Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 03/08/07

AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
230 PM PST WED MAR 7 2007 .SYNOPSIS... INCREASING ONSHORE FLOW WILL CAUSE AREAS OF COASTAL LOW CLOUDS AND FOG IN THE NIGHTS AND MORNINGS THROUGH FRIDAY. OTHERWISE...FAIR AND SLIGHTLY COOLER THROUGH FRIDAY. BUILDING HIGH PRESSURE ALOFT AND WEAK OFFSHORE FLOW WILL BRING MOSTLY CLEAR AND WARMER WEATHER THIS WEEKEND AND EARLY NEXT WEEK WITH NEAR RECORD HIGH TEMPERATURES POSSIBLE FOR SOME LOCATIONS SUNDAY AND MONDAY. COOLER TOWARD THE MIDDLE OF NEXT WEEK AS THE HIGH WEAKENS. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM (TODAY-SAT)... THERE WERE VARIABLE MID AND HIGH CLOUDS WITH A FEW SPRINKLES TODAY. EARLY AFTERNOON ACARS SOUNDINGS SHOWED SW WINDS ALOFT. ONSHORE GRADIENTS AND TRENDS WITH 3-4 MB SAN-IPL. A WEAK UPPER TROUGH WILL MOVE E TONIGHT FOLLOWED BY SHORT WAVE RIDGING THU AND ANOTHER VERY WEAK SHORT WAVE TROUGH FRI. THERE COULD STILL BE ISOLATED SPRINKLES LATE THIS AFTERNOON BUT THE MID AND HIGH LEVEL MOISTURE WILL DECREASE THIS EVENING. HIGH CLOUDS SHOULD RETURN FRI WITH THE NEXT WEAK SHORT WAVE. STRONGER ONSHORE FLOW AND A DEVELOPING MARINE LAYER WILL RESULT IN AREAS OF COASTAL LOW CLOUDS AND FOG LATE TONIGHT AND THU MORNING...BECOMING A LITTLE MORE WIDESPREAD THU NIGHT AND FRI MORNING. A LITTLE COOLER THU AND FRI. BUILDING HIGH PRESSURE ALOFT AND DEVELOPING OFFSHORE FLOW WILL BRING FAIR AND WARMER WEATHER SAT. && .LONG TERM (SUN-WED)... HIGH PRESSURE ALOFT...COMBINED WITH WEAK OFFSHORE FLOW...WILL CAUSE MUCH WARMER WEATHER SUN AND MON WITH NEAR RECORD HIGH TEMPERATURES POSSIBLE IN SOME LOCATIONS. UPPER LEVEL LOW PRESSURE WILL BRING COOLING TUE AND WED ALONG WITH A POSSIBLE RETURN OF THE MARINE LAYER. && .AVIATION... 072125Z...THROUGH 0300Z MID AND HIGH LEVEL SUBTROPICAL MOISTURE ASSOCIATED WITH WEAK TROUGH MOVING NORTHEAST ACROSS AREA. EXPECT BROKEN TO SCATTERED CLOUDS BETWEEN FL100-FL200 WITH LIGHT MIXED ICING BETWEEN FL120-FL160. AFTER 08/0300Z...DEWPOINTS IN THE 50S BELOW FL008 AND CONTINUED ONSHORE FLOW BEHIND DEPARTING TROUGH SHOULD ALLOW SCATTERED STRATUS TO FORM OVER COASTAL WATERS/IMMEDIATE COAST WITH BASES INITIALLY AROUND FL005. STRATUS EXPECTED TO BECOME BROKEN-OVERCAST AFTER 08/0600Z THEN SPREAD INLAND ACROSS COASTAL PLAIN BY 08/1200Z WITH BASES LIFTING TO FL010 AND TOPS AROUND FL016. OVERCAST STRATUS LAYER LINGERING THROUGH 08/1600Z THEN BECOMING SCATTERED AROUND 1800Z. && .SGX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...DVA AVIATION...BALFOUR
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
600 AM PST TUE MAR 6 2007 ...UPDATED PUBLIC DISCUSSION... .SHORT TERM...(TODAY-THU) LATEST SATELLITE IMAGERY INDICATED A FAIRLY WIDE BAND OF MID TO HIGH LEVEL CLOUDS CONTINUING TO MOVE ACROSS THE FORECAST AREA THIS MORNING. A SPOTTER CALLED IN FROM PALMDALE REPORTING A FEW DROPS HITTING THE GROUND. SO ADDED MENTION OF SPRINKLES FOR THE LA/VTU COUNTY MOUNTAINS AND THE ANTELOPE VALLEY. SHOULD BE TRACE AMOUNTS. WITH THE LOWER ATMOSPHERE AS DRY AS IT IS...NOT EXPECTING THIS TO LAST LONG. THERE WILL BE SOME VIRGA ACROSS THE SOUTHERN PORTIONS OF THE AREA. MODELS CONTINUE TO FEED HIGH CLOUDS ACROSS THE REGION THROUGH WED NIGHT IN MOST LOCATIONS. SFC PRESSURE GRADIENTS ARE TRENDING ONSHORE THIS MORNING...BUT LAX-DGT STILL -0.7MB. WRF CONTINUES THIS ONSHORE TREND TO NEAR +5 MB LATER TODAY. THIS SHOULD HELP TEMPS LOWER A FEW DEGREES ALONG THE COASTAL PLAIN TODAY COMPARED TO YESTERDAY. THERE COULD BE A FEW SITES ALONG THE LA COASTAL PLAIN TO REACH 80 DEGREES...BUT THE MAJORITY SHOULD BE IN THE 70S. LATEST PROFILERS AND ACARS SHOW A VERY SHALLOW INVERSION IN PLACE. THIS SHOULD BE SHORT LIVED AS COOLER AIR ADVECTS IN WITH ONSHORE FLOW. SOMETIMES DURING TRANSITIONS FROM OFFSHORE TO ONSHORE FLOW...POCKETS OF DENSE FOG COULD FORM ALONG THE IMMEDIATE COAST NEAR DAWN. HOWEVER DEWPOINT DEPRESSIONS ARE SO FAR APART THAT STRATUS DEVELOPMENT THIS MORNING IS NOT LIKELY. TEMPS WILL BE A FEW DEGREES COOLER JUST ABOUT EVERYWHERE TODAY. TEMPS WILL CONTINUE TO FALL ON WED AS THICKNESS LVLS AND SLIGHT INCREASE IN ONSHORE FLOW WILL KEEP TEMPS NEAR NORMAL WEDNESDAY WITH A BETTER CHANCE OF LOW CLOUDS TO AFFECT THE COASTAL AREAS FROM SAN LUIS OBISPO COUNTY SOUTH TO LA COUNTY. LOW CLOUDS SHOULD BE PATCHY IN NATURE AND COULD BE DENSE LATE TONIGHT INTO WED MORNING. THERE COULD BE SOME GUSTY NORTHWEST WINDS ACROSS THE SBA COUNTY MOUNTAINS AND SOUTH COAST BETWEEN 20 AND 30 MPH POSSIBLE WED AFTERNOON THROUGH THE OVERNIGHT HOURS. THURSDAY TEMPS SHOULD REMAIN SIMILAR TO WEDNESDAY WITH MAYBE A COUPLE OF DEGREES OF WARMING OVER THE VALLEYS AS BOUNDARY LAYER TEMPS WARM SLIGHTLY. .LONG TERM...(FRI-MON) AN UPPER LVL RIDGE WILL BEGIN TO BUILD IN FROM THE SOUTHWEST ON FRIDAY. BOTH GFS AND ECMWF KEEP RIDGE OVER SRN CAL THROUGH SUNDAY. THE GFS CONTINUES THIS PATTERN THROUGH MONDAY. SFC GRADIENTS BECOME OFFSHORE SAT THROUGH MON. THIS WILL TRANSLATE INTO WELL ABOVE NORMAL TEMPS THROUGH THE WEEKEND AND MONDAY WITH SOME GUSTY OFFSHORE WINDS. AT THIS TIME...LOOKS LIKE NO RAIN IN SITE FOR THE NEXT 10 DAYS. && .AVIATION... 06/1200Z VFR CONDITIONS WILL PREVAIL AT MOST AIRFIELDS THROUGHOUT THE DAY WITH ONLY SCT150-200 DECKS CONTINUING TO STREAM IN FROM THE SOUTHWEST. STILL MONITORING THE CENTRAL COAST...WHERE KSBP AND KSMX MAY SEE SOME MVFR VSBYS BEFORE 16Z. ELSEWHERE...LOW LEVELS ARE TOO DRY FOR STRATUS AND FOG FORMATION. COASTAL AIRFIELDS HAVE A BETTER CHANCE AT IFR CONDITIONS AFTER MIDNIGHT TONIGHT...AS ONSHORE FLOW WILL INCREASE MOISTURE IN THE AREA. KLAX WILL REMAIN VFR THROUGH THE DAY WITH ONLY HIGH CLOUDS STREAMING THROUGH THE AREA. TYPICAL WESTERLY SEABREEZE AROUND 10 TO 12 KT WILL FORM AROUND 20Z. STRATUS AND FOG ARE POSSIBLE BRINGING IFR CONDITIONS TO THE AIRFIELD LATE TONIGHT. KBUR WILL BE VFR WITH LIGHT SOUTHERLY WIND DEVELOPING AFTER 20Z. && .LOX WATCHES/WARNINGS/ADVISORIES... NONE && $$ PUBLIC...KAPLAN AVIATION...MEIER/RORKE WWW.WEATHER.GOV/LOSANGELES
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
400 AM PST TUE MAR 6 2007 ...UPDATED FOR AVIATION DISCUSSION... .SHORT TERM...(TODAY-THU) LATEST SATELLITE IMAGERY INDICATED A FAIRLY WIDE BAND OF HIGH CLOUDS CONTINUING TO MOVE ACROSS THE FORECAST AREA THIS MORNING. MODELS CONTINUE TO FEED HIGH CLOUDS ACROSS THE REGION THROUGH WED NIGHT IN MOST LOCATIONS. SFC PRESSURE GRADIENTS ARE TRENDING ONSHORE THIS MORNING...BUT LAX-DGT STILL -0.7MB. WRF CONTINUES THIS ONSHORE TREND TO NEAR +5 MB LATER TODAY. THIS SHOULD HELP TEMPS LOWER A FEW DEGREES ALONG THE COASTAL PLAIN TODAY COMPARED TO YESTERDAY. THERE COULD BE A FEW SITES ALONG THE LA COASTAL PLAIN TO REACH 80 DEGREES...BUT THE MAJORITY SHOULD BE IN THE 70S. LATEST PROFILERS AND ACARS SHOW A VERY SHALLOW INVERSION IN PLACE. THIS SHOULD BE SHORT LIVED AS COOLER AIR ADVECTS IN WITH ONSHORE FLOW. SOMETIMES DURING TRANSITIONS FROM OFFSHORE TO ONSHORE FLOW...POCKETS OF DENSE FOG COULD FORM ALONG THE IMMEDIATE COAST NEAR DAWN. HOWEVER DEWPOINT DEPRESSIONS ARE SO FAR APART THAT STRATUS DEVELOPMENT THIS MORNING IS NOT LIKELY. TEMPS WILL BE A FEW DEGREES COOLER JUST ABOUT EVERYWHERE TODAY. TEMPS WILL CONTINUE TO FALL ON WED AS THICKNESS LVLS AND SLIGHT INCREASE IN ONSHORE FLOW WILL KEEP TEMPS NEAR NORMAL WEDNESDAY WITH A BETTER CHANCE OF LOW CLOUDS TO AFFECT THE COASTAL AREAS FROM SAN LUIS OBISPO COUNTY SOUTH TO LA COUNTY. LOW CLOUDS SHOULD BE PATCHY IN NATURE AND COULD BE DENSE LATE TONIGHT INTO WED MORNING. THERE COULD BE SOME GUSTY NORTHWEST WINDS ACROSS THE SBA COUNTY MOUNTAINS AND SOUTH COAST BETWEEN 20 AND 30 MPH POSSIBLE WED AFTERNOON THROUGH THE OVERNIGHT HOURS. THURSDAY TEMPS SHOULD REMAIN SIMILAR TO WEDNESDAY WITH MAYBE A COUPLE OF DEGREES OF WARMING OVER THE VALLEYS AS BOUNDARY LAYER TEMPS WARM SLIGHTLY. .LONG TERM...(FRI-MON) AN UPPER LVL RIDGE WILL BEGIN TO BUILD IN FROM THE SOUTHWEST ON FRIDAY. BOTH GFS AND ECMWF KEEP RIDGE OVER SRN CAL THROUGH SUNDAY. THE GFS CONTINUES THIS PATTERN THROUGH MONDAY. SFC GRADIENTS BECOME OFFSHORE SAT THROUGH MON. THIS WILL TRANSLATE INTO WELL ABOVE NORMAL TEMPS THROUGH THE WEEKEND AND MONDAY WITH SOME GUSTY OFFSHORE WINDS. AT THIS TIME...LOOKS LIKE NO RAIN IN SITE FOR THE NEXT 10 DAYS. && .AVIATION... 06/1200Z VFR CONDITIONS WILL PREVAIL AT MOST AIRFIELDS THROUGHOUT THE DAY WITH ONLY SCT150-200 DECKS CONTINUING TO STREAM IN FROM THE SOUTHWEST. STILL MONITORING THE CENTRAL COAST...WHERE KSBP AND KSMX MAY SEE SOME MVFR VSBYS BEFORE 16Z. ELSEWHERE...LOW LEVELS ARE TOO DRY FOR STRATUS AND FOG FORMATION. COASTAL AIRFIELDS HAVE A BETTER CHANCE AT IFR CONDITIONS AFTER MIDNIGHT TONIGHT...AS ONSHORE FLOW WILL INCREASE MOISTURE IN THE AREA. KLAX WILL REMAIN VFR THROUGH THE DAY WITH ONLY HIGH CLOUDS STREAMING THROUGH THE AREA. TYPICAL WESTERLY SEABREEZE AROUND 10 TO 12 KT WILL FORM AROUND 20Z. STRATUS AND FOG ARE POSSIBLE BRINGING IFR CONDITIONS TO THE AIRFIELD LATE TONIGHT. KBUR WILL BE VFR WITH LIGHT SOUTHERLY WIND DEVELOPING AFTER 20Z. && .LOX WATCHES/WARNINGS/ADVISORIES... NONE && $$ PUBLIC...KAPLAN AVIATION...MEIER/RORKE WWW.WEATHER.GOV/LOSANGELES
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
310 AM PST TUE MAR 6 2007 .SHORT TERM...(TODAY-THU) LATEST SATELLITE IMAGERY INDICATED A FAIRLY WIDE BAND OF HIGH CLOUDS CONTINUING TO MOVE ACROSS THE FORECAST AREA THIS MORNING. MODELS CONTINUE TO FEED HIGH CLOUDS ACROSS THE REGION THROUGH WED NIGHT IN MOST LOCATIONS. SFC PRESSURE GRADIENTS ARE TRENDING ONSHORE THIS MORNING...BUT LAX-DGT STILL -0.7MB. WRF CONTINUES THIS ONSHORE TREND TO NEAR +5 MB LATER TODAY. THIS SHOULD HELP TEMPS LOWER A FEW DEGREES ALONG THE COASTAL PLAIN TODAY COMPARED TO YESTERDAY. THERE COULD BE A FEW SITES ALONG THE LA COASTAL PLAIN TO REACH 80 DEGREES...BUT THE MAJORITY SHOULD BE IN THE 70S. LATEST PROFILERS AND ACARS SHOW A VERY SHALLOW INVERSION IN PLACE. THIS SHOULD BE SHORT LIVED AS COOLER AIR ADVECTS IN WITH ONSHORE FLOW. SOMETIMES DURING TRANSITIONS FROM OFFSHORE TO ONSHORE FLOW...POCKETS OF DENSE FOG COULD FORM ALONG THE IMMEDIATE COAST NEAR DAWN. HOWEVER DEWPOINT DEPRESSIONS ARE SO FAR APART THAT STRATUS DEVELOPMENT THIS MORNING IS NOT LIKELY. TEMPS WILL BE A FEW DEGREES COOLER JUST ABOUT EVERYWHERE TODAY. TEMPS WILL CONTINUE TO FALL ON WED AS THICKNESS LVLS AND SLIGHT INCREASE IN ONSHORE FLOW WILL KEEP TEMPS NEAR NORMAL WEDNESDAY WITH A BETTER CHANCE OF LOW CLOUDS TO AFFECT THE COASTAL AREAS FROM SAN LUIS OBISPO COUNTY SOUTH TO LA COUNTY. LOW CLOUDS SHOULD BE PATCHY IN NATURE AND COULD BE DENSE LATE TONIGHT INTO WED MORNING. THERE COULD BE SOME GUSTY NORTHWEST WINDS ACROSS THE SBA COUNTY MOUNTAINS AND SOUTH COAST BETWEEN 20 AND 30 MPH POSSIBLE WED AFTERNOON THROUGH THE OVERNIGHT HOURS. THURSDAY TEMPS SHOULD REMAIN SIMILAR TO WEDNESDAY WITH MAYBE A COUPLE OF DEGREES OF WARMING OVER THE VALLEYS AS BOUNDARY LAYER TEMPS WARM SLIGHTLY. .LONG TERM...(FRI-MON) AN UPPER LVL RIDGE WILL BEGIN TO BUILD IN FROM THE SOUTHWEST ON FRIDAY. BOTH GFS AND ECMWF KEEP RIDGE OVER SRN CAL THROUGH SUNDAY. THE GFS CONTINUES THIS PATTERN THROUGH MONDAY. SFC GRADIENTS BECOME OFFSHORE SAT THROUGH MON. THIS WILL TRANSLATE INTO WELL ABOVE NORMAL TEMPS THROUGH THE WEEKEND AND MONDAY WITH SOME GUSTY OFFSHORE WINDS. AT THIS TIME...LOOKS LIKE NO RAIN IN SITE FOR THE NEXT 10 DAYS. && .AVIATION... NEW DISCUSSION AFTER 12Z TAF PACKAGE. && .LOX WATCHES/WARNINGS/ADVISORIES... NONE && $$ PUBLIC...KAPLAN AVIATION...MEIER/RORKE WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSONVILLE FL
946 AM EST TUE MAR 6 2007 .UPDATE...SFC HIGH PRES DOMINATES THE AREA WITH HIGH CENTER TO OUR NW. NORTHERLY FLOW IS CURRENTLY ABOUT 5-10 KT. ONLY A FEW-SCT CI EXPECTED DURING THE DAY AS THEY SPILL OVER A MID-UPPER LEVEL RIDGE OVER THE LOWER CONUS. WEAK SHORTWAVE NOTED OVER TX MOVING E EXPECTED TO WEAKEN AS IT MOVES INTO CONFLUENT FLOW ALOFT. COLD FRONT IS ANALYZED OVER THE CAROLINAS MOVING SWD. MODELS INDICATE THE FRONT WILL CONTINUE TO SINK SWD BUT BECOME MORE DIFFUSE AS IT ENTERS OUR NERN ZONES...WITH LLVL WINDS BECOMING NELY THIS AFTERNOON. ALREADY HAVE SEEN JAX SOUNDING INDICATING A STIFF NLY WIND AT 1-3 KFT AT 20-25 KT...WITH 13Z ACARS DATA SHOWING SIMILAR WINDS...SO HAVE INDICATED A BIT STRONGER WINDS IN COASTAL ZONES WHERE GRADIENT WILL BE STRONGER. DESPITE WEAK FRONT...MOSTLY SUNNY CONDS AND TEMPS SHOULD REACH THE MID 60S TO LOWER 70S AREA-WIDE. && .AVIATION...VFR CONDS WILL PREVAIL TODAY WITH PERHAPS SOME STRATO CU DEVELOPMENT LATER THIS AFTERNOON AS LLVL FLOW TURNS NE. MORE STRATO CU EXPECTED TONIGHT ESPECIALLY OUR ERN ZONES AS LLVL HIGH PRES CENTER MOVES OFFSHORE ADVECTING A TONGUE OF MOISTURE ON THE SRN SIDE. FOR NOW...WE HAVE ADVERTISED MVFR CIGS STARTING AROUND 06Z TONIGHT. LLWS THIS MORNING SHOULD BE QUICKLY WEAKENING AS MIXING COMMENCES. && .MARINE...BUOY REPORTS FROM 41008 AND 41012 SHOW NLY WINDS 12-14 KT WITH GUSTS TO 17 KT WITH SEAS OF 1-3 FT. THINK SURGE OF NELY FLOW WILL OCCUR A BIT LATER SO WILL INITIALIZE WINDS AND SEAS A BIT LOWER FOR THE UPDATE BUT STILL EXPECT WINDS UP TO 15 TO 20 KT AT TIMES THIS AFTERNOON ESPECIALLY THE NRN WATERS. && .FIRE WEATHER...NO CHANGES PLANNED FOR CURRENT RED FLAG WARNINGS. RH VALUES ALREADY DROPPING TO 35-45% OVER PORTIONS OF THE AREA. && .JAX WATCHES/WARNINGS/ADVISORIES... FL...RED FLAG WARNING UNTIL 7 PM EST THIS EVENING FOR ALACHUA-BAKER- BRADFORD-CLAY-COLUMBIA-DUVAL-FLAGLER-GILCHRIST-HAMILTON- MARION-NASSAU-PUTNAM-ST JOHNS-SUWANNEE-UNION. FIRE WEATHER WATCH WEDNESDAY AFTERNOON FOR COLUMBIA-GILCHRIST- HAMILTON-SUWANNEE. GA...RED FLAG WARNING UNTIL 6 PM EST THIS AFTERNOON FOR APPLING- ATKINSON-BACON-BRANTLEY-CHARLTON-CLINCH-COFFEE-ECHOLS-JEFF DAVIS-PIERCE-WARE-WAYNE. AM...NONE. && $$ SHASHY/KEEGAN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
158 PM CST WED MAR 7 2007 .DISCUSSION...AFTERNOON DISCUSSION BIPOLAR TROUGH REGIME ACROSS THE LOWER 48 HAS ONE MAIN VORTEX OFF THE SRN ALASKAN COAST AND ANOTHER EAST OF HUDSONS BAY. RIDGING THROUGH THE PLAINS INTO CENTRAL CANADA HOLDS SWAY WITH WEAK SHORT WAVES DESTINED TO MOVE THROUGH SPLIT REGIME NEXT SEVERAL DAYS. NW FLOW AT REAR OF EASTERN CANADA VORTEX WILL DRAG AN ANTICYCLONE FROM MINN SEWD ACROSS THE REGION TONIGHT. SUBSIDENCE AND DRIER AIR SEEPING IN FROM N AND NE ARE ERODING LOCAL CLOUDS AND CLEARING EXPECTED THIS EVENING. WITH SFC DEW POINTS IN THE MID TEENS AND DYING WINDS EXPECT TEENS FOR TEMPS MOST SPOTS TONIGHT. RETURN FLOW SETTING UP THURS AND FRIDAY BEFORE THE NEXT DISTURBANCE WORKS EASTWARD. TIMING IS CONSISTENT WITH PREV MODEL RUNS ALTHOUGH PRECIP SHOULD HOLD OFF UNTIL FRI NIGHT. MOISTURE IN RETURN SE FLOW WILL BE LIMITED AND DYNDAMICS FAIRLY WEEK SO PRECIP THREAT...MAINLY RAIN...WILL BE IN CHC CATAGORY FRI NIGHT INTO EARLY SAT. THE LATE FRI INTO SAT DISTURBANCE WILL DRAG A VERY WEAK COOL FRONT ALONG INTO THE MID MISS VLY BUT BRIDGING ACROSS THIS BOUNDARY BY SATURDAY SUGGESTS SYSTEM WILL BE WEAKENING ALONG WITH ANY PRECIP THREAT. THERMAL CONTRAST WILL BE MINIMAL SETTING THE STAGE FOR A HIGHER PLATEAU FOR LAUNCHING WARMING NEXT WEEK. EXTENDED MODELS /GFS AND ECWMF/ IN GOOD AGREEMENT IN SUN-MONDAY TIME FRAME OF FORMING UPPER CUTOFF CIRCULATION OVER SRN MISS VLY FROM WANDERING COLD POOL. NWD EXTENSION OF THIS WILL SPREAD CLOUDS INTO OUR REGION ALONG AXIS OF TROUGH SUNDAY NIGHT AND MONDAY. HOWEVER...AS SRN SYSTEM BECOMES DETACHED AND WESTERLYS RE ESTABLISH THROUGH WESTERN LAKES USHERING IN DOWNSLOPE MODIFIED AIR FROM THE PLAINS. THIS SHOULD INITIATE THE MAIN MODERATION TUE ONWARD. ANY LINGERING SPITS OF SNOW FROM LK MICH WILL END NEAR THE ILL SHORE BY SUNDSET WITH CLEARING THIS EVENING ALL AREAS. MOS NUMBERS APPEAR GENLY GOOD FIRST 4 PDS ALTHOUGH STRONGER MARCH SUN MAY RESULT IN DAYTIME MAXS BEING A TAD LOW THUR AND FRI. KML && .AVIATION... 1150 AM CST VIS SATELLITE SHOWS BAND OF STRATOCU FM NE IL ACROSS NRN IN CONTINUING TO CLR SWRD AS HI PRESS BUILDS ACROSS MNN AND WI. THESE CLOUDS WILL BE S OF TERMINALS BY 18Z...LEAVING ONLY LK EFFECT CLOUDS AND -SHSN FOR THIS AFTERNOON. SATELLITE SHOWS MID LK BAND INTERSECTING THE SW LK SHORE FM AROUNF KUGN SWRD. DEPTH OF CLOUDS AND INTENSITY OF SNO SHOWERS LIMITED BY STRONG TEMP INVERSION BTWN 030-035 PER ACARS AND FCST SOUNDINGS. RUC AND NAM LLVL WIND AND RH PROGS MAINTAIN THE FINGER OF LAKE EFFECT POINTED AT THE CHI VC UNTIL MID AFTERNOON THEN LOOSING IT/S IDENTITY LATER AFTERNOON AS THE FETCH GETS CUT OFF AS THE CENTER OF THE ANTICYCLONE SETTLES INTO CNTRL WI AND CNTRL LK MI. SKC AND CALM AIR WITH HI PRES OVER TERMINALS TONIGHT. TRS && .LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1150 AM CST WED MAR 7 2007 .DISCUSSION...UPDATED AT 1000 AM TRAILING CLOUD BAND FROM LAST NIGHTS SHORT WAVE IS INTEREACTING WITH SHALLOW LAKE PLUME UNDER A BROAD NE FLOW. ACARS SOUNDINGS SHOW STRONG INVERSION TO 800MB OR SO THUS CLOUDS ARE SHALLOW BUT WILL LKLY BE PERSISTENT THROUGH THE AFTERNOON. RADAR DETECTS A FEW PATCHES OF LIGHT SNOW APPROACHING IL SHORELINE FROM THE NE AND A FEW FLAKES HAVE BEEN REPORTED AT MDW THIS MRNG. GIVEN PERSISTENCE OF CLOUDS AND ORIGIN OFF LAKE HAVE UPDATED FIRST PERIOD FCST TO REFLECT MORE CLOUDS ALL AREAS AND A FEW LIGHT SNOW FLURRIES ALONG THE LAKE SHORE AND JUST INLAND UNTIL MID AFTN. TEMPS ARE STRUGGLING THIS MORNING BUT FCST MAXS LOOK REASONABLE SINCE ANOTHER 3-5 DEG RISE EVEN UNDER CLOUDS BUT STRONGER MARCH SUN ANGLE IS DOABLE. KML PREVIOUS DISCUSSION 345 AM CST LT SNOW COMING TO AN END ACROSS NW INDIANA EARLY THIS MORNING AS WAA SLIDES EAST TOWARD ERN INDIANA AND OHIO. ALL PRECIP IS WELL NORTH OF SFC LOW CENTER STILL BACK NEAR STL. STRONG 1033 MB HIGH PRESSURE BUILDING SOUTHEASTWARD OUT OF ND/MN WILL BRING CLEARING SKIES TO THE AREA BY EVENING. HIGH PASSES DIRECTLY OVERHEAD LATE TONIGHT AND THURS MORNING. ONCE HIGH MOVES TO OUR EAST...THE DOOR OPENS WIDE TO WARM ADVECTION AS A LONGWAVE RIDGE PUSHES EAST ACROSS THE PLAINS. H8 TEMPS WARM FROM CURRENT -5C TO +3C BY FRI AFTN. AMPLE INSOLATION ON THURS SHOULD ALLOW SFC TEMPS TO CLIMB ABV 40 DEG RFD-PNT...THOUGH A LAKE BREEZE MAY DEVELOP IN RESPONSE TO LAND/LAKE TEMP DIFF GREATER THAN 10 DEG...KEEPING TEMPS COOLER BY THE LAKE. MID/UPR TROPOSPHERIC DISTURBANCES AND ASSOCIATED SFC TROUGH ARRIVING ON FRI OR SAT LOOK RATHER ANEMIC AND DISORGANIZED. 00Z GFS SUGGESTS SOME WEAK FROPA ON FRI...BUT FOCUSES MOST QPF WELL TO THE NORTH AND SOUTH OF OUR LOCAL AREA. THE 06Z NAM CONCENTRATES THE H3 JET STREAK AND ACCOMPANYING SHORTWAVE OVR NRN IL...BUT DELAYS ARRIVAL TIL SAT. WILL MAINTAIN THE STATUS QUO WITH CHANCE POPS FRI/FRI NT WITH SOMEWHAT MORE DEFERENCE GIVEN TO THE GFS SOLN. FAIRLY NEUTRAL TEMP ADVECTION THROUGH THE WEEKEND. TREMENDOUS WARM ADVECTION INDICATED BY THE BY BOTH THE ECMWF AND THE GFS COULD DRAW +20C H8 AIR INTO KS WITH THE 10 DEG C ISOTHERM INTO OUR AREA. THUS...TEMPS INTO THE 50S SEEMS QUITE PLAUSIBLE. RRH && .AVIATION... 1150 AM CST VIS SATELLITE SHOWS BAND OF STRATOCU FM NE IL ACROSS NRN IN CONTINUING TO CLR SWRD AS HI PRESS BUILDS ACROSS MNN AND WI. THESE CLOUDS WILL BE S OF TERMINALS BY 18Z...LEAVING ONLY LK EFFECT CLOUDS AND -SHSN FOR THIS AFTERNOON. SATELLITE SHOWS MID LK BAND INTERSECTING THE SW LK SHORE FM AROUNF KUGN SWRD. DEPTH OF CLOUDS AND INTENSITY OF SNO SHOWERS LIMITED BY STRONG TEMP INVERSION BTWN 030-035 PER ACARS AND FCST SOUNDINGS. RUC AND NAM LLVL WIND AND RH PROGS MAINTAIN THE FINGER OF LAKE EFFECT POINTED AT THE CHI VC UNTIL MID AFTERNOON THEN LOOSING IT/S IDENTITY LATER AFTERNOON AS THE FETCH GETS CUT OFF AS THE CENTER OF THE ANTICYCLONE SETTLES INTO CNTRL WI AND CNTRL LK MI. SKC AND CALM AIR WITH HI PRES OVER TERMINALS TONIGHT. TRS && .LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
916 PM EST WED MAR 7 2007 .EVENING UPDATE (OVERNIGHT)... COLD AIR ADVECTION CONTINUES ACROSS THE REGION TONIGHT. CURRENT OBS SHOWING ABOUT A 20 DEGREE TEMPERATURE SPREAD FROM COVINGTON DOWN TO BOWLING GREEN. SKIES HAVE CLEARED ACROSS THE REGION...WITH THE EXCEPTION OF A FEW AIRCRAFT CONTRAILS OUT THERE. CURRENT IR SAT IMAGERY SHOWING CLEAR SKIES UPSTREAM...THEREFORE WILL UPDATE THE FORECASTS AND GO WITH MOSTLY CLEAR FOR THE OVERNIGHT. WITH TEMPERATURES FALLING INTO THE LOWER 30S ACROSS THE NORTHEAST...HAVE LOWERED OVERNIGHT MINS SLIGHTLY. OTHER WEATHER ELEMENTS LOOK GOOD. UPDATED PRODUCTS WILL BE AVAILABLE BY 930 PM EST. -MJ .SHORT LONG TERM (TONIGHT-THURSDAY)... A WARM FRONT MOVED NORTH THROUGH THE AREA THIS MORNING WITH TEMPERATURES SOARING INTO THE UPPER 60S ACROSS SOUTH CENTRAL KENTUCKY AND INTO THE LOWER AND MID 60S ACROSS AREAS NEAR THE OHIO RIVER. JUST TO THE NORTH OF THE FRONT TEMPERATURES WERE IN THE 50S...GIVING A SHARP TEMPERATURE GRADIENT ACROSS THE AREA TODAY. A LOW PRESSURE AREA ALONG THE FRONT TRACKED ACROSS SOUTH CENTRAL INDIANA...ACROSS LOUISVILLE AND INTO EASTERN KENTUCKY DURING THE DAY. AS THE LOW PASSED TO THE EAST...THE COOLER AIR NORTH OF THE FRONT BEGAN TO FILTER INTO THE NORTHWEST PARTS OF THE FORECAST AREA. LOCATIONS ACROSS THE NORTHWEST REACHED HIGHS AROUND 18Z. MAIN FORECAST PROBLEMS FOR THE TONIGHT AND THURSDAY PERIODS WILL BE HOW FAST THE TEMPERATURES WILL FALL THIS EVENING AND HOW MUCH COOLER READINGS WILL BE ON THURSDAY. ANOTHER POTENTIAL PROBLEM IS AN AREA OF LOWER CLOUDS ACROSS THE NORTHERN HALF OF ILLINOIS EXTENDING INTO INDIANA THAT IS DROPPING TO THE SOUTH. ALTHOUGH MODEL TIME SECTIONS SHOWS INCREASE IN RH IN THE LOWEST LAYERS LATE TONIGHT INTO EARLY THURSDAY THE CLOUDS HAVE BEEN THINNING TO OUR NORTH. FOR NOW WILL MENTION ONLY A FEW CLOUDS WITH MOSTLY CLEAR SKIES OVER THE FA. WILL HAVE TO WATCH TRENDS THIS EVENING. ON THURSDAY HIGH PRESSURE TO OUR NORTH WILL MOVE EAST ACROSS THE GREAT LAKES AREA WITH LIGHT WINDS ACROSS THE LOWER OHIO VALLEY. EXPECT ONLY SCATTER CLOUDS...BUT TEMPERATURES WILL BE SOME 10 DEGREES COOLER THAN TODAY. SCHOLZ .LONG TERM (THURSDAY NIGHT THROUGH WEDNESDAY)... HIGH PRESSURE SLIDING FROM SOUTHEAST CANADA THROUGH THE NORTHEAST UNITED STATES WILL KEEP US DRY INTO FRIDAY. BITTERLY COLD AIR ASSOCIATED WITH THE HIGH WILL STAY WELL TO OUR NORTHEAST. A WEAK COOL FRONT IS STILL EXPECTED TO DAMPEN OUR WEEKEND. THE FRONT WILL APPROACH FROM THE WEST FRIDAY NIGHT AND THEN CROSS SOUTHERN INDIANA AND CENTRAL KENTUCKY ON SATURDAY...LIKELY DURING THE AFTERNOON HOURS. SCATTERED SHOWERS WILL BE FOUND ALONG THE FRONT...PRIMARILY ON SATURDAY INTO SATURDAY EVENING....TAPERING OFF SUNDAY AS THE FRONT BECOMES DIFFUSE. INSTABILITY CONTINUES TO BE WEAK WITH THIS SYSTEM SO WILL ONCE AGAIN KEEP THUNDER OUT OF THE FORECAST AND WILL LET POPS REMAIN IN THE CHANCE CATEGORY. PRECIPITATION CHANCES APPEAR SMALL SUNDAY NIGHT THROUGH WEDNESDAY AS WE SIT BETWEEN STORM SYSTEMS TO OUR NORTH AND SOUTH. DUE TO LOW CONFIDENCE WITH ANY PARTICULAR RAIN CHANCE WILL KEEP FORECAST DRY FOR NOW...REFINEMENTS CAN BE MADE WITH FUTURE FORECASTS. THIS IS IN GOOD AGREEMENT WITH SURROUNDING OFFICES. 13 .AVIATION (00Z TAFS)... VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD. LAST SET OF VIS SAT IMAGERY SHOWING SCT HIGH CLOUDS DRIFTING SOUTH AND SOUTHWEST ACROSS THE REGION. THESE CLOUDS LOOK TO DEPART THE AREA AFTER MIDNIGHT. SFC WIND FLOW ACROSS THE NORTHERN TAF SITES WILL BE OUT OF THE NORTH AND NORTHEAST TONIGHT WITH KBWG SEEING SW FLOW EARLY...THEN VEERING TO THE NORTH AND NORTHEAST LATER TONIGHT. CLOUDS ACROSS CENTRAL ILLINOIS LOOK TO BE DROPPING SOUTHWEST AND SHOULD STAY WEST OF THE TAF SITES THIS EVENING. -MJ && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
810 PM EST WED MAR 7 2007 .UPDATE... UPDATE TO LOWER MIN TEMPS AT A NUMBER OF LOCATIONS SINCE TEMPS ALREADY APRCHG PREVIOUS SHIFT`S FCST VALUES WITH BULK OF WAD CLD STILL WELL UPSTREAM TO THE NW OF CYQT. CUT -SHSN POPS E OF MQT A BIT TO REFLECT LATEST RADAR IMAGERY AND CLRG/INFLUX OF LLVL DRY AIR SHOWN ON 00Z GRB RAOB/RECENT TAMDAR SDNGS FM DLH/CMX. SINCE LATEST HI RES MODELS CONT TO SUPPORT MORE SHSN DVLPG ON BACKDOOR COLD FNT FCST TO MOVE INTO ERN LK SUP/THE FAR ERN U.P. LATE TNGT UNDER DVLPG ISENTROPIC LIFT/ MOISTENING DEPICTED ON THE 280K SFC TO THE SW OF BLDG HI PRES INTO ERN ONTARIO...BUMPED UP POPS OVER THE FAR E LATE TO MATCH APX FCST. KC .PREVIOUS DISCUSSION (ISSUED AT 405 PM)... WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED A LARGE RIDGE OVER THE EASTERN CONUS AND CANADIAN ROCKIES...PUSHING A PLUME OF MOISTURE INTO CENTRAL CANADA. FARTHER TO THE EAST...WEAK TROUGHING OFF THE EASTERN SEABOARD WILL KEEP NORTHWESTERLY UPPER LVL FLOW ACRS THE UPPER GREAT LAKES REGION. RIDING DOWN THE RIDGE IS A SHORTWAVE OVER THE NORTHERN PLAINS. AT THE SURFACE...HIGH PRESSURE OVER THE MN-WI LINE IS SLOWLY DRIFTING TO THE E-SE. THE DRY AIR AND SUBSIDENCE FROM THE HIGH...COMBINED WITH BACKING WINDS HAS KEPT LES LIMITED TO THE EASTERN LAKE SUPERIOR AREAS...WITH -SHSN TAPERING THIS AFTERNOON. LIMITED MOISTURE SUPPLY FROM MOSTLY ICED OVER WESTERN LAKE SUPERIOR HAS KEPT LES IN CHECK OVER THE WESTERN COUNTIES. .SHORT TERM (TONIGHT AND THURSDAY)... FOR TONIGHT...DESPITE LIMITED MOISTURE...KEPT A MENTION OF FLURRIES FOR AREAS WEST NEAR THE LAKE BECAUSE OF UPSLOPE FLOW AND SOME NON-ICY REGIONS. AS THE WINDS BACK...H85 TEMPS WILL CONTINUE TO WARM AHEAD OF AN H85 RIDGE PUSHING ACROSS LAKE SUPERIOR AROUND 18Z THURSDAY SO FEEL COMFORTABLE DROPPING FLURRIES TONIGHT. LATE TONIGHT THROUGH THURSDAY NAM/RUC/LOCAL 5KM WRF-ARW BRINGS A BACK DOOR FRONT ACROSS EASTERN LAKE SUPERIOR...WITH A QUICK SHOT FOR -SHSN OVER THE EASTERN LAKE. BEST QPF LINES UP FROM DUE E OF THE KEWEENAW TO THE SOO LOCKS...ALTHOUGH WOULD NOT BE SURPRISED IF CHANCE POPS NEED TO BE ADDED OVER THE KEWEENAW...DEPENDING ON THE TIMING AND SPEED OF THE FRONT. INCREASED WIND SPEEDS OVER THE LAKE TO CONGEAL WITH TIMING OF FRONT. PUSHED BACK -SHSN FROM THE W UNTIL LATE IN THE DAY THURSDAY TO BETTER AGREE WITH CURRENT MODEL TRENDS. DROPPED TEMPS A FEW DEGREES FOR TONIGHT FROM PREVIOUS FORECAST OVER SELECT INLAND LOCATIONS WHERE LESS CLOUD COVER IS LIKELY. DID NOT MAKE TOO MUCH CHANGE TO THURSDAYS HIGHS...STUCK CLOSE TO MOS GUIDANCE. .LONG TERM (THURSDAY NIGHT THROUGH WEDNESDAY)... AT THIS TIME NO LARGE SCALE SYSTEMS ARE FIGURED THROUGH NEXT WEDNESDAY. A WARM UP TREND IS ANTICIPATED. CLIMATOLOGICAL NORMAL TEMPERATURES FOR THIS TIME OF YEAR INCLUDE AFTERNOON HIGH TEMPERATURES AROUND 30 DEGREES...AND MORNING LOW TEMPERATURES AROUND 10 DEGREES. IF THE CURRENT FORECAST HOLDS TRUE...HIGH TEMPERATURES FOR NEXT WEEK SHOULD BE 10 TO 15 DEGREES ABOVE NORMAL. THE LARGE 500MB RIDGE CURRENTLY OVER EASTERN MONTANA AND THE WESTERN DAKOTAS WILL DIMINISH IN STRENGTH AND SLIDE OVER THE WESTERN GREAT LAKES REGION BY THURSDAY NIGHT. CONTINUED THE SLOWER TREND FOR WEATHER INVADING FROM THE WEST THURSDAY NIGHT...OUT AHEAD OF THE SURFACE LOW TO OUR NORTHWEST...WHICH SEEMED REASONABLE ACCORDING TO CONSENSUS. THE LOW WILL TRACK FROM EAST CENTRAL MANITOBA AT 12Z FRIDAY...TO HUDSON BAY BY 12Z SATURDAY. ZONAL FLOW WILL RULE ALOFT. A COLD FRONT WILL BE ABLE TO SWEEP ACROSS THE UPPER PENINSULA OF MICHIGAN DURING THE DAY FRIDAY. HIGH PRESSURE CENTERED ACROSS THE CENTRAL PLAINS STATES WILL THEN SURGE IN BEHIND THIS FRONT...FOR FRIDAY NIGHT AND SATURDAY...BRINGING AN END TO ANY SNOW LATE FRIDAY NIGHT. AT 500MB THE TROUGH WILL SKIRT NORTHERN AND CENTRAL LAKE SUPERIOR...WITH MUCH OF THE ENERGY REMAINING WELL TO OUR NORTH. A DRY PERIOD IS THEN ANTICIPATED UNTIL LATE SUNDAY NIGHT. THE MAIN CHANGE FROM THIS PERIOD ON WILL BE THE WARM UP IN AFTERNOON TEMPERATURES. FROM OUR PREVIOUS FORECAST PACKAGE ISSUANCE...AFTERNOON HIGH TEMPERATURES HAVE BEEN INCREASED AN AVERAGE OF 5 DEGREES FROM SUNDAY THROUGH WEDNESDAY. THIS WILL ASSIST IN MELTING SOME OF THE SNOW ACROSS THE REGION. STILL...CONDITIONS WILL REMAIN COOL ENOUGH EACH NIGHT TO RE-FREEZE...WITH LOWS EXPECTED TO BE IN THE UPPER TEENS TO LOW 20S. FOR THE DAYS 4 TROUGH 7 PERIOD...HOVERED CLOSE TO HPC GUIDANCE...WHICH WAS GENERALLY A BLEND OF THE ECMWF AND GFS WHICH HAD BEEN FAIRLY CONSISTENT OVER THE PAST COUPLE OF DAYS. .SHORT TERM...JLL .LONG TERM...KF && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
608 PM EST WED MAR 7 2007 .AVIATION... THE CURRENT SATELLITE/SURFACE OBS SHOW SOME LINGERING VFR STRATO CU ACROSS PORTIONS OF SE MI...MAINLY AROUND DTW/DET. DESPITE THE HIGH PRESSURE BUILDING INTO THE SOUTHERN GREAT LAKES TONIGHT...THERE IS SOME CONCERN THAT THE CLOUDS WILL TAKE SOME TIME TO DIMINISH THIS EVENING. THE LATEST TAMDAR SOUNDINGS OUT OF DTW SHOW A STRONG INVERSION BASED NEAR 4800 FT...WITH SOME MOISTURE TRAPPED BELOW THIS INVERSION. WITH THE WEAK FLOW...THERE MAY BE SOME STRATUS EXPANSION UNDER THE INVERSION THIS EVENING AROUND DETROIT AFTER SUNSET. THE LOW LEVEL WIND FIELD WILL THEN INCREASE OVERNIGHT...WHICH SHOULD ACT TO PUSH THE CLOUDS EAST OF THE TAF SITES. WEST-NORTHWESTERLY FLOW OVERNIGHT MAY ALLOW SOME MVFR STRATUS TO EXPAND INTO THE SAGINAW VALLEY FROM LAKE MICHIGAN. THIS POTENTIAL WILL HAVE TO BE MONITORED THROUGH THE EVENING. && .PREV DISCUSSION...ISSUED 336 PM EST WED MAR 7 2007 SHORT TERM...TONIGHT AND THURSDAY CONTINUED COLD WITH TEMPERATURES WELL BELOW NORMAL DURING THE NEXT 24 HOURS. UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE WILL ALLOW SURFACE HIGH PRESSURE TO BUILD INTO FAR SOUTHERN LOWER MICHIGAN/NORTHERN INDIANA THROUGH TOMORROW MORNING. BROKEN DIURNAL STRATO-CU HAS DEVELOPED THIS AFTERNOON...BUT IS EXPECTED TO DISSIPATE EARLY THIS EVENING. THE 12Z NAM LOOKS TOO MOIST AT 925 MB...A TYPICAL BIAS...WITH THE GFS PROBABLY MORE REPRESENTATIVE. NONE-THE-LESS...THERE IS STILL SOME LEGITIMATE CONCERN FOR SOME CLOUDS OVERNIGHT AS THE NORTHERLY LOW LEVEL FLOW OVER LAKE MICHIGAN BACKS TO THE WEST-NORTHWEST. WHETHER THE LAKE CLOUDS CAN SURVIVE THE TRIP TO THIS SIDE OF THE STATE IS THE QUESTION. WILL BE CARRYING MOSTLY CLEAR/PARTLY CLOUDY CONDITIONS THROUGH THE NIGHT. EVEN WITH A FEW PATCHES OF CLOUDS...WILL BE UNDERCUTTING GUIDANCE SIGNIFICANTLY WITH THE FRESH SNOW PACK AND SURFACE HIGH MOVING IN. WILL BE GOING WITH MINS PREDOMINATELY IN THE MID TO UPPER SINGLE NUMBERS. THE EXCEPTION BEING LOWER TEENS IN THE CITY OF DETROIT. SURFACE RIDGE WILL BE RELUCTANT TO SLIDE EAST DURING THE DAY TOMORROW AND EXPECTING MAXES IN THE MID 20S TO LOWER 30S (NEAR OR SLIGHTLY BELOW GUIDANCE)...EVEN WITH PARTLY SUNNY SKIES AS BOUNDARY LAYER MIXING DEPTH WILL BE LIMITED. LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY A SHORT WAVE RIDGE WILL MOVE OVER THE REGION IN THE UPPER LEVELS THURSDAY NIGHT AND SURFACE HIGH PRESSURE WILL SLIDE TOWARD THE EAST COAST. THIS WILL KEEP SE MICHIGAN DRY BUT WITH LOW TEMPERATURES STILL A FEW DEGREES BELOW NORMAL, IN THE TEENS RATHER THAN THE LOWER TO MID 20S. HOWEVER, A PUSH CLOSER TO NORMAL HIGHS ON FRIDAY AROUND 40 WILL BE AIDED BY INCREASED SOUTHERLY SURFACE WINDS AS LOW PRESSURE TRACKS THROUGH CENTRAL CANADA TO NEAR JAMES BAY. AGREEMENT AMONG THE 12Z MODELS IS GOOD SHOWING A SOUTHWARD EXTENSION OF THE JAMES BAY UPPER WAVE SUPPORTING A SURFACE TROUGH MOVING THROUGH LOWER MICHIGAN FRIDAY NIGHT. PREFER A SOLUTION ALONG THE LINES OF THE 12Z NAM. ITS SURFACE PRESSURE PATTERN IS LESS INFLUENCED BY THE CONVECTIVE POTENTIAL/SHOWERY POTENTIAL OF THE LOW LEVEL MOISTURE TRANSPORT COMPARED TO THE GFS. EVEN WITH THE WEAKER LOW LEVEL FLOW, THE NAM MANAGES TO PULL SURFACE DEW POINT ABOVE FREEZING ALONG AND AHEAD OF THE SURFACE TROUGH LATE FRIDAY NIGHT INTO SATURDAY MORNING. AT THE SAME TIME, PARTIAL THICKNESS FIELDS AND MODEL SOUNDINGS INDICATE MORE OF A LIQUID PRECIPITATION TYPE WITH THE MOISTURE EXITING THE AREA ON SATURDAY BEFORE TEMPERATURES CAN FALL ENOUGH TO SUPPORT SNOW. AT THIS POINT, WE WILL HAVE EVENING LOW TEMPERATURES IN LINE WITH GUIDANCE FOLLOWED BY RISING TEMPERATURES OVERNIGHT AND A CHANCE OF LIGHT RAIN AFTER MIDNIGHT THROUGH SATURDAY MORNING. THE SURFACE TROUGH/FRONT WILL BE THROUGH SE MICHIGAN BY SATURDAY AFTERNOON. THE LATEST MODEL SOLUTIONS INDICATE DRY HIGH PRESSURE BUILDING INTO THE AREA AND MOISTURE PROFILES SUGGESTING AT LEAST PARTLY SUNNY CONDITIONS. THICKNESS IN THE 1000-850 MB LAYER AROUND 1305 METERS IS ON THE COOL SIDE OF THE MEDIUM RANGE TEMPERATURE GUIDANCE BUT MARCH SUNSHINE SHOULD HELP US REACH HIGHS IN THE LOWER 40S. THE 12Z GFS THEN SHOWS THE SURFACE HIGH MOVING TO OUR NORTH AND EAST ON SUNDAY. A CHILLY START TO THE DAY IS EXPECTED WITH GOOD RADIATIONAL COOLING CONDITIONS IN PLACE. THIS, ALONG WITH EASTERLY LOW LEVEL FLOW, WILL KEEP HIGHS ON THE COOL SIDE OF 12Z MEX TEMPERATURE GUIDANCE, BUT STILL NEAR NORMAL LOWER AND MID 40S. THE REAL WARMING TREND WILL GET UNDERWAY NEXT WEEK AS THE RESIDENT POLAR VORTEX OVER EASTERN CANADA MOVES INTO THE NORTH ATLANTIC AND FILLS. THIS WILL OCCUR AS HIGH AMPLITUDE UPPER FLOW REMAINS IN PLACE OVER THE NORTH PACIFIC. THE EASTERN PACIFIC UPPER TROUGH WILL FORCE THE WESTERLIES INTO CANADA AND RISING HEIGHTS OVER THE GREAT LAKES. THIS IS A PRETTY SOLID LARGE SCALE UPPER AIR PATTERN ADJUSTMENT THAT IS USUALLY FORECAST WITH GOOD CONFIDENCE IN THE GLOBAL MODELS. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION...CONSIDINE SHORT TERM...SF LONG TERM....BT YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATE
NWS LOS ANGELES/OXNARD CA
930 PM PST WED MAR 7 2007 .SHORT TERM (TONIGHT-SAT)...LOCAL GUSTY NORTH CANYON WINDS WERE NOTED ALONG THE SBA S COAST AND MTNS THIS EVENING OTHERWISE GENERALLY FAIR WX OVER THE REGION. SOME LOW CLOUDS HAVE MOVED INTO PORTIONS OF THE CENTRAL COAST BUT NOT MUCH IN THE WAY OF FOG AS THE MARINE LAYER DEPTH THERE IS NEAR 1300 FT DEEP. A DYING COLD FRONT WILL SPREAD MORE LOW CLOUDS INTO THE CENTRAL COAST OVERNIGHT WITH SOME FOG POSSIBLE. S OF PT CONCEPTION...A WEAK EDDY OF FORECAST TO DEVELOP AFTER MIDNIGHT AND WITH A BIT OF LOW LEVEL MOISTURE PRESENT SOME LOW CLOUDS AND FOG SHOULD DEVELOP AND AFFECT THE COAST OF VTU/L.A. COUNTIES LATE TONIGHT. LOCAL DENSE FOG WILL NOT BE OUT OF THE QUESTION AS WELL AS THE LATEST LAX ACARS SOUNDINGS SHOWING THE MARINE LAYER THERE TO BE QUITE SHALLOW AT LESS THAN 500 FT. OTHERWISE SKIES WILL BE MOSTLY CLEAR ACROSS THE REGION OVERNIGHT. A BROAD WLY FLOW ALOFT WILL PREVAIL OVER SRN CA THRU THU ALONG WITH SLOWLY RISING 500 MB HEIGHTS. THE FLOW ALOFT WILL REMAIN W TO WNW THRU FRI AS AN UPPER RIDGE STARTS TO BUILD OFF THE SRN CA COAST. IT LOOKS LIKE THE UPPER RIDGE SHOULD SLOWLY BUILD INTO SRN CA FRI NIGHT INTO SAT. DRY WEATHER IS EXPECTED TO CONTINUE THRU SAT OVER THE REGION. SOME LOW CLOUDS AND FOG WILL BE POSSIBLE ALONG THE COAST NIGHT AND MORNING HOURS OTHERWISE GENERALLY FAIR SKIES ARE EXPECTED THRU THE PERIOD. TEMPS ACROSS THE REGION ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE NORMAL THU AND FRI THEN WARM TO SEVERAL DEGREES ABOVE NORMAL IN ALL AREAS FOR SAT. ...FROM PREVIOUS DISCUSSION... .LONG TERM (SUN-WED)...MODELS STILL ADVERTISING AN UPPER RIDGE OVER THE AREA SUNDAY...AND REMAINING OVER THE AREA ON MONDAY. NEAR THE SURFACE...OFFSHORE GRADIENTS WILL DEVELOP SUNDAY THROUGH MONDAY. AT THIS TIME...WILL NOT EXPECT ANY WIDESPREAD SIGNIFICANT CANYONS WINDS AS UPPER/THERMAL SUPPORT IS NOT GREAT. HOWEVER...THE OFFSHORE GRADIENTS WILL ALLOW FOR A VERY NICE WARMUP ACROSS THE AREA SATURDAY AND ESPECIALLY SUNDAY WITH WARMEST LOCATIONS TOPPING OUT AROUND 90 DEGREES. MONDAY WILL ALSO BE A WARM DAY AS THE RIDGE STARTS TO PASS BY TO OUR EAST. TUESDAY AND WEDNESDAY THE UPPER RIDGE FLATTENS OUT AND ONSHORE FLOW RETURNS. SO...WILL EXPECT DRY AND COOLER CONDITIONS. && .AVIATION... 08/0527Z VFR CONDITIONS WILL PREVAIL THROUGH THU...EXCEPT FOR KSMX AND KSBP...WHERE REDUCED IFR CIGS CAN BE EXPECTED OVERNIGHT INTO THU MORNING. EXPECTING MOST OF THE FOG AND LOW CIGS TO STAY N OF KSBA...BUT THERE IS A CHANCE OF SOME MVFR/IFR CATS FORMING OVER KOXR KLAX AND KLGB AFTER 10Z...MOST LIKELY SCENARIO WILL BE MVFR AND BRIEF IFR MIST FORMING WITHOUT A DEFINITIVE CIG. KLAX WILL BE MOSTLY VFR THROUGH THU...ALTHO THERE IS AN OUTSIDE CHANCE OF FOG CREEPING IN 13Z-17Z...BUT MVFR MIST IS THE MOST LIKELY OUTCOME. WILL HAVE TO SEE WHAT FORMS OVERNIGHT AND SEE JUST HOW COLD IT WILL GET WITH A BREAK FROM THE MIDLEVEL CLOUDS. && .LOX WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY (SEE LAXCWFLOX). && $$ PUBLIC...SIRARD/SWEET AVIATION...SIRARD WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1217 AM EST THU MAR 8 2007 .AVIATION DISCUSSION (06Z TAFS)... VERY LITTLE TO DISCUSS OVERALL THROUGH THE PERIOD...WITH VFR CONDITIONS ...CLEAR SKIES AND LIGHT ENE WINDS. AS SURFACE HIGH PRESSURE MOVES ACROSS THE SOUTHERN GREAT LAKES...WINDS WILL START TO BECOME MORE EASTERLY BY LATE AFTERNOON OR EARLY EVENING. LIGHT AND VARIABLE WINDS WILL BE POSSIBLE AT BWG AFTER 00Z. LITTLE IF ANY CLOUD COVER EXPECTED...THIN CIRRUS ABOVE 20K FT MAY BRUSH THE AREA DURING THE DAYLIGHT HOURS. SCHOTT && .PREV DISCUSSION... /ISSUED 916 PM EST WED MAR 7 2007/ EVENING UPDATE (OVERNIGHT)... COLD AIR ADVECTION CONTINUES ACROSS THE REGION TONIGHT. CURRENT OBS SHOWING ABOUT A 20 DEGREE TEMPERATURE SPREAD FROM COVINGTON DOWN TO BOWLING GREEN. SKIES HAVE CLEARED ACROSS THE REGION...WITH THE EXCEPTION OF A FEW AIRCRAFT CONTRAILS OUT THERE. CURRENT IR SAT IMAGERY SHOWING CLEAR SKIES UPSTREAM...THEREFORE WILL UPDATE THE FORECASTS AND GO WITH MOSTLY CLEAR FOR THE OVERNIGHT. WITH TEMPERATURES FALLING INTO THE LOWER 30S ACROSS THE NORTHEAST...HAVE LOWERED OVERNIGHT MINS SLIGHTLY. OTHER WEATHER ELEMENTS LOOK GOOD. UPDATED PRODUCTS WILL BE AVAILABLE BY 930 PM EST. -MJ SHORT LONG TERM (TONIGHT-THURSDAY)... A WARM FRONT MOVED NORTH THROUGH THE AREA THIS MORNING WITH TEMPERATURES SOARING INTO THE UPPER 60S ACROSS SOUTH CENTRAL KENTUCKY AND INTO THE LOWER AND MID 60S ACROSS AREAS NEAR THE OHIO RIVER. JUST TO THE NORTH OF THE FRONT TEMPERATURES WERE IN THE 50S...GIVING A SHARP TEMPERATURE GRADIENT ACROSS THE AREA TODAY. A LOW PRESSURE AREA ALONG THE FRONT TRACKED ACROSS SOUTH CENTRAL INDIANA...ACROSS LOUISVILLE AND INTO EASTERN KENTUCKY DURING THE DAY. AS THE LOW PASSED TO THE EAST...THE COOLER AIR NORTH OF THE FRONT BEGAN TO FILTER INTO THE NORTHWEST PARTS OF THE FORECAST AREA. LOCATIONS ACROSS THE NORTHWEST REACHED HIGHS AROUND 18Z. MAIN FORECAST PROBLEMS FOR THE TONIGHT AND THURSDAY PERIODS WILL BE HOW FAST THE TEMPERATURES WILL FALL THIS EVENING AND HOW MUCH COOLER READINGS WILL BE ON THURSDAY. ANOTHER POTENTIAL PROBLEM IS AN AREA OF LOWER CLOUDS ACROSS THE NORTHERN HALF OF ILLINOIS EXTENDING INTO INDIANA THAT IS DROPPING TO THE SOUTH. ALTHOUGH MODEL TIME SECTIONS SHOWS INCREASE IN RH IN THE LOWEST LAYERS LATE TONIGHT INTO EARLY THURSDAY THE CLOUDS HAVE BEEN THINNING TO OUR NORTH. FOR NOW WILL MENTION ONLY A FEW CLOUDS WITH MOSTLY CLEAR SKIES OVER THE FA. WILL HAVE TO WATCH TRENDS THIS EVENING. ON THURSDAY HIGH PRESSURE TO OUR NORTH WILL MOVE EAST ACROSS THE GREAT LAKES AREA WITH LIGHT WINDS ACROSS THE LOWER OHIO VALLEY. EXPECT ONLY SCATTER CLOUDS...BUT TEMPERATURES WILL BE SOME 10 DEGREES COOLER THAN TODAY. SCHOLZ LONG TERM (THURSDAY NIGHT THROUGH WEDNESDAY)... HIGH PRESSURE SLIDING FROM SOUTHEAST CANADA THROUGH THE NORTHEAST UNITED STATES WILL KEEP US DRY INTO FRIDAY. BITTERLY COLD AIR ASSOCIATED WITH THE HIGH WILL STAY WELL TO OUR NORTHEAST. A WEAK COOL FRONT IS STILL EXPECTED TO DAMPEN OUR WEEKEND. THE FRONT WILL APPROACH FROM THE WEST FRIDAY NIGHT AND THEN CROSS SOUTHERN INDIANA AND CENTRAL KENTUCKY ON SATURDAY...LIKELY DURING THE AFTERNOON HOURS. SCATTERED SHOWERS WILL BE FOUND ALONG THE FRONT...PRIMARILY ON SATURDAY INTO SATURDAY EVENING....TAPERING OFF SUNDAY AS THE FRONT BECOMES DIFFUSE. INSTABILITY CONTINUES TO BE WEAK WITH THIS SYSTEM SO WILL ONCE AGAIN KEEP THUNDER OUT OF THE FORECAST AND WILL LET POPS REMAIN IN THE CHANCE CATEGORY. PRECIPITATION CHANCES APPEAR SMALL SUNDAY NIGHT THROUGH WEDNESDAY AS WE SIT BETWEEN STORM SYSTEMS TO OUR NORTH AND SOUTH. DUE TO LOW CONFIDENCE WITH ANY PARTICULAR RAIN CHANCE WILL KEEP FORECAST DRY FOR NOW...REFINEMENTS CAN BE MADE WITH FUTURE FORECASTS. THIS IS IN GOOD AGREEMENT WITH SURROUNDING OFFICES. 13 .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
851 PM CST WED MAR 7 2007 FORECAST CHALLENGES CONCERN TEMPERATURES AND PCPN CHANCES/PHASE TODAY/TONIGHT. MODELS IN REASONABLE AGREEMENT THROUGH PERIOD AND WILL USE BLEND FOR FORECAST. MID LEVEL RIDGE AXIS TO SHIFT OVER FA AT 12Z AND FROM WATER VAPOR SEEMS TO BE SHOWING MORE AMPLITUDE THAN MODELS DEPICT. STEADY WARM ADVECTION CONTINUES AS THERMAL RIDGE AXIS REACHES FA BY EVENING. MVFR/IFR STRATUS EXPANDING NORTHWARD AND HAS COVERED ENTIRE FA. WITH LOW LEVEL MOIST FLUX IN RETURN FLOW EXPECT CLOUDS TO HANG TODAY. MOIST LAYER LOW AND VERY SHALLOW...1K FROM TAMDAR SOUNDINGS. WITH LITTLE IN THE WAY OF DEEPER UPSTREAM CLOUD COVER ANY LIFT IN WARM ADVECTION LIKELY WILL ONLY PRODUCE SOME PATCHY FZDZ OR FLURRIES. WITH MIXING...CLOUDS AND WARM ADVECTION TEMPERATURES LIKELY TO HOLD STEADY REMAINDER OF NIGHT. IN SPITE OF APPROACHING THERMAL RIDGE CLOUDS...SNOW PACK AND SOUTHERLY SURFACE FLOW VS WARMER SW FLOW AHEAD OF APPROACHING TROUGH WILL MAKE IT TOUGH FOR TEMPERATURES TO CLIMB TOO FAR INTO THE 30S. WILL CONTINUE TREND OF PAST COUPLE OF DAYS OF UNDERCUTTING NUMERICAL GUIDANCE. BETTER LIFT TONIGHT AS SHORTWAVE AND ASSOCIATED SURFACE TROUGH CROSSES FA. DEEP LAYERED RH STILL LOOKS LIMITED AS FEATURE PASSES SO WILL MAINTAIN LOW POPS. BASED ON SURFACE AND ELEVATED TEMPERATURES WILL CONTINUE WITH CURRENT PHASE POTENTIAL. COLUMN COOLS SOMEWHAT IN WAKE OF SHORTWAVE FRIDAY HOWEVER WITH COLUMN DRYING WE SHOULD HAVE SOME MARCH SOLAR TO WORK WITH ALONG WITH LOW LEVEL WESTERLY FLOW. WILL LEAN CLOSER TO COOLER MAV NUMERICAL GUIDANCE BASED ON DEEP AND RELATIVELY FRESH SNOWPACK. RELATIVELY ZONAL MID LEVEL FLOW EXPECTED THROUGH WEEKEND. BEST LOW LEVEL CONVERGENCE AND MID LEVEL FORCING SUNDAY TO OUR SOUTH SO OVERALL LOOKS DRY. THERMAL PROFILE SHOULD RESULT IN ABOVE FREEZING TEMPERATURES DURING DAY. WILL NOT RAISE TEMPERATURES DURING PERIOD AS WITH MELTING OF EXISTING SNOW PACK AND WEAK FLOW COULD SEE BR DEVELOPMENT AT NIGHT AND RESIDUAL CLOUDS MAY TEMPER HEATING. .AVIATION... MVFR/IFR CIGS TO PERSIST TODAY WITH SOME SPOTTY LOWER VSBY IN BR. NOT EXPECTING PCPN TO HAVE SIGNIFICANT IMPACT ON VSBY DURING DAY. BETTER CHANCES FOR PCPN TONIGHT WITH PASSAGE OF SHORT WAVE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ VOELKER
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
355 AM PST THU MAR 8 2007 .SYNOPSIS... A WEAK COASTAL EDDY WILL BRING AREAS OF NIGHT AND MORNING LOW CLOUDS AND DENSE FOG NEAR THE COAST INLAND TO THE LOWER COASTAL VALLEYS THROUGH FRIDAY MORNING WITH COOLING WEST OF THE MOUNTAINS THROUGH FRIDAY. BUILDING HIGH PRESSURE ALOFT AND WEAK OFFSHORE FLOW WILL BRING WARMER WEATHER THIS WEEKEND AND EARLY NEXT WEEK WITH NEAR RECORD HIGH TEMPERATURES POSSIBLE FOR SOME LOCATIONS SUNDAY AND MONDAY...POSSIBLY INTO TUESDAY. SLOW COOLING AND A GRADUAL RETURN OF THE MARINE LAYER THE LATTER HALF OF NEXT WEEK AS HIGH PRESSURE WEAKENS AND WEAK ONSHORE FLOW RETURNS. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM (TODAY THROUGH SATURDAY)... MID AND HIGH LEVEL MOISTURE OF THE PAST FEW DAYS HAS THINNED OUT CONSIDERABLY. A WEAK COASTAL EDDY HAS BROUGHT A RETURN OF STRATUS TO AREAS NEAR THE COAST. LATE EVENING ACARS SOUNDINGS SHOWED AN INVERSION BASE NEAR 1000 FEET. EXPECT STRATUS WITH AREAS OF DENSE FOG TO INCREASE IN COVERAGE NEAR THE COAST THROUGH SUNRISE... EXTENDING AS FAR INLAND AS THE MESAS. A WEAK EDDY IS EXPECTED TO REDEVELOP TONIGHT AND CONTINUE INTO FRIDAY MORNING WITH ENOUGH DEEPENING OF THE MARINE LAYER TO ALLOW STRATUS TO EXTEND INTO THE WESTERN VALLEYS OF SAN DIEGO COUNTY. MOST AREAS SAW SOME COOLING YESTERDAY...GREATEST NEAR THE COAST. COOLING TODAY AND FRIDAY WILL EXTEND FARTHER INLAND INTO THE VALLEYS. MOUNTAINS AND DESERTS WILL SEE ONLY MINOR COOLING. FOR SATURDAY...HIGH PRESSURE WILL BEGIN TO BUILD INTO CALIFORNIA FROM THE SOUTHWEST. COMBINED WITH WEAK OFFSHORE FLOW...THIS SHOULD BRING AN END TO THE BRIEF STRATUS EPISODE WITH WARMING TO ABOVE SEASONAL LEVELS WEST OF THE MOUNTAINS. && .LONG TERM (SUNDAY THROUGH WEDNESDAY)... HIGH PRESSURE OVER CALIFORNIA WILL BUILD THROUGH MONDAY...THEN SLOWLY WEAKEN. WEAK OFFSHORE FLOW WILL CONTINUE AT TIMES SUNDAY AND MONDAY. TEMPERATURES SHOULD BE NEAR RECORD LEVELS IN SOME LOCATIONS FOR SUNDAY AND MONDAY AND MAY CONTINUE INTO TUESDAY, FOR THE LATTER HALF OF THE WEEK...A TROUGH OF LOW PRESSURE MOVING THROUGH THE PACIFIC NORTHWEST WILL WEAKEN THE HIGH PRESSURE OVER SOUTHERN CALIFORNIA AND BRING A RETURN OF WEAK ONSHORE FLOW WITH SLOW COOLING. THE MARINE LAYER MAY RETURN LATE IN THE WEEK. && .AVIATION... 081150Z...STRATUS DEVELOPING NEAR THE COAST EARLY THIS MORNING. EXPECT AREAS OF MVFR VIS AND ISOLDATED IFR NEAR THE COAST. BASES ABOUT 1000 FT MSL WITH LOCAL BASES NEAR 500 FT MSL. STRATUS WILL EVAPORATE BY 16-18Z WITH SOME MVFR VIS DUE TO HAZE NEAR THE COAST. STRATUS WILL RETURN TONIGHT AT ABOUT THE SAME BASES AND VIS ABOUT 6-8Z. WINDS AT 5K FT...WEST TO NORTHWEST 10-15 KT...BECOMING WEST 5-10 KT TONIGHT THROUGH FRI AFTERNOON. WINDS AT 10K FT... NORTHWEST 15-20 KT...BECOMING WEST 10-15 KT TONIGHT THROUGH FRI AFTERNOON. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...DENSE FOG ADVISORY UNTIL 8 AM PST THIS MORNING FOR ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS. PZ...NONE. && $$ PUBLIC...MARTIN AVIATION/MARINE...WHITLOW NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1026 AM EST THU MAR 8 2007 .UPDATE...BACKDOOR ARCTIC FRONT...CURRENTLY STRETCHING FROM WHITEFISH POINT SOUTHEAST ACROSS CENTRAL LAKE HURON...CONTINUES TO EVER SO SLOWLY MOVE TO THE SOUTHWEST IN RESPONSE TO SHEARED DPVA LOBE DROPPING INTO THE NORTHEAST. COMBINATION OF ENHANCED LOW LEVEL CONVERGENCE ALONG FRONT...ALONG WITH SOME WEAK NORTHWEST FLOW LAKE EFFECT OVER EASTERN LAKE SUPERIOR...RESULTING IN SCATTERED LIGHT SNOW SHOWERS OVER THE NORTHERN HALF OF CHIPPEWA COUNTY...PER MONTREAL RIVER CANADA AND KMQT RADARS. CONDITIONS REMAIN DRY OVER THE NORTHERN LOWER...WITH SOLID SHEET OF 5-6KFT OVERCAST COVERING ROUGHLY THE NORTHEAST HALF...WITH NEARLY CLOUD FREE SKIES SOUTHWEST OF A LINE EXTENDING FROM THE TIP OF THE LEELANAU PENINSULA TO STANDISH. FORECAST CONCERNS FOR THE REMAINDER OF THE DAY CENTER ON LINGERING LIGHT SNOW/FLURRY CHANCES WITH APPROACH OF ARCTIC FRONT. RECENT SATELLITE TRENDS/12 NAM-WRF GUIDANCE SHOW ARCTIC FRONT CONTINUING TO SLOW ITS SOUTHWEST DRIFT. STILL EXPECTING IT TO EVENTUALLY BRUSH NORTHEAST LOWER LATER THIS MORNING BEFORE DECAYING IN PLACE DURING THE AFTERNOON. RADAR TRENDS FROM MONTREAL RIVER STILL SHOWS DISTINCT NORTHWEST FLOW LAKE EFFECT (ALBEIT LIGHT) AFFECTING NORTHERN CHIPPEWA COUNTY. EXPECT THIS TO CONTINUE THROUGH THE MORNING BEFORE WINDS VEER AROUND TO SOUTHEAST. THEREFORE...HAVE GONE AHEAD AND EXTENDED SCATTERED SNOW SHOWER WORDING FOR THIS AREA THROUGH EARLY AFTERNOON. FOR THE NORTHERN LOWER...WEAKENING LOW LEVEL CONVERGENCE ALONG FRONT...COMBINED WITH ANEMIC LAKE EFFECT PARAMETERS (RECENT ACARS SOUNDING OUT OF ALPENA SHOWS STRONG SUBSIDENCE INVERSION UP AROUND 3.7KFT) SHOULD RESULT IN NOTHING MORE THAN SOME SCATTERED FLURRIES. EXPECT THESE FLURRIES TO SPREAD UP INTO SOUTHEAST SECTIONS OF EASTERN UPPER AS WINDS BECOME SOUTHEAST. OTHERWISE...HAVE GONE AHEAD AND REDUCED CLOUD COVER OVER SOUTHWEST SECTIONS FOR THE REMAINDER OF THE DAY AS VISIBLE SATELLITE IMAGERY SHOWS CLOUD SHIELD HALTING ITS SOUTHEAST ADVANCE. TEMPERATURES/WINDS APPEAR ON TARGET WITH NO CHANGES WARRANTED. UPDATED GRIDS/ZONES/NEARSHORES OUT SHORTLY. MSB && .AVIATION...ISSUED 634 AM EST THU MAR 8 2007 GENERAL HIGH PRESSURE OVER THE AREA WILL RESULT IN VFR CEILING/VISIBILITIES FOR ALL TAF SITES THROUGH THE PERIOD. BACKDOOR COLD FRONT STILL EXPECTED TO WORK INTO APN AND PLN AROUND MIDDAY (18Z). ONLY FLURRIES ARE POSSIBLE...AS CONVERGENCE WITH THIS FEATURE IS WEAK...AND LOW LEVEL TEMPERATURES LOOKING TOO WARM FOR LAKE EFFECT TO RESULT IN ANY RESTRICTIONS TO VISIBILITIES. WINDS WILL REMAIN LIGHT THROUGH THE PERIOD AS WELL...A GENERAL SOUTHEAST FLOW IS EXPECTED BY LATE THIS AFTERNOON AND EVENING. SMD && .PREV DISCUSSION...ISSUED 408 AM EST THU MAR 8 2007 SFC/RUC/SATELLITE/RADAR AND UPPER AIR ANALYSIS SHOWING LONGWAVE TROUGH ACROSS EASTERN CANADA AND THE NE CONUS WHILE RIDGING WAS SEEN ACROSS THE DAKOTAS. SHORTWAVE WORKING DOWN THE BACKSIDE OF THE UPPER TROUGH THROUGH SOUTH OF JAMES BAY WITH THE FORCING FROM THIS FEATURE FROM EASTERN ONTARIO TO NEW ENGLAND. SFC BACKDOOR...AND NEARLY STATIONARY...ARCTIC FRONT WAS POSITIONED JUST NORTHEAST OF LAKE SUPERIOR...THE SAULT AND LAKE ERIE WHILE SFC HIGH PRESSURE WAS CENTERED OVER LOWER MICHIGAN. IN NRN MI...-12 TO -14C H8 AIR AND 15KT WNW FLOW WAS RESULTING IN A SWATH OF 2500FT STRATO CU AND FLURRIES. LOOKING UPSTREAM...WARM FRONT NOTED ACROSS THE DAKOTAS...EXTENDING FROM LOW PRESSURE IN ALBERTA CANADA. CEILINGS BETWEEN 4-10KFT WERE TRYING TO PUSH SE TOWARD NRN MICHIGAN...WHILE A CORRIDOR OF LOW LEVEL CLOUDS WITH CEILINGS UNDER 2KFT WERE SNEAKING EASTWARD INTO MINNESOTA AND FAR WESTERN WISCONSIN. FORECAST CONCERNS...CHANCES OF LIGHT PRECIPITATION THROUGH FRIDAY NIGHT...WITH SOME TYPE CONCERNS FRIDAY AND FRIDAY NIGHT. ALSO... TEMPERATURES ARE A FOCUS OF THE FORECAST AS MODERATING/WARMING AIR MASS EXPECTED TO DEVELOP INTO THE REGION THROUGH THE WEEKEND. TODAY...SHORTWAVE DIGS SSE THROUGH NEW YORK AND VERMONT TODAY WITH SYNOPTIC FORCING REMAINING EAST OF NRN MICHIGAN. THE PASSAGE OF THIS TROUGH DOES ALLOW LOW LEVEL WINDS TO VEER MORE NORTHEAST ACROSS EASTERN ONTARIO. THIS WILL ALLOW FOR AT LEAST A SLIGHT WESTWARD PUSH TO THE ARCTIC BOUNDARY POISED JUST TO OUR NE. THIS FRONTAL ZONE WILL HAVE THE BEST CHANCE TO MAKE IT INTO CHIPPEWA COUNTY...ENHANCING THE LOW LEVEL CONVERGENCE FOR A BRIEF TIME THROUGH MID MORNING OR SO...BUT NOT ENTIRELY SOLD ON THIS IDEA. AT THE SAME TIME...4-10KFT MOISTURE SEEN WORKING IT`S WAY TOWARD CHIPPEWA COUNTY...WELL NORTH OF WARM FRONT TO OUR WEST...WILL TRY AND PHASE IN WITH THIS ENHANCED LOW LEVEL CONVERGENCE. THIS WILL BE OCCURRING IN AN INCREASINGLY UNFAVORABLE LES REGIME WHICH WILL BE CHARACTERIZED BY SHALLOW INVERSION HEIGHTS TO 3-3.5KFT AND WARMING H8 TEMPS FROM -8C (GTV BAY) TO -14C (SSM/APN) AT 12Z...TO -6C (GTV BAY) AND -14C SSM/APN) BY 00Z (VERY SLIGHT TIGHTENING OF THE LOW LEVEL BAROCLINIC ZONE). 1000-850MB W/WNW WINDS OF 15KTS VERY EARLY THIS MORNING WEAKEN INTO MIDDAY...THEN BECOME SE AT 10KTS BY 00Z...WHILE MOISTURE INCREASES TO >80% IN BOTH THE H9-H7 AND H8-H5 LAYERS. THE RESULT WILL BE FOR BEST CHANCES OF LIGHT SNOW SHOWERS THIS MORNING (THROUGH 15Z) ACROSS CHIPPEWA COUNTY...WHERE COOLEST H8 AIR AND SUFFICIENT STRENGTH OF LOW LEVEL WINDS CAN RESULT IN INLAND TRANSPORT OF HEAT/MOISTURE FLUX FROM OFF THE BAY. JUST A CHANCE FOR FLURRIES IN NRN LOWER DUE TO CONTINUED WARMING OF THE LOW LEVEL AIR MASS. AS WINDS TURN SE LATE THIS AFTERNOON... TEMPS WILL ONLY BE COLD ENOUGH FOR SNOW SNEAKING INTO EASTERN CHIP/MACK COUNTIES (MOST LIKELY DRUMMOND ISLAND)...PER ONGOING FORECAST. HIGHS WILL REMAIN COOL IN THE NE WITH LOW-MID 20S WHILE LOWER 30S SEEN NEAR GTV BAY. TONIGHT...POSSIBLY A CHANCE OF FLURRIES HANGING ON NEAR DRUMMOND ISLAND EARLY IN THE EVENING...BUT THIS SHOULD BE SHORT-LIVED AS LOW LEVEL AIR MASS WARM FURTHER. H8 TEMPS RISE TO 0C (GTV BAY) TO -4C (SSM) BY DAYBREAK AS WARM FRONT TRACKS INTO THE WESTERN GREAT LAKES. INCREASED MID AND UPPER LEVEL MOISTURE WILL STREAM IN OVER NRN MICHIGAN...WHILE AFOREMENTIONED SUB 2.5KFT CEILINGS FROM OUT OVER MN/FAR WESTERN WISCONSIN SHOULD BE MAKING THEIR WAY UP INTO EASTERN UPPER/FAR NRN LOWER MICHIGAN. ISENTROPIC ASCENT LEADS TO CDP`S BELOW 20MB ACROSS EASTERN UPPER/NW LOWER AFTER MIDNIGHT...BUT IT IS QUITE DIFFICULT TO DETERMINE WHETHER OR NOT THIS LIFT WILL BE SUFFICIENT FOR MEASURABLE PRECIPITATION...OR WHETHER THE INFLUX OF LOWER LEVEL MOISTURE WILL LEAD TO MORE OF A DRIZZLE. WITH THE ENTIRE SOUNDING COLDER THAN 0C...AND THE TOP OF THE MOISTURE DANGLING AROUND -10C...WILL JUST GO WITH A 30% CHANCE OF LIGHT SNOW OR FREEZING DRIZZLE. FRIDAY...SAME QUESTIONS CONCERNING THE PRECIPITATION TYPE HOLD FRIDAY MORNING...SO WILL GO WITH A CHANCE OF LIGHT SNOW OR FREEZING DRIZZLE. SHALLOW SHORTWAVE ARRIVES FRIDAY AFTERNOON ALONG WITH THE SFC COOL FRONT FOR BETTER LIFT...WHICH WOULD MORE LIKELY LEAD TO A NON-DRIZZLE PRECIP TYPE. AIR MASS ACROSS EASTERN UPPER STILL APPEARS TO REMAIN ENTIRELY COLDER THAN 0C...SO WILL GO WITH A CHANCE FOR LIGHT SNOW. ACROSS NRN LOWER...SFC TEMPS ABOVE FREEZING AS WELL AS A POTENTIAL WARM NOSE ALOFT EXTENDING THROUGH 850-800MB...LEADS TO MORE OF A CHANCE FOR LIGHT RAIN...BUT WITH SOME EVAP COOLING POTENTIAL...WILL GO WITH THE RAIN AND SNOW THAT HAS BEEN FORECAST FOR THE LAST FEW DAYS. ANY SNOW ACCUMULATION IN EASTERN UPPER WILL BE INSIGNIFICANT...MAYBE A FEW TENTHS. FRIDAY NIGHT...IF ONE WERE TO BUY OFF ON THE FORECAST SOUNDINGS...THERE WOULD BE NO PRECIP AS PLENTY OF MID LEVEL DRY AIR COMES IN...ALONG WITH INVERSIONS DOWN TO 850-900MB. WITH A SECONDARY...AND ACCORDING TO THE MODELS...A MORE DEFINED SHORTWAVE ARRIVES. CANNOT RULE OUT PRECIP ATTM...ESPECIALLY WHEN THROWING IN UNCERTAINTY OF TIMING OF THE COOL FRONT ITSELF. MORE MILD LOWS WITH READINGS IN THE MIDDLE 20S. SATURDAY ONWARD...WEAK MID LEVEL RIDGING AND SFC HIGH PRESSURE ARRIVE FOR THE WEEKEND AND PLENTY OF SUN EXPECTED. 925-850MB TEMPS DANCING AROUND 32F...AND WITH DECENT SUNSHINE...HIGH TEMPS WILL BE ABLE TO EASILY TAP INTO THE UPPER HALF OF THE 30S. INCREASED MARCH SUN ANGLE WILL LIKELY LEAD TO HIGHS AROUND 40F OR EVEN THE LOWER 40S. THE DECENT MELTING THAT WE GET OVER THE WEEKEND...WOULD LEAD TO SOME FOG DEVELOPMENT SATURDAY NIGHT INTO SUNDAY MORNING. NO OTHER CHANGES. SMD APX WATCHES/WARNINGS/ADVISORIES...NONE. && .APX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
920 AM CST THU MAR 8 2007 .UPDATE... EXTENSIVE LOW CLOUDS/FOG AND SOME FREEZING DRIZZLE WILL PERSIST THROUGH THE DAY IN ALL AREAS. THERE IS ONE HOLE IN THE CLOUDS IN OUR FAR NW...AND TEMPS MAY BE WARMER HERE. ELSEWHERE...WITH VERY STEEP INVERSION PER BIS/ABR AND TAMDAR SOUNDINGS TRAPPING LOW LEVEL MOISTURE...AREAS OF FOG AND FREEZING DRIZZLE WILL PERSIST THROUGH THE DAY. THEREFORE...WE WILL EXTEND THIS MENTION THROUGH THE DAY. TEMPS WILL ALSO STRUGGLE TO WARM WITH FOG AND DEEP SNOW PACK...BUT WE SHOULD APPROACH 30 IN THE FAR SOUTH AND UPPER 20S IN THE NORTH. IF ANY BREAKS IN THE CLOUDS DEVELOP THIS AFTERNOON TEMPS COULD WARM A BIT MORE...BUT NOT EXPECTING TOO MUCH SUN ANYWHERE. THE FOG MAY BECOME DENSE FOR A TIME THIS EVENING WITH THE APPROACH OF A SFC TROUGH AND WEAKENING WINDS...SO THIS THREAT WILL NEED TO BE MONITORED. UPDATE GRIDS/TEXT PRODUCTS WILL BE ISSUED BY 1030 AM TO ADDRESS ABOVE CONCERNS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ DK
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
230 PM PST THU MAR 8 2007 .SYNOPSIS... A SHALLOW MARINE LAYER WILL CAUSE COASTAL LOW CLOUDS AND PATCHY DENSE FOG TONIGHT AND FRIDAY MORNING...EXTENDING LOCALLY INLAND. OTHERWISE...FAIR WITH A LITTLE COOLER DAY FRIDAY. BUILDING HIGH PRESSURE ALOFT AND WEAK OFFSHORE FLOW WILL BRING WARMER WEATHER THIS WEEKEND AND EARLY NEXT WEEK WITH NEAR RECORD HIGH TEMPERATURES IN SOME INLAND LOCATIONS SUNDAY AND MONDAY. LOCALLY WINDY THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES SUNDAY AND MONDAY. SLOW COOLING AND A GRADUAL RETURN OF THE MARINE LAYER DURING THE SECOND HALF OF NEXT WEEK AS HIGH PRESSURE WEAKENS AND ONSHORE FLOW RETURNS. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM (TODAY-SUN)... THERE WERE AREAS OF LOW CLOUDS AND DENSE FOG IN THE COASTAL AREAS THIS MORNING...MANLY IN SAN DIEGO COUNTY. OTHERWISE...VARIABLE HIGH CLOUDINESS. EARLY AFTERNOON ACARS SOUNDING HAD INCREASING NW WINDS ALOFT. ONSHORE GRADIENTS WITH ABOUT 5 MB SAN-IPL. A WEAK SHORT TROUGH WILL MOVE THROUGH FRI. ONSHORE FLOW WILL CONTINUE AND THE MARINE LAYER WILL DEEPEN A LITTLE AND BECOME MORE WIDESPREAD TONIGHT AND SHOULD EXTEND INTO THE WRN SAN DIEGO INLAND VALLEYS. THERE COULD BE DENSE FOG NEAR THE INLAND EDGE OF THE STRATUS AND ON HIGHER COASTAL TERRAIN. A LITTLE COOLER...MAINLY W OF THE MOUNTAINS. MORE HIGH CLOUDS FRI INTO SAT MORNING IN NW FLOW ALOFT. PATCHY...IF ANY...MARINE LAYER FRI NIGHT INTO SAT MORNING. MOSTLY CLEAR AND WARMER SAT AND SUN AS HIGH PRESSURE BUILDS ALOFT AND WEAK OFFSHORE FLOW DEVELOPS. THERE COULD BE A FEW RECORD HIGH MAX TEMPS SUN...MAINLY INLAND. GUSTY WINDS THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES...STARTING SAT AND BECOMING STRONGER SUN. LOCAL WINDS COULD GET NEAR ADVISORY STRENGTH IN THE FAVORED AREAS BELOW PASSES IN THE INLAND EMPIRE AND IN THE SANTA ANA MOUNTAINS. THE WARM DRY WEATHER AND OFFSHORE FLOW WILL INCREASE THE FIRE WEATHER HAZARD SUN TO NEAR CRITICAL LEVELS INLAND. MAY NEED A FIRE WEATHER WATCH SUN. && .LONG TERM (MON-THU)... CONTINUED WARMING INTO MON UNDER THE HIGH ALOFT WITH WEAK OFFSHORE FLOW. A FEW RECORD MAX TEMPS WILL BE LIKELY AGAIN MON AND THE FIRE WEATHER HAZARD WILL REMAIN NEAR CRITICAL LEVELS INLAND. MAY NEED A FIRE WEATHER WATCH MON. GRADUALLY COOLER TUE THROUGH THU AS THE HIGH WEAKENS AND THEN UPPER LEVEL LOW PRESSURE MOVES PAST TO THE N AND ONSHORE FLOW RETURNS. THE MARINE LAYER SHOULD REDEVELOP AROUND THU. && AVIATION... 082120Z...STRATUS SHOULD REFORM A BROKEN-OVERCAST LAYER BY 01 OVER WATER...PUSHING INLAND BETWEEN 03Z-06Z TO COASTAL AIRPORTS WITH BASES FL010-FL012 TOPS FL020...REACHING ABOUT 25 MILES INLAND BY 12Z...ERODING AFTER 17Z FRIDAY MORNING. HIGHER BASES SHOULD PRECLUDE LOW VISIBILITY PROBLEMS...EXCEPT AT ONTARIO/OTHER INLAND AIRPORTS WITH ELEVATIONS BETWEEN FL010-FL020. SIMILAR SCENARIO EXPECTED FRIDAY NIGHT/SATURDAY MORNING. AFTER THAT OFFSHORE FLOW SHOULD SCOUR OUT MARINE LAYER. && .SGX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...DVA AVIATION...BALFOUR