURTHER NORTH...PROBABLY NORTH OF THE OHIO RIVER. GIVEN THIS EVENT IS SOME 60-72 HORUS...WILL ISSUE A SPECIAL WX STMT THIS MORNING HIGHLIGHT IMPACTS OF THE EVENT.

SNOW WILL LIKELY CONTINUE THURSDAY NIGHT AND DIMINISH SOME BY FRIDAY. SECONDARY CLIPPER TYPE SYSTEM IS FORECAST TO SWING THROUGH THE REGION FRIDAY AFTERNOON AND EVENING AND MAY BRING ANOTHER ROUND OF SNOW SHOWERS TO THE REGION. THUS...HAVE PRETTY MUCH LEFT ONGOING FORECAST INTACT FOR FRIDAY AND FRIDAY NIGHT. AS FOR TEMPERATURES THROUGH THE PERIOD...GENERALLY FOLLOWED A BLEND OF OP GFS RAW SFC TEMPS WITH A SPLASH OF THE MOS STAT GUIDANCE.

JARVIS

FORECAST FROM SATURDAY ONWARD WAS LEFT AS IS...PREVIOUS FORECAST DISCUSSION FOLLOWS...

WILL STAY CLOSE TO THE EURO THROUGH THE PERIOD...WITH SOME SUPPORT FROM THE GFS THROUGH THIS PERIOD AS WELL. INDICES (PNA/EPO/AO) STILL SUPPORT THE COLDER AIR TO CONTINUE TO REPLENISH ITSELF THROUGH THE NEXT FEW WEEKS. DEEP LONGWAVE TROUGH EXTENDS FROM HUDSON BAY POLAR VORTEX(PV) ROTATING FROM THE MS VALLEY THROUGH THE OHIO VALLEY OVER THE WEEKEND...WITH POSSIBLY THE COLDEST AIR OF THE WINTER TO DATE IN THIS PERIOD. SFC HI PRESSURE MOVES ACROSS THE REGION SATURDAY INTO SUNDAY...WEAK CLIPPER STILL LOOKS POSSIBLE SUNDAY EVENING INTO EARLY MONDAY BEFORE ANOTHER VERY COLD ARCTIC AIR MASS DROPS INTO THE CENTRAL US AND INTO THE OHIO VALLEY EARLY NEXT WEEK. AS MENTIONED EARLIER IF AN SNOW COVER ON THE GROUND DURING THIS PERIOD...MAY SEE TEMPS APPROACH ZERO FOR LOWS...WILL NOT ADJUST THAT WAY AS OF NOW...BUT HAVE TRENDED COLDER THRU THE PERIOD.

-SCHOTT

&&

.AVIATION (06Z TAFS)... FOCUS FOR THE NEXT 6-12 HOURS IN THE TAFS CENTERS ON CHCS FOR SNOW SHOWERS ALONG WITH WIND SHIFT AS CLIPPER/COLD FRONT PASSES THROUGH THE REGION. AREA RADARS SHOW SCT SHSN OVER IL/IN...BASED ON TRENDS AND LATEST RUC/NAM DATA...A FEW OF THESE MAY AFFECT LEX/SDF TAF SITES THROUGH 15Z...THOUGH COVERAGE WILL LIKELY BE ISLTD SUCH THAT WE WILL NOT CARRY A PREVAILING SHSN GROUP IN THE TAFS...WILL RATHER HANDLE WITH TEMPOS AS NEEDED.

CIGS OVER THE REGION ARE NOT TERRIBLY LOW (GENERALLY MVFR-VFR) AND PLAN ON CONTINUING THAT BASED ON FCST SOUNDINGS. SOME CIGS CLOSE TO 1-1.5KFT AGL MAY DROP INTO SRN IND AND PARTS OF CNTRL KY NORTH OF I-64 BETWEEN 12-15Z (PER NAM)...BUT WILL NOT MENTION THOSE IN THE TAFS AT THIS TIME. WINDS WILL SHIFT TO THE W/NW AS COLD FRONT PUSHES THROUGH THE AREA THIS MORNING (11-14Z TIMEFRAME). WHEN THIS HAPPENS WINDS WILL GET GUSTY (GUSTS TO 20-23KTS OR SO) FOR THE BALANCE OF THE DAYLIGHT HOURS.

CS

&&

.LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. &&

$$


AREA FORECAST DISCUSSION...CORRECTED
NWS MIAMI FL
AFDMFL 1015 AM EST TUE JAN 30 2007

.UPDATE... LATEST SURFACE ANALYSIS CONTINUES TO SHOW HIGH PRESSURE BUILDING INTO THE STATE WITH SATELLITE IMAGERY SHOWING ADDITIONAL BATCH OF MID UPR LEVEL CLOUDS APPROACHING THE AREA. MAIN ISSUE FOR TODAY IS THE RED FLAG WARNING. ANALYZING THE 12Z SNDG DATA AND ASSUMING TEMPS WARM UP INTO AT LEAST THE UPPER 60S THERE SHOULD BE ENOUGH DRY AIR ABOVE THE SURFACE FOR AFTERNOON MINRHS TO PLUMMET AGAIN. HOWEVER...THE SNDG AS WELL AS LATEST ACARS DATA SHOW A NARROW LAYER OF ESE WINDS A FEW HUNDRED FEET ABOVE THE SFC. THIS IS INCREASING MOISTURE ABOVE THE SURFACE LAYER WHICH COULD PREVENT MIXING MECHANISMS FROM CAUSING THE EXPECTED DROP IN AFTERNOON RHS MAINLY ALONG THE EAST COAST. HOWEVER...WITH RIDGE BUILDING IN AND LOW LEVEL FLOW REMAINING LIGHT THROUGHOUT THE DAY...THE POTENTIAL IS STILL THERE SINCE IT IS POSSIBLE THIS LIGHT EASTERLY BREEZES WILL SHUT OFF BY THE AFTERNOON AS SHOWN BY FCST SNDGS. SO WILL LEAVE RFW AS IS GIVEN THE UNCERTAINTY.

.PREVIOUS DISCUSSION... HIGH PRESSURE WAS LOCATED OVER THE PANHANDLE OF FLORIDA EARLY THIS MORNING WHICH WAS ALLOWING FOR MOSTLY CALM WINDS OVER THE CWA. HOWEVER...THERE HAS BEEN SOME CIRRUS CLOUDS COMING INTO SOUTH FLORIDA EARLY THIS MORNING FROM THE GULF OF MEXICO WHICH WAS HELPING TO KEEP SOME OF THE HEAT FROM ESCAPING FROM THE GROUND. TEMPS EARLY THIS MORNING HAVE BEEN RUNNING IN THE MID 30S OVER THE FREEZE WARNING AREA WITH PALMDALE FAWN SITE REPORTING 32 DEGREES AT THE 2 FEET LEVEL. BECAUSE THE TEMPS ARE VERY CLOSE TO FREEZING...CALM WINDS...AND THE LOW TEMPS USUALLY OCCUR AT SUNRISE...PLAN ON KEEPING THE FREEZE WARNING UP FOR THE CENTRAL AND NORTHERN INTERIOR AREAS UNTIL 8 AM EST THIS MORNING.

THE HIGH WILL MOVE SLOWLY EAST TODAY AND INTO THE WESTERN ATLANTIC WATERS BY TONIGHT...AS A COLD FRONT OVER THE CENTRAL PLAINS STATES MOVES SOUTHEAST AND INTO NORTH FLORIDA BEFORE DISSIPATING ON WEDNESDAY. THIS WILL KEEP THE WX OVER THE CWA DRY WEDNESDAY...AND ALLOW FOR ANOTHER GOOD RADIATION COOLING NIGHT TONIGHT. TEMPS SHOULD GET DOWN INTO THE UPPER 30S TO AROUND 40 OVER THE INTERIOR AREAS TO MID 40S TO LOWER 50S ALONG THE COASTAL AREAS. THERE COULD EVEN BE SOME ISOLATED AREAS OF FROST OVER THE NORTHERN INTERIOR AREAS LATE TONIGHT IF THE LOW TEMPS FALL A LITTLE BIT LOWER THAN FORECAST. HOWEVER...WILL NOT MENTION THIS IN THE ZONES AT THIS TIME...AND LET THE DAY SHIFT TAKE A CLOSER LOOK AT THIS TO SEE IF THE PATCHY FROST NEEDS TO BE ADDED TO THE NORTHERN INTERIOR AREAS FOR TONIGHT.

LOW PRESSURE SHOULD THEN DEVELOP OVER THE NORTHWEST GULF OF MEXICO WEDNESDAY NIGHT AND MOVE NORTHEAST THROUGH THE SOUTHEAST UNITED STATES LATE THIS WEEK. THIS WILL ALLOW FOR THE WINDS OVER THE CWA TO SWING TO A SOUTHERLY DIRECTION AND INCREASE TO BREEZY TO WINDY CONDITIONS. SOME LOW LEVEL MOISTURE COULD ALSO WORK INTO THE AREA ON THE SOUTHERLY WIND FLOW. SO HAVE KEPT A SLIGHT CHANCE OF SHOWERS IN THE FORECAST FOR LATE THIS WEEK.

.EXTENDED FORECAST... THE COLD FRONT ASSOCIATED WITH THE LOW WILL MOVE SLOWLY DOWN THE SUNSHINE STATE AND THROUGH SOUTH FLORIDA LATE THIS WEEKEND...AS A STRONG HIGH PRESSURE SYSTEM WILL MOVE SOUTHEAST FROM CENTRAL CANADA INTO THE TENNESSEE VALLEY. THERE COULD BE SOME SHOWERS AHEAD OF THE FRONT...SO HAVE KEPT SOME SHOWERS IN THE FORECAST FOR THIS WEEKEND OVER SOUTH FLORIDA.

THE FRONT WILL THEN BE SOUTH OF THE AREA EARLY NEXT WEEK WITH BREEZY TO WINDY NORTHERLY WIND FLOW OVER THE CWA. THESE BREEZY TO WINDY CONDITIONS COULD HELP GENERATE A FEW SHOWERS OVER THE COASTAL WATERS THAT COULD MOVE INTO THE CWA EARLY NEXT WEEK. SO HAVE PUT A SLIGHT CHANCE OF SHOWERS IN FOR EARLY NEXT WEEK.

&&

.AVIATION... VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD.

&&

.MARINE... THE WINDS WILL BE FROM THE NORTHERLY DIRECTION TODAY INTO TONIGHT BEFORE SWING TO A SOUTHERLY DIRECTION BY LATE THIS WEEK. THE SPEEDS WILL REMAIN BELOW 10 KNOTS THROUGH TONIGHT BEFORE SLOWLY INCREASING TO 20 TO 25 KNOTS BY LATE THIS WEEK. THIS WILL KEEP THE SEAS BELOW 6 FEET THROUGH WEDNESDAY NIGHT BEFORE INCREASING THEM TO 7 FEET BY THURSDAY IN THE GULF STREAM. SO THE BOATING WEATHER LOOKS GOOD THROUGH WEDNESDAY.

&&

.FIRE WEATHER... AS MENTION ABOVE...THE WINDS WILL REMAIN MAINLY OUT OF THE NORTH TODAY AROUND 5 TO 10 MPH. THIS WILL ALLOW FOR SOME DRY AIR ALOFT TO MIX DOWN TO THE SURFACE. TEMPS SHOULD GET INTO THE LOWER 70S THIS AFTERNOON ALLOWING FOR THE RELATIVE HUMIDITIES TO FALL BELOW 35 PERCENT FOR 4 HOURS OR MORE THIS AFTERNOON. THEREFORE...WILL UPGRADE THE FIRE WEATHER WATCH TO A RED FLAG WARING FOR ALL OF THE CWA FROM NOON TO 6 PM EST TODAY.

&&

.PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 68 44 70 61 / - - 10 10 FORT LAUDERDALE 70 49 71 64 / - - 10 10 MIAMI 71 50 72 63 / - - 10 10 NAPLES 66 45 71 54 / - - 10 -

&&

.MFL WATCHES/WARNINGS/ADVISORIES... FL...RED FLAG WARNING FROM 11 AM THIS MORNING TO 6 PM EST THIS AFTERNOON FOR FLZ063-FLZ066-FLZ067-FLZ068-FLZ069-FLZ070- FLZ071-FLZ072-FLZ073-FLZ074-FLZ075.

FREEZE WARNING UNTIL 8 AM EST THIS MORNING FOR FLZ063-FLZ066- FLZ067-FLZ070-FLZ071.

AM...NONE. GM...NONE. &&

$$

LONG TERM...BAXTER SHORT TERM...BAXTER AVIATION...GREGORIA


AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
AFDLMK 1105 AM EST TUE JAN 30 2007

.SHORT TERM (THIS AFTERNOON)...

AT 16Z A COLD FRONT WAS LOCATED EAST OF A LINE FROM WINCHESTER IN CENTRAL KY TO GLASGOW. TEMPERATURES HAD DROPPED 5 TO 10 DEGREES JUST AFTER THE FRONTAL PASSAGE AND LOOKING UP STREAM READINGS WERE IN THE TEENS. JUST LIKE SUNDAY... DEW POINTS HAVE DROPPED INTO THE SINGLE DIGITS ACROSS THE NORTHERN PORTION OF THE CWFA.

WILL CONTINUE TO MENTION ISOLATED TO LIGHT SNOW SHOWERS THIS AFTERNOON AS CU FIELD DEVELOPS BEHIND THE FRONT AND WITH STEEPENING LAPSE RATES. TEMPERATURES WILL CONTINUE THEIR SLOW DOWNWARD TREND EVEN WITH SOME SUNSHINE. UPDATED FORECAST OUT BY 1115. --JA

PREVIOUS DISCUSSION BELOW.

CLIPPER SHORT WAVE MOVING ESE THROUGH IOWA INTO IL/IN ATTM...WITH ASSOC SFC TROF/FRONT STRETCHING FROM NEAR IND TO PAH AS OF 6Z. MOISTURE POOLING ALONG THE FRONT...WITH DEWPOINTS RISING INTO THE MID 20S. SCT SHSN HAVE DEVELOPED ALONG/AHEAD OF THE SFC FRONT...WITH A FEW MOVING INTO THE LMK CWA AND AS FAR S AS NEAR LEITCHFIELD. RECENT ACARS DATA AT KSDF SHOW VERY STEEP LAPSE RATES TO 700MB... HELPING PROMOTE THIS PRECIP.

EXPECT ISLTD-SCT SHSN TO REMAIN POSSIBLE THROUGH THE MORNING HOURS...WITH HIGHEST CHCS OVER THE N 1/2 OF THE CWA...DECREASING SOUTHWARD. ANY SNOW AMTS SHOULD BE MINOR AT BEST THOUGH SOME OF THE SHSN HAVE BEEN INTENSE OVER IL/IN/OH BASED ON RADAR REFLECTIVITIES NEAR 35DBZ OR HIGHER...SO IF SOME OF THESE WERE TO AFFECT OUR CWA THERE COULD BE LOCALIZED ACCUMS OF A COUPLE TENTHS OF AN INCH IN A SHORT PERIOD OF TIME. WILL CONTINUE TO MONITOR AS WE GET CLOSER TO THE MORNING DRIVE.

BASED ON NAM/RUC...SFC FRONT WILL PASS THROUGH WRN COUNTIES AROUND 10-12Z...INTO ERN/SRN COUNTIES 12-14Z TIMEFRAME. THIS WILL BRING A ROUND OF GUSTY W/NW WINDS TODAY. BUFKIT DIAGNOSTICS INDICATE GUSTS TO 20-25KTS POSSIBLE AND THIS SEEMS REASONABLE BASED ON UPSTREAM OBSERVATIONS. THIS WILL ALSO BRING STEADY OR FALLING TEMPS (EXCEPT PERHAPS THE FAR SE COUNTIES). HAVE FOLLOWED A RUC/NAM BLEND FOR TEMPS TODAY INTO TONIGHT.

CHANCES FOR SHSN WILL CONTINUE INTO THE AFTN WITH STEEP LAPSE RATES...THOUGH FEEL THAT OVERALL THREAT WILL BE LOWER THAN IN THE MORNING DUE TO SIGNIFICANTLY DRIER AIR ADVECTING INTO THE LOWER OHIO VALLEY. DEWPOINTS WILL LIKELY FALL INTO THE SINGLE DIGITS THIS AFTN. WILL WORD AFTERNOON POPS AS CHANCE VERSUS MORNING COVERAGE WORDING.

GUSTY WINDS WILL LIGHTEN AFTER SUNSET...THOUGH BEFORE THAT OCCURS WIND CHILL VALUES THIS AFTN INTO THE EARLY EVENING WILL LIKELY DROP INTO THE SINGLE DIGITS WITH A FEW NEAR-ZERO VALUES POSSIBLE. HAVE ALLOWED SKIES TO CLEAR OVERNIGHT...THOUGH DID NOT GO WITH COMPLETE CLEARING SINCE NAM AND TO A LESSER EXTENT GFS SUGGEST AN AREA OF 3-5KFT CLOUDS SWEEPING ACROSS THE CWA BETWEEN 6-9Z/WED (OVERNIGHT).

CS

.AVIATION (12Z TAFS)... COLD FRONT NOW ROLLING THROUGH THE LMK CWA AS OF 11Z...WITH WINDS AT HNB SOLIDLY NW WHILE DIRECTIONS AT SDF/FTK SWITCHING SOON. WITH FROPA...WE EXPECT WNW WINDS WILL INCREASE AND BECOME GUSTY. GUSTS TO 20-25KTS ARE LIKELY THROUGH AT LEAST MID-AFTERNOON TODAY. SHSN ARE WIDELY SCATTERED AT THIS POINT AND CIGS ARE VFR-MVFR UPSTREAM OVER SRN IL AND SW IN. LATEST NAM SHOWS CIGS DROPPING TO AROUND 3000 FEET THIS MORNING AT SDF/LEX...THEN RISING TO NEAR 5KFT WITH SKIES ACTUALLY GOING SCT (EVEN FEW OVER SRN KY).

-SHSN THREAT FOR THE TAF SITES SEEMS MINIMAL...WILL NOT MENTION IN PREVAILING GROUPS AND HANDLE ANY -SHSN WITH TEMPO GROUPS IF NECESSARY. GFS/NAM HAVE BEEN CONSISTENT IN BRINGING AN AREA OF LOWER CIGS (~2KFT) TONIGHT BETWEEN 0Z-6Z...AND WILL ACCOUNT FOR THIS. WINDS WILL SUBSIDE CONSIDERABLY AFTER 3Z AS SFC HIGH PRES SLIDES INTO THE REGION.

CS

&&

.LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. &&

$$


AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
AFDLMK 605 AM EST TUE JAN 30 2007

.AVIATION (12Z TAFS)... COLD FRONT NOW ROLLING THROUGH THE LMK CWA AS OF 11Z...WITH WINDS AT HNB SOLIDLY NW WHILE DIRECTIONS AT SDF/FTK SWITCHING SOON. WITH FROPA...WE EXPECT WNW WINDS WILL INCREASE AND BECOME GUSTY. GUSTS TO 20-25KTS ARE LIKELY THROUGH AT LEAST MID-AFTERNOON TODAY. SHSN ARE WIDELY SCATTERED AT THIS POINT AND CIGS ARE VFR-MVFR UPSTREAM OVER SRN IL AND SW IN. LATEST NAM SHOWS CIGS DROPPING TO AROUND 3000 FEET THIS MORNING AT SDF/LEX...THEN RISING TO NEAR 5KFT WITH SKIES ACTUALLY GOING SCT (EVEN FEW OVER SRN KY).

-SHSN THREAT FOR THE TAF SITES SEEMS MINIMAL...WILL NOT MENTION IN PREVAILING GROUPS AND HANDLE ANY -SHSN WITH TEMPO GROUPS IF NECESSARY. GFS/NAM HAVE BEEN CONSISTENT IN BRINGING AN AREA OF LOWER CIGS (~2KFT) TONIGHT BETWEEN 0Z-6Z...AND WILL ACCOUNT FOR THIS. WINDS WILL SUBSIDE CONSIDERABLY AFTER 3Z AS SFC HIGH PRES SLIDES INTO THE REGION.

CS

&&

.SHORT TERM (TODAY-TONIGHT)...

CLIPPER SHORT WAVE MOVING ESE THROUGH IOWA INTO IL/IN ATTM...WITH ASSOC SFC TROF/FRONT STRETCHING FROM NEAR IND TO PAH AS OF 6Z. MOISTURE POOLING ALONG THE FRONT...WITH DEWPOINTS RISING INTO THE MID 20S. SCT SHSN HAVE DEVELOPED ALONG/AHEAD OF THE SFC FRONT...WITH A FEW MOVING INTO THE LMK CWA AND AS FAR S AS NEAR LEITCHFIELD. RECENT ACARS DATA AT KSDF SHOW VERY STEEP LAPSE RATES TO 700MB... HELPING PROMOTE THIS PRECIP.

EXPECT ISLTD-SCT SHSN TO REMAIN POSSIBLE THROUGH THE MORNING HOURS...WITH HIGHEST CHCS OVER THE N 1/2 OF THE CWA...DECREASING SOUTHWARD. ANY SNOW AMTS SHOULD BE MINOR AT BEST THOUGH SOME OF THE SHSN HAVE BEEN INTENSE OVER IL/IN/OH BASED ON RADAR REFLECTIVITIES NEAR 35DBZ OR HIGHER...SO IF SOME OF THESE WERE TO AFFECT OUR CWA THERE COULD BE LOCALIZED ACCUMS OF A COUPLE TENTHS OF AN INCH IN A SHORT PERIOD OF TIME. WILL CONTINUE TO MONITOR AS WE GET CLOSER TO THE MORNING DRIVE.

BASED ON NAM/RUC...SFC FRONT WILL PASS THROUGH WRN COUNTIES AROUND 10-12Z...INTO ERN/SRN COUNTIES 12-14Z TIMEFRAME. THIS WILL BRING A ROUND OF GUSTY W/NW WINDS TODAY. BUFKIT DIAGNOSTICS INDICATE GUSTS TO 20-25KTS POSSIBLE AND THIS SEEMS REASONABLE BASED ON UPSTREAM OBSERVATIONS. THIS WILL ALSO BRING STEADY OR FALLING TEMPS (EXCEPT PERHAPS THE FAR SE COUNTIES). HAVE FOLLOWED A RUC/NAM BLEND FOR TEMPS TODAY INTO TONIGHT.

CHANCES FOR SHSN WILL CONTINUE INTO THE AFTN WITH STEEP LAPSE RATES...THOUGH FEEL THAT OVERALL THREAT WILL BE LOWER THAN IN THE MORNING DUE TO SIGNIFICANTLY DRIER AIR ADVECTING INTO THE LOWER OHIO VALLEY. DEWPOINTS WILL LIKELY FALL INTO THE SINGLE DIGITS THIS AFTN. WILL WORD AFTERNOON POPS AS CHANCE VERSUS MORNING COVERAGE WORDING.

GUSTY WINDS WILL LIGHTEN AFTER SUNSET...THOUGH BEFORE THAT OCCURS WIND CHILL VALUES THIS AFTN INTO THE EARLY EVENING WILL LIKELY DROP INTO THE SINGLE DIGITS WITH A FEW NEAR-ZERO VALUES POSSIBLE. HAVE ALLOWED SKIES TO CLEAR OVERNIGHT...THOUGH DID NOT GO WITH COMPLETE CLEARING SINCE NAM AND TO A LESSER EXTENT GFS SUGGEST AN AREA OF 3-5KFT CLOUDS SWEEPING ACROSS THE CWA BETWEEN 6-9Z/WED (OVERNIGHT).

CS

.LONG TERM (WEDNESDAY-MONDAY)...

...ACTIVE WEATHER PERIOD WITH POTENTIAL FOR ACCUMULATING SNOWS LATE WED THROUGH THURSDAY NIGHT...

WEDNESDAY THROUGH FRIDAY NIGHT...

FAIRLY ACTIVE AND CHALLENGING FORECAST PERIOD APPEARS TO BE IN STORE FOR THIS PART OF THE FORECAST PERIOD. LATE EVENING MODELS CONTINUE TO BE IN GENERAL AGREEMENT WITH SOUTHWESTERN U.S. UPPER LEVEL WAVE EJECTING EASTWARD DURING THE PERIOD. ALL THE MODELS INDUCE SFC CYCLOGENESIS ACROSS THE DEEP SOUTH AND BRING A SFC LOW EASTWARD ACROSS THE NORTHERN GULF STATES. THE PAST FEW RUNS OF THE MODELS HAVE BEEN TRENDING NORTHWARD WITH THE TRACK OF THE SFC LOW ACROSS THE SOUTHEAST U.S. WE STILL HAVE TWO CAMPS OF TRACKS TONIGHT...WITH THE CANADIAN GLOBAL AND NAM-WRF BEING THE FARTHEST NORTH WITH THE LOW COMING ACROSS THE FA...WHILE THE UKMET AND EURO ARE FURTHER SOUTH. THE 00Z OP GFS IS BETWEEN THESE TWO CAMPS AND OFFERS A PRETTY GOOD COMPROMISE.

USING A CONSENSUS OF THE MODEL DATA...WEDNESDAY WILL GENERALLY BE A DRY DAY WITH MID-HIGH LEVEL CLOUDS INCREASING FROM WEST TO EAST. ISENTROPIC UPGLIDE WILL INCREASE WEDNESDAY EVENING AS SFC LOW BEGINS ITS TREK TOWARDS THE NORTHEAST. ANTECEDENT DRY AIRMASS WILL TAKE SOME TIME TO MOISTEN UP WEDNESDAY NIGHT SO PRECIPITATION MAY NOT START UNTIL LATE WEDNESDAY NIGHT. NONETHELESS...IT DOES APPEAR PRECIPITATION WILL BE LIKELY AND THUS HAVE INCREASED POPS TO LIKELY FOR THIS PERIOD. MODEL PROFILES FROM THE GFS SUGGEST ALL SNOW AS THE PRECIPITATION TYPE FOR WEDNESDAY NIGHT.

MAIN BULK OF PRECIPITATION WILL FALL ON THURSDAY AS ISENTROPIC LIFT AND FRONTOGENETICAL FORCING WILL BE MAXIMIZED OVER KENTUCKY. BANDED PRECIPITATION WILL LIKELY LIFT NORTHWARD THROUGH THE DAY AND BE ORIENTED ALONG THE OHIO RIVER BY EVENING. HAVE GONE WITH LIKELY POPS HERE BUT PRECIPITATION TYPE WILL BE CHALLENGING. IN THE PAST SEVERAL EVENTS...WE HAVE SEEN STORMS SYSTEMS OUT IN THE LONG RANGE BEING FORECAST TO GO SOUTH...ONLY TO SEE A NORTHWARD TRACK VERIFY AS THE EVENT CAME CLOSER/UNFOLDED. IN ADDITION...THE NUMERICAL MODELS HAVE HAD A TOUGH TIME ESTIMATING THE AMOUNT OF WARM AIR ADVECTING IN ALOFT...WHICH HAS RESULTED IN MORE LIQUID PRECIPITATION OCCURRING. TONIGHT...WE ARE IN THE SAME DILEMMA.

BASED ON ALL THE AVAILABLE DATA...AND NOT COMPLETELY THROWING OUT THE NAM-WRF...AM INCLINED TO LEAVE A MIX OF RAIN/SLEET/SNOW IN ACROSS THE SOUTHERN FA SOUTH OF A LINE FROM NEAR HARTFORD TO JUST SOUTH OF RICHMOND. NORTH OF THAT LINE...FEEL THAT DOMINANT PRECIPITATION TYPE WILL BE SNOW. AS SFC LOW HEADS EAST THU NIGHT...SHOULD SEE ALL AREAS GO TO SNOW. ACCUMULATIONS OF SNOW APPEAR LIKELY AT THIS TIME WITH TWO TO FOUR INCHES ACROSS THE NORTHERN HALF OF THE FA WITH ONE TO TWO ACROSS SOUTHERN KY. HOWEVER...IF THE NORTHWARD TREND IN THE SURFACE TRACK OCCURS...LESS SNOW WILL BE LIKELY IN THE SOUTH AND THE 2-4 INCH BAND WOULD BE DISPLACED FURTHER NORTH...PROBABLY NORTH OF THE OHIO RIVER. GIVEN THIS EVENT IS SOME 60-72 HORUS...WILL ISSUE A SPECIAL WX STMT THIS MORNING HIGHLIGHT IMPACTS OF THE EVENT.

SNOW WILL LIKELY CONTINUE THURSDAY NIGHT AND DIMINISH SOME BY FRIDAY. SECONDARY CLIPPER TYPE SYSTEM IS FORECAST TO SWING THROUGH THE REGION FRIDAY AFTERNOON AND EVENING AND MAY BRING ANOTHER ROUND OF SNOW SHOWERS TO THE REGION. THUS...HAVE PRETTY MUCH LEFT ONGOING FORECAST INTACT FOR FRIDAY AND FRIDAY NIGHT. AS FOR TEMPERATURES THROUGH THE PERIOD...GENERALLY FOLLOWED A BLEND OF OP GFS RAW SFC TEMPS WITH A SPLASH OF THE MOS STAT GUIDANCE.

JARVIS

FORECAST FROM SATURDAY ONWARD WAS LEFT AS IS...PREVIOUS FORECAST DISCUSSION FOLLOWS...

WILL STAY CLOSE TO THE EURO THROUGH THE PERIOD...WITH SOME SUPPORT FROM THE GFS THROUGH THIS PERIOD AS WELL. INDICES (PNA/EPO/AO) STILL SUPPORT THE COLDER AIR TO CONTINUE TO REPLENISH ITSELF THROUGH THE NEXT FEW WEEKS. DEEP LONGWAVE TROUGH EXTENDS FROM HUDSON BAY POLAR VORTEX(PV) ROTATING FROM THE MS VALLEY THROUGH THE OHIO VALLEY OVER THE WEEKEND...WITH POSSIBLY THE COLDEST AIR OF THE WINTER TO DATE IN THIS PERIOD. SFC HI PRESSURE MOVES ACROSS THE REGION SATURDAY INTO SUNDAY...WEAK CLIPPER STILL LOOKS POSSIBLE SUNDAY EVENING INTO EARLY MONDAY BEFORE ANOTHER VERY COLD ARCTIC AIR MASS DROPS INTO THE CENTRAL US AND INTO THE OHIO VALLEY EARLY NEXT WEEK. AS MENTIONED EARLIER IF AN SNOW COVER ON THE GROUND DURING THIS PERIOD...MAY SEE TEMPS APPROACH ZERO FOR LOWS...WILL NOT ADJUST THAT WAY AS OF NOW...BUT HAVE TRENDED COLDER THRU THE PERIOD.

-SCHOTT

&&

.LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. &&

$$


AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
AFDLMK 1220 PM EST TUE JAN 30 2007

.AVIATION (18Z TAFS)...

GUSTY NORTHWEST WINDS TO 22KTS ARE EXPECTED IN THE WAKE OF A COLD FRONT WHICH HAS MOVED EAST OF THE TAF SITES. THESE GUSTY WINDS WILL DIMINISH AROUND 00Z. SCT TO BKN CU WILL BE POSSIBLE ACROSS SDF AND LEX THIS AFTERNOON AS AN UPPER TROUGH MOVES THROUGH THE LOWER OHIO VALLEY. CLEAR SKIES AND VFR VSBYS EXPECTED AFTER 02Z. --JA

.SHORT TERM (THIS AFTERNOON)...

AT 16Z A COLD FRONT WAS LOCATED EAST OF A LINE FROM WINCHESTER IN CENTRAL KY TO GLASGOW. TEMPERATURES HAD DROPPED 5 TO 10 DEGREES JUST AFTER THE FRONTAL PASSAGE AND LOOKING UP STREAM READINGS WERE IN THE TEENS. JUST LIKE SUNDAY... DEW POINTS HAVE DROPPED INTO THE SINGLE DIGITS ACROSS THE NORTHERN PORTION OF THE CWFA.

WILL CONTINUE TO MENTION ISOLATED TO LIGHT SNOW SHOWERS THIS AFTERNOON AS CU FIELD DEVELOPS BEHIND THE FRONT AND WITH STEEPENING LAPSE RATES. TEMPERATURES WILL CONTINUE THEIR SLOW DOWNWARD TREND EVEN WITH SOME SUNSHINE. UPDATED FORECAST OUT BY 1115. --JA

PREVIOUS DISCUSSION BELOW.

CLIPPER SHORT WAVE MOVING ESE THROUGH IOWA INTO IL/IN ATTM...WITH ASSOC SFC TROF/FRONT STRETCHING FROM NEAR IND TO PAH AS OF 6Z. MOISTURE POOLING ALONG THE FRONT...WITH DEWPOINTS RISING INTO THE MID 20S. SCT SHSN HAVE DEVELOPED ALONG/AHEAD OF THE SFC FRONT...WITH A FEW MOVING INTO THE LMK CWA AND AS FAR S AS NEAR LEITCHFIELD. RECENT ACARS DATA AT KSDF SHOW VERY STEEP LAPSE RATES TO 700MB... HELPING PROMOTE THIS PRECIP.

EXPECT ISLTD-SCT SHSN TO REMAIN POSSIBLE THROUGH THE MORNING HOURS...WITH HIGHEST CHCS OVER THE N 1/2 OF THE CWA...DECREASING SOUTHWARD. ANY SNOW AMTS SHOULD BE MINOR AT BEST THOUGH SOME OF THE SHSN HAVE BEEN INTENSE OVER IL/IN/OH BASED ON RADAR REFLECTIVITIES NEAR 35DBZ OR HIGHER...SO IF SOME OF THESE WERE TO AFFECT OUR CWA THERE COULD BE LOCALIZED ACCUMS OF A COUPLE TENTHS OF AN INCH IN A SHORT PERIOD OF TIME. WILL CONTINUE TO MONITOR AS WE GET CLOSER TO THE MORNING DRIVE.

BASED ON NAM/RUC...SFC FRONT WILL PASS THROUGH WRN COUNTIES AROUND 10-12Z...INTO ERN/SRN COUNTIES 12-14Z TIMEFRAME. THIS WILL BRING A ROUND OF GUSTY W/NW WINDS TODAY. BUFKIT DIAGNOSTICS INDICATE GUSTS TO 20-25KTS POSSIBLE AND THIS SEEMS REASONABLE BASED ON UPSTREAM OBSERVATIONS. THIS WILL ALSO BRING STEADY OR FALLING TEMPS (EXCEPT PERHAPS THE FAR SE COUNTIES). HAVE FOLLOWED A RUC/NAM BLEND FOR TEMPS TODAY INTO TONIGHT.

CHANCES FOR SHSN WILL CONTINUE INTO THE AFTN WITH STEEP LAPSE RATES...THOUGH FEEL THAT OVERALL THREAT WILL BE LOWER THAN IN THE MORNING DUE TO SIGNIFICANTLY DRIER AIR ADVECTING INTO THE LOWER OHIO VALLEY. DEWPOINTS WILL LIKELY FALL INTO THE SINGLE DIGITS THIS AFTN. WILL WORD AFTERNOON POPS AS CHANCE VERSUS MORNING COVERAGE WORDING.

GUSTY WINDS WILL LIGHTEN AFTER SUNSET...THOUGH BEFORE THAT OCCURS WIND CHILL VALUES THIS AFTN INTO THE EARLY EVENING WILL LIKELY DROP INTO THE SINGLE DIGITS WITH A FEW NEAR-ZERO VALUES POSSIBLE. HAVE ALLOWED SKIES TO CLEAR OVERNIGHT...THOUGH DID NOT GO WITH COMPLETE CLEARING SINCE NAM AND TO A LESSER EXTENT GFS SUGGEST AN AREA OF 3-5KFT CLOUDS SWEEPING ACROSS THE CWA BETWEEN 6-9Z/WED (OVERNIGHT).

CS

&&

.LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. &&

$$