Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 02/04/07

.SYNOPSIS... HIGH PRESSURE BUILDING ALONG THE WEST COAST WILL BRING FAIR AND WARMER WEATHER THROUGH TUESDAY. NEAR RECORD HIGH TEMPERATURES ARE POSSIBLE SUNDAY AND MONDAY. HIGH PRESSURE WILL BEGIN TO WEAKEN EARLY NEXT WEEK WITH CHANCES FOR PRECIPITATION THE LATTER HALF OF NEXT WEEK.

&&

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

.SHORT TERM... TAIL END OF AN UPPER TROUGH RIDING DOWN THE BACK SIDE OF THE HIGH AMPLITUDE RIDGE BRUSHED THE AREA WITH A FEW HIGH LEVEL CLOUDS TODAY...WHILE STRONG DRYING AND WARMING TOOK PLACE BETWEEN 3000 AND 10000 FEET. MODELS MOVE THE HIGH PRESSURE RIDGE SLOWLY EAST ACROSS THE AREA THROUGH TUESDAY...FOR CONTINUED DRYING AND WARMING TREND WITH PREVAILING OFFSHORE FLOW BELOW 15000 FEET. ABOVE THIS LEVEL MODEL CROSS SECTIONS DO SHOW FLUCTUATIONS IN MID/UPPER LEVEL MOISTURE. THIS IS LIKELY COMING FROM SHORT WAVES BUMPING INTO AND RIDING OVER THE RIDGE...SO NEXT FOUR DAYS WILL NOT BE COMPLETELY CLOUD FREE BUT FAIR SKIES WILL PREVAIL. IT WILL CERTAINLY BE MUCH WARMER AND DRIER THAN OF LATE AND NEAR RECORD HIGH TEMPERATURES ARE FORECAST FOR SUNDAY AND MONDAY.

&&

.LONG TERM... MODELS UNDERCUT HIGH PRESSURE RIDGE BY WEDNESDAY AND ESTABLISH STORM TRACK ALONG 30-35N LATITUDE FROM THEN ON. ONLY ARGUMENT AGAINST THIS IS THAT THE OMEGA BLOCK THAT IS IN PLACE SATURDAY THROUGH MONDAY COULD BECOME A PERSISTENT REX BLOCK IF LOW CENTERED OVER MEXICO IS NOT KICKED OUT. LEFT EXTENDED FORECASTS ALONE FOR NOW.

&&

.AVIATION... LATE MORNING ACARS SOUNDINGS INDICATE THE MARINE LAYER DEPTH HAD LOWERED TO AROUND 3000 FEET SINCE EARLY THIS MORNING. EXPECT FURTHER LOWERING THROUGH THE NIGHT. DEVELOPING OFFSHORE FLOW WILL BRING VFR CONDITIONS WITH A MOSTLY CLEAR SKY AND UNRESTRICTED VISIBILITIES THROUGH SATURDAY.

THERE COULD BE SOME PATCHY DENSE FOG WITH LIFR CONDITIONS FOR A BRIEF PERIOD BEFORE SUNRISE SATURDAY MORNING...ESPECIALLY NEAR KOKB AND KCNO BUT CONFIDENCE IS LOW. ANY FOG THAT DEVELOPS SHOULD BE GONE SHORTLY AFTER SUNRISE.

&&

.FIRE WEATHER... A PROLONGED PERIOD OF VERY LOW RELATIVE HUMIDITY AND POOR NIGHT TIME RECOVERY WILL AFFECT ALL AREAS SATURDAY THROUGH MONDAY AND CONTINUE OVER THE MOUNTAINS AND FOOTHILLS ON TUESDAY. THE OFFSHORE SURFACE PRESSURE GRADIENTS BEING ADVERTISED BY THE MODELS OF 10-14 MB FOR SUNDAY WOULD SUPPORT WINDS GUSTS TO 40 MPH BELOW PASSES AND CANYONS IN SAN DIEGO COUNTY. HOWEVER ONLY THE LOCAL WIND PROGRAM RUN OFF THE 12Z NGM MODEL SUPPORTS THESE STRENGTHS...THE OTHER TWO MODELS SHOWED WIND GUSTS ABOUT HALF AS STRONG ACROSS SAN DIEGO COUNTY WIND PRONE AREAS. THIS MIXED SIGNAL COUPLED WITH INPUT FROM GACC SOUTH OPS THAT THE RECENT RAINS SHOULD HAVE A DAMPENING EFFECT FOR ABOUT FIVE DAYS...INTO TUESDAY...WEIGHED IN FAVOR OF NOT ISSUING A FIRE WEATHER WATCH FOR SUNDAY. HOWEVER DID ISSUE AN AFTERNOON FIRE WEATHER ZONE FORECAST UPDATE TO INDICATE VERY DRY CONDITIONS AND GUSTY EAST TO NORTHEAST WINDS.

&&

.MARINE... THE OUTER BUOYS ARE SHOWING ABOUT A TWO FOOT DROP IN HEIGHTS SINCE THIS MORNING SO DECISION NOT TO REISSUE THE HIGH SURF ADVISORY WAS WARRANTED. INNER BUOYS STILL RUNNING BETWEEN 4 AND 7 FEET AND EXPECT OCCASIONAL HIGHER BREAKERS THROUGH THIS EVENING OVER REEFS AND AROUND POINTS DUE TO LOWER TIDE.

&&

.SGX WATCHES/WARNINGS/ADVISORIES... NONE AT THIS TIME.

&&

$$

PUBLIC/FIRE WEATHER...BALFOUR AVIATION/MARINE...HORTON

NWS ON THE WEB AT WEATHER.GOV/SANDIEGO

.SHORT TERM /REST OF TODAY/... LOW CLOUDINESS HAS PERSISTED UNDER THE STRONG INVERSION,..BUT EXPECT SOME BREAKS IN THE CLOUDINESS WILL OCCUR WITH THE MIXING AHEAD OF THE COLD FRONT LATER THIS AFTERNOON. WILL UPDATE THE TEXT TO REMOVE THE MORNING FORECAST. WILL ALSO ADJUST THE TEMPERATURE GRIDS SLIGHTLY DOWNWARD BASED ON CURRENT OBSERVATIONS. &&

.PREV DISCUSSION... /ISSUED 643 AM EST FRI FEB 2 2007/

AVIATION /12Z-12Z/... LAPS AND ACARS SOUNDINGS INDICATE LOW LEVEL INVERSION STRONG. EXPECT INVERSION WILL BE SLOW TO ERODE TODAY...SO LOW IFR CONDITIONS FORECAST THROUGH THE MORNING. VISIBILITY WILL BE LOW DUE TO DRIZZLE AND FOG. SLOW IMPROVEMENT AFTER 18Z AS COLD FRONT APPROACHES. BOUNDARY LAYER WINDS INCREASING MAY MIX OUT. VFR CONDITIONS FORECAST AFTER 00Z AS DRIER AIR SPREADS ACROSS THE REGION WITH WEST FLOW BEHIND THE COLD FRONT.

PREV DISCUSSION... /ISSUED 247 AM EST FRI FEB 2 2007/

SHORT TERM /REST OF TODAY THROUGH SUNDAY NIGHT/...

REGIONAL RADAR CURRENTLY SHOWING THE HEAVIER PRECIPITATION HAS SHIFTED EAST OF THE FORECAST AREA THIS MORNING. MESONET DATA SUGGESTS THAT SURFACE TEMPERATURES ARE HOLDING IN THE MID TO UPPER 30S ACROSS MOST OF THE AREA WITH SOME 33 TO 35 READINGS IN THE NORTHERN COUNTIES...SO WATER REFREEZING ON ROADWAYS IS NOT A BIG CONCERN AT THIS TIME. WATER VAPOR LOOP IS SHOWING SOME SIGNIFICANT DRYING IN THE MID LEVELS...LEAVING THE SHALLOW LAYER OF MOISTURE TRAPPED BELOW 850 MB.

GFS APPEARS A BIT OPTIMISTIC IN BREAKING OUT CLOUDS BY LATE MORNING...AND WILL BE FAVORING THE MORE PESSIMISTIC WRF...THINKING THAT CLOUDS WILL NOT BREAK UNTIL MID TO LATE AFTERNOON...IF AT ALL TODAY. THE EXTENDED CLOUD COVER...COMBINED WITH SOME WEAK COLD ADVECTION WILL AFFECT MAX TEMPERATURES...AND HAVE LOWERED THEM A BIT AND WENT WELL BELOW THE MAV GUIDANCE WHICH GAVE A HIGH OF 57 AT CAE. CLOUDS SHOULD BREAK SOMETIME LATE AFTERNOON INTO THE EVENING HOURS AS HIGH PRESSURE BUILDS IN AND DRIER AIR WORKS INTO THE AREA.

DRY WEATHER IS FIGURED FOR THE WEEKEND WITH SURFACE HIGH PRESSURE IN PLACE. THE MODELS HAVE COME INTO GOOD AGREEMENT ON KEEPING MOISTURE AND THE MAIN BAROCLINIC ZONE TO OUR SOUTH ON SATURDAY WITH SUPPORT FROM THE ENSEMBLE DATA...WHERE BEFORE THEY WERE BRINGING SOME PRECIPITATION ACROSS OUR SOUTHERN COUNTIES. TEMPERATURES WILL REMAIN COOL THOUGH...STAYING BELOW NORMAL.

LONG TERM /MONDAY THROUGH THURSDAY/...

NO CHANGES WERE MADE DURING THIS PERIOD. THE POLAR VORTEX REMAINS OVER THE HUDSON BAY AREA AND SOUTHEAST CANADA THROUGHOUT THE EXTENDED PERIODS...KEEPING A BROAD TROUGH OVER THE EASTERN PART OF THE COUNTRY WITH A RIDGE ALONG THE WEST COAST AND INTERMOUNTAIN WEST. A BRIEF...REINFORCING SHOT OFF COLD AIR WILL ARRIVE MONDAY EVENING AS A DRY COLD FRONT PUSHES THROUGH THE AREA. A FAST MOVING CLIPPER SYSTEM WILL TRACK ACROSS THE OHIO VALLEY ON TUESDAY AND OFF THE MID ATLANTIC COAST BY WEDNESDAY MORNING. THIS FEATURE SHOULD REMAIN TO OUR NORTH. THE REMAINDER OF THE WEEK WILL BE CHARACTERIZED BY WEST-NORTHWESTERLY FLOW ALOFT AND DRY WEATHER...WITH TEMPERATURES NEAR NORMAL.

PREV DISCUSSION... /ISSUED 1228 AM EST FRI FEB 2 2007/

AVIATION /06Z-06Z/... 06Z-12Z...STATIONARY FRONT WILL REMAIN SOUTH OF THE CAE CWA WITH WEDGE OF COLD AIR AT THE SURFACE. IFR CONDITIONS EXPECTED WITH CIGS AOB 5 HUNDRED FT AND VSBYS BELOW 3 MILES IN LIGHT RAIN AND FOG. 12Z-21Z...LOW PRESSURE AREA OFFSHORE OF THE CAROLINAS WILL PULL FRONT AWAY FROM THE AREA AS A COLD FRONT. MVFR CIGS 1-2 THOUSAND FT. IFR VSBYS 2-3 MILES IN FOG TIL 16Z THEN VSBYS 7 MILES. 21Z-06Z...HIGH PRESSURE WILL BUILD OVER AREA BEHIND COLD FRONT. SCATTERED TO BROKEN CLOUDS NEAR 3 THOUSAND FT AND VSBYS 7 MILES.

PREV DISCUSSION... /ISSUED 258 PM EST THU FEB 1 2007/

SHORT TERM /TONIGHT/... COMPLEX SITUATION CONTINUES TO UNFOLD AS ONE AREA OF LOW PRESSURE MOVES UP THE ATLANTIC COAST AND ANOTHER LOW DEVELOPS OVER THE GULF COAST. CURRENT OBSERVATIONS INDICATE ALL BUT THE FAR NORTHERN REACHES OF THE CWA HAVE WARMED TO SLIGHTLY ABOVE FREEZING...WITH LANCASTER COUNTY REMAINING AT OR JUST BELOW FREEZING. FOR THE REMAINDER OF THE AFTERNOON WILL EXPECT RAIN FOR MUCH OF THE CWA AS THE REMNANTS OF THE FIRST LOW PRESSURE SYSTEM PULL OUT OF THE AREA. THIS WILL LEAVE A COUPLE OF HOURS THROUGH EARLY EVENING WITH A BREAK IN THE PRECIPITATION. WITH THE PRECIPITATION EXITING THE AREA AND TEMPERATURES WARMING ABOVE FREEZING THE WINTER STORM WARNING HAS BEEN CANCELLED. BY MID EVENING THE NEXT LOW PRESSURE WILL BEGIN MOVING INTO THE REGION WITH RAIN AGAIN ENVELOPING THE MIDLANDS. FOR THIS ROUND OF PRECIPITATION THE LEVELS JUST ABOVE THE SURFACE WILL BE SEVERAL DEGREES WARMER THAN THIS MORNING ENSURING THE PRECIPITATION WILL BE ALL RAIN. OVERNIGHT LOW TEMPERATURES WILL ONLY BE SLIGHTLY LOWER THAN THE AFTERNOON HIGHS AS CLOUD COVER AND PRECIPITATION WILL PREVENTING THE TEMPERATURES FROM FALLING. THIS SYSTEM WILL QUICKLY CROSS THE REGION OVERNIGHT WITH THE RAIN ENDING BY FRIDAY MORNING.

LONG TERM /FRIDAY THROUGH THURSDAY/... FRIDAY THROUGH SATURDAY NIGHT...HIGH LOW-LEVEL MOISTURE ASSOCIATED WITH THE DEPARTING SURFACE LOW SHOULD CONTINUE FRIDAY MORNING AND EXPECT THE DAY WILL BEGIN CLOUDY. THE MOISTURE APPEARS TOO SHALLOW FOR RAIN AND BOTH THE NAM AND GFS SHOW H85 COLD ADVECTION DURING THIS TIME. WEST FLOW AND MIXING WILL PROBABLY CAUSE BREAKS IN THE LOW CLOUDINESS DURING THE AFTERNOON. THE MAV MOS IS THE COLDER GUIDANCE FOR FRIDAY AND THIS APPEARS REASONABLE BECAUSE OF THE CLOUDINESS AND COLD GROUND ASSOCIATED WITH THE RECENTLY MELTED ICE OVER MUCH OF THE AREA.

EXPECT CONSIDERABLE HIGH CLOUDINESS IN THE SOUTHWEST FLOW ALOFT FRIDAY NIGHT THROUGH SATURDAY NIGHT. BOTH MODELS KEEP DEEP MOISTURE JUST EAST AND SOUTH OF THE FORECAST AREA AND SHOW H85 COLD ADVECTION DURING THE PERIOD. PLAN TO USE THE MAV MOS AND KEEP THE FORECAST DRY. WILL ALSO USE THE MAV MOS TEMPERATURES. CONFIDENCE IS LOW DURING THIS PERIOD BECAUSE OF THE NEARBY TIGHT MOISTURE GRADIENT AND AFFECTS OF ANY SHORTWAVE TROUGHS IN THE SOUTHWEST FLOW ALOFT. IF MOISTURE DOES ADVANCE FARTHER INLAND THAN FORECAST THEN WOULD EXPECT WARMER LOW TEMPERATURES BECAUSE OF LOW-LEVEL WARM ADVECTION AND CLOUDINESS. ANY PRECIPITATION SHOULD BE ALL RAIN.

SUNDAY THROUGH THURSDAY...THE OPERATIONAL GFS AND ENSEMBLE GUIDANCE SUPPORT A COLD AND DRY PERIOD. THE GFS SHOWS REINFORCING DRY FRONTS SUNDAY AND MONDAY. GENERALLY USED THE ENSEMBLE MEAN GUIDANCE FOR THE TEMPERATURE FORECAST.

&&

.CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. &&

$$

SHORT TERM...05

.AVIATION /12Z-12Z/... LAPS AND ACARS SOUNDINGS INDICATE LOW LEVEL INVERSION STRONG. EXPECT INVERSION WILL BE SLOW TO ERODE TODAY...SO LOW IFR CONDITIONS FORECAST THROUGH THE MORNING. VISIBILITY WILL BE LOW DUE TO DRIZZLE AND FOG. SLOW IMPROVEMENT AFTER 18ZZ AS COLD FRONT APPROACHES. BOUNDARY LAYER WINDS INCREASING MAY MIX OUT. VFR CONDITIONS FORECAST AFTER 00Z AS DRIER AIR SPREADS ACROSS THE REGION WITH WEST FLOW BEHIND THE COLD FRONT.

&&

.PREV DISCUSSION... /ISSUED 247 AM EST FRI FEB 2 2007/

SHORT TERM /REST OF TODAY THROUGH SUNDAY NIGHT/...

REGIONAL RADAR CURRENTLY SHOWING THE HEAVIER PRECIPITATION HAS SHIFTED EAST OF THE FORECAST AREA THIS MORNING. MESONET DATA SUGGESTS THAT SURFACE TEMPERATURES ARE HOLDING IN THE MID TO UPPER 30S ACROSS MOST OF THE AREA WITH SOME 33 TO 35 READINGS IN THE NORTHERN COUNTIES...SO WATER REFREEZING ON ROADWAYS IS NOT A BIG CONCERN AT THIS TIME. WATER VAPOR LOOP IS SHOWING SOME SIGNIFICANT DRYING IN THE MID LEVELS...LEAVING THE SHALLOW LAYER OF MOISTURE TRAPPED BELOW 850 MB.

GFS APPEARS A BIT OPTIMISTIC IN BREAKING OUT CLOUDS BY LATE MORNING...AND WILL BE FAVORING THE MORE PESSIMISTIC WRF...THINKING THAT CLOUDS WILL NOT BREAK UNTIL MID TO LATE AFTERNOON...IF AT ALL TODAY. THE EXTENDED CLOUD COVER...COMBINED WITH SOME WEAK COLD ADVECTION WILL AFFECT MAX TEMPERATURES...AND HAVE LOWERED THEM A BIT AND WENT WELL BELOW THE MAV GUIDANCE WHICH GAVE A HIGH OF 57 AT CAE. CLOUDS SHOULD BREAK SOMETIME LATE AFTERNOON INTO THE EVENING HOURS AS HIGH PRESSURE BUILDS IN AND DRIER AIR WORKS INTO THE AREA.

DRY WEATHER IS FIGURED FOR THE WEEKEND WITH SURFACE HIGH PRESSURE IN PLACE. THE MODELS HAVE COME INTO GOOD AGREEMENT ON KEEPING MOISTURE AND THE MAIN BAROCLINIC ZONE TO OUR SOUTH ON SATURDAY WITH SUPPORT FROM THE ENSEMBLE DATA...WHERE BEFORE THEY WERE BRINGING SOME PRECIPITATION ACROSS OUR SOUTHERN COUNTIES. TEMPERATURES WILL REMAIN COOL THOUGH...STAYING BELOW NORMAL.

LONG TERM /MONDAY THROUGH THURSDAY/...

NO CHANGES WERE MADE DURING THIS PERIOD. THE POLAR VORTEX REMAINS OVER THE HUDSON BAY AREA AND SOUTHEAST CANADA THROUGHOUT THE EXTENDED PERIODS...KEEPING A BROAD TROUGH OVER THE EASTERN PART OF THE COUNTRY WITH A RIDGE ALONG THE WEST COAST AND INTERMOUNTAIN WEST. A BRIEF...REINFORCING SHOT OFF COLD AIR WILL ARRIVE MONDAY EVENING AS A DRY COLD FRONT PUSHES THROUGH THE AREA. A FAST MOVING CLIPPER SYSTEM WILL TRACK ACROSS THE OHIO VALLEY ON TUESDAY AND OFF THE MID ATLANTIC COAST BY WEDNESDAY MORNING. THIS FEATURE SHOULD REMAIN TO OUR NORTH. THE REMAINDER OF THE WEEK WILL BE CHARACTERIZED BY WEST-NORTHWESTERLY FLOW ALOFT AND DRY WEATHER...WITH TEMPERATURES NEAR NORMAL.

PREV DISCUSSION... /ISSUED 1228 AM EST FRI FEB 2 2007/

AVIATION /06Z-06Z/... 06Z-12Z...STATIONARY FRONT WILL REMAIN SOUTH OF THE CAE CWA WITH WEDGE OF COLD AIR AT THE SURFACE. IFR CONDITIONS EXPECTED WITH CIGS AOB 5 HUNDRED FT AND VSBYS BELOW 3 MILES IN LIGHT RAIN AND FOG. 12Z-21Z...LOW PRESSURE AREA OFFSHORE OF THE CAROLINAS WILL PULL FRONT AWAY FROM THE AREA AS A COLD FRONT. MVFR CIGS 1-2 THOUSAND FT. IFR VSBYS 2-3 MILES IN FOG TIL 16Z THEN VSBYS 7 MILES. 21Z-06Z...HIGH PRESSURE WILL BUILD OVER AREA BEHIND COLD FRONT. SCATTERED TO BROKEN CLOUDS NEAR 3 THOUSAND FT AND VSBYS 7 MILES.

PREV DISCUSSION... /ISSUED 258 PM EST THU FEB 1 2007/

SHORT TERM /TONIGHT/... COMPLEX SITUATION CONTINUES TO UNFOLD AS ONE AREA OF LOW PRESSURE MOVES UP THE ATLANTIC COAST AND ANOTHER LOW DEVELOPS OVER THE GULF COAST. CURRENT OBSERVATIONS INDICATE ALL BUT THE FAR NORTHERN REACHES OF THE CWA HAVE WARMED TO SLIGHTLY ABOVE FREEZING...WITH LANCASTER COUNTY REMAINING AT OR JUST BELOW FREEZING. FOR THE REMAINDER OF THE AFTERNOON WILL EXPECT RAIN FOR MUCH OF THE CWA AS THE REMNANTS OF THE FIRST LOW PRESSURE SYSTEM PULL OUT OF THE AREA. THIS WILL LEAVE A COUPLE OF HOURS THROUGH EARLY EVENING WITH A BREAK IN THE PRECIPITATION. WITH THE PRECIPITATION EXITING THE AREA AND TEMPERATURES WARMING ABOVE FREEZING THE WINTER STORM WARNING HAS BEEN CANCELLED. BY MID EVENING THE NEXT LOW PRESSURE WILL BEGIN MOVING INTO THE REGION WITH RAIN AGAIN ENVELOPING THE MIDLANDS. FOR THIS ROUND OF PRECIPITATION THE LEVELS JUST ABOVE THE SURFACE WILL BE SEVERAL DEGREES WARMER THAN THIS MORNING ENSURING THE PRECIPITATION WILL BE ALL RAIN. OVERNIGHT LOW TEMPERATURES WILL ONLY BE SLIGHTLY LOWER THAN THE AFTERNOON HIGHS AS CLOUD COVER AND PRECIPITATION WILL PREVENTING THE TEMPERATURES FROM FALLING. THIS SYSTEM WILL QUICKLY CROSS THE REGION OVERNIGHT WITH THE RAIN ENDING BY FRIDAY MORNING.

LONG TERM /FRIDAY THROUGH THURSDAY/... FRIDAY THROUGH SATURDAY NIGHT...HIGH LOW-LEVEL MOISTURE ASSOCIATED WITH THE DEPARTING SURFACE LOW SHOULD CONTINUE FRIDAY MORNING AND EXPECT THE DAY WILL BEGIN CLOUDY. THE MOISTURE APPEARS TOO SHALLOW FOR RAIN AND BOTH THE NAM AND GFS SHOW H85 COLD ADVECTION DURING THIS TIME. WEST FLOW AND MIXING WILL PROBABLY CAUSE BREAKS IN THE LOW CLOUDINESS DURING THE AFTERNOON. THE MAV MOS IS THE COLDER GUIDANCE FOR FRIDAY AND THIS APPEARS REASONABLE BECAUSE OF THE CLOUDINESS AND COLD GROUND ASSOCIATED WITH THE RECENTLY MELTED ICE OVER MUCH OF THE AREA.

EXPECT CONSIDERABLE HIGH CLOUDINESS IN THE SOUTHWEST FLOW ALOFT FRIDAY NIGHT THROUGH SATURDAY NIGHT. BOTH MODELS KEEP DEEP MOISTURE JUST EAST AND SOUTH OF THE FORECAST AREA AND SHOW H85 COLD ADVECTION DURING THE PERIOD. PLAN TO USE THE MAV MOS AND KEEP THE FORECAST DRY. WILL ALSO USE THE MAV MOS TEMPERATURES. CONFIDENCE IS LOW DURING THIS PERIOD BECAUSE OF THE NEARBY TIGHT MOISTURE GRADIENT AND AFFECTS OF ANY SHORTWAVE TROUGHS IN THE SOUTHWEST FLOW ALOFT. IF MOISTURE DOES ADVANCE FARTHER INLAND THAN FORECAST THEN WOULD EXPECT WARMER LOW TEMPERATURES BECAUSE OF LOW-LEVEL WARM ADVECTION AND CLOUDINESS. ANY PRECIPITATION SHOULD BE ALL RAIN.

SUNDAY THROUGH THURSDAY...THE OPERATIONAL GFS AND ENSEMBLE GUIDANCE SUPPORT A COLD AND DRY PERIOD. THE GFS SHOWS REINFORCING DRY FRONTS SUNDAY AND MONDAY. GENERALLY USED THE ENSEMBLE MEAN GUIDANCE FOR THE TEMPERATURE FORECAST.

&&

.CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. &&

$$

.SHORT TERM (TODAY AND TONIGHT)... WATER VAPOR LOOP SHOWS UPPER LEVEL MOISTURE STREAMING FROM TEXAS NORTHEAST OFF THE NEW ENGLAND COAST. A WAVE HAS PASSED EAST INTO NEW ENGLAND...AS THE NEXT SHORT WAVE ENTERS THE TENNESSEE VALLEY. ACARS 400-250MB WIND OBSERVATIONS REVEAL A 175-220KT SOUTHWESTERLY JET EXTENDS FROM THE PLAINS THROUGH THE MID ATLANTIC AND ALONG THE NEW ENGLAND COAST. 04Z SURFACE ANALYSIS PLACED A COLD FRONT FROM NEW YORK STATE SOUTHWEST ALONG THE APPALACHIANS INTO THE PLAINS. A TROUGH WAS NOTED IN THE LEE OF THE APPALACHIANS. A 1029MB ANTICYCLONE DOMINATED THE GULF COAST STATES...WITH A 1028MB ANTICYCLONE ACROSS THE MIDWEST.

HIGH CLOUDINESS ASSOCIATED WITH THE UPPER LEVEL JET WILL BE PUSHING SOUTHEAST EARLY THIS MORNING WITH THE JET AXIS. MEANWHILE...UPSLOPE MOISTURE REMAINS ACROSS THE MOUNTAINS WITH CLEAR SKIES IN BETWEEN.

CLOUDS ASSOCIATED WITH THE NEXT SHORT WAVE WILL OVERSPREAD PRIMARILY THE SOUTHERN FORECAST AREA TODAY FROM THE TENNESSEE VALLEY. WENT WITH LOWER NGM MOS GUIDANCE FOR HIGHS TODAY...A FEW DEGREES COOLER THAN YESTERDAY WITH RENEWED COLD ADVECTION. WINDS WILL BEGIN TO GUST FROM THE WEST WITH MIXING LATE THIS MORNING AND AFTERNOON. WIND CHILLS ACROSS MUCH OF THE INITIAL ADVISORY AREA WILL BE NEAR CRITERIA DURING MUCH OF THE AFTERNOON...SO DECIDED TO KEEP THE ADVISORY GOING THROUGH THE DAY.

THE PASSAGE OF THE SHORT WAVE SHOULD REINVIGORATE THE UPSLOPE SNOW SHOWERS TONIGHT...AND BRING A PERIOD OF MOSTLY CLOUDY SKIES ACROSS THE WESTERN AND NORTHERN FORECAST AREA WITH COLD ADVECTION STRATO-CU. LOW LEVEL LAPSE RATES APPEAR FAVORABLE TO ALLOW MIXING WIND GUSTS OF 30 MPH TO THE SURFACE AT TIMES TONIGHT. WENT ON THE HIGHER SIDE OF MOS FOR LOW TEMPERATURES DUE TO THE MIXED BOUNDARY LATER. THIS STILL PLACED MOST OF THE FORECAST AREA WEST OF THE BLUE RIDGE AND ALONG THE PENNSYLVANIA BORDER INTO WIND CHILL ADVISORY RANGE LATE TONIGHT AND MONDAY MORNING.

&&

.AVIATION... COLD FRONT PRESSING THROUGH THE EASTERN FORECAST AREA CONTINUES TO SUPPORT A WIND SHIFT AND SOME COLD ADVECTION STRATO-CU...WHILE UPPER LEVEL MOISTURE RESIDES ALONG THE UPPER LEVEL JET AXIS. EXPECT CLOUDS ASSOCIATED WITH THE NEXT SHORT WAVE FROM THE TENNESSEE VALLEY TO STREAM INTO THE AREA DURING THE DAY AS THE UPPER LEVEL JET AXIS SHIFTS TO THE SOUTHEAST. COLD ADVECTION TONIGHT WILL VEER WINDS AND PROVIDE GUSTS...WITH ANOTHER OPPORTUNITY FOR STRATO-CU.

&&

.MARINE... SMALL CRAFT ADVISORY IS IN EFFECT.

00Z ETA/GFS MOS AT THOMAS POINT INDICATES SUSTAINED WINDS WILL INCREASE TO 20KT BEGINNING THIS AFTERNOON. 00Z PROXIMITY NAM/GFS BUFKIT FORECAST SOUNDINGS INDICATE WIND GUST POTENTIAL OF 25KT TO 30KT TONIGHT.

STILL A RATHER STRONG GRAD FORCE MON EVNG SO HAVE EXTENDED THE SCA WINDS TIL ABOUT 10 PM. NOT A LOT OF CONFIDENCE IN SCA WINDS CONTINUING BEYOND THAT TIMEFRAME SO HAVE DROPPED WINDS BACK BELOW 20 KTS MON NGT AND LATER PERIODS.

&&

.TIDES... WATER LEVELS ARE CURRENTLY UP TO A HALF FOOT ABOVE ASTRONOMICAL PREDICTIONS. THE LUNAR CYCLE IS AT FULL MOON (96% FULL).

THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM AND THE NOAA EXTRATROPICAL SURGE MODEL BOTH SUGGEST WATER LEVELS FALL UP TO A FOOT BELOW ASTRONOMIC PREDICTIONS THIS AFTERNOON.

&&

.LONG TERM...MONDAY THROUGH SATURDAY...

COLDEST AIRMASS OVERHEAD MONDAY AND EARLY TUESDAY ACROSS OUR AREA. WE WILL CONTINUE TO UNDERCUT MOS TEMPS SEVERAL DEGREES THROUGH TUESDAY ALTHOUGH LATEST MOS PREDICTIONS NOW REFLECT THE COLD AIRMASS MUCH BETTER THAN PREVIOUS RUNS. WIND CHILL HEADLINES WILL LIKELY BE NEEDED INTO TUESDAY MORNING...MAINLY FOR THE PREDICTED MIN TEMPS AS THE WINDS WILL NOT BE ALL THAT STRONG AT THAT POINT.

UPSLOPE SNOW SHOWERS WILL BE WAINING BY MONDAY EVENING...ONLY TO BE RE-INVIGORATED AROUND TUESDAY EVENING ON THE CUSP OF ANOTHER CLIPPER AND WEAK LOW PRES WAVE. THIS SYSTEM SEEMS TO DROP FROM EASTERN KY INTO SOUTHERN VA AND ANY PRECIP SHOULD BE SHUNTED TO THE SOUTH OF OUR AREA...SAVE THE WESTERN HIGHLANDS.

SLIGHT MODERATING TEMPS THU AND FRI AND THEN ANOTHER CLIPPER IS EXPECTED TO PASS THROUGH SOMETIME AROUND FRI OR SAT...BRINGING COLDER TEMPS BACK TO THE REGION.

&&

.LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...WIND CHILL ADVISORY UNTIL 12 PM EST MONDAY FOR MDZ003-501-502.

WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 12 PM EST MONDAY FOR MDZ004>007.

VA...WIND CHILL ADVISORY UNTIL 12 PM EST MONDAY FOR VAZ021.

WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 12 PM EST MONDAY FOR VAZ025>031.

WV...WIND CHILL ADVISORY UNTIL 12 PM EST MONDAY FOR WVZ050-051-054- 055-501>504.

WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 12 PM EST MONDAY FOR WVZ052-053.

MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST MONDAY FOR ANZ530>537.

&&

$$

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

.SHORT TERM /REST OF TODAY/... S/WV EVIDENT IN OBS/STLT ENTERING SRN WVA. PCPN /SNW/ AHD OF IT APPCHG SRWN ZNS. DOUBT MUCH OF THE PCPN WL SURVIVE CROSSING THE APPLCHNS...BUT THE MID/UPR MSTR /AKA CLDS/ WL. CUD SEE UP TO AN INCH IN FAR WRN HIGHLAND/PNDLTN CNTYS TDA. LTL/NONE ELSW. SHARP DEMARKATION ON VSBL SATPIX WL CROSS CWFA...SO SRN CNTYS SHUD BE MOCLDY WHILE NRN CNTYS MOSUN. WL ATTEMPT TO CREATE GRIDS/ZONES TO ADEQUATELY REFLECT THAT THINKING.

WNDS RATHER BENIGN ATTM. GUSTS SHUD RTN ON BACK SIDE OF VORT. HWVR...TEMPS WL BE WARM ENUF BY THEN SO CRIT WONT BE MET ANYWHERE TIL TNGT. WSW FOR CHILLS NEEDS TO BE REISSUED THIS MRNG ANYWAY. IT WIBIS W/ A SUSPENSION OF THE WND CHILL ADVSRY DURING THE MIDDAY AND AFTN HRS.

LAMP GDNC AND RAOB FULL SUN TEMPS IN LINE W/ GOING MAXT FCST. GRANTED...SRN CNTYS WONT BE RECEIVING FULL SUN...BUT THERE WL BE A PINCH OF WAA INSTEAD. WL LEAVE TEMP FCST AS IS. &&

.AVIATION /15Z-12Z/... VFR CONDS THRU PD. GUSTY WNW WNDS RTN FOR THE AFTN/EVE BHD S/WV.

MRB TAF NIL FOR CONTD FAA COMMS PRBLMS. LIKELY WL ISSUE TAF NIL AMD AT 18Z SINCE WX SITUATION BENIGN...AND SUSPEND IF LWR FLGT CATEGORIES THREATEN. &&

.MARINE... WNDS BLO SCA CRIT ATTM...BUT SHUD RTN TAFTN ONCE S/WV CROSSES WATERS. WL CARRY HEADLINE ALONG. &&

.PREV DISCUSSION... /ISSUED 300 AM EST SUN FEB 4 2007/

SHORT TERM (TODAY AND TONIGHT)... WATER VAPOR LOOP SHOWS UPPER LEVEL MOISTURE STREAMING FROM TEXAS NORTHEAST OFF THE NEW ENGLAND COAST. A WAVE HAS PASSED EAST INTO NEW ENGLAND...AS THE NEXT SHORT WAVE ENTERS THE TENNESSEE VALLEY. ACARS 400-250MB WIND OBSERVATIONS REVEAL A 175-220KT SOUTHWESTERLY JET EXTENDS FROM THE PLAINS THROUGH THE MID ATLANTIC AND ALONG THE NEW ENGLAND COAST. 04Z SURFACE ANALYSIS PLACED A COLD FRONT FROM NEW YORK STATE SOUTHWEST ALONG THE APPALACHIANS INTO THE PLAINS. A TROUGH WAS NOTED IN THE LEE OF THE APPALACHIANS. A 1029MB ANTICYCLONE DOMINATED THE GULF COAST STATES...WITH A 1028MB ANTICYCLONE ACROSS THE MIDWEST.

HIGH CLOUDINESS ASSOCIATED WITH THE UPPER LEVEL JET WILL BE PUSHING SOUTHEAST EARLY THIS MORNING WITH THE JET AXIS. MEANWHILE...UPSLOPE MOISTURE REMAINS ACROSS THE MOUNTAINS WITH CLEAR SKIES IN BETWEEN.

CLOUDS ASSOCIATED WITH THE NEXT SHORT WAVE WILL OVERSPREAD PRIMARILY THE SOUTHERN FORECAST AREA TODAY FROM THE TENNESSEE VALLEY. WENT WITH LOWER NGM MOS GUIDANCE FOR HIGHS TODAY...A FEW DEGREES COOLER THAN YESTERDAY WITH RENEWED COLD ADVECTION. WINDS WILL BEGIN TO GUST FROM THE WEST WITH MIXING LATE THIS MORNING AND AFTERNOON. WIND CHILLS ACROSS MUCH OF THE INITIAL ADVISORY AREA WILL BE NEAR CRITERIA DURING MUCH OF THE AFTERNOON...SO DECIDED TO KEEP THE ADVISORY GOING THROUGH THE DAY.

THE PASSAGE OF THE SHORT WAVE SHOULD REINVIGORATE THE UPSLOPE SNOW SHOWERS TONIGHT...AND BRING A PERIOD OF MOSTLY CLOUDY SKIES ACROSS THE WESTERN AND NORTHERN FORECAST AREA WITH COLD ADVECTION STRATO-CU. LOW LEVEL LAPSE RATES APPEAR FAVORABLE TO ALLOW MIXING WIND GUSTS OF 30 MPH TO THE SURFACE AT TIMES TONIGHT. WENT ON THE HIGHER SIDE OF MOS FOR LOW TEMPERATURES DUE TO THE MIXED BOUNDARY LATER. THIS STILL PLACED MOST OF THE FORECAST AREA WEST OF THE BLUE RIDGE AND ALONG THE PENNSYLVANIA BORDER INTO WIND CHILL ADVISORY RANGE LATE TONIGHT AND MONDAY MORNING.

AVIATION... COLD FRONT PRESSING THROUGH THE EASTERN FORECAST AREA CONTINUES TO SUPPORT A WIND SHIFT AND SOME COLD ADVECTION STRATO-CU...WHILE UPPER LEVEL MOISTURE RESIDES ALONG THE UPPER LEVEL JET AXIS. EXPECT CLOUDS ASSOCIATED WITH THE NEXT SHORT WAVE FROM THE TENNESSEE VALLEY TO STREAM INTO THE AREA DURING THE DAY AS THE UPPER LEVEL JET AXIS SHIFTS TO THE SOUTHEAST. COLD ADVECTION TONIGHT WILL VEER WINDS AND PROVIDE GUSTS...WITH ANOTHER OPPORTUNITY FOR STRATO-CU.

MARINE... SMALL CRAFT ADVISORY IS IN EFFECT.

00Z ETA/GFS MOS AT THOMAS POINT INDICATES SUSTAINED WINDS WILL INCREASE TO 20KT BEGINNING THIS AFTERNOON. 00Z PROXIMITY NAM/GFS BUFKIT FORECAST SOUNDINGS INDICATE WIND GUST POTENTIAL OF 25KT TO 30KT TONIGHT.

STILL A RATHER STRONG GRAD FORCE MON EVNG SO HAVE EXTENDED THE SCA WINDS TIL ABOUT 10 PM. NOT A LOT OF CONFIDENCE IN SCA WINDS CONTINUING BEYOND THAT TIMEFRAME SO HAVE DROPPED WINDS BACK BELOW 20 KTS MON NGT AND LATER PERIODS.

TIDES... WATER LEVELS ARE CURRENTLY UP TO A HALF FOOT ABOVE ASTRONOMICAL PREDICTIONS. THE LUNAR CYCLE IS AT FULL MOON (96% FULL).

THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM AND THE NOAA EXTRATROPICAL SURGE MODEL BOTH SUGGEST WATER LEVELS FALL UP TO A FOOT BELOW ASTRONOMIC PREDICTIONS THIS AFTERNOON.

LONG TERM...MONDAY THROUGH SATURDAY...

COLDEST AIRMASS OVERHEAD MONDAY AND EARLY TUESDAY ACROSS OUR AREA. WE WILL CONTINUE TO UNDERCUT MOS TEMPS SEVERAL DEGREES THROUGH TUESDAY ALTHOUGH LATEST MOS PREDICTIONS NOW REFLECT THE COLD AIRMASS MUCH BETTER THAN PREVIOUS RUNS. WIND CHILL HEADLINES WILL LIKELY BE NEEDED INTO TUESDAY MORNING...MAINLY FOR THE PREDICTED MIN TEMPS AS THE WINDS WILL NOT BE ALL THAT STRONG AT THAT POINT.

UPSLOPE SNOW SHOWERS WILL BE WAINING BY MONDAY EVENING...ONLY TO BE RE-INVIGORATED AROUND TUESDAY EVENING ON THE CUSP OF ANOTHER CLIPPER AND WEAK LOW PRES WAVE. THIS SYSTEM SEEMS TO DROP FROM EASTERN KY INTO SOUTHERN VA AND ANY PRECIP SHOULD BE SHUNTED TO THE SOUTH OF OUR AREA...SAVE THE WESTERN HIGHLANDS.

SLIGHT MODERATING TEMPS THU AND FRI AND THEN ANOTHER CLIPPER IS EXPECTED TO PASS THROUGH SOMETIME AROUND FRI OR SAT...BRINGING COLDER TEMPS BACK TO THE REGION.

&&

.LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 12 PM EST MONDAY FOR MDZ003>007-501-502.

VA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 12 PM EST MONDAY FOR VAZ021-025>031.

WV...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 12 PM EST MONDAY FOR WVZ050>055-501>504.

MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST MONDAY FOR ANZ530>537.

&&

$$

UPDATED SHORT TERM/AVIATION/MARINE...HTS PREVIOUS DISCUSSION...ROGOWSKI/JB

.SYNOPSIS...STRONG HIGH PRESSURE ALOFT AND WEAK OFFSHORE FLOW WILL CONTINUE MOSTLY CLEAR SKIES THROUGH MONDAY WITH NEAR RECORD HIGH TEMPERATURES. LOCAL GUSTY WINDS THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES AT TIMES THROUGH MONDAY. HIGH PRESSURE WILL WEAKEN WITH COOLER WEATHER AND INCREASING CLOUDS WEDNESDAY THROUGH FRIDAY. UPPER LEVEL LOW PRESSURE WILL BRING A CHANCE OF SHOWERS NEXT WEEKEND.

&&

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

.SHORT TERM (TODAY-WED)...CLEAR TODAY EXCEPT FOR A FEW CI. ACARS SOUNDINGS HAD WEAK E-NE WINDS IN THE LOW LEVELS AND MODERATELY STRONG NW WINDS ALOFT. OFFSHORE GRADIENTS WITH ABOUT -8 MB SAN-TPH.

A HIGH AMPLITUDE RIDGE OF HIGH PRESSURE ALOFT WILL SLOWLY SHIFT E AND WEAK OFFSHORE FLOW WILL CONTINUE THROUGH MON. THIS WILL BRING MOSTLY CLEAR SKIES WITH JUST A FEW HIGH CLOUDS AT TIMES AND ANOTHER WARM DAY MON. THERE COULD BE SOME NEAR RECORD MAX TEMPS MON WITH SOME WARMER INLAND VALLEY LOCATIONS GETTING CLOSE TO 90 DEGREES. THE OFFSHORE GRADIENTS WILL CAUSE LOCAL GUSTY WINDS THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES AT TIMES THROUGH MON...BUT MOST WINDS WILL REMAIN BELOW ADVISORY STRENGTH. THE WARM DRY OFFSHORE FLOW WILL INCREASE THE FIRE WEATHER HAZARD. THE HIGH ALOFT WILL WEAKEN AND SHIFT FARTHER E TUE AND WEAK ONSHORE FLOW WILL RETURN FOR A LITTLE COOLING. A WEAK UPPER TROUGH WILL APPROACH FROM THE W WED WHICH WILL FURTHER DECREASE LOCAL HEIGHTS AND INCREASE THE ONSHORE GRADIENTS. THIS WILL BRING MORE COOLING WED WITH INCREASING HIGH CLOUDINESS IN SW WINDS ALOFT. PATCHY MARINE LAYER CLOUDS AND FOG COULD RETURN TUE NIGHT AND WED MORNING.

&&

.LONG TERM (THU-SUN)...STRONG LOWER LATITUDE FLOW WILL PREVAIL ACROSS THE PAC AND THIS WILL MAKE THE TIMING OF SHORT WAVES DIFFICULT. IT CURRENTLY LOOKS LIKE THE TROUGH MOVING THROUGH THU AND FRI WILL BE TOO WEAK TO BRING ANY PRECIP TO OUR AREA. HOWEVER...THERE WILL BE MORE CLOUDS AND COOLING. PREVIOUS MODEL RUNS HAD A STRONGER TROUGH OF LOW PRESSURE COULD BRING PRECIP NEXT WEEKEND BUT THE LATEST GFS RUN SHOW WEAK RIDING. WILL KEEP SLIGHT CHANCES OF PRECIP IN THE FORECAST FOR NOW.

&&

.AVIATION... OFFSHORE FLOW WILL CONTINUE THROUGH MONDAY BRINGING VFR CONDITIONS WITH A MOSTLY CLEAR SKY AND UNRESTRICTED VISIBILITIES.

LOCAL GUSTY NORTHEAST WINDS THROUGH AND BELOW MOUNTAIN PASSES AND CANYONS WITH ASSOCIATED UP AND DOWN DRAFTS AND LOW LEVEL WIND SHEAR THROUGH MONDAY.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...DVA AVIATION...HORTON

.DISCUSSION... THE BIG CHILL AGAIN THE FOCUS OF SHORT TERM. PER 1616Z TAMDAR RAOB FOR KSUX AND 12Z KABR RAOB...FAIRLY ISOTHERMAL THRU LOWEST 300 HPA. PROFILERS AT NLG AND WDL...ESPECIALLY THE LATTER...SUGGEST FAIRLY STRONG WNDS AGAIN SITTING JUST OFF THE SFC...WITH LOW LVL RIDGE AXIS PROTECTING AREAS FROM THE JAMES VALLEY AND W. FOR THIS REASON... DROPPED A BIT EARLY THE WRN WIND CHILL ADVY. IF NLG PROFILER CORRECT...WL LKLY CONTINUE TO EXPERIENCE ISSUES WITH WINDS DROPPING OFF MUCH ALG THE I29 CORRIDOR...AND 30KTS IN LOWER GATE OF WDL ALONG WITH CONTINUED LOW LVL CAA PRETTY MUCH KEEP ERN AREAS WELL UNDER DANGEROUS WIND CHILL THREAT PER FCST...UNTIL BETTER WIND DECOUPLING THIS EVENING. WL LKLY BE ABLE TO WHITTLE A BIT MORE OF WIND CHILL ADVY AWAY THAN JUST THE REMAINING EXPIRING SEGMENT THRU LOWER JAMES VALLEY AT NOON.

ONE ISSUE FOR TDA IS MID AND HIGH CLOUDS STREAMING IN FROM THE NW. THICKEST CLDS LKLY TO REMAIN ACRS THE FAR WRN CWA THIS AFTN...BUT TIME SECTIONS SUGGEST THAT WL NOT DISSIPATE HEADING SE...SO UPPED SKY GRIDS CONSIDERABLY TODAY AND TONIGHT. THIS INTRODUCES A BIT OF CONCERN THAT LOWS WL NOT REACH NEARLY AS COLD TNGT AS FCST IN AREAS W OF A LINE FROM KHON TO KSUX WHERE CLOUDS LKLY TO BE A MORE SIG ISSUE. HOWEVER...VERY LIGHT WINDS WL MAKE ANY CLEARING PERIOD SUSCEPTABLE TO DRASTIC TEMP DROPS...SO WL ONLY PUSH LOWS UP A HALF TO FULL CATEGORY FOR THE MOMENT.

&&

.PREV DISCUSSION... ANOTHER FRIGID DAY ON TAP OVER THE REGION AS COLD SURFACE HIGH CURRENTLY CENTERED ALONG THE U.S. AND CANADIAN BORDER CONTINUES TO SLIDE SOUTHWARD. WILL REMAIN BREEZY ENOUGH THROUGH THE DAY TO KEEP THE WIND CHILL ADVISORY GOING OVER MOST OF THE AREA THROUGH EARLY TONIGHT...THOUGH THE ADVISORY WILL DROP OFF OVER OUR SOUTHWESTERN ZONES BY AFTERNOON AS TEMPERATURES WARM AND WINDS LEVEL OFF AS HIGH PRESSURE AXIS DROPS INTO THE AREA. STILL APPEARS THAT THE COLDEST NIGHT IN THIS ARCTIC EPISODE WILL BE TONIGHT...WITH HIGH PRESSURE PARKED OVERHEAD AND RESULTANT VERY LIGHT WINDS OVER THE FA. COLDEST READINGS WILL BE THROUGH THE NORTHEASTERN HALF OF THE CWA CLOSEST TO THE HIGH PRESSURE CENTER. THE SOUTHWESTERN PORTIONS OF THE CWA WILL BE A CONSIDERABLE AMOUNT WARMER...BEING FURTHER ON THE BACKSIDE OF THE HIGH...AS WELL AS FEELING THE EFFECT OF INCREASING CLOUDS WITH WAA IN THE MID LEVELS.

WARMED TEMPERATURES SOME ON MONDAY WITH RESPECT TO PREVIOUS FORECAST WITH MODELS COMING IN SEVERAL DEGREES WARMER THAN BEFORE. AS HAS BEEN ADVERTISED THE PAST COUPLE OF DAYS...STRONG BAROCLINIC BAND WILL SET UP OVER THE WESTERN PORTIONS OF THE CWA BY MONDAY AFTERNOON...WITH STRONG MID LEVEL WAA...AND DECENT LOWER LEVEL FRONTOGENESIS...WHICH WILL PUSH EASTWARD OVER THE CWA ON MONDAY NIGHT AND TUESDAY. UPPED THE POPS SLIGHTLY FROM THE PREVIOUS FORECAST WITH THESE DYNAMICS AS THEY CROSS OUR FA. STILL LOOKS LIKE TEMPERATURES WILL RISE OVER THE AREA DURING THE OVERNIGHT HOURS OF MONDAY INTO TUESDAY WITH THE WAA IN PROGRESS. LIGHT PRECIPITATION SHOULD END FROM WEST TO EAST BY TUESDAY AFTERNOON AS BEST DYNAMICS PUSH EASTWARD.

WEAK SHORTWAVE DROPS SOUTHWARD THROUGH OUR AREA ON WEDNESDAY...AND KEPT BROADBRUSHED SMALL CHANCE POPS OVER THE CWA FOR WEDNESDAY INTO EARLY WEDNESDAY NIGHT WITH THE SYSTEM. DID JUST NOTE THAT THE LATEST GFS RUN KEPT THE BEST ENERGY WITH THIS FEATURE TO OUR SOUTHWEST...SO WE WILL HAVE TO SEE HOW IT PANS OUT. AS FOR TEMPERATURES THROUGH THE END OF THE WEEK...WHILE WE WILL SEE SOME MODERATION...ESPECIALLY IN COMPARISON WITH THE CURRENT BOUT OF BITTER COLD...IT STILL WILL REMAIN MUCH BELOW NORMAL WITH SMALL SHOTS OF REINFORCING COLD AIR EVERY COUPLE DAYS OR SO.

&&

.FSD WATCHES/WARNINGS/ADVISORIES... IA...WIND CHILL ADVY UNTIL 9 PM IAZ001>003-012>014-020>022-031- 032. MN...WIND CHILL ADVY UNTIL 9 PM MNZ071-072-080-081-089-090-097- 098. NE...WIND CHILL ADVY UNTIL 9 PM FOR NEZ014. WIND CHILL ADVY UNTIL NOON FOR NEZ013. SD...WIND CHILL ADVY UNTIL 9 PM FOR SDZ038>040-053>056-060>062- 066-067-071. WIND CHILL ADVY UNTIL NOON FOR SDZ059-065-069-070. &&

$$

CHAPMAN/JM

.SYNOPSIS...HIGH PRESSURE ALOFT WILL REBUILD OVER THE AREA THROUGH TONIGHT...SLOWLY DRYING OUT THE REGION. DRY WEATHER WILL PREVAIL ON MONDAY UNDER HIGH PRESSURE ALOFT...ALTHOUGH THE DAY WILL START OFF FOGGY. A LOW PRESSURE SYSTEM IS EXPECTED TO APPROACH ON TUESDAY...RESULTING IN A CHANCE OF RAIN OVER SOUTHWEST WASHINGTON IN THE AFTERNOON. LOOK FOR UNSETTLED WEATHER THE REST OF THIS WEEK.

&&

.SHORT TERM...GOOEY DAY TODAY. UPPER RIDGE BUILDING STEADILY OVER THE REGION AND THE IMMEDIATE RESULT IS THE RAIN LIFTING NORTH OF THE REGION. CURRENTLY MAIN AREAS OF PRECIP ARE STREAMING BY NORTH OF WASHINGTON...WHILE JUST CLIPPING THE NORTHERN OLYMPIC PENINSULA AND NORTHWEST INTERIOR. WITH MOIST AIR MASS IN PLACE OVER THE AREA STILL GETTING A SPIT OR SPATTER HERE AND THERE OVER THE REST OF THE AREA. AS THE RIDGE BUILDS...MID AND UPPER LEVELS WILL CONTINUE TO DRY UP BRINGING AN END TO THE PRECIP.

MAIN PROBLEM IS ALL THE LOW LEVEL MOISTURE THAT IS BEING LEFT BEHIND. ACARS SOUNDINGS SHOW AN INVERSION ABOUT 800-1000 FEET OFF THE GROUND WITH LIGHT OFFSHORE FLOW BELOW THE INVERSION...AND DECENT SW FLOW ABOVE IT. UNTIL WE GET RID OF THE HIGHER CLOUDS AND OR INCREASE THE OFFSHORE FLOW SIGNIFICANTLY...DON`T THINK WE WILL BE ERODING THAT INVERSION ALL THAT QUICKLY. AT THIS POINT THINK WE WILL ONLY SEE LIMITED IMPROVEMENT TODAY AND THEN MAINLY SOUTHERN AREAS. ONCE THE SUN GOES DOWN TONIGHT...THE GOO WILL LIKELY LOCK IN AS THE OFFSHORE GRADIENTS ARE NOT ALL THAT STRONG AND RADIATIONAL COOLING SHOULD STRENGTHEN THE INVERSION. WILL HAVE TO WAIT UNTIL MONDAY BEFORE WE BREAK OUT AND SEE THE SUN ON A LARGER SCALE.

WITH THE BULK OF THE RAIN PRETTY MUCH OVER FOR A LARGE PART OF THE AREA WILL UPDATE THE FORECAST TO LOWER THREAT OF STEADIER RAIN...AND REPLACE IT WITH LOCAL DRIZZLE...SPOTTY LIGHT RAIN WORDING...ALONG WITH HITTING THE FOG A BIT MORE. CERNIGLIA

.LONG TERM...FROM PREVIOUS DISCUSSION...THIS PERIOD WILL BE DOMINATED BY AN UNSETTLED WEATHER REGIME AS A SERIES OF PAC STORMS IN THE NRN BRANCH MOVE ACROSS THE REGION. SUSPECT THAT THE POPS MAY STILL BE TOO LOW...ESPECIALLY FOR THE LATTER PART OF THE WEEK.

&&

.AVIATION...SLOPPY MORNING AVIATION WISE IN PROGRESS. MULTIPLE CLOUD DECKS IN THE LOWER LAYERS WITH THE MAIN SC DECK AROUND 2000 FEET. AREAS OF VISIBILITIES 1-3SM IN FOG AND CEILINGS 500 TO 1000 FEET WITH PLENTY OF LOW LEVEL MOISTURE. SLOW IMPROVEMENT FROM THE SOUTH TODAY WITH CEILINGS EXPECTED TO BE IN THE 2000 TO 3000 FOOT RANGE BY MID TO LATE AFTERNOON WITH JUST ISOLATED REDUCED VISIBILITIES IN FOG. NOT MUCH WIND IN THE LOWER LEVELS AS WELL SO EXPECT CONDITIONS TO DETERIORATE TONIGHT BACK DOWN TO CEILINGS BELOW 1000 FEET WITH AREAS OF VISIBILITIES 1-3SM IN FOG.

FOR KSEA...CEILINGS 2000 TO 3000 FEET THROUGH THE AFTERNOON HOURS LOWERING BACK DOWN BELOW 1000 FEET 03-06Z. VISIBILITIES AS LOW AS 2 MILES UNTIL 21Z VISIBILITIES ALSO LOWER AGAIN AFTER 03Z TO 1-3SM IN FOG. LIGHT WIND THROUGH THIS EVENING. FELTON

&&

.SEW WATCHES/WARNINGS/ADVISORIES...SMALL CRAFT ADVISORY WEST ENTRANCE TO THE STRAIT THIS MORNING.

$$

WEATHER.GOV/SEATTLE