Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 01/08/07

...OFFSHORE WINDS AND VERY DRY WEATHER THROUGH TUESDAY...

...MAINLY DRY INSIDE SLIDER FOR LATE WEEK...WITH A RETURN TO STRONG OFFSHORE WINDS NEXT WEEKEND...

.SHORT TERM... THE DOMINANT WEATHER FEATURE THIS AFTERNOON CONTINUES TO BE THE LARGE SURFACE HIGH CENTERED OVER THE GREAT BASIN. THIS SYSTEM IS EXPECTED TO LINGER OVER THE GREAT BASIN THROUGH MONDAY. THIS WILL KEEP A TIGHT OFFSHORE PRESSURE GRADIENT PATTERN OVER THE REGION THROUGH MONDAY. CURRENT LAX GRADIENTS ARE 7.6 MB OFFSHORE TO DAGGETT...9.2 MB OFFSHORE TO BAKERSFIELD AND 10.4 MB OFFSHORE TO TONOPAH. THE GRADIENT TO BAKERSFIELD HAS ACTUALLY INCREASED IN THE LAST FEW HOURS. GRADIENTS TO DAG AND TPH ARE EXPECTED TO TIGHTEN UP OVERNIGHT.

WINDS EARLIER TODAY WERE GUSTING TO OVER 95 MPH AT LAGUNA PEAK IN THE SANTA MONICA MOUNTAINS AND TO 85 MPH AT CHILAO IN THE SAN GABRIEL MOUNTAINS. WINDS THIS AFTERNOON HAVE DIMINISHED SOMEWHAT... AS EXPECTED. HOWEVER...WE ARE ALSO EXPECTING THE WINDS TO INCREASE AGAIN OVERNIGHT. THEREFORE...WHILE SOME AREAS ARE NOT EXPERIENCING WARNING OR ADVISORY LEVEL WINDS AT THIS TIME...THE WARNINGS AND ADVISORIES WILL BE KEPT IN EFFECT IN ANTICIPATION OF THE REDEVELOPMENT OF STRONGER WINDS. WITH THE HIGH PRESSURE OVER THE GREAT BASIN BEGINNING TO WEAKEN ON MONDAY AFTERNOON...EXPECT THE WINDS TO TAPER OFF MONDAY AFTERNOON. HOWEVER...SOME WARNINGS OR ADVISORIES MAY NEED TO BE CONTINUED BEYOND THEIR CURRENT EXPIRATION TIME OF NOON TOMORROW.

ALSO AS EXPECTED...THE COMBINATION OF DRY AIR...LOTS OF SUNSHINE... AND COMPRESSIONAL WARMING GAVE US A MUCH WARMER DAY TODAY COMPARED TO YESTERDAY. HIGHS TODAY WERE MOSTLY 5 TO 10 DEGREES WARMER THAN YESTERDAY. THE BIGGEST JUMP OCCURRED OVER THE COASTAL AREAS OF WESTERN SANTA BARBARA WHERE TEMPERATURES ROSE 10 TO 18 DEGREES ABOVE SATURDAYS HIGHS. SOUTH OF POINT CONCEPTION...TEMPERATURE WERE UP 10 TO 15 DEGREES OR MORE IN SOME COASTAL AREAS. THIS WARMTH EXTENDED OFFSHORE TO THE COASTAL ISLANDS WHERE TEMPERATURES WERE UP MOSTLY 6 TO 12 DEGREES IN THE LAST 24 HOURS.

LOOK FOR TEMPERATURES ON MONDAY TO BE SIMILAR TO TODAY...WITH PERHAPS A FEW DEGREES OF COOLING ON TUESDAY. WEDNESDAY THE WINDS WILL TURN ONSHORE AND THE TEMPERATURES WILL FALL 5 TO 10 DEGREES IN MOST AREAS. REGARDLESS....THE PATTERN REMAINS DRY THROUGH THE SHORT TERM.

.LONG TERM... MEDIUM RANGE MODEL AGREEMENT LOOKS GOOD RIGHT THROUGH THE WEEK... BEFORE SOLUTIONS BEGIN TO DIVERGE NEXT WEEKEND. THIS SHOULD GIVE GOOD CONFIDENCE IN THE FORECAST FOR THE WEEK. BOTH THE ECMWF AND THE GFS HAVE A DOMINANT UPPER RIDGE OVER THE EASTERN PACIFIC TODAY. THIS HIGH SHIFTS ONSHORE AND FLATTENS TUESDAY WITH THE UPPER LEVEL FLOW BECOMING MORE ZONAL. ON WEDNESDAY...BOTH MODELS SHOW A TROUGH DEVELOPING OVER MUCH OF THE WEST...AS AN INSIDE SLIDER DEVELOPS OVER THE PACNW. THIS INSIDE SLIDER MOVES SOUTHWARD TOWARDS THE REGION ON THURSDAY AND PASSES OVER LAS VEGAS BY LATE FRIDAY. THE UPPER LOW THEN SHIFTS TO OUR EAST AND SETS UP STRONG UPPER LEVEL SUPPORT FOR A POTENTIALLY VERY WINDY NEXT WEEKEND...AGAIN.

OVERALL...THE PATTERN LOOKS MAINLY DRY FOR THE WEEK...EXCEPT FOR THURSDAY AND FRIDAY WHEN THERE IS A CHANCE FOR SOME SHOWERS...SNOW SHOWERS IN THE MOUNTAINS. AT THIS TIME...THIS ONLY LOOKS LIKE A SLIGHT CHANCE AT THAT. TEMPERATURES WILL NOTCH DOWN AGAIN THURSDAY AND FRIDAY...COMPARED TO WEDNESDAYS HIGHS. THURSDAY AND FRIDAY SHOULD BE THE COLDEST DAYS OF THE WEEK. WINDS WILL TURN STRONGLY OFFSHORE FOR THE WEEKEND...WHICH WILL CAUSE A REBOUND IN OUR TEMPERATURES AND ANOTHER BOUT WITH VERY DRY CONDITIONS FOR THE FIRE WEATHER COMMUNITY.

&&

.AVIATION...[NOT UPDATED] STRONG OFFSHORE FLOW WILL CONTINUE ACROSS THE SOUTHLAND S OF POINT CONCEPTION...AS WELL AS N OF POINT CONCEPTION BUT MUCH WEAKER TO THE NORTH. S OF POINT CONCEPTION...EXPECT STG UDDF AND LLWS ACROSS MANY AIR FIELDS THROUGH MONDAY AFTERNOON...ESPECIALLY KBUR AND KVNY. SOME SPEED SHEAR COULD AFFECT SOME AIRCRAFT NEAR LAX...BUT THE FOCUS SHOULD REMAIN OVER THE MOUNTAINS AND VALLEYS WITH THE GREATEST UDDF AND LLWS.

KLAX WILL EXPERIENCE NORTHEAST WINDS BETWEEN 6 TO 12 KT AT THE SURFACE. SOME SOME SPEED SHEAR COULD AFFECT AIRCRAFT BELOW 10K FT

&&

.LOX WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING (SEE LAXNPWLOX). RED FLAG WARNING (SEE LAXRFWLOX). WIND ADVISORY (SEE LAXNPWLOX). SMALL CRAFT ADVISORY (SEE LAXCWFLOX). MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...DANIELSON AVIATION...KAPLAN

.SYNOPSIS...OFFSHORE FLOW WILL CAUSE LOCAL STRONG GUSTY WINDS AT TIMES THROUGH EARLY NEXT WEEK...MAINLY THROUGH AND BELOW CANYONS AND PASSES. THE WINDS WILL PEAK THIS MORNING AND AGAIN MONDAY. WARMER DAYS THROUGH MONDAY. FAIR MID WEEK UNDER HIGH PRESSURE. LOW PRESSURE WILL BRING MORE CLOUDS...COOLING...GUSTY WINDS AND A CHANCE OF SHOWERS TOWARD THE END OF NEXT WEEK.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES...

.SHORT TERM (TODAY-MONDAY)...SKIES WERE CLEAR EARLY THIS MORNING. ACARS SOUNDINGS SHOWED NE WINDS IN THE LOW LEVELS AND STRONG N WINDS ALOFT. OFFSHORE GRADIENTS WITH ABOUT -10 MB SAN-TPH AND THERE WERE LOCAL STRONG GUSTY WINDS.

THERE WILL BE STRONG UPPER SUPPORT AND MODERATE THERMAL AND GRADIENT SUPPORT FOR LOCAL GUSTY OFFSHORE WINDS TODAY. THE STRONGEST WINDS WILL SURFACE BELOW THE CAJON PASS AND IN THE SANTA ANA MOUNTAINS BUT THERE WILL ALSO BE STRONG WINDS THROUGH AND BELOW OTHER MOUNTAIN CANYONS AND PASSES. THE STRONGEST WINDS WILL GUST TO NEAR 70 MPH AND COULD CAUSE DAMAGE. THERE WILL ALSO BE AREAS OF REDUCED VISIBILITY IN BLOWING DUST AND SAND. THE SUPPORT FOR OFFSHORE WINDS WILL WEAKEN LATE TODAY. OFFSHORE GRADIENTS WILL BRIEFLY SUN MORNING AND AGAIN MON. THE CURRENT WINDS WARNINGS AND ADVISORIES LOOK OK...ALTHOUGH THEY PROBABLY CAN BE DOWNGRADED OR CANCELLED BEFORE 6 PM TONIGHT. LOCAL WIND ADVISORIES OR WARNING MAY BE NEEDED AGAIN SUN AND/OR MON. THE DRY OFFSHORE WINDS WILL MAINTAIN A HIGH FIRE WEATHER HAZARD AND A RED FLAG WARNING IS IN EFFECT. SKIES WILL BE CLEAR EXCEPT FOR A FEW HIGH CLOUDS AT TIMES. WARMER DAYS...ESPECIALLY W OF THE MOUNTAINS SUN AND MON. THE MOUNTAINS AND DESERTS WILL ALSO HAVE SIGNIFICANT WARNING DUE TO LESS COLD AIR ADVECTION AND HIGH PRESSURE ALOFT SUN AND MON. COLD AT NIGHT IN AREAS PROTECTED FROM THE WIND.

.LONG TERM (TUESDAY-FRIDAY)...FAIR BUT COOLER TUE AND MORE SO ON WED AND HEIGHTS DECREASE AND ONSHORE FLOW DEVELOPS. A COLD UPPER LOW WILL BRING MORE CLOUDS AND COOLING THU AND FRI WITH GUSTY WINDS AND A CHANCE OF SHOWERS. CURRENT TRENDS DIG THE LOW FARTHER E WITH LIMITED MOISTURE. HOWEVER...THE EXACT TRACK OF THIS LOW IS STILL UNCERTAIN.

&&

.AVIATION... OFFSHORE FLOW WILL CONTINUE THROUGH TODAY RESULTING IN SUNNY SKIES AND UNRESTRICTED VISIBILITIES...EXCEPT FOR LOCAL AREAS OF SMOKE AND HAZE FROM BLOWING DUST.

THE STRONG AND GUSTY NORTHEAST WINDS WILL CONTINUE THROUGH AND BELOW MOUNTAIN PASSES AND CANYONS THROUGH THIS MORNING...THEN WEAKEN AFTER 22Z THROUGH THE EVENING. THE STRONGEST WINDS WILL BE THROUGH AND BELOW THE SANTA ANA MOUNTAIN CANYONS...AND BELOW THE CAJON PASS THIS MORNING WHERE SIGNIFICANT TURBULENCE CAN BE EXPECTED. ALSO...STRONG WINDS ACROSS THE SAN BERNARDINO AND SAN GABRIEL MOUNTAIN RANGE WILL CONTINUE THE MOUNTAIN WAVE AND ROTOR ACTIVITY ALONG THE LEE SIDE OF THESE MOUNTAIN RANGES IN THE VICINITY OF KONT AND KSBD RESULTING IN STRONG UP AND DOWN DRAFTS AND CONSIDERABLE LOW LEVEL WIND SHEAR.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...

HIGH WIND WARNING UNTIL 6 PM SATURDAY FOR SAN BERNARDINO MOUNTAINS...INLAND EMPIRE AND SANTA ANA MOUNTAINS. SEE LAXNPWSGX.

WIND ADVISORY UNTIL 6 PM SATURDAY FOR ORANGE COUNTY COASTAL AREAS...SAN DIEGO COUNTY VALLEYS...SAN DIEGO COUNTY MOUNTAINS AND RIVERSIDE COUNTY MOUNTAINS. SEE LAXNPWSGX.

RED FLAG WARNING FOR THE MOUNTAINS AND INLAND VALLEYS THROUGH MONDAY AFTERNOON. SEE LAXRFWSGX.

$$

PUBLIC...DVA AVIATION/MARINE...JAD

.SYNOPSIS... 20Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED RIDGING NEAR THE WEST COAST...A DEEPENING TROUGH OVER THE NORTHERN ROCKIES INTO SOUTH CENTRAL CANADA...WEAK RIDGING AHEAD OF THE TROUGH IN WESTERN MINNESOTA AND TROUGHING MOVING OUT OF THE WESTERN GREAT LAKES. WITH UPPER MICHIGAN BETWEEN THE WEAK RIDGE AND TROUGH...SUBSIDENCE AND SURFACE HIGH PRESSURE RIDGING HAS BEEN MOVING INTO THE CWA. DESPITE THESE TWO FACTORS...LOW CLOUDS HAVE BEEN STUBBORN TO DISSIPATE. PART OF THE REASON IS THAT THE SUBSIDENCE IS TRAPPING LOW LEVEL MOISTURE...WHICH CAN BE SEEN NICELY ON AREA TAMDAR SOUNDINGS WITH SATURATED CONDITIONS AROUND 900MB. THESE CLOUDS HAVE ALSO HELD TEMPERATURES FROM RISING...THUS OUR HIGHEST TEMPERATURE AT THE OFFICE SO FAR FOR THE CALENDAR DAY STILL REMAINS AT THE RECORD VALUE OF 32. A CLEARING LINE IS APPROACHING FROM THE SOUTHWEST...STRETCHING FROM AITKIN TO MANITOWOC. TO THE WEST...MID AND HIGH CLOUDS ARE SPREADING EASTWARD ACROSS THE DAKOTAS AHEAD OF THE DEEPENING SHRTWV TROUGH. RADAR IMAGERY DOES SHOW SOME DECENT RETURNS ACROSS CENTRAL NORTH DAKOTA INTO WESTERN SOUTH DAKOTA...BUT OBSERVATIONS IN THIS AREA HAVE YET TO REPORT ANY PCPN. 12Z SOUNDINGS FROM BIS...UNR AND ABR ARE ALL QUITE DRY (E.G. BIS PRECIPITABLE WATER AT 0.14 INCHES)...WHICH IS PROBABLY WHY NO PCPN HAS BEEN REPORTED YET. ALTHOUGH PCPN IS LACKING...WINDS CONTINUE TO INCREASE ACROSS THE DAKOTAS DUE TO A 994 MB LOW OVER SE SASKATCHEWAN. EVEN FARTHER AHEAD OF THE LOW...850MB WINDS AT THE WOOD LAKE PROFILER HAVE INCREASED TO 25 KT.

&&

.SHORT TERM (TONIGHT AND SUNDAY)...

TONIGHT...AS THE SHRTWV TROUGH OVER THE NORTHERN ROCKIES CONTINUES TO DEEPEN AND DIG TOWARDS THE CENTRAL PLAINS...UPPER RIDGING OVER WESTERN MINNESOTA WILL BUILD OVER UPPER MICHIGAN. THIS INCREASING SUBSIDENCE FROM THE RIDGE...ALONG WITH THE WIND TURNING MORE SOUTHERLY...WILL HELP TO BRING THE CLEARING LINE ACROSS MOST...IF NOT ALL OF THE CWA BY MIDNIGHT. 18Z RUC 900MB RH HAD A GOOD HANDLE ON THIS...AND HAVE USED THE OUTPUT FOR THE SKY FORECAST. THIS CLEARING...ALONG WITH THE LOW PRECIPITABLE WATER MOVING IN FROM THE PLAINS AND LIGHT WINDS FROM THE SURFACE RIDGE AXIS MAY RESULT IN A DECENT PERIOD OF COOLING. HOWEVER...HOW MUCH COOLING WILL DEPEND ON EXACT TIMING OF THE LOW CLOUD DEPARTURE AND WHEN THE HIGH CLOUDS MOVE IN FROM THE DAKOTAS. FOR NOW...HAVE PLAYED LOWS MORE CONSERVATIVE WITH ONLY LOW 20S IN THE INTERIOR AS PER MAV GUIDANCE SINCE THE THOUGHT IS FOR ONLY A FEW HOURS OF CLEARING. HOWEVER...IF SKIES CAN CLEAR OUT FOR A LONGER PERIOD OF TIME...COOP GUIDANCE VALUES SUCH AS 10 ABOVE AT CHAMPION OF 10 ABOVE MAY BE REALIZED. GIVEN DRY AIR AROUND...MOST OF THE PRECIPITATION CHANCES WILL HOLD OFF UNTIL SUNDAY...THOUGH A LITTLE LIGHT SNOW IS NOT OUT OF THE QUESTION OVER WESTERN LAKE SUPERIOR LATE WHERE DECENT HEIGHT FALLS BEGIN TO OCCUR.

SUNDAY...DECENT HEIGHT FALLS ARE PROGGED TO OCCUR ACROSS ALL OF THE CWA AS THE UPPER LEVEL SHRTWV TROUGH MOVES IN. 850-500MB Q-VECTOR CONVERGENCE ASSOCIATED WITH THE TROUGH COMBINED WITH ISENTROPIC LIFT MAY BE ENOUGH TO SQUEEZE OUT SOME LIGHT SNOW...THOUGH A LOT OF THESE DYNAMICS ARE GOING TO GO TO MOISTENING THE AIRMASS. HAVE STILL MAINTAINED LIKELY POPS IN THE AFTERNOON OVER THE KEWEENAW INTO THE NORTHERN HALF OF LAKE SUPERIOR AS THIS IS WHERE THE BEST COMBINATION OF DYNAMICS...THERMODYNAMICS AND MOISTURE OCCUR. MAV GUIDANCE POPS ALSO REFLECT THE SAME. THE BIGGER CONCERN WITH THE SHRTWV TROUGH IS WINDS. INCREASING WINDS SEEN OVER THE PLAINS ARE EXPECTED TO MOVE OVER THE WESTERN GREAT LAKES DURING THE DAY. THE QUESTION WILL BE HOW STRONG THE SURFACE LOW IS WHEN IT REACHES THE PICKLE LAKE ONTARIO AREA AT 00Z MONDAY. RIGHT NOW THERE IS A 10MB DISAGREEMENT IN STRENGTH...RANGING FROM 1001MB BY THE GFS/NAM TO 992MB BY THE 13KM RUC. GIVEN THAT THE MAIN SHRTWV IN THE TROUGH IS EXPECTED TO DIVE INTO THE CENTRAL PLAINS TONIGHT...FIGURE THE LOW PROBABLY WILL NOT DEEPEN ANY MORE...SO TENDED TOWARDS THE SOMEWHAT WEAKER SOLUTIONS. NONETHELESS...THESE WEAKER MODELS STILL POINT AT MARGINAL SOUTHERLY GALE CONDITIONS OCCURRING OVER LAKE MICHIGAN AND EASTERN LAKE SUPERIOR. THEREFORE HAVE PUT A GALE WARNING ON EASTERN LAKE SUPERIOR. THESE SOUTHERLY WINDS WILL ALSO HELP IN KEEPING TEMPERATURES ABOVE NORMAL AND HAVE FOLLOWED CLOSE TO THE MAV GUIDANCE FOR HIGHS.

.LONG TERM (SUNDAY NIGHT THROUGH NEXT SATURDAY)...

NAM SHOWS A 500 MB TROUGH AXIS PASSING ACROSS THE CWA SUN NIGHT WITH THE TROUGH AXIS PAST THE CWA BY 18Z MON WITH THE TROUGH DIGGING INTO THE ERN U.S. LAKE EFFECT SNOW WILL BE THE PROBLEM FOR THIS FORECAST.

GFS BUFKIT SOUNDINGS SHOWING INVERSION HEIGHTS RISING TO 4000-6000 FEET SUNDAY NIGHT AND MONDAY AND THIS REMAINS THROUGH MONDAY NIGHT AND TUESDAY. WITH WEST TO NORTHWEST WINDS...THESE AREAS WILL GET HIT WITH LAKE EFFECT SNOW AND BUMPED POPS UP TO LIKELY WITH 850 MB TEMPERATURES DROPPING BELOW -8C SUN NIGHT AND BELOW -10C ON MON. LAKE SUPERIOR TEMPERATURES ARE RUNNING AROUND 3C TO 4C...SO THIS SHOULD BE ENOUGH FOR LAKE EFFECT SNOW. FOR LATE SUNDAY NIGHT THROUGH TUESDAY...THIS COULD END UP BEING A SIGNIFICANT LAKE EFFECT SNOW EVENT IN NORTHWEST AND WEST FAVORED AREAS AND THINK THERE COULD BE UP TO 9 INCHES OF SNOW IN A FEW PLACES LATE SUN NIGHT THROUGH TUE. THIS WILL ALL DEPEND ON WHERE THE BANDS SET UP AND HOW MANY BANDS THERE ARE. WILL MENTION THIS IN THE HWO FOR NOW. ONLY FLY IN THE OINTMENT IS THERE IS AN INVERTED-V LOOK TO THE GFS BUFKIT SOUNDINGS FOR MARQUETTE...NEWBERRY...HOUGHTON AND IRONWOOD AND THIS IS SHOWING SOME DRY AIR IN THE LOW LEVELS WHICH COULD BE A PROBLEM. THIS WOULD TEND TO CUT INTO THE SNOWFALL AMOUNTS AND WILL HAVE TO MONITOR THIS FOR LATER SHIFTS TO SEE IF THIS AFFECTS THE SNOWFALL. FOR THIS REASON...DID NOT GO TOO HIGH FOR SNOWFALL AMOUNTS RIGHT NOW WITH THIS SINCE THERE IS SOME UNCERTAINTY ABOUT HOW MUCH DRY AIR WILL BE AVAILABLE TO WORK WITH.

ENDED UP GOING CLOSE TO ADJMVR FOR TEMPERATURES WHICH SEEMED REASONABLE. OVERALL...DID NOT MAKE TOO MANY DRASTIC CHANGES TO THE GOING FORECAST.

IN THE EXTENDED...GFS...ECMWF AND CANADIAN ALL SHOW THE 500 MB PATTERN CONSISTS OF A 500 MB TROUGH ACROSS THE EASTERN U.S. AND PACIFIC NW WITH RIDGING ACROSS THE NORTHERN PLAINS 00Z WED. SHORTWAVE RIDGING AFFECTS THE CWA ON WED. TROUGHING THEN WORKS INTO THE AREA FOR THU AND FRI AND SAT. TEMPERATURES LOOK COLDER AND WENT WITH A COMBINATION OF ADJMXR...ADJENS AND ADJMEH FOR TEMPERATURES. TEMPERATURES WILL COOL DOWN TO NEAR NORMAL OR SLIGHTLY BELOW TOWARDS THE LATER END OF THE PERIOD. LOOKS UNSETTLED WITH SOME SYNOPTIC SNOW THROWN IN WITH SOME LAKE EFFECT SNOWS AND ONLY DRY PERIOD LOOKS TO BE WEDNESDAY WITH UPPER LEVEL RIDGING IN THE AREA THEN. OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST.

&&

.MQT WATCHES/WARNINGS/ADVISORIES... GALE WARNING EAST HALF LAKE SUPERIOR. &&

$$

AJ (SHORT TERM) MICHELS (LONG TERM)

.UPDATED... LITTLE QUESTION ABOUT IT...THE COLDER AIR HAS ARRIVED. NOW WE WILL BE ONLY 10 DEGREES ABOVE NORMAL INSTEAD OF +20 DEGREES AS WE WERE THE PAST FEW DAYS. HOWEVER... IT STILL IS NOT COLD ENOUGH TO GET SNOWFLAKES TO REACH THE GROUND SOUTH OF ROUTE 10 THIS AFTERNOON. CURRENT TAMDAR SOUNDINGS SHOW THE FREEZING LEVEL NEAR 2000 FT AGL. ANOTHER PROBLEM IS THE SURFACE DEW POINTS ARE ABOVE FREEZING. IF WE HAD PRECIPITATION OVER SOUTHWEST LOWER MICHIGAN THIS AFTERNOON... FOR THE MOST PART... IT WOULD BE SPRINKLES.

ALSO...THERE IS ANOTHER ISSUE FOR FORECASTING ANY SNOW THIS AFTERNOON. THAT WOULD BE...FOR IT TO SNOW OVER SOUTHWEST MICHIGAN... THE -12C ISOTHERM NEEDS TO BE SATURATED. THAT WOULD MEAN THERE WOULD HAVE TO BE NEAR SATURATION AT OR ABOVE 8000 FT THIS AFTERNOON. THAT IS SO... NOT GOING TO HAPPEN! THANKS TO ALL THAT STRONGLY SINKING AIR BEHIND THE SHORTWAVE THAT CAME THROUGH EARLIER AND THE WAVE PASSING SOUTH OF MICHIGAN THIS AFTERNOON THERE IS A CONSIDERABLE AMOUNT OF MID LEVEL SUBSIDENCE. THAT SHOWS UP ON THE WATER VAPOR LOOPS VERY NICELY. THE 300 MB FORECAST FOR THIS AFTERNOON SHOWS STRONG CONVERGENCE ALOFT OVER SOUTHERN LOWER MICHIGAN THIS AFTERNOON. THAT IDEA AGREES NICELY WITH WHAT THE WATER VAPOR LOOPS SUGGEST. THUS THE INVERSION HEIGHTS WILL CRASH TO 3000 FT OR SO BY 18Z OVER THE CWA. THAT IS NOT ALL THAT SUPPORTIVE FOR MUCH MORE THEN SHALLOW LOW CLOUDS.

BOTTOM LINE HERE IS I PULLED THE PRECIPITATION OUT OF THE AFTERNOON FORECAST. I DID LEAVE SPRINKLES IN FOR EARLY THIS AFTERNOON TO ALLOW WHAT WHAT REMAINED TO MOVE OUT.

.MARINE... LOOKING AT WEB CAMS WAVES IN THE NEAR SHORE IT SEEM WAVES ARE CLOSE TO 4 FEET FROM HOLLAND SOUTH. THE MODEL FORECAST SUPPORTS THAT SORT OF WAVE HEIGHT INTO MID AFTERNOON. HOWEVER WINDS DECREASE BY MID AFTERNOON THUS DECREASING THE WAVES HEIGHTS. I DID NOT ISSUE A SMALL CRAFT ADVISORY SINCE IT SEEMS MARGINAL. WE LIKELY WILL NEED SMALL CRAFT ADVISORY FOR SUNDAY AFTERNOON AS THE SECOND STRONGER PUSH OF COLD AIR MOVES IN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...NONE

&&

$$

WDM

.SHORT TERM (TONIGHT THROUGH TUESDAY)... WATER VAPOR LOOP SHOWS A WAVE MOVING THROUGH EASTERN QUEBEC...WITH A SHARP TROUGH MARCHING EAST ACROSS THE CENTRAL CONUS. ACARS 400-250MB WIND OBSERVATIONS REVEAL THE UPPER LEVEL TROUGH ACROSS THE CENTRAL CONUS...WITH A 140-170KT JET FROM THE BASE OF THE TROUGH IN THE PLAINS NORTHEAST THROUGH THE EASTERN GREAT LAKES AND EAST ACROSS MAINE. 04Z SURFACE ANALYSIS PLACED A 1004MB OCCLUDED CYCLONE OVER LAKE ERIE...WITH THE OCCLUDED/COLD FRONT SOUTH THROUGH THE TENNESSEE VALLEY AND CENTRAL GULF OF MEXICO. THE WARM/STATIONARY BOUNDARY DRAPED EAST/NORTHEAST FROM SOUTHWEST VIRGINIA THROUGH THE CENTRAL DELMARVA. A SECOND COLD FRONT STRETCHED SOUTH FROM A 999MB CYCLONE NORTH OF LAKE SUPERIOR THROUGH THE MIDWEST.

COLLABORATION WITH NEIGHBORING OFFICES TO THE SOUTH AND NORTH HAS YIELDED A CONTINUATION OF THE FLOOD WATCH. ANTICIPATE AN EARLY MORNING UPDATE WITH THE EXPIRATION OF THE WATCH. PLEASE REFER TO THE HYDROLOGY SECTION FOR FURTHER DETAILS.

THE PASSAGE OF THE OCCLUDED BOUNDARY THROUGH MID MORNING WILL PROMOTE GREATER MIXING...AND ALLOW CLOUDS TO BEGIN TO BREAK. GREATEST WIND GUSTS OF THE DAY EXPECTED DURING THE MID TO LATE AFTERNOON WITH THE PASSAGE OF THE TRAILING COLD FRONT. SCATTERED UPSLOPE SNOW SHOWERS SHOULD OCCUR IN THE MOUNTAINS WITH INCREASING WESTERLY FLOW...AS TEMPERATURES IN THE HIGHER TERRAIN FALL. DOWNSLOPE WARMING SHOULD OFFSET INITIAL COLD ADVECTION AND ALLOW TEMPERATURES EAST OF THE MOUNTAINS TO RISE INTO THE 50S.

RIDGING BUILDING INTO THE REGION TONIGHT WILL ENCOURAGE ANTICYCLONIC FLOW...BRINGING AN END TO THE MOUNTAIN SNOW SHOWERS. EXPECT LESS THAN AN INCH IN THE UPSLOPE REGIONS.

A MOSTLY CLEAR TO CLEAR SKY WILL BE THE RULE THROUGH MUCH OF THE OVERNIGHT...UNTIL THE NEXT WAVE EMBEDDED WITHIN NORTHWEST FLOW APPROACHES EARLY TUESDAY MORNING. THE DRYING DEWPOINTS AND SLACKENING FLOW UNDER A MOSTLY CLEAR SKY SHOULD ALLOW TEMPERATURES TO DROP INTO THE 20S OUTSIDE OF DOWNTOWN WASHINGTON AND BALTIMORE.

&&

.HYDROLOGY... RAINFALL TOTALS FROM MULTISENSOR PRECIPITATION ESTIMATOR THROUGH 07Z...METAR SITES AND IFLOWS GAGES INDICATE A GENERAL THIRD TO HALF INCH OF RAINFALL THUS FAR...WITH A HALF INCH TO AN INCH ACROSS CENTRAL VIRGINIA AND ALONG THE PENNSYLVANIA BORDER OF NORTH CENTRAL MARYLAND.

THERE COULD BE SOME LOCAL ENHANCEMENT WITHIN CONVECTIVE ACTIVITY NEAR THE WARM FRONT ACROSS LOWER SOUTHERN MARYLAND. THE -5C LEVEL IS NEAR 14KFT INDICATING A FAIRLY DEEP WARM RAIN LAYER WITHIN AN AIRMASS WITH PRECIPITABLE WATER VALUES NEAR 1.65" (NEAR THE HIGHEST OBSERVED IN JANUARY AT KIAD BETWEEN 1960 AND 2005). ALSO...THERE WILL BE A GENERAL INCREASE IN LIGHT TO MODERATE RAINFALL ACROSS THE AREA AS THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET PASSES OVER THE REGION EARLY THIS MORNING. DESPITE THESE FACTORS...WITH FLASH FLOOD GUIDANCE NEAR 2 INCHES FOR THE 1/3/6 HOUR PERIOD...DO NOT EXPECT ANYTHING BUT LOCALIZED FLOOD ISSUES THROUGH THE REMAINDER OF THE WATCH.

EXPECT BACK EDGE OF THE RAIN TO REACH THE BAY BY LATE MORNING AS THE AXIS OF THE UPPER LEVEL JET SHIFTS EAST OVERHEAD.

&&

.AVIATION... PASSAGE OF OCCLUDED BOUNDARY EARLY THIS MORNING WILL ALLOW CEILINGS/VISIBILITIES TO IMPROVE AND WESTERLY WINDS TO BEGIN TO GUST. A SECOND COLD FRONTAL PASSAGE DURING THE AFTERNOON WILL BRING FURTHER VEERING AND GREATER WIND GUSTS TO THE REGION. WINDS DECOUPLE THROUGH THE EVENING AS STRATOCU WHICH DEVELOPS DURING MORNING MIXING DISSIPATES DUE TO DRY ADVECTION AND DOWNSLOPE DRYING.

&&

.MARINE... 00Z GFS/ETA MOS AT THOMAS POINT BOTH SUGGEST SUSTAINED WINDS WILL INCREASE TO 20KT DURING THE DAY...FALLING TO NEAR 10KT BY TUESDAY MORNING. 00Z NAM PROXIMITY LAND BUFKIT FORECAST SOUNDINGS SUGGEST ADDITIONAL WIND GUST MOMENTUM OF 25-30 KNOTS DURING THE AFTERNOON HOURS...WHILE THE 00Z GFS INDICATES GUSTS BETWEEN 28-33 KNOTS. WILL KEEP A MARGINAL GALE WARNING ON ALL WATERS FOR WIND GUSTS TO 35 KNOTS.

SCA WINDS LIKELY TUE NGT AND WED UNDER COOL NW FLOW REGIME AND WITH STRONG S/W PASSAGE.

&&

.TIDES... WATER LEVELS ARE CURRENTLY A QUARTER FOOT ABOVE ASTRONOMIC PREDICTIONS. THE LUNAR CYCLE IS WANING FROM A FULL MOON (80% FULL). BOTH THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM AND NOAA EXTRATROPICAL STORM SURGE MODEL GUIDANCE SHOW TIDAL DEPARTURES RISING TO ABOUT A FOOT AHEAD OF THE FRONTAL PASSAGE THIS MORNING.

&&

.LONG TERM...TUESDAY THROUGH SUNDAY...

LAKE MOISTURE IN CONJUNCTION WITH UPPER TROUGH SHOULD GENERATE UPSLOPE SNOW SHOWERS BEGINNING TUESDAY AND CONTINUING INTO WEDNESDAY MORNING. AGREE WITH LATEST HPC SNOW CHARTS INDICATING HIGH-END SNOW ADVISORY CRITERIA OVER THREE PERIODS (TUE-WED)...WITH TOTAL ACCUM AROUND 4 INCHES ALONG THE WESTERN SLOPES OF THE ALLEGANY FRONT. AROUND AN INCH ACCUM POSSIBLE ALONG THE WEST FACING SLOPES EAST OF THE FRONT TO THE BLUE RIDGE...INCLUDING THE SKYLINE DR. REMAINING AREAS E OF THE BLUE RIDGE WILL CONTINUE TO MENTION A CHC OF RA/SN SHOWERS ON TUESDAY AFTERNOON. FOR NOW WILL ISSUE A SPECIAL WX STMT TO HIGHLIGHT THE PTNL FOR ACCUMULATING SNOW...BUT TOO EARLY TO ISSUE THE ADVISORY.

FAIRLY ROBUST RIDGING ENSUES FROM WEDNESDAY THROUGH FRIDAY WITH TEMPS MODERATING BACK TO WELL ABOVE NORMAL READING BY NEXT WEEKEND...WHEN MAX TEMPS INTO THE UPPER 50S TO AROUND 60 WILL BE LIKELY. A CHC OF RAIN SHOWERS SAT AND SUN IN A WARM ADVECTION PRECIP PATTERN...THEN A STRONG COLD FRONT MOVES THROUGH SUN NGT OR MONDAY BRINGING A RETURN TO COOLER TEMPERATURES...THOUGH STILL NO COLD OUTBREAKS ON THE ANYTIME ON THE HORIZON.

&&

.LWX WATCHES/WARNINGS/ADVISORIES... DC...FLOOD WATCH UNTIL 7 AM EST THIS MORNING FOR DCZ001. MD...FLOOD WATCH UNTIL 7 AM EST THIS MORNING FOR MDZ003>007-009>011-013-014-501-502. VA...FLOOD WATCH UNTIL 7 AM EST THIS MORNING FOR VAZ021-025>031- 036>042-050>057. WV...FLOOD WATCH UNTIL 7 AM EST THIS MORNING FOR WVZ050>055-501>504. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ530>537. SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO MIDNIGHT EST TONIGHT FOR ANZ530>537. GALE WARNING FROM 10 AM THIS MORNING TO 5 PM EST THIS AFTERNOON FOR ANZ530>537.

&&

$$

SHORT TERM/HYDROLOGY/AVIATION/TIDES...ROGOWSKI LONG TERM...BROTHERTON MARINE...ROGOWSKI/BROTHERTON

.SHORT TERM (MONDAY THROUGH WEDNESDAY)... LATEST SURFACE OBS/MODEL SOLUTIONS INDICATE THAT STRONG OFFSHORE WINDS SHOULD CONTINUE ACROSS VENTURA AND LOS ANGELES COUNTIES THIS MORNING. BY THIS AFTERNOON...THE WINDS SHOULD START TO DIMINISH...BUT STILL WILL LIKELY BE ADVISORY CRITERIA ACROSS THE MOUNTAINS AND SOME VALLEY LOCALES. WILL LET DAY SHIFT MAKE THAT DETERMINATION. FOR TUESDAY... OFFSHORE GRADIENTS AND UPPER SUPPORT WILL BE WEAKER...SO WILL STILL HAVE CANYON WINDS...BUT MUCH WEAKER THAN TODAY. BY WEDNESDAY...THE FLOW WILL TURN ONSHORE AS NEXT SYSTEM STARTS TO DEVELOP.

AS FOR TEMPERATURES...TODAY SHOULD BE WELL ABOVE NORMAL WITH MANY COASTAL AND VALLEY AREAS IN THE LOWER TO MID 80S. ON TUESDAY...THE WEAKER OFFSHORE FLOW SHOULD ALLOW FOR SOME SLIGHT COOLING ACROSS COASTAL AND COASTAL VALLEY AREAS...WHILE INLAND AREAS WILL ACTUALLY WARM UP A COUPLE OF DEGREES. ON WEDNESDAY...TEMPS WILL FALL DRAMATICALLY WITH RETURN OF ONSHORE FLOW AND UPPER TROUGH OVER THE AREA.

.LONG TERM (THURSDAY THROUGH SUNDAY)... FOR THURSDAY AND FRIDAY...MODELS CONTINUE TO ADVERTISE A VERY POTENT INSIDE SLIDER FOR THE AREA. QPF PROGS FROM THE MODELS STILL GENERATE SOME SCATTERED LIGHT PRECIP AMOUNTS. SO...WILL CONTINUE WITH MENTION OF SLIGHT CHANCE POPS FOR THE AREA THURSDAY AND FRIDAY. THIS SYSTEM WILL BRING IN QUITE A SHOT OF COLD AIR. SO...BY THURSDAY NIGHT AND FRIDAY...SNOW LEVELS COULD BE BETWEEN 2000 AND 2500 FEET. SO...IF ANY SHOWERS DO DEVELOP...SOME SNOW COULD BE SEEN ACROSS THE SLO INTERIOR VALLEYS...CUYAMA VALLEY AND ANTELOPE VALLEY. FOR SATURDAY AND SUNDAY...DRY CONDITIONS SHOULD PREVAIL AS THE SLIDER MOVES EAST OF THE AREA.

AS WITH MOST INSIDE SLIDERS...SOME GUSTY NORTHERLY WINDS CAN BE EXPECTED THURSDAY AND FRIDAY. GIVEN THE AMOUNT OF COLD ADVECTION THE WINDS COULD BE SIGNIFICANT. FUTURE SHIFTS WILL HAVE TO MONITOR THE WIND POTENTIAL CLOSELY THE NEXT COUPLE OF DAYS.

&&

.AVIATION...STRONG OFFSHORE FLOW WILL CONTINUE ACROSS THE SOUTHLAND S OF POINT CONCEPTION...AS WELL AS N OF POINT CONCEPTION BUT MUCH WEAKER TO THE NORTH. S OF POINT CONCEPTION...EXPECT STG UDDF AND LLWS ACROSS MANY AIR FIELDS THROUGH THE AFTERNOON...ESPECIALLY KBUR AND KVNY. SOME SPEED SHEAR COULD AFFECT SOME AIRCRAFT NEAR LAX...BUT THE FOCUS SHOULD REMAIN OVER THE MOUNTAINS AND VALLEYS.

KLAX WILL EXPERIENCE NORTHEAST WINDS BETWEEN 6-12 KT IN THE MORNING AND THEN A WEAK SEABREEZE IN THE AFTERNOON. SOME SOME SPEED SHEAR COULD AFFECT AIRCRAFT BELOW 10K FT IN THE MORNING.

&&

.LOX WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING (SEE LAXNPWLOX). RED FLAG WARNING (SEE LAXRFWLOX). WIND ADVISORY (SEE LAXNPWLOX). SMALL CRAFT ADVISORY (SEE LAXCWFLOX). MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...THOMPSON AVIATION...RORKE

.SHORT TERM /REST OF TODAY/...

FORECAST WELL IN HAND. MADE A FEW UPDATES TO ACCOUNT FOR CURRENT POSITION OF RAIN SHIELD MOVING OUT AND SKY GRIDS. THE REST IS JUST FINE AND DISCUSSED IN THE SEGMENT BELOW.

&&

.PREV DISCUSSION... /ISSUED 625 AM EST MON JAN 8 2006/

UPDATE... WILL BE UPDATING TO ALLOW THE FLOOD WATCH TO EXPIRE AT 12Z. HOURLY RAINFALL TOTALS OVERNIGHT HAVE BEEN A TENTH OF AN INCH OR LESS ACCORDING TO RADAR/METAR/IFLOWS GAGES. IN ADDITION...WILL REMOVE THUNDER ACROSS LOWER SOUTHERN MARYLAND AS CONVECTIVE ELEMENTS ARE FIRMLY WITHIN THE WARM SECTOR...MOVING TOWARD THE DELMARVA. FINALLY...MAY ADJUST POPS SLIGHTLY FOR RADAR TRENDS...AND INCREASE POPS IN MOUNTAINS FOR SNOW SHOWERS THIS AFTERNOON INTO THE LIKELY CATEGORY.

SHORT TERM (TONIGHT THROUGH TUESDAY)... WATER VAPOR LOOP SHOWS A WAVE MOVING THROUGH EASTERN QUEBEC...WITH A SHARP TROUGH MARCHING EAST ACROSS THE CENTRAL CONUS. ACARS 400-250MB WIND OBSERVATIONS REVEAL THE UPPER LEVEL TROUGH ACROSS THE CENTRAL CONUS...WITH A 140-170KT JET FROM THE BASE OF THE TROUGH IN THE PLAINS NORTHEAST THROUGH THE EASTERN GREAT LAKES AND EAST ACROSS MAINE. 04Z SURFACE ANALYSIS PLACED A 1004MB OCCLUDED CYCLONE OVER LAKE ERIE...WITH THE OCCLUDED/COLD FRONT SOUTH THROUGH THE TENNESSEE VALLEY AND CENTRAL GULF OF MEXICO. THE WARM/STATIONARY BOUNDARY DRAPED EAST/NORTHEAST FROM SOUTHWEST VIRGINIA THROUGH THE CENTRAL DELMARVA. A SECOND COLD FRONT STRETCHED SOUTH FROM A 999MB CYCLONE NORTH OF LAKE SUPERIOR THROUGH THE MIDWEST.

COLLABORATION WITH NEIGHBORING OFFICES TO THE SOUTH AND NORTH HAS YIELDED A CONTINUATION OF THE FLOOD WATCH. ANTICIPATE AN EARLY MORNING UPDATE WITH THE EXPIRATION OF THE WATCH. PLEASE REFER TO THE HYDROLOGY SECTION FOR FURTHER DETAILS.

THE PASSAGE OF THE OCCLUDED BOUNDARY THROUGH MID MORNING WILL PROMOTE GREATER MIXING...AND ALLOW CLOUDS TO BEGIN TO BREAK. GREATEST WIND GUSTS OF THE DAY EXPECTED DURING THE MID TO LATE AFTERNOON WITH THE PASSAGE OF THE TRAILING COLD FRONT. SCATTERED UPSLOPE SNOW SHOWERS SHOULD OCCUR IN THE MOUNTAINS WITH INCREASING WESTERLY FLOW...AS TEMPERATURES IN THE HIGHER TERRAIN FALL. DOWNSLOPE WARMING SHOULD OFFSET INITIAL COLD ADVECTION AND ALLOW TEMPERATURES EAST OF THE MOUNTAINS TO RISE INTO THE 50S.

RIDGING BUILDING INTO THE REGION TONIGHT WILL ENCOURAGE ANTICYCLONIC FLOW...BRINGING AN END TO THE MOUNTAIN SNOW SHOWERS. EXPECT LESS THAN AN INCH IN THE UPSLOPE REGIONS.

A MOSTLY CLEAR TO CLEAR SKY WILL BE THE RULE THROUGH MUCH OF THE OVERNIGHT...UNTIL THE NEXT WAVE EMBEDDED WITHIN NORTHWEST FLOW APPROACHES EARLY TUESDAY MORNING. THE DRYING DEWPOINTS AND SLACKENING FLOW UNDER A MOSTLY CLEAR SKY SHOULD ALLOW TEMPERATURES TO DROP INTO THE 20S OUTSIDE OF DOWNTOWN WASHINGTON AND BALTIMORE.

HYDROLOGY... RAINFALL TOTALS FROM MULTISENSOR PRECIPITATION ESTIMATOR THROUGH 07Z...METAR SITES AND IFLOWS GAGES INDICATE A GENERAL THIRD TO HALF INCH OF RAINFALL THUS FAR...WITH A HALF INCH TO AN INCH ACROSS CENTRAL VIRGINIA AND ALONG THE PENNSYLVANIA BORDER OF NORTH CENTRAL MARYLAND.

THERE COULD BE SOME LOCAL ENHANCEMENT WITHIN CONVECTIVE ACTIVITY NEAR THE WARM FRONT ACROSS LOWER SOUTHERN MARYLAND. THE -5C LEVEL IS NEAR 14KFT INDICATING A FAIRLY DEEP WARM RAIN LAYER WITHIN AN AIRMASS WITH PRECIPITABLE WATER VALUES NEAR 1.65" (NEAR THE HIGHEST OBSERVED IN JANUARY AT KIAD BETWEEN 1960 AND 2005). ALSO...THERE WILL BE A GENERAL INCREASE IN LIGHT TO MODERATE RAINFALL ACROSS THE AREA AS THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET PASSES OVER THE REGION EARLY THIS MORNING. DESPITE THESE FACTORS...WITH FLASH FLOOD GUIDANCE NEAR 2 INCHES FOR THE 1/3/6 HOUR PERIOD...DO NOT EXPECT ANYTHING BUT LOCALIZED FLOOD ISSUES THROUGH THE REMAINDER OF THE WATCH.

EXPECT BACK EDGE OF THE RAIN TO REACH THE BAY BY LATE MORNING AS THE AXIS OF THE UPPER LEVEL JET SHIFTS EAST OVERHEAD.

AVIATION... PASSAGE OF OCCLUDED BOUNDARY EARLY THIS MORNING WILL ALLOW CEILINGS/VISIBILITIES TO IMPROVE AND WESTERLY WINDS TO BEGIN TO GUST. A SECOND COLD FRONTAL PASSAGE DURING THE AFTERNOON WILL BRING FURTHER VEERING AND GREATER WIND GUSTS TO THE REGION. WINDS DECOUPLE THROUGH THE EVENING AS STRATOCU WHICH DEVELOPS DURING MORNING MIXING DISSIPATES DUE TO DRY ADVECTION AND DOWNSLOPE DRYING.

MARINE... 00Z GFS/ETA MOS AT THOMAS POINT BOTH SUGGEST SUSTAINED WINDS WILL INCREASE TO 20KT DURING THE DAY...FALLING TO NEAR 10KT BY TUESDAY MORNING. 00Z NAM PROXIMITY LAND BUFKIT FORECAST SOUNDINGS SUGGEST ADDITIONAL WIND GUST MOMENTUM OF 25-30 KNOTS DURING THE AFTERNOON HOURS...WHILE THE 00Z GFS INDICATES GUSTS BETWEEN 28-33 KNOTS. WILL KEEP A MARGINAL GALE WARNING ON ALL WATERS FOR WIND GUSTS TO 35 KNOTS.

SCA WINDS LIKELY TUE NGT AND WED UNDER COOL NW FLOW REGIME AND WITH STRONG S/W PASSAGE.

TIDES... WATER LEVELS ARE CURRENTLY A QUARTER FOOT ABOVE ASTRONOMIC PREDICTIONS. THE LUNAR CYCLE IS WANING FROM A FULL MOON (80% FULL). BOTH THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM AND NOAA EXTRATROPICAL STORM SURGE MODEL GUIDANCE SHOW TIDAL DEPARTURES RISING TO ABOUT A FOOT AHEAD OF THE FRONTAL PASSAGE THIS MORNING.

LONG TERM...TUESDAY THROUGH SUNDAY...

LAKE MOISTURE IN CONJUNCTION WITH UPPER TROUGH SHOULD GENERATE UPSLOPE SNOW SHOWERS BEGINNING TUESDAY AND CONTINUING INTO WEDNESDAY MORNING. AGREE WITH LATEST HPC SNOW CHARTS INDICATING HIGH-END SNOW ADVISORY CRITERIA OVER THREE PERIODS (TUE-WED)...WITH TOTAL ACCUM AROUND 4 INCHES ALONG THE WESTERN SLOPES OF THE ALLEGANY FRONT. AROUND AN INCH ACCUM POSSIBLE ALONG THE WEST FACING SLOPES EAST OF THE FRONT TO THE BLUE RIDGE...INCLUDING THE SKYLINE DR. REMAINING AREAS E OF THE BLUE RIDGE WILL CONTINUE TO MENTION A CHC OF RA/SN SHOWERS ON TUESDAY AFTERNOON. FOR NOW WILL ISSUE A SPECIAL WX STMT TO HIGHLIGHT THE PTNL FOR ACCUMULATING SNOW...BUT TOO EARLY TO ISSUE THE ADVISORY.

FAIRLY ROBUST RIDGING ENSUES FROM WEDNESDAY THROUGH FRIDAY WITH TEMPS MODERATING BACK TO WELL ABOVE NORMAL READING BY NEXT WEEKEND...WHEN MAX TEMPS INTO THE UPPER 50S TO AROUND 60 WILL BE LIKELY. A CHC OF RAIN SHOWERS SAT AND SUN IN A WARM ADVECTION PRECIP PATTERN...THEN A STRONG COLD FRONT MOVES THROUGH SUN NGT OR MONDAY BRINGING A RETURN TO COOLER TEMPERATURES...THOUGH STILL NO COLD OUTBREAKS ON THE ANYTIME ON THE HORIZON.

&&

.LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO MIDNIGHT EST TONIGHT FOR ANZ530>537.

GALE WARNING UNTIL 5 PM EST THIS AFTERNOON FOR ANZ530>537.

&&

$$

SHORT TERM...STRONG PREV FORECAST...ROGOWSKI/JB

.UPDATE... WILL BE UPDATING TO ALLOW THE FLOOD WATCH TO EXPIRE AT 12Z. HOURLY RAINFALL TOTALS OVERNIGHT HAVE BEEN A TENTH OF AN INCH OR LESS ACCORDING TO RADAR/METAR/IFLOWS GAGES. IN ADDITION...WILL REMOVE THUNDER ACROSS LOWER SOUTHERN MARYLAND AS CONVECTIVE ELEMENTS ARE FIRMLY WITHIN THE WARM SECTOR...MOVING TOWARD THE DELMARVA. FINALLY...MAY ADJUST POPS SLIGHTLY FOR RADAR TRENDS...AND INCREASE POPS IN MOUNTAINS FOR SNOW SHOWERS THIS AFTERNOON INTO THE LIKELY CATEGORY.

&&

.SHORT TERM (TONIGHT THROUGH TUESDAY)... WATER VAPOR LOOP SHOWS A WAVE MOVING THROUGH EASTERN QUEBEC...WITH A SHARP TROUGH MARCHING EAST ACROSS THE CENTRAL CONUS. ACARS 400-250MB WIND OBSERVATIONS REVEAL THE UPPER LEVEL TROUGH ACROSS THE CENTRAL CONUS...WITH A 140-170KT JET FROM THE BASE OF THE TROUGH IN THE PLAINS NORTHEAST THROUGH THE EASTERN GREAT LAKES AND EAST ACROSS MAINE. 04Z SURFACE ANALYSIS PLACED A 1004MB OCCLUDED CYCLONE OVER LAKE ERIE...WITH THE OCCLUDED/COLD FRONT SOUTH THROUGH THE TENNESSEE VALLEY AND CENTRAL GULF OF MEXICO. THE WARM/STATIONARY BOUNDARY DRAPED EAST/NORTHEAST FROM SOUTHWEST VIRGINIA THROUGH THE CENTRAL DELMARVA. A SECOND COLD FRONT STRETCHED SOUTH FROM A 999MB CYCLONE NORTH OF LAKE SUPERIOR THROUGH THE MIDWEST.

COLLABORATION WITH NEIGHBORING OFFICES TO THE SOUTH AND NORTH HAS YIELDED A CONTINUATION OF THE FLOOD WATCH. ANTICIPATE AN EARLY MORNING UPDATE WITH THE EXPIRATION OF THE WATCH. PLEASE REFER TO THE HYDROLOGY SECTION FOR FURTHER DETAILS.

THE PASSAGE OF THE OCCLUDED BOUNDARY THROUGH MID MORNING WILL PROMOTE GREATER MIXING...AND ALLOW CLOUDS TO BEGIN TO BREAK. GREATEST WIND GUSTS OF THE DAY EXPECTED DURING THE MID TO LATE AFTERNOON WITH THE PASSAGE OF THE TRAILING COLD FRONT. SCATTERED UPSLOPE SNOW SHOWERS SHOULD OCCUR IN THE MOUNTAINS WITH INCREASING WESTERLY FLOW...AS TEMPERATURES IN THE HIGHER TERRAIN FALL. DOWNSLOPE WARMING SHOULD OFFSET INITIAL COLD ADVECTION AND ALLOW TEMPERATURES EAST OF THE MOUNTAINS TO RISE INTO THE 50S.

RIDGING BUILDING INTO THE REGION TONIGHT WILL ENCOURAGE ANTICYCLONIC FLOW...BRINGING AN END TO THE MOUNTAIN SNOW SHOWERS. EXPECT LESS THAN AN INCH IN THE UPSLOPE REGIONS.

A MOSTLY CLEAR TO CLEAR SKY WILL BE THE RULE THROUGH MUCH OF THE OVERNIGHT...UNTIL THE NEXT WAVE EMBEDDED WITHIN NORTHWEST FLOW APPROACHES EARLY TUESDAY MORNING. THE DRYING DEWPOINTS AND SLACKENING FLOW UNDER A MOSTLY CLEAR SKY SHOULD ALLOW TEMPERATURES TO DROP INTO THE 20S OUTSIDE OF DOWNTOWN WASHINGTON AND BALTIMORE.

&&

.HYDROLOGY... RAINFALL TOTALS FROM MULTISENSOR PRECIPITATION ESTIMATOR THROUGH 07Z...METAR SITES AND IFLOWS GAGES INDICATE A GENERAL THIRD TO HALF INCH OF RAINFALL THUS FAR...WITH A HALF INCH TO AN INCH ACROSS CENTRAL VIRGINIA AND ALONG THE PENNSYLVANIA BORDER OF NORTH CENTRAL MARYLAND.

THERE COULD BE SOME LOCAL ENHANCEMENT WITHIN CONVECTIVE ACTIVITY NEAR THE WARM FRONT ACROSS LOWER SOUTHERN MARYLAND. THE -5C LEVEL IS NEAR 14KFT INDICATING A FAIRLY DEEP WARM RAIN LAYER WITHIN AN AIRMASS WITH PRECIPITABLE WATER VALUES NEAR 1.65" (NEAR THE HIGHEST OBSERVED IN JANUARY AT KIAD BETWEEN 1960 AND 2005). ALSO...THERE WILL BE A GENERAL INCREASE IN LIGHT TO MODERATE RAINFALL ACROSS THE AREA AS THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET PASSES OVER THE REGION EARLY THIS MORNING. DESPITE THESE FACTORS...WITH FLASH FLOOD GUIDANCE NEAR 2 INCHES FOR THE 1/3/6 HOUR PERIOD...DO NOT EXPECT ANYTHING BUT LOCALIZED FLOOD ISSUES THROUGH THE REMAINDER OF THE WATCH.

EXPECT BACK EDGE OF THE RAIN TO REACH THE BAY BY LATE MORNING AS THE AXIS OF THE UPPER LEVEL JET SHIFTS EAST OVERHEAD.

&&

.AVIATION... PASSAGE OF OCCLUDED BOUNDARY EARLY THIS MORNING WILL ALLOW CEILINGS/VISIBILITIES TO IMPROVE AND WESTERLY WINDS TO BEGIN TO GUST. A SECOND COLD FRONTAL PASSAGE DURING THE AFTERNOON WILL BRING FURTHER VEERING AND GREATER WIND GUSTS TO THE REGION. WINDS DECOUPLE THROUGH THE EVENING AS STRATOCU WHICH DEVELOPS DURING MORNING MIXING DISSIPATES DUE TO DRY ADVECTION AND DOWNSLOPE DRYING.

&&

.MARINE... 00Z GFS/ETA MOS AT THOMAS POINT BOTH SUGGEST SUSTAINED WINDS WILL INCREASE TO 20KT DURING THE DAY...FALLING TO NEAR 10KT BY TUESDAY MORNING. 00Z NAM PROXIMITY LAND BUFKIT FORECAST SOUNDINGS SUGGEST ADDITIONAL WIND GUST MOMENTUM OF 25-30 KNOTS DURING THE AFTERNOON HOURS...WHILE THE 00Z GFS INDICATES GUSTS BETWEEN 28-33 KNOTS. WILL KEEP A MARGINAL GALE WARNING ON ALL WATERS FOR WIND GUSTS TO 35 KNOTS.

SCA WINDS LIKELY TUE NGT AND WED UNDER COOL NW FLOW REGIME AND WITH STRONG S/W PASSAGE.

&&

.TIDES... WATER LEVELS ARE CURRENTLY A QUARTER FOOT ABOVE ASTRONOMIC PREDICTIONS. THE LUNAR CYCLE IS WANING FROM A FULL MOON (80% FULL). BOTH THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM AND NOAA EXTRATROPICAL STORM SURGE MODEL GUIDANCE SHOW TIDAL DEPARTURES RISING TO ABOUT A FOOT AHEAD OF THE FRONTAL PASSAGE THIS MORNING.

&&

.LONG TERM...TUESDAY THROUGH SUNDAY...

LAKE MOISTURE IN CONJUNCTION WITH UPPER TROUGH SHOULD GENERATE UPSLOPE SNOW SHOWERS BEGINNING TUESDAY AND CONTINUING INTO WEDNESDAY MORNING. AGREE WITH LATEST HPC SNOW CHARTS INDICATING HIGH-END SNOW ADVISORY CRITERIA OVER THREE PERIODS (TUE-WED)...WITH TOTAL ACCUM AROUND 4 INCHES ALONG THE WESTERN SLOPES OF THE ALLEGANY FRONT. AROUND AN INCH ACCUM POSSIBLE ALONG THE WEST FACING SLOPES EAST OF THE FRONT TO THE BLUE RIDGE...INCLUDING THE SKYLINE DR. REMAINING AREAS E OF THE BLUE RIDGE WILL CONTINUE TO MENTION A CHC OF RA/SN SHOWERS ON TUESDAY AFTERNOON. FOR NOW WILL ISSUE A SPECIAL WX STMT TO HIGHLIGHT THE PTNL FOR ACCUMULATING SNOW...BUT TOO EARLY TO ISSUE THE ADVISORY.

FAIRLY ROBUST RIDGING ENSUES FROM WEDNESDAY THROUGH FRIDAY WITH TEMPS MODERATING BACK TO WELL ABOVE NORMAL READING BY NEXT WEEKEND...WHEN MAX TEMPS INTO THE UPPER 50S TO AROUND 60 WILL BE LIKELY. A CHC OF RAIN SHOWERS SAT AND SUN IN A WARM ADVECTION PRECIP PATTERN...THEN A STRONG COLD FRONT MOVES THROUGH SUN NGT OR MONDAY BRINGING A RETURN TO COOLER TEMPERATURES...THOUGH STILL NO COLD OUTBREAKS ON THE ANYTIME ON THE HORIZON.

&&

.LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ530>537. SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO MIDNIGHT EST TONIGHT FOR ANZ530>537. GALE WARNING FROM 10 AM THIS MORNING TO 5 PM EST THIS AFTERNOON FOR ANZ530>537.

&&

$$

UPDATE...ROGOWSKI SHORT TERM/HYDROLOGY/AVIATION/TIDES...ROGOWSKI LONG TERM...BROTHERTON MARINE...ROGOWSKI/BROTHERTON