Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 11/09/08

AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NWS KEY WEST FL
1145 AM EST SAT NOV 8 2008 .DISCUSSION... MOSTLY CLOUDY SKIES COVER THE THE FLORIDA KEYS AND ADJACENT COASTAL WATERS FOR THE THIRD DAY IN A ROW. SHOWERS HAVE BEEN ABSENT IN MOST ISLAND COMMUNITIES TODAY WITH THE EXCEPTION OF A FEW LIGHT SPRINKLES. HOWEVER...IT HAS BEEN RAINING HEAVILY AND NEARLY CONTINUOUSLY NOT FAR AWAY OVER THE LOWER STRAITS OF FLORIDA...ABOUT 60-70 NAUTICAL MILES SOUTH OF THE MARQUESAS KEYS. IN FACT...KEY WEST DOPPLER RADAR ESTIMATES SHOW UP TO 14 INCHES OF RAINFALL IN THIS AREA DURING THE LAST 48 HOURS. MEANWHILE...MAJOR HURRICANE PALOMA...THE SECOND MOST INTENSE NOVEMBER HURRICANE IN HISTORY IN THE ATLANTIC BASIN...IS MOVING EAST-NORTHEASTWARD OVER THE NORTHWESTERN CARIBBEAN SEA... TOWARD EASTERN CUBA. A WEAKENING COLD FRONT WAS ANALYZED ACROSS THE GULF OF MEXICO A FEW HUNDRED MILES NORTHWEST OF THE KEYS. THE COASTAL WATERS FORECAST WAS UPDATED TO HOIST SMALL CRAFT ADVISORIES FOR ATLANTIC OFFSHORE ZONES COVERING WATERS 20 TO 60 NAUTICAL MILES SOUTH...AND WATERS FROM KEY WEST THROUGH THE DRY TORTUGAS OUT 60 NAUTICAL MILES. THESE UPDATES WERE BASED ON A COMBINATION OF SHIP AND SATELLITE OBSERVATIONS...AS WELL AS FROM STEPPED FREQUENCY MICROWAVE RADIOMETER DATA FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT ON ITS WAY INTO HURRICANE PALOMA -- SEE MARINE SECTION BELOW FOR DETAILS. && .MARINE... A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THE ATLANTIC WATERS FROM OCEAN REEF TO KEY WEST 20 TO 60 NAUTICAL MILES OUT...AND FOR THE WATERS FROM KEY WEST THROUGH THE DRY TORTUGAS OUT 60 NAUTICAL MILES. WINDS INCREASE FROM NORTH TO SOUTH OVER THE SERVICE AREA ACCORDING TO AVAILABLE SHIP...AIRCRAFT...AND SATELLITE DATA...INCREASING FROM 15-20KT NEARSHORE TO OVER 20KT 60 NAUTICAL MILES OUT. SEAS OF 6-8FT HAVE BEEN OBSERVED BY SHIPS TRAVERSING WATERS BEYOND 20 NAUTICAL MILES SOUTH OF THE KEYS...WITH SEAS UP TO 10FT REPORTED IN THE GULF STREAM. SMALL CRAFT SHOULD EXERCISE CAUTION ACROSS THE ATLANTIC WATERS WITHIN 20 NAUTICAL MILES OF SHORE...DUE TO NORTHEAST WINDS BLOWING 15-20KT AND SEAS UP TO 6FT. CONDITIONS ARE MUCH CALMER ON THE FLORIDA BAY AND GULF OF MEXICO SIDES...WITH WINDS GENERALLY BETWEEN 10 AND 15KT AND SEAS OF 2-4FT IN DEEPER WATER. SHOWERS WILL BE MOST FREQUENT AND HEAVIEST BEYOND 20 NAUTICAL MILES SOUTH OF THE KEYS THIS AFTERNOON. && .AVIATION... VFR CONDITIONS WILL PREVAIL ACROSS THE KEYS THROUGH TONIGHT. CEILINGS HAVE LIFTED THIS MORNING TO FL100-120 WITH LOWEST CEILINGS NEAR KMTH. THERE HAS BEEN VERY LITTLE IF ANY RAIN NEAR THE TERMINALS...MOSTLY SPRINKLES AT KEYW. GRADUAL DISSIPATION OF THE VFR CEILINGS WILL BEGIN LATE TONIGHT. SURFACE WINDS WILL BE NORTH TO NORTHEAST NEAR 10 KNOTS THROUGH TONIGHT...BUT NORTH CROSSWINDS NEAR 12 TO 15 KNOTS CAN BE EXPECTED ON SUNDAY. && .CLIMATE... ON THIS DATE IN KEYS WEATHER HISTORY...IN 1888...0.60 INCHES OF RAINFALL WAS MEASURED IN KEY WEST. THIS SET THE DAILY RECORD FOR MAXIMUM RAINFALL MEASURED IN KEY WEST ON NOVEMBER 8TH...A RECORD WHICH STILL STANDS 120 YEARS LATER. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...NONE. GM...SMALL CRAFT ADVISORY FOR GMZ072-GMZ073-GMZ074-GMZ075. && $$ PUBLIC/MARINE.........KASPER AVIATION/NOWCASTS.....RIZZO DATA COLLECTION.......FUENTES VISIT US ON THE WEB AT WWW.WEATHER.GOV/KEYWEST
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1041 AM EST FRI NOV 7 2008 .SYNOPSIS.../ISSUED AT 327 AM/ DEEP LOW PRESSURE WILL GRADUALLY MAKE ITS WAY EASTWARD THRU THE GREAT LAKES REGION THIS WEEKEND...USHERING IN COLDER AIR AND UNSETTLED WEATHER FOR ALL OF MICHIGAN. THE LAKES WILL BECOME ACTIVE AS THE COLD AIR ARRIVES...PROVIDING ENHANCEMENT TO ONGOING PRECIPITATION. RAIN SHOWERS WILL EVENTUALLY MIX WITH AND CHANGE TO SNOW SHOWERS OVER THE WEEKEND AS THE COLD AIR FILTERS INTO THE REGION. COOL AND UNSETTLED WX WILL PERSIST INTO MONDAY...WITH DRY WX RETURNING BY THE MIDDLE OF NEXT WEEK. && .SHORT TERM.../ISSUED AT 1041 AM/...THIS AFTERNOON 13Z SURFACE ANALYSIS SHOWS WRAPPED UP 997MB LOW ALONG THE MN/IA BORDER...OCCLUDED/COLD FRONT LOOPS ACROSS MN...BACK EAST/SOUTHEAST ACROSS LAKE SUPERIOR/UPPER MI...THEN DOWN ACROSS WESTERN LOWER MI INTO EASTERN IN. MUCH OF THE PRECIPITATION AHEAD OF THE COLD FRONT HAS MOVED OUT OF THE AREA...THOUGH SCATTERED SHOWERS CONTINUE TO GENERATE OVER THE THUMB/LAKE HURON. ADDITIONAL MORE WIDESPREAD SHOWERS MOVING NORTH-NORTHEAST OUT OF OH...ATTACHED TO A COUPLE STRUNG OUT VORTICITY MAXIMA PER WATER VAPOR IMAGERY. SKIES HAVE CLEARED OVER NORTHWEST LOWER...BUT LOW CLOUDS/FOG ARE SPREAD ACROSS THE HIGHER TERRAIN OF NORTHERN LOWER...AS WELL AS ACROSS EASTERN UPPER. FOR THIS AFTERNOON...HAVE MADE SOME ADJUSTMENTS TO CLOUD COVER FORECAST GIVEN THE AFOREMENTIONED STRATUS DECK. 12Z APX SOUNDING AND AIRCRAFT SOUNDINGS SUGGEST THIS IS PRETTY THIN...SO EVEN WITH A SHALLOWER NOVEMBER SUN ANGLE THIS STUFF SHOULD MIX OUT WITH TIME. ACROSS NORTHEAST LOWER AND FAR EASTERN UPPER...WITH LOW LEVEL COLD ADVECTION DEVELOPING THIS MORNING OVER TOP OF A STILL RELATIVELY MOIST BOUNDARY LAYER...DIURNAL CU/SC SHOULD DEVELOP AND WILL KEEP SKIES CLOUDIER IN THESE AREAS. NORTHWEST LOWER WILL SEE SUN FOR THE BALANCE OF THE AFTERNOON BEFORE ST/SC SPREADS IN FROM THE SOUTHWEST TOWARD EVENING. JPB && .LONG TERM.../ISSUED AT 327 AM/...TONIGHT AND BEYOND DEEP WRAP AROUND MOISTURE (1000-500 MB RH OF 90 PCT) WILL SWING INTO MICHIGAN TONIGHT AS THE DRY SLOT PUSHES EAST OF THE REGION. SURFACE LOW WILL MOVE INTO UPPER MICHIGAN AS THE UPPER LOW REACHES CENTRAL LAKE MICHIGAN BY 12Z SATURDAY. RATHER STRONG VORT MAX DIRECTLY UNDER THE UPPER LOW WILL APPROACH OUR CWA LATE TONIGHT...AND THEN MOVE RIGHT OVERHEAD SATURDAY AND SATURDAY NIGHT. COMBINATION OF DEEP MOISTURE...SHARP CYCLONIC FLOW AND UPPER SUPPORT VIA THE SHORT WAVE AND UPPER LOW WILL CERTAINLY PRODUCE PLENTY OF SHOWER ACTIVITY TONIGHT THRU SATURDAY NIGHT. LOW LEVEL CAA WILL CONTINUE TONIGHT... DROPPING 850 MB TEMPS TO AROUND -5 C BY LATE EVENING. CERTAINLY THIS WILL PROVIDE ENOUGH OVER-LAKE INSTABILITY TO PRODUCE LAKE ENHANCEMENT OF ONGOING PRECIP. HOWEVER...LOW LEVEL FLOW WILL REMAIN OUT OF THE S/SW...WHICH LIMITS LOW LEVEL TRAJECTORIES OF LAKE ENHANCEMENT TO MAINLY WRN MACKINAC COUNTY. LOW LEVEL FLOW WILL EVENTUALLY SHIFT WEST AND THEN NW SATURDAY NIGHT...INITIATING A MUCH BETTER TRAJECTORY FOR LAKE ENHANCEMENT AND PRECONDITIONING OF LAKE SUPERIOR. THE BIG QUESTION IS PRECIP TYPE. MODEL SOUNDINGS SUGGEST PRECIP SHOULD REMAIN LIQUID THRU TONIGHT. PRECIP WILL BECOME MORE STRONGLY CONVECTIVE IN NATURE ON SATURDAY AS 500 MB TEMPS DROP TO AROUND -26 C. MODEL SOUNDING STILL POINT TO LIQUID PRECIP ON SATURDAY...BUT CANNOT RULE OUT SOME SLEET WITHIN HEAVIER CONVECTIVE SHOWER ACTIVITY. PRECIP WILL MIX WITH AND THEN CHANGE TO SNOW SATURDAY NIGHT...ESPECIALLY WITHIN THE HIGHER ELEVATIONS. UPPER LOW WILL PUSH NE OF OUR CWA BY SUNDAY...BUT PLENTY OF DEEP MOISTURE...SYNOPTIC LIFT AND OVER-LAKE INSTABILITY WILL LINGER BEHIND THE LOW IN ONGOING LOW LEVEL CAA. NO DOUBT LAKE ENHANCED PRECIP WILL CONTINUE SUNDAY INTO MONDAY...WITH PRECIP TYPE MAINLY FALLING IN FROZEN FORM PER MODEL SOUNDINGS. SOME MINOR ACCUMULATION IS POSSIBLE SUNDAY NIGHT AS TEMPS FALL BELOW FREEZING. && .MARINE.../ISSUED AT 327 AM/ PASSAGE OF COLD/OCCLUDED FRONT THIS MORNING WILL RESULT IN A SMALL SHIFT IN THE WINDS FROM SOUTHEAST TO SOUTH/SOUTHWEST. MAY SEE A FEW STRONGER GUSTS...BUT AT THIS POINT DO NOT EXPECT SCA CONDITIONS THROUGH TONIGHT. && .AVIATION.../ISSUED AT 626 AM/...VALID FOR 12Z TAFS SHOWERS WILL EXIT NE LWR MICHIGAN EARLY THIS MORNING...WITH A STEADY DIMINISH IN CLOUD COVER FROM WEST TO EAST ACROSS ALL OF NRN LWR MICHIGAN AS THE DRY SLOT ARRIVES. EXPECT VFR CONDITIONS UNTIL THIS EVENING WHEN CLOUDS AND SHOWERS MOVE BACK INTO THE REGION JUST AHEAD OF THE UPPER LOW. EXPECT CONDITIONS TO DETERIORATE TO MVFR WITH THESE WRAP-AROUND SHOWERS TONIGHT. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. LH...NONE. LS...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
120 AM EST FRI NOV 7 2008 UPDATED FOR 06Z AVIATION DISCUSSION .SYNOPSIS... WV IMAGERY AND RUC ANALYSIS SHOW A LARGE UPPER LOW ROTATING OVER THE CNTRL US. H500 LOW IS VERTICALLY STACKED OVER 997MB LOW OVER SE SD AND NE NEB...WHILE A SECOND LOW OF 994MB LOCATED OVER CNTRL MN. VERY STRONG PRESSURE GRADIENT BEHIND THE LOW IS PRODUCING VERY STRONG WINDS ACROSS WRN DAKOTAS PRODUCING BLIZZARD CONDITIONS...WITH NUMEROUS LOCATIONS GUSTING ABOVE 35KTS AND A COUPLE SITES NEAR THE BLACK HILLS GUSTING ABOVE 60KTS. CLOSER TO HOME...INITIAL PCPN WAVE STARTING TO MOVE INTO THE UP AS OF 19Z. THIS IS AHEAD OF COLD FRONT...AND ANOTHER LINE OF SHOWERS...THAT IS MOVING THROUGH SW WI. THERE IS DRY AIR IN PLACE ABOVE H850 ON 19Z KSAW AND 18Z KPLN TAMDAR SOUNDINGS...WHICH HAS BEEN PRODUCING PARTLY TO MOSTLY SUNNY SKIES ACROSS ERN UP. HIGH CIRRUS HAVE BEEN SLIDING NORTH OVER THE REST OF THE UP. && .SHORT TERM (TONIGHT AND FRIDAY)... UPPER TROUGH WILL CONTINUE TO DIG S ACROSS SRN PLAINS TONIGHT AND GRADUALLY MERGE WITH THE SUB TROPICAL JET LATER IN THE DAY ON FRI. WITH THE TROUGH DIGGING DEEP OVER THE CNTRL US...DUE TO H250 100KT JET MOVING SE OVER THE ROCKIES...IT PULLS THE UPPER SUPPORT JUST FAR ENOUGH AWAY FROM SFC LOW TO ALLOW IT TO GRADUALLY WEAKEN AND DRIFT NE THROUGH THE SHORT TERM PERIOD. EXPECT THE PCPN TO CONTINUE NORTH DURING THE LATE AFTN HRS. DRY AIR MENTIONED PREVIOUSLY SHOULD QUICKLY BE EATEN AWAY ACROSS THE REST OF THE CWA BY ABUNDANT H900 AND ABOVE MOISTURE MOVING IN FROM WI...AS SEEN ON WV IMAGERY AND CNTRL WI TAMDAR SOUNDINGS. HAVE LEFT MENTION OF ISOLATED THUNDER IN FOR THE LATE AFTN...AS STEEP LAPSE RATES ABOVE H850 WERE SEEN ON 18Z KCWA TAMDAR SOUNDING...BUT HAVE NOT SEEN ANY LIGHTING STRIKES IN NRN WI SO FAR. THIS MOISTURE IS SITUATED AHEAD OF SFC COLD/OCCLUDED FRONT THAT WILL PUSH N THROUGH CWA...MAINLY THIS EVENING. MOISTURE IS ABUNDANT FOR THIS TIME OF YEAR...WITH PWAT VALUES NEAR OR ABOVE AN INCH...WHICH IS 200-300 PERCENT OF NORMAL. SHOULD BE PLENTY OF FORCING ALONG THE FRONT...WITH 290-305K ISENTROPIC SFCS SHOWING WELL DEFINED BOUNDARY PUSHING NE THROUGH WRN HALF OF CWA BY 06Z AND THEN OVER THE FAR ERN CWA BY 12Z FRI...AND DECENT H850-500 Q VECTOR CONVERGENCE. THEREFORE...EXPECT NW TO SE ORIENTATED BAND OF SHOWERS TO TRANSITION FROM SW TO NE ACROSS THE CWA...WITH BEST PCPN CHANCES OVER THE WRN UP DURING THE EVENING AND ERN UP INTO THE OVERNIGHT HOURS. EXPECT THE WIDTH OF THE PCPN TO SHRINK TONIGHT...AS DRY AIR AHEAD OF THE FRONT AND DRY SLOT MOVING IN FROM BEHIND TO PINCH THE MOISTURE FIELD INTO FRI MORN. EXISTING FORECAST HAD PRETTY GOOD TIMING ON PCPN...SO DID NOT MAKE MANY ADJUSTMENTS. CONTINUED THE DECREASING CLOUDS OVERNIGHT FROM SW TO NE ACROSS THE CWA. SHOULD SEE A PERIOD OF PARTLY CLOUDY SKIES MOVING THROUGH THE CWA BEHIND THE FRONT...BEFORE UPPER LOW MOVES CLOSE ENOUGH TO MOVE H850-700 MOISTURE/CLOUDS OVER THE KIWD AREA LATE TONIGHT. LOW PRESSURE SYSTEM NEARLY BECOMES VERTICALLY STACKED DURING THE DAY ON FRI...AS IT DRIFTS TO THE SE. LOOKS LIKE THERE WILL BE A BROAD AREA OF CLOUDS AND SHOWERS ACROSS MN AND WI...AS COLD H850 TEMPS NEARLY WRAP ALL THE WAY AROUND THE LOW. BEST CHANCE OF PCPN TOMORROW LOOKS TO BE S AND W OF A LINE FROM KCMX TO KESC...MAINLY IN THE AFTN AS H850 COLD NOSE MOVES N INTO THE AREA AND SFC LOW MOVES TO JUST N OF KIWD. EXPECT A FEW SHOWERS TO DEVELOP THROUGH THE DAY. WITH COLD AIR ALOFT MOVING AROUND THE LOW...IT SHOULD PRODUCE FAIRLY STEEP LLVL LAPSE RATES BETWEEN SFC AND H750 INVERSION. THIS COMBINED WITH PLENTY OF MOISTURE BELOW THE INVERSION...SHOULD ALLOW SHOWERS TO DEVELOP ACROSS THE SW PART OF THE CWA AND GRADUALLY SHIFT NE. DID EXPAND THE CHANCE PCPN AREA FARTHER TO THE NE DURING THE AFTN...BUT LEFT THE FAR ERN CWA IN SLIGHT CHANCES DUE TO DRY SLOT STILL WORKING OUT OF THAT AREA. OVERALL...EXPECT THE SHOWERS TO BE HIT OR MISS...WITH QPF BEING LIGHT DUE TO LIMITED CLOUD DEPTH. ADDED SOME SLIGHT CHANCES OF SNOW ALONG THE WI BORDER AREA FOR LATE TOMORROW AFTN. H850 TEMPS DROP FROM -2C AT 18Z FRI TO AROUND -5-6C AT 0Z. SFC TEMPS SHOULD ALSO DROP DURING THE AFTN ALONG THE WI BORDER...WITH VALUES IN THE UPPER 30S BY 00Z. WBZ HEIGHTS WILL DROP BELOW 1.5KFT AGL BETWEEN 21-00Z ON NAM AND LOCAL HI-RES WRF-ARW. SO WOULD NOT BE SURPRISED IF PCPN MIXED WITH SNOW IN THE STRONGER SHOWERS LATE IN THE DAY FRI. LONGER TERM...00Z SAT ONWARD... NAM SHOWS THE CLOSED 500 MB LOW AND TROUGH AFFECTING THE UPPER GREAT LAKES 00Z SAT AND THEN SLOWLY TAKES THE LOW EAST WITH THE LOW CROSSING NORTHERN LAKE MICHIGAN ON SAT. MORE SHORTWAVE ENERGY DROPS DOWN THE BACKSIDE OF THE TROUGH SAT NIGHT AND SUN AND HELPS KEEP THE CLOSED 500 MB LOW FROM MOVING TO FAR TO THE EAST OF THE LAKE SUPERIOR REGION. NAM SHOWS SOME WEAK 850-500 MB Q-VECTOR CONVERGENCE PASSING ACROSS THE CWA FRI NIGHT WITH AMPLE MOISTURE AND THEN THE CONVERGENCE STAYS OVER THE NORTH AND EASTERN CWA ON SAT. NAM SHOWING SOME ISENTROPIC LIFT ON I280K-I295K SURFACES AND MOISTURE FRI NIGHT WITH LIFT MOVING OUT SAT NIGHT. SYSTEM IS REALLY WRAPPED UP ON THE ISENTROPIC SURFACES. COLD AIR WILL COME IN SLOWLY FROM THE SW FOR FRI NIGHT AND PUT IN SOME SNOW MIX FOR THE WEST HALF. BEST MOISTURE IS GONE THEN...BUT COULD STILL SEE UP TO 2 INCHES OF SNOW IN A FEW SPOTS FOR FRI NIGHT ANYWAY. COLD AIR SLOWLY MOVES EAST ON SAT...BUT DOES NOT GET INTO THE FAR EASTERN CWA UNTIL SAT EVENING. MOISTURE IS STILL NOT THAT PLENTIFUL ON SAT...BUT COULD SEE ANOTHER 2 INCHES ACROSS THE WEST. LAKE EFFECT REALLY GETS GOING THEN AS IT IS COLD ENOUGH AT 850 MB TO ADD SOME LAKE MOISTURE INTO THE EQUATION AS WINDS TURN TO THE NORTH DURING THE DAY. OVERALL...BESIDES MOVING THE COLD AIR IN QUICKER AND CHANGING THE PCPN OVER TO SNOW QUICKER OVER THE WEST...DID NOT MAKE MANY CHANGES TO THE GOING FORECAST. IN THE EXTENDED...GFS...ECMWF AND CANADIAN ALL SHOW A 500 MB TROUGH AND LOW ACROSS THE UPPER GREAT LAKES 00Z MON WITH TROUGHING REMAINING THROUGH 00Z TUE WHILE RIDGING BUILDS INTO THE NORTHERN PLAINS. THE RIDGE THEN MOVES IN FOR 00Z WED WITH ANOTHER TROUGH THEN FOR THU AFFECTING THE NORTHERN PLAINS. WILL KEEP LAKE EFFECT PCPN IN THROUGH TUE MORNING...THEN GO DRY THROUGH THE REST OF THE EXTENDED PERIOD. TEMPERATURES LOOK TO STAY NEAR NORMAL. DID NOT MAKE ANY HUGE CHANGES TO THE EXTENDED AS GOING FORECAST LOOKED PRETTY GOOD. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... EVEN THOUGH SHOWERS WERE ENDING ACROSS CENTRAL UPPER MICHIGAN KEPT SOME IFR CIGS AT KSAW FOR A TIME...AS SE WINDS AND EXISTING MOISTURE HELP SUSTAIN LOWER CLOUDS. AT KCMX...WEAK EAST WINDS AND LEFTOVER MOISTURE SHOULD CONTINUE TO SUSTAIN VLIFR CONDITIONS UNTIL LATE TONIGHT WHEN WINDS VEER MORE TO THE SE. BROUGHT THE CONDITIONS BACK UP TO VFR LATE TONIGHT AND TOMORROW MORNING AT BOTH SITES...AS DRIER AIR MOVES IN BEFORE ADDITIONAL SHOWERS LATER IN THE DAY. CONDITIONS MAY DROP INTO THE MVFR RANGE FRI EVENING AS ADDITIONAL MOISTURE AND PCPN MOVES IN FROM THE SOUTH AHEAD OF THE SLOW MOVING MID LEVEL LOW. && .MARINE... SFC LOW OVER MN WILL SLOWLY DRIFT TO THE NE ACROSS THE UPPER GREAT LAKES THROUGH SATURDAY AFTN. EXPECT THE FEW NE GALE FORCE GUSTS NEAR THE ARROWHEAD OF MN TO DIMINISH THIS EVENING...BUT MAY SEE SOME GUSTS TO 30KTS EARLY AND SE GUSTS TO 30KTS ACROSS ERN SUPERIOR THROUGH THE NIGHT. AS THE LOW MOVES ACROSS THE AREA...WINDS SHOULD BE IN THE 15 TO 25 KNOTS RANGE...BEFORE STRENGTHENING ON THE BACK SIDE OF THE LOW. EXPECT GALE FORCE GUSTS ACROSS MOST OF LAKE SUPERIOR ON SAT AND SUN. THE LOW WILL EXIT THE REGION ON SUN...WITH HIGH PRESSURE MOVING OVER THE WRN GREAT LAKES FOR MON THROUGH THURS...KEEPING WINDS LESS THAN 25 KNOTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ SYNOPSIS...SRF SHORT TERM...SRF LONG TERM...GM AVIATION...JLA MARINE...SRF
AREA FORECAST DISCUSSION
NWS DULUTH MN
921 PM CST SAT NOV 8 2008 .DISCUSSION... SOUTH SHORE SNOWFALL WILL BE THE MAIN FOCUS OF THE FORECAST TONIGHT INTO SUNDAY. LAKE EFFECT SNOW SHOWERS CONTINUE ALONG THE SOUTH SHORE...ESPECIALLY OVER NORTHERN IRON COUNTY...WHICH HAS RECEIVED 2 TO 5 INCHES SO FAR. THE 5 INCH REPORT OCCURRED EARLIER THIS EVENING AND WAS FROM WHITECAP MOUNTAIN...WHICH IS WEST OF MONTREAL. A SPOTTER IN UPSON...ABOUT A MILE SOUTH OF WHITECAP MT. ONLY HAD AN INCH AT 8 PM...SO AMOUNTS ARE QUITE VARIABLE. INVERSION LEVELS EXPECTED TO INCREASE TONIGHT...WITH DELTA-T`S INCREASING TO NEAR 20C. LOW LEVEL FLOW IS FORECAST TO BACK OVERNIGHT...AND WE WILL GET INTO SOME SUBSIDENCE SUNDAY MORNING BEHIND THE SHORTWAVE DIVING TOWARD NORTHEAST MINNESOTA. THE BACKING FLOW MAY SHIFT THE SNOWBANDS A BIT FURTHER NORTHEAST AWAY FROM WHITECAP. WE`VE THOUGHT ABOUT UPGRADING THE ADVISORY TO A WARNING FOR IRON COUNTY...SINCE WE COULD GET ANOTHER 2-3 INCHES TONIGHT...AND ON SUNDAY. THIS IS A LONG EVENT...AND WILL SPAN OVER 24 HOURS...SO WE WILL STICK WITH AN ADVISORY AND INCREASE EXPECTED SNOWFALL UP SLIGHTLY. TOTAL SNOWFALL COULD REACH AROUND 8 INCHES BY SUNDAY EVENING. THE ADVISORY FOR BAYFIELD AND DOUGLAS COUNTIES IS MORE COMPLICATED. THE GRAVITY INDUCED SNOWBAND HAS ENDED ALTOGETHER THIS EVENING...LEAVING BEHIND 2 TO 3 INCHES. THE ADVISORY GOES UNTIL 6 AM...AND CONFIDENCE IN THE BAND REFORMING TONIGHT IS LOWER THAN AVERAGE. FORECAST SOUNDINGS AND TAMDAR SOUNDINGS AT KDLH AT 0050Z ARE NOT IN REAL GOOD AGREEMENT. TAMDAR SOUNDINGS SHOWING A MORE PRONOUNCED AND LOWER INVERSION...WHILE FORECAST SOUNDINGS NOT AS STRONG. FORECAST SOUNDINGS RAISE AND ERODE THE INVERSION...AND OBSERVATIONS SUPPORT THIS. INVERSION THEN REFORMS PER FORECAST SOUNDINGS LATE TONIGHT. CROSS SECTIONS SHOW OMEGA PARTIALLY IN THE DRIER AIR THIS EVENING...BUT LATE TONIGHT MOISTURE INCREASES IN BEST AREA OF OMEGA. MEAN LOW LEVEL FLOW REMAINS NEARLY CONSTANT THROUGH SUNDAY. WE WILL CONTINUE THE ADVISORY FOR DOUGLAS/BAYFIELD COUNTIES...BUT DELAY HIGHER POPS UNTIL LATE TONIGHT. WE WILL ALSO ONLY GO WITH AN ADDITIONAL INCH. IT`S POSSIBLE WE MAY HAVE TO EXTEND THE ADVISORY INTO SUNDAY...BUT THERE IS JUST TOO MANY QUESTIONS AND CONFIDENCE IS TOO LOW AT THIS TIME. THESE GRAVITY WAVE SNOWBANDS CAN BE DIFFICULT TO FORECAST. WE HAD A REPORT OF FREEZING DRIZZLE AROUND THE KBRD AREA THIS EVENING...AND HAVE A FEW OBSERVATIONS OF UNKNOWN PRECIP. WE LOOKED AT SOUNDINGS EARLIER...AND THOUGHT THE CHANCES WERE SLIM...BUT AGAIN...CAN`T ARGUE WITH OBSERVATIONS. WE ADDED PATCHY FZDZ TO OUR WESTERN ZONES TONIGHT. && POINT TEMPS/POPS... DLH 20 32 20 34 / 30 20 10 10 INL 18 31 17 33 / 10 10 10 0 BRD 21 32 18 36 / 10 10 10 10 HYR 22 32 18 34 / 40 20 10 10 ASX 23 33 22 34 / 90 40 30 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST SUNDAY FOR ASHLAND-IRON. WINTER WEATHER ADVISORY UNTIL 6 AM CST SUNDAY FOR BAYFIELD- DOUGLAS. LS...SMALL CRAFT ADVISORY UNTIL 6 PM CST SUNDAY FOR LSZ121-LSZ140- LSZ141-LSZ142-LSZ143-LSZ144-LSZ145-LSZ146-LSZ147-LSZ148. $$ MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
507 PM CST SAT NOV 8 2008 .UPDATE... GRAVITY WAVE INDUCED SNOW BAND HAS BEEN DIMINISHING FROM NORTHWEST TO SOUTHEAST EARLY THIS EVENING...AND RADAR SHOWED A TRANSITION FROM STRATI FORM LOOKING RETURNS UPSTREAM...TO MORE CONVECTIVE. NAM12 FORECAST SOUNDINGS SHOW INVERSION WEAKENING AND RISING THIS EVENING. HOWEVER...21Z TAMDAR SOUNDINGS FROM KHIB STILL SHOWED A DECENT INVERSION AROUND 870MB...BUT IT WAS WEAKER THAN A TAMDAR SOUNDING AT 2015Z AND IT OCCURRED JUST AS THE CONVECTIVE RETURNS WERE MOVING THROUGH. THE 2057Z SOUNDING WAS ALSO A BIT DRIER. A CROSS SECTION THROUGH THIS BAND REVEALS THE BEST OMEGA AT 00Z SUN WAS PARTIALLY IN THE DRIER AIR...BUT IT DOES COME BACK DOWN AND BECOME STRONGER BETWEEN 03Z AND 06Z. UNCERTAINTY EXISTS ON THE EVOLUTION OF THIS BAND FOR THE REST OF THE NIGHT. WE HAVE OMEGA IN THE MOIST LAYER INCREASING LATER THIS EVENING...WITH 1000-850MB MEAN WIND CONTINUING AROUND 20 OR 25KT. WE ALSO HAVE WEAKER INVERSION HEIGHTS...WHICH WOULD NOT BE AS SUPPORTIVE OF THE SNOW BAND. WE WILL CONTINUE TO MONITOR RADAR AND TAMDAR SOUNDINGS THROUGH THE EVENING...AND NOT MAKE ANY MAJOR CHANGES AT THIS TIME. SPOTTERS HAVE REPORTED 2 TO 3 INCHES OF SNOW DURING THE DAY TODAY...WITH MOST OF IT ON GRASSY SURFACES. ROAD TEMPERATURES ALONG HIGHWAY 2 IN THAT AREA HAVE BEEN A FEW DEGREES ABOVE FREEZING...BUT AS TEMPS FALL TONIGHT...THERE COULD BE SLICK SPOTS ON EVEN WELL TRAVELED ROADS. && .PREV DISCUSSION... /ISSUED 311 PM CST SAT NOV 8 2008/ DISCUSSION...MAIN FORECAST FOCUS IS LAKE EFFECT SNOW TONIGHT THROUGH SUNDAY. AFTERNOON SURFACE ANALYSIS SHOWS DLH FA IN TIGHT 11MB PRESSURE GRADIENT...RESULTING IN CONTINUED BREEZY AND GUST CONDITIONS. MAIN UPPER CURRENTLY ROTATING OVER THE CENTRAL GREAT LAKES PER LATEST WATER VAPOR LOOP. EVIDENCE OF GRAVITY WAVE INDUCED SNOW BAND STILL PRESENT ON THE RADAR THIS AFTERNOON AS WELL...WITH CONTINUED REDEVELOPMENT OF 20 TO 25 DBZ BANDS. REPORTS FROM LAW ENFORCEMENT AND OBSERVERS...AS WELL AS WEB CAMS INDICATE A LOT OF MELTING WITH THE SNOW ALONG THE SOUTH SHORE INTO NORTHWEST WISCONSIN. SOME SIDE ROADS ARE SLICK...AND GRASSY AREAS HAVE SEEN ANYWHERE FROM A TRACE UP TO 3 INCHES THUS FAR. CROSS SECTIONS ACROSS THE HEAD OF THE LAKE CONTINUE TO SHOW OMEGA RESPONSE ALONG WITH SUFFICIENT RH TO SUPPORT THE GRAVITY WAVE SNOW THROUGH EARLY MORNING...BEFORE DRIER AIR ADVECTS INTO THE REGION. THEREFORE HAVE EXPANDED THE ADVISORY TO THE ENTIRE SOUTH SHORE FOR TONIGHT. LAKE EFFECT SNOW ALONG THE GOGEBIC RANGE AND SNOW BELT OF NORTHERN WISCONSIN SHOULD INCREASE IN INTENSITY TONIGHT...WITH CONTINUED CAA AND AS SECONDARY LOW CURRENTLY OVER NORTHWEST ONTARIO DIVES SOUTHWARD OVER THE FA. FORECAST SOUNDINGS SHOW CONTINUE FAVORABLE FETCH...AND INCREASING LAKE INDUCED LOW LEVEL CAPE WITH RISING INVERSION HEIGHTS. WITH DELTA T`S...FETCH...AND INVERSION HEIGHTS REMAINING FAVORABLE THROUGH TOMORROW...HAVE ALSO EXTENDED ADVISORY THROUGH 00Z MONDAY. TEMPERATURES WILL CONTINUE TO COOL AS WELL...ALLOWING FOR SNOW ACCUMULATION OVERNIGHT AND THROUGH SUNDAY. MODELS IN GOOD AGREEMENT...WITH THE SLOW EXIT OF THE SYSTEM...AS THE LOW DUMBBELL ENEWRD. SHOULD SEE SOME LINGERING SNOW SHOWERS INTO SUNDAY NIGHT...THEN DRYING OUT COMPLETELY ON MONDAY. TEMPERATURES WILL ALSO MODERATE A BIT THROUGH MID WEEK AS UPPER RIDGE BUILDS OVERHEAD. EXTENDED...WED THRU FRIDAY...ALTHOUGH EC/GFS/CMC AGREE THAT A MID LVL TROF WILL SWING THROUGH WEDNESDAY...TIMING/STRENGTH DIFFERENCES OF SYNOPTIC SCALE LIFT ARE SIGNIFICANT. WILL LEAVE FCST DRY FOR NOW ALTHOUGH SUSPECT THAT LATER MDLS OUTPUT MAY WARRANT INTRO TO POPS. MAIN STORY THUR/FRI IS NWRLY FLOW WITH GFS MORE AGGRESSIVE ON AMPLIFICATION OF MID LVL FEATURES...TROF/COLD AIR...SINCE OPS GFS SEEMS A BIT OVERDONE ON AMPLIFYING TROF COMPARED TO ITS GEFS MEMBERS...WILL LEAN WITH A BLEND OF GFS/EC. THERMAL PROFILES SUGGEST RASN MIX THROUGH THURSDAY...THEN MORE SNOW THAN RAIN BY FRIDAY. MAY SEE ANOTHER ROUND OF LES LATE FRIDAY/SATURDAY AS SYNOPTIC BACKGROUND FAVORS NWRLY BDRY LYR TRAJECTORY/LL CAA/DEEP LAYER MOISTURE. AVIATION...INTENSE VERTICALLY STACKED LOW PRESSURE SYSTEM OVER ERN ONTARIO HAS DOMINATED REGION TODAY. DEEP LAYERED CYCLONIC CIRCULATION IS MAINTAINING A HUGE STRATUS DECK WITH PRIMARILY MVFR BASES. USING LATEST SREF PROBABILITY OF 3K FT CEILINGS AND LATEST VISIBLE SATELLITE/SFC OB TRENDS...WILL KEEP MVFR THROUGH MOST OF NIGHT EXCEPT BRD/HYR WHERE SOME CLEARING MAY DEVELOP LATE TONIGHT/EARLY SUNDAY. SNSH EXPECTED TO INCREASE AGAIN TONIGHT NEAR INL/HIB AS SECONDARY UPPER DISTURBANCE MOVES INTO REGION...AND THEN HYR FROM 12Z-18Z SUNDAY.LOCALIZED IFR IN LAKE EFFECT SNOW OVER INTERIOR ERN WI ZONES TONIGHT. && POINT TEMPS/POPS... DLH 20 32 20 34 / 30 20 10 10 INL 18 31 17 33 / 20 10 10 0 BRD 21 32 18 36 / 10 10 10 10 HYR 22 32 18 34 / 50 20 10 10 ASX 23 33 22 34 / 90 40 30 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST SUNDAY FOR ASHLAND-IRON. WINTER WEATHER ADVISORY UNTIL 6 AM CST SUNDAY FOR BAYFIELD- DOUGLAS. LS...SMALL CRAFT ADVISORY UNTIL 6 PM CST SUNDAY FOR LSZ121-LSZ140- LSZ141-LSZ142-LSZ143-LSZ144-LSZ145-LSZ146-LSZ147-LSZ148. $$ MELDE/LILES/CANNON
AREA FORECAST DISCUSSION...UPDATED
NWS SALT LAKE CITY UT
1007 PM MST THU NOV 6 2008 .SYNOPSIS..HIGH PRESSURE ALOFT OVER THE GREAT BASIN WILL YIELD TO THE NEXT PACIFIC STORM LATE IN THE WEEKEND. COOL AND UNSETTLED WEATHER WILL LINGER THROUGH THE EARLY PORTION OF NEXT WEEK. && .DISCUSSION...WATER VAPOR LOOP SHOWS A BROAD UPPER LOW SLOWLY LIFTING OVER THE UPPER PLAINS AND UPPER MIDWEST...WITH RIDGING BUILDING OVER THE WEST COAST IN ITS WAKE. VIGOROUS WAVES WERE LOCATED OVER THE GULF OF ALASKA AND NEAR 40N/150W. ACARS 400-250MB WIND OBSERVATIONS REVEAL A 100-120KT ANTICYCLONICALLY CURVED JET FROM SOUTHWEST CANADA SOUTH OVER THE ROCKIES. 700MB ANALYSIS PLACED A RIDGE FROM CENTRAL CALIFORNIA NORTHEAST TOWARD LAKE WINNIPEG. A DEEP CYCLONE WAS LOCATED OVER NORTHEAST SOUTH DAKOTA...WITH A STRONG HEIGHT GRADIENT PLACED JUST EAST OF THE ROCKIES. 00Z KSLC RAOB INDICATES +10C OF WARMING BETWEEN 650-500MB DURING THE PAST 24 HOURS. MID LEVEL MOISTURE HAS BEEN INVADING AROUND THE RIDGE...ALLOWING MOSTLY CLOUDY CONDITIONS TO DEVELOP ACROSS NORTHERN UTAH. THIS SHOULD KEEP TEMPERATURES FROM DROPPING AS COLD AS LAST NIGHT ACROSS THE WASATCH FRONT. FRESH SNOWPACK IN THE MOUNTAINS WILL SUPPORT TEMPERATURES IN THE TEENS...PERHAPS A FEW REPORTS IN THE SINGLE DIGITS. A WIND ADVISORY IS IN EFFECT FOR THE GAPS OF WASHINGTON COUNTY. BEST COLD ADVECTION/PRESSURE GRADIENT IS IN PLACE THIS EVENING...DIMINISHING OVERNIGHT. WIND GUSTS AT BADGER SPRING AND WHITE REEF HAVE INCREASED ABOVE 30 MPH...SO HAVE LEFT THE ADVISORY IN PLACE. OTHERWISE INCREASED CLOUD COVER AND LOW TEMPERATURES ACROSS THE NORTHERN AND WEST CENTRAL ZONES. THE NEXT TROUGH TO AFFECT THE REGION IS EXPECTED TO MOVE ONSHORE ALONG THE PACIFIC NORTHWEST COAST SATURDAY BEFORE MOVING THROUGH THE FORECAST AREA ON SUNDAY. LATEST GFS IS A LITTLE SLOWER WITH THE INITIAL ARRIVAL OF PRECIP THAN PREVIOUS RUNS...AND IN THE NEW SOLUTION IT DOES NOT ARRIVE UNTIL SUNDAY MORNING. THE NEW RUN IS ALSO FARTHER NORTH WITH THE TROUGH...CONTINUING THE TREND OF THE PREVIOUS SOLUTIONS...AND NOW IT IS SIGNIFICANTLY FARTHER NORTH THAN THE ECMWF. IN FACT...IT NOW BRINGS THE STORMS COLD POOL OVER NORTHERN UTAH SUNDAY EVENING. ENSEMBLE SPREAD REMAINS CONSIDERABLE WITH RESPECT TO THE LOCATION OF THE TROUGH...AND THE 00Z GFS IS NOTICEABLY TO THE NORTH OF THE MEAN. GFS ALSO REMAINS MORE PROGRESSIVE THAN THE ECMWF. DESPITE THE CONTINUED PROGRESSIVE TREND OF THE GFS...THE SLOWER EC SOLUTION IS PREFERRED GIVEN THE OVERALL PATTERN. && .AVIATION...CEILINGS AT THE SLC TERMINAL WILL REMAIN PRIMARILY BELOW 7000 AGL THROUGH 18Z FRIDAY. TEMPORARY BREAKS MAY OCCUR BUT SHOULD NOT LAST MORE THAN 30 MIN AT A TIME. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...WIND ADVISORY UNTIL 9 AM FRIDAY FOR UTZ019. WY...NONE. && $$ PUBLIC...ROGOWSKI/TRAPHAGAN AVIATION...STRUTHWOLF FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
344 AM CST SUN NOV 9 2008 .DISCUSSION... COLD CYCLONIC FLOW COVERS THE REGION EARLY THIS MORNING. AN UPPER LOW IS DROPPING SOUTH ACROSS LAKE SUPERIOR AND WILL ADVANCE TO MI DURING THE DAY. STRONG PV ANOMALY WITH 100M 12 HOUR HEIGHT FALLS PASSING ACROSS WI TODAY. WILL MENTION FLURRIES MOST AREAS THROUGH THE DAY WITH HIGHS ONLY IN THE LOWER TO MIDDLE 30S. THE 00Z NAM/GFS LOW LEVEL MODEL RH A DISASTER WITH NO SIGNS OF THE EXTENSIVE LOW CEILINGS THAT STRETCH FROM THE GREAT LAKES TO THE WESTERN DAKOTAS. THE LAYER IS SHALLOW PER ACARS DATA FROM KMSP. HOWEVER...THE WESTERN EDGE LIES CLOSE TO THE 850 MB RIDGE AXIS AND THIS ONLY SHIFTS TO THE EASTERN DAKOTAS BY EVENING AS CYCLONIC FLOW PREVAILS OVERHEAD. THEREFORE...SHOWED LITTLE IMPROVEMENT WITH THE SKY CONDITION TODAY AND WAS SLOW TO DECREASE CLOUDS OVER THE NE CWA TONIGHT WITH THE LOW LEVEL FLOW STILL COMING DOWN FROM THE NORTH. IMPROVEMENT SHOULD OCCUR ON MONDAY AS THE UPPER LOW MOVES INTO QUEBEC AND THE FLOW ALOFT BECOME MORE ZONAL. THE NEXT PROBLEM ON THE HORIZON IS THE UPPER LOW MOVING SE ACROSS CA THIS MORNING. THIS FEATURE IS PROGGED TO PASS THROUGH THE 4 CORNERS ON MONDAY AND THEN HEAD NORTHEAST INTO IA/MO ON TUESDAY ACCORDING TO THE NAM AND GFS. THE LAST TWO 00Z ECMWF RUNS SHOW A SIMILAR MOVEMENT UNTIL TUESDAY WHEN IT OPENS THE UPPER LOW AND LIFTS IT ACROSS THE CWA TUESDAY NIGHT AND WEDNESDAY WITH PRECIPITATION INDICATED. OFFICES TO OUR SOUTH NOT BUYING THE NORTHERN TRACK AND STAYING DRY. EVEN THE 00Z CANADIAN IS BRINGING PRECIPITATION INTO SOUTHERN MN ON TUESDAY. WILL KEEP THINGS DRY FOR NOW TO PREVENT A POTENTIAL FLIP-FLOP AS WELL AS BRINING ON COLLABORATION PROBLEMS. ONE AREA WHERE A CHANGE WAS MADE WAS ON THURSDAY. BOTH THE ECMWF AND GFS AGREE ON PRECIPITATION BUT THEY ARE DOING IT BY DIFFERENT MEANS. ADDED SMALL POPS DURING THE DAY ON THURSDAY WHICH BLENDED WELL INTO THE PRECIPITATION CHANCES ALREADY FORECAST FOR THURSDAY NIGHT. THE END OF THE WEEK/WEEKEND IS A REAL MESS ON THE GFS WITH A LARGE UPPER LOW SETTLING SOUTH OVER THE AREA WITH A LONG DURATION PRECIPITATION EVENT. THE ECMWF ON THE OTHER HAND CONTINUES THE TREND OF THE PAST FEW NIGHTS ON DRIVING A PACIFIC COLD FRONT THROUGH ON FRIDAY AND A CANADIAN COLD FRONT THROUGH ON SATURDAY. IT WOULD BE WINDY AND COLD WITH SOME SNOW...BUT NOT TO THE DEGREE AS ADVERTISED BY THE GFS. CURRENT GRIDS MORE IN LINE WITH THE ECMWF. && .AVIATION... /06Z TAF ISSUANCE/ SFC OBS AND 11-3.9 SATELLITE IMAGERY INDICATE LARGE AREA OF MVFR CLOUDINESS ACROSS ALL OF MN...ERN DAKOTAS...WISC AND INTO CANADA. ONLY THE RUC CATCHES ON TO THIS IN THE 950-875 MB LAYER. UNFORTUNATELY NONE OF THIS IS NOTED BY ANY OTHER MODEL. MAY EVEN HAVE TO DUST OFF THE OLD MSP PROG. HOWEVER... MODELS ARE IN AGREEMENT ON LOW LEVEL TRAJECTORIES REMAINING CYCLONIC THROUGH SUNDAY EVENING IN WISC AND ERN MN. SOME HINT OF THIS INTO WRN MN. THIS SUGGESTS KEEPING MVFR INTO MID AFTERNOON AT ALL SITES. FOR NOW WILL SCATTER OUT AXN AND RWF LATER SUNDAY AFTERNOON AND KEEP OTHER SITES WITH MVFR CIGS INTO SUNDAY EVENING. ENHANCED LIFT NOW EVIDENT INTO NERN MN PER SATELLITE SHOULD REACH RNH AND EAU SUNDAY MID MORNING AND MAY CLIP MSP...THIS IS NOTED ON THE NAM AND GFS. HAVE INDICATED SHSN BUT NO VSBY RESTRICTION. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ RAH/TDK
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
400 AM PST SUN NOV 9 2008 .SYNOPSIS...AN UPPER LOW WILL MOVE THROUGH TODAY BRINGING SCATTERED SHOWERS. MUCH COOLER TODAY. LOCAL STRONG GUSTY WINDS...ESPECIALLY IN THE MOUNTAINS AND DESERTS TODAY. COOL WEATHER WILL CONTINUE MONDAY WITH DECREASING CLOUDINESS IN DRY NORTHWEST FLOW. BUILDING HIGH PRESSURE AND OFFSHORE FLOW WILL BRING CLEAR SKIES AND MUCH WARMER WEATHER DURING THE SECOND HALF OF THE WEEK. && .DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO... ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES. .SHORT TERM (TODAY-TUE)...THERE WAS A MIX OF CLOUDS AT MULTIPLE LEVELS AND SCATTERED SHOWERS THIS MORNING. ACARS SOUNDINGS SHOWED INCREASING W TO NW WINDS ALOFT. ONSHORE GRADIENTS AND TRENDS WITH ABOUT 5 MB SAN-IPL AND 11 MB SAN-TPH. A VIGOROUS UPPER LOW WILL MOVE THROUGH TODAY WITH STRONG PVA THIS MORNING AND A JET MAX JUST TO OUR N. THIS WILL BRING SCATTERED SHOWERS...MAINLY OVER AND W OF THE MOUNTAINS WITH MOISTURE MAINLY LIMITED TO A MARINE LAYER RAPIDLY DEEPENING TO 4000-5000 FEET DEEP. A FEW SHOWERS COULD GET INTO THE HIGH DESERTS BUT PROBABLY NOT THE LOWER DESERTS. THE CHANCE OF SHOWERS WILL DROP OFF QUICKLY THIS AFTERNOON AS THE LOW MOVES E. THE BRIEF PERIOD THAT WILL BE FAVORABLE FOR PRECIP AND LIMITED MOISTURE WILL KEEP PRECIP ACCUMULATIONS LESS THAN A QUARTER INCH AND MOST WILL BE LESS THAN A TENTH OF AN INCH. THE STRONG WINDS ALOFT AND ONSHORE GRADIENTS WILL CAUSE LOCAL STRONG GUSTY WINDS. THE STRONGEST WINDS WILL BE IN THE MOUNTAINS AND DESERTS WHERE THERE COULD BE GUSTS NEAR 50 MPH AND POSSIBLY STRONGER IN THE HIGH DESERTS AND ACROSS THE RIDGETOPS LATE THIS MORNING THROUGH THE AFTERNOON. THERE WILL ALSO BE STRONG WINDS IN THE COASTAL WATERS. LINGERING LOW LEVEL MOISTURE W OF THE MOUNTAINS AND HIGH CLOUDS WILL CAUSE VARIABLE BUT GENERALLY DECREASING CLOUDINESS THROUGH TUE. MUCH COOLER TODAY THEN JUST SLIGHT WARMING MON AS HEIGHTS SLOWLY INCREASE IN NW FLOW. WARMER TUE AS STRONG UPPER LEVEL HIGH PRESSURE IN THE ERN PAC SLOWLY MOVES TOWARD THE W COAST. && .LONG TERM (WED-SAT)...THE HIGH ALOFT AND OFFSHORE FLOW WILL BRING CLEAR SKIES WITH WARM AND DRY WEATHER. LOCAL GUSTY WINDS THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES AT TIMES. && .AVIATION... 090900Z...FAST MOVING SYSTEM WILL MOVE THROUGH TODAY WITH THE MARINE LAYER INCREASING QUICKLY TO ABOUT 5000 FEET BY THIS MORNING. BASES AROUND 1500 TO 2K FT MSL EARLY THIS MORNING...BECOMING 3-4K FT LATER THIS MORNING. LOCAL SHOWERS POSSIBLE TODAY...MAINLY THIS MORNING. MOSTLY CLOUDY THIS MORNING WITH AREAS OF BROKEN CLOUDS EXPECTED TO REMAIN THIS AFTERNOON IN THE COASTAL BASIN AND CONTINUE THROUGH MONDAY...BECOMING MOSTLY CLEAR MONDAY AFTERNOON. STRONG GUSTY SOUTHWEST TO WEST WINDS OVER THE MOUNTAINS AND DESERTS TODAY INTO THIS EVENING. && .MARINE... 090900Z...INCREASING WINDS TODAY WITH POSSIBLY GALE FORCE WINDS IN THE OUTER WATERS AND SMALL CRAFT HAZARDOUS SEAS IN THE INNER WATERS. WINDS WILL DECREASE TONIGHT. AN INCREASING NORTHWEST SWELL IS EXPECTED TODAY THROUGH MONDAY. THE SWELL ALONG WITH WIND WAVES MAY APPROACH 10 FT IN THE INNER WATERS TODAY. LARGE SURF POSSIBLE IF THE SWELL IS NOT TOO STEEP WITH HIGH A SURF ADVISORY FOR SAN DIEGO COUNTY. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...WIND ADVISORY FOR THE MOUNTAINS AND DESERTS...SEE LAXNPWSGX. HIGH SURF ADVISORY UNTIL 2 PM PST MONDAY FOR SAN DIEGO COUNTY COASTAL AREAS. SEE LAXCFWSGX. PZ...GALE WARNING FROM 4 AM TO 4 PM PST SUNDAY FOR WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING 30 TO 60 NM OUT INCLUDING SAN CLEMENTE ISLAND. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 4 PM SUNDAY TO 4 AM PST MONDAY FOR COASTAL WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER AND OUT 30 NM-WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING 30 TO 60 NM OUT INCLUDING SAN CLEMENTE ISLAND. SEE LAXMWWSGX. && $$ PUBLIC...ATKIN AVIATION/MARINE...WHITLOW
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
330 AM PST SUN NOV 9 2008 .SYNOPSIS...AN UPPER LOW WILL MOVE THROUGH TODAY BRINGING SCATTERED SHOWERS WEST OF THE MOUNTAINS. MUCH COOLER TODAY. LOCAL STRONG GUSTY WINDS IN THE MOUNTAINS AND DESERTS TODAY. COOL WEATHER WILL CONTINUE MONDAY WITH DECREASING CLOUDINESS IN DRY NORTHWEST FLOW. BUILDING HIGH PRESSURE AND OFFSHORE FLOW WILL BRING CLEAR SKIES AND MUCH WARMER WEATHER DURING THE SECOND HALF OF THE WEEK. && .DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO... ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES. .SHORT TERM (TODAY-TUE)...THERE WERE AREAS OF LOW CLOUDS AND LIGHT SHOWERS W OF THE MOUNTAINS AND VARIABLE HIGH CLOUDINESS EARLY THIS MORNING. ACARS SOUNDINGS SHOWED INCREASING W TO NW WINDS ALOFT. ONSHORE GRADIENTS AND TRENDS WITH ABOUT 5 MB SAN-IPL AND 11 MB SAN-TPH. A VIGOROUS UPPER LOW WILL MOVE THROUGH TODAY WITH STRONG PVA THIS MORNING AND A JET MAX JUST TO OUR N. THIS WILL BRING SCATTERED SHOWERS OVER AND W OF THE MOUNTAINS WITH MOISTURE MAINLY LIMITED TO A MARINE LAYER RAPIDLY DEEPENING TO 4000-5000 FEET DEEP. THE CHANCE OF SHOWERS WILL DROP OFF QUICKLY THIS AFTERNOON AS THE LOW MOVES E. THE BRIEF PERIOD THAT WILL BE FAVORABLE FOR PRECIP AND LIMITED MOISTURE WILL KEEP PRECIP ACCUMULATIONS LESS THAN A QUARTER INCH AND MOST WILL BE LESS THAN A TENTH OF AN INCH. THE STRONG WINDS ALOFT AND ONSHORE GRADIENTS WILL CAUSE LOCAL STRONG GUSTY WINDS. THE STRONGEST WINDS WILL BE IN THE MOUNTAINS AND DESERTS WHERE THERE COULD BE GUSTS NEAR 50 MPH AND POSSIBLY STRONGER IN THE HIGH DESERTS AND ACROSS THE RIDGETOPS LATE THIS MORNING THROUGH THE AFTERNOON. THERE WILL ALSO BE STRONG WINDS IN THE COASTAL WATERS. LINGERING LOW LEVEL MOISTURE W OF THE MOUNTAINS AND HIGH CLOUDS WILL CAUSE VARIABLE BUT GENERALLY DECREASING CLOUDINESS THROUGH TUE. MUCH COOLER TODAY THEN JUST SLIGHT WARMING MON AS HEIGHTS SLOWLY INCREASE IN NW FLOW. WARMER TUE AS STRONG UPPER LEVEL HIGH PRESSURE IN THE ERN PAC SLOWLY MOVES TOWARD THE W COAST. && .LONG TERM (WED-SAT)...THE HIGH ALOFT AND OFFSHORE FLOW WILL BRING CLEAR SKIES WITH WARM AND DRY WEATHER. LOCAL GUSTY WINDS THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES AT TIMES. && .AVIATION... 090900Z...FAST MOVING SYSTEM WILL MOVE THROUGH TODAY WITH THE MARINE LAYER INCREASING QUICKLY TO ABOUT 5000 FEET BY THIS MORNING. BASES AROUND 1500 TO 2K FT MSL EARLY THIS MORNING...BECOMING 3-4K FT LATER THIS MORNING. LOCAL SHOWERS POSSIBLE TODAY...MAINLY THIS MORNING. MOSTLY CLOUDY THIS MORNING WITH AREAS OF BROKEN CLOUDS EXPECTED TO REMAIN THIS AFTERNOON IN THE COASTAL BASIN AND CONTINUE THROUGH MONDAY...BECOMING MOSTLY CLEAR MONDAY AFTERNOON. STRONG GUSTY SOUTHWEST TO WEST WINDS OVER THE MOUNTAINS AND DESERTS TODAY INTO THIS EVENING. && .MARINE... 090900Z...INCREASING WINDS TODAY WITH POSSIBLY GALE FORCE WINDS IN THE OUTER WATERS AND SMALL CRAFT HAZARDOUS SEAS IN THE INNER WATERS. WINDS WILL DECREASE TONIGHT. AN INCREASING NORTHWEST SWELL IS EXPECTED TODAY THROUGH MONDAY. THE SWELL ALONG WITH WIND WAVES MAY APPROACH 10 FT IN THE INNER WATERS TODAY. LARGE SURF POSSIBLE IF THE SWELL IS NOT TOO STEEP WITH HIGH A SURF ADVISORY FOR SAN DIEGO COUNTY. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...WIND ADVISORY FOR THE MOUNTAINS AND DESERTS...SEE LAXNPWSGX. HIGH SURF ADVISORY UNTIL 2 PM PST MONDAY FOR SAN DIEGO COUNTY COASTAL AREAS. SEE LAXCFWSGX. PZ...GALE WARNING FROM 4 AM TO 4 PM PST SUNDAY FOR WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING 30 TO 60 NM OUT INCLUDING SAN CLEMENTE ISLAND. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 4 PM SUNDAY TO 4 AM PST MONDAY FOR COASTAL WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER AND OUT 30 NM-WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING 30 TO 60 NM OUT INCLUDING SAN CLEMENTE ISLAND. SEE LAXMWWSGX. && $$ PUBLIC...ATKIN AVIATION/MARINE...WHITLOW
THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS...

/TODAY THROUGH TUESDAY/ THE MODELS ALL AGREE THAT AN AREA OF LOW PRESSURE AND ITS ASSOCIATED WEATHER...WILL MOVE OUT OF THE CENTRAL PLAINS ON TUESDAY. AS IT DOES...A WARM FRONT WILL APPROACH THE AREA FROM THE SOUTHWEST ON TUESDAY MORNING...BRINGING AN AREA OF RAIN SHOWERS WITH IT. THE LATEST MODEL GUIDANCE SUGGESTS THAT SOUTHEAST FLOW WILL SET UP ACROSS THE MOUNTAINS ALONG THE VIRGINIA BORDER AS THE LOW BECOMES BETTER ORGANIZED AND MOVES ACROSS THE OHIO VALLEY. THIS SCENARIO TYPICALLY LEADS TO DOWNSLOPE WARMING AND THUS DRYING OF WHATEVER AIR MASS IS IN PLACE ACROSS EASTERN KENTUCKY. THIS PATTERN IS FURTHER SUPPORTED BY THE GFS AND NAM12 MODEL SOUNDINGS AND TIME HEIGHT CROSS SECTIONS...AS THE LOWEST LEVELS OF THE ATMOSPHERE REMAIN DRY...WITH SATURATION OCCURRING FROM THE 700HPA LEVEL ON DOWNWARD. THE MODELS ALSO ARE NOW NOT BRINGING ANY QPF INTO THE FORECAST AREA UNTIL AT LEAST 12Z TUESDAY. THE LATEST HPC QPF FORECAST IS EVEN MORE PESSIMISTIC...BRINGING BARELY ANY PRECIP AT ALL INTO EASTERN KENTUCKY BY 18Z TUESDAY. WITH ALL THIS IN MIND...DECIDED TO DELAY ONSET OF PRECIPITATION UNTIL AFTER 9Z ON TUESDAY...AS ISENTROPIC LIFT OCCURS ALONG THE APPROACHING WARM FRONT...AND TO LOWER PRECIP CHANCES...AT LEAST UNTIL A MORE FAVORABLE SYNOPTIC PATTERN STARTS SHOWING UP IN THE MODELS. BASED ON THE MODIFIED TIMING OF PRECIP ONSET...IT APPEARS NOW THAT BY THE TIME ANY PRECIPITATION IS ABLE TO OVERSPREAD THE FORECAST AREA...THAT TEMPERATURES WILL BE WARM ENOUGH FOR THE PRECIP TO BE ENTIRELY LIQUID. AS THE WARM FRONT MOVES NORTH ACROSS THE AREA...TEMPERATURES WILL WARM STEADILY. THE MAVMOS DATA FROM THE PAST FEW RUNS SEEM TO HAVE THE BEST HANDLE ON TEMPERATURES...SO WENT WITH THE MAVMOS FOR THE TEMP FORECAST...GOING A COUPLE OF DEGREES COOLER THAN THE MAV FOR DAYTIME HIGHS...AND SLIGHTLY WARMER FOR OVERNIGHT LOWS...ACCOUNTING IN BOTH CASES FOR THE EXTENSIVE CLOUD COVER EXPECTED. WINDS WERE ALSO MODIFIED TO REFLECT THE CHANGE IN TIMING OF THE WARM FRONT THAT WILL BE MOVING ACROSS THE AREA ON TUESDAY. DEWPOINTS NEEDED A LITTLE TWEAKING AS WELL...BUT NOTHING MAJOR WAS REQUIRED. .LONG TERM.../TUESDAY NIGHT THROUGH SATURDAY/ THE MODELS START IN PRETTY GOOD AGREEMENT ON MONDAY WITH THE UPPER LOW WHICH HAS BEEN OVER THE GREAT LAKES STARTING TO MOVE OUT TO THE NORTHEAST. ON MONDAY WE START OUT WITH AN UPPER RIDGE EXTENDING FROM ARKANSAS TO THE BLACK HILLS AND THEN NORTHWARD INTO MANITOBA. THE BIG QUESTION ON THE EXTENDED IS THE MOVEMENT OF AN UPPER LOW FROM OVER THE GREAT BASIN TO THE GREAT PLAINS. ON TUESDAY...THE POSITION OF THE UPPER LOW PRETTY MUCH SETS UP A SPLIT FLOW REGIME WITH PART OF THE ENERGY EXTENDING ACROSS THE NORTHERN TIER AND ANOTHER BRANCH OF THE POLAR JET EXTENDING AROUND THE LOW. AFTER TUESDAY...THE MODEL DISAGREEMENT STARTS TO GROW. EVEN THOUGH THE GENERAL PATTERN IS THE SAME...THE DEPTH AND POSITIONS OF THE UPPER TROUGHS ARE SIGNIFICANT ENOUGH THAT IT WILL WRECK HAVOC WITH THE FORECAST. THIS IS NOT TOO UNCOMMON WHEN UPPER RIDGES ARE BEING ASSAULTED BY THE APPROACHING TROUGHS. WITH THAT SAID...THE CONFIDENCE THAT WE ARE GOING INTO AN UNSETTLED PATTER IS HIGH...HOWEVER THE TIMING AND THE DETAILS OF THE FORECAST ARE FAIRLY LOW. THE FIRST PRECIPITATION IS EXPECTED FROM MONDAY NIGHT INTO TUESDAY AS A WARM FRONT APPROACHES THE AREA. THE TRICKY PART OF THE FORECAST IS GOING TO BE THE PRECIPITATION TYPE. IT SHOULD BE COOL ENOUGH ALOFT SO THAT PARTS OF THE AREA WILL SEE A MIX OF RAIN AND SNOW SHOWERS... HOWEVER IT SHOULD BE WARM ENOUGH SO THAT LITTLE OR NO ACCUMULATION IS EXPECTED. A COLD FRONT WILL TRY TO MAKE A PUSH TO THE WEST AND WILL HAVE SOME TOUGH GOING. SOME OF THE MODELS ARE ACTUALLY HAVE TWO FRONTS WHICH MERGE INTO ONE AS IT PUSHES TOWARDS KENTUCKY. THE MAIN FRONT WILL FINALLY PUSH THROUGH THE AREA ON THURSDAY AND WILL BRING WITH IT SOME MUCH COOLER AIR. WENT WITH A BLEND OF THE NCEP FORECAST AND MOS FOR THE TEMPS. THESE TEMPS COULD BE QUITE A BIT OFF DEPENDING ON THE TIMING OF THE UPPER TROUGH AND HOW DEEP IT IS WHEN IT PASSES. && .AVIATION.../12Z TO 12Z/ MODELS CONTINUE TRYING TO MOISTEN LOWER LEVELS ENOUGH TO PRODUCE A WIDESPREAD MVFR CIG OVER EAST KY THIS MORNING. THERE HAS BEEN A HINT OF SOME OF THAT FORMING AT JKL WHILE ANY WIDESPREAD STRATUS THAT LOW IS STILL CONFINED TO AREAS NEAR AND NORTHWEST OF THE OHIO RIVER. MOS GUIDANCE HAS BEEN INDICATING THAT TAF SITES WOULD NOT REACH MVFR FOR CIGS AND HAVE SIDED WITH THAT CAMP UNTIL CIGS GET A LITTLE MORE SERIOUS ABOUT LOWERING. BELIEVE THE BEST CHANCE OF AT LEAST BRIEF CIGS IN MVFR CATEGORY IS LATER THIS MORNING BUT ONLY INCLUDED A TEMPO GROUP AT JKL AND NOT LOZ/SME. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...AR/WJM LONG TERM....JJ AVIATION...GV
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
510 AM CST SUN NOV 9 2008 .UPDATED FOR AVIATION DISCUSSION BELOW... .DISCUSSION... COLD CYCLONIC FLOW COVERS THE REGION EARLY THIS MORNING. AN UPPER LOW IS DROPPING SOUTH ACROSS LAKE SUPERIOR AND WILL ADVANCE TO MI DURING THE DAY. STRONG PV ANOMALY WITH 100M 12 HOUR HEIGHT FALLS PASSING ACROSS WI TODAY. WILL MENTION FLURRIES MOST AREAS THROUGH THE DAY WITH HIGHS ONLY IN THE LOWER TO MIDDLE 30S. THE 00Z NAM/GFS LOW LEVEL MODEL RH A DISASTER WITH NO SIGNS OF THE EXTENSIVE LOW CEILINGS THAT STRETCH FROM THE GREAT LAKES TO THE WESTERN DAKOTAS. THE LAYER IS SHALLOW PER ACARS DATA FROM KMSP. HOWEVER...THE WESTERN EDGE LIES CLOSE TO THE 850 MB RIDGE AXIS AND THIS ONLY SHIFTS TO THE EASTERN DAKOTAS BY EVENING AS CYCLONIC FLOW PREVAILS OVERHEAD. THEREFORE...SHOWED LITTLE IMPROVEMENT WITH THE SKY CONDITION TODAY AND WAS SLOW TO DECREASE CLOUDS OVER THE NE CWA TONIGHT WITH THE LOW LEVEL FLOW STILL COMING DOWN FROM THE NORTH. IMPROVEMENT SHOULD OCCUR ON MONDAY AS THE UPPER LOW MOVES INTO QUEBEC AND THE FLOW ALOFT BECOME MORE ZONAL. THE NEXT PROBLEM ON THE HORIZON IS THE UPPER LOW MOVING SE ACROSS CA THIS MORNING. THIS FEATURE IS PROGGED TO PASS THROUGH THE 4 CORNERS ON MONDAY AND THEN HEAD NORTHEAST INTO IA/MO ON TUESDAY ACCORDING TO THE NAM AND GFS. THE LAST TWO 00Z ECMWF RUNS SHOW A SIMILAR MOVEMENT UNTIL TUESDAY WHEN IT OPENS THE UPPER LOW AND LIFTS IT ACROSS THE CWA TUESDAY NIGHT AND WEDNESDAY WITH PRECIPITATION INDICATED. OFFICES TO OUR SOUTH NOT BUYING THE NORTHERN TRACK AND STAYING DRY. EVEN THE 00Z CANADIAN IS BRINGING PRECIPITATION INTO SOUTHERN MN ON TUESDAY. WILL KEEP THINGS DRY FOR NOW TO PREVENT A POTENTIAL FLIP-FLOP AS WELL AS BRINING ON COLLABORATION PROBLEMS. ONE AREA WHERE A CHANGE WAS MADE WAS ON THURSDAY. BOTH THE ECMWF AND GFS AGREE ON PRECIPITATION BUT THEY ARE DOING IT BY DIFFERENT MEANS. ADDED SMALL POPS DURING THE DAY ON THURSDAY WHICH BLENDED WELL INTO THE PRECIPITATION CHANCES ALREADY FORECAST FOR THURSDAY NIGHT. THE END OF THE WEEK/WEEKEND IS A REAL MESS ON THE GFS WITH A LARGE UPPER LOW SETTLING SOUTH OVER THE AREA WITH A LONG DURATION PRECIPITATION EVENT. THE ECMWF ON THE OTHER HAND CONTINUES THE TREND OF THE PAST FEW NIGHTS ON DRIVING A PACIFIC COLD FRONT THROUGH ON FRIDAY AND A CANADIAN COLD FRONT THROUGH ON SATURDAY. IT WOULD BE WINDY AND COLD WITH SOME SNOW...BUT NOT TO THE DEGREE AS ADVERTISED BY THE GFS. CURRENT GRIDS MORE IN LINE WITH THE ECMWF. && .AVIATION... /12Z TAF ISSUANCE/ WATER VAPOR IMAGERY SHOWING UPPER LOW ROTATING OVER NORTHEAST MN AND IS FORECAST TO MOVE ACROSS THE CWA DURING THE MORNING. SHOULD AFFECT EASTERN TAF SITES THE MOST. EXPECT SOME -SHSN EAST AND DID MENTION VSBY RESTRICTION AT KRNH/KEAU AS COLD TROUGH SWINGS THROUGH ABOUT 19Z. CURRENT LOW MVFR CIGS AFFECTING WESTERN AREAS/WHICH IS CLOSER TO SFC RIDGE OVER THE DAKOTAS. THIS RIDGE WILL MOVE SLOWLY EAST DURING THE DAY...INTO SOUTHWEST MN BY EVENING. THIN LAYER OF STRATUS/SC ASSOCIATED IS EXPECTED TO THIN AND CLEAR BY EARLY EVENING AT KAXN/KRWF. 06Z NAM IS NOW TRENDING A BIT MORE PESSIMISTIC IN CLEARING OVER THE EAST TONIGHT. WE DO MAINTAIN CYCLONIC CURVATURE INTO THE COMING NIGHT OVER THE EAST AS WELL. WILL BRING CIGS UP SOME DURING THE EVENING AND TRY AND SCT OUT AT KMSP-KRNH AFTER 05Z-06Z MON. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ RAH/DWE
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
652 AM EST SUN NOV 9 2008 .SYNOPSIS... LOW PRESSURE OVER QUEBEC TODAY WILL MOVE EAST AND ALLOW HIGH PRESSURE TO BUILD IN FOR LATE MONDAY AND TUESDAY. WEDNESDAY THE HIGH WILL BEGIN TO DRIFT EAST AND ALLOW ANOTHER AREA OF LOW PRESSURE TO MOVE TOWARD THE OHIO VALLEY WEDNESDAY NIGHT AND THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LAKE EFFECT RAIN SHOWERS NOW OCCURRING OVER LAKE ERIE AND OFF OF LAKE MICHIGAN. FLOW OFF MICHIGAN IS FAVORABLE ENOUGH TO ALLOW SCATTERED SHOWERS TO REACH INTO THE NORTHERN TIER OF COUNTIES. MODELS SHOW COOLER AIR WORKING IN ALOFT THIS AFTERNOON SO A MIX WITH SNOW IS POSSIBLE FAR WEST MID/LATE AFTERNOON. EXPECT NO ACCUM HOWEVER. ACROSS THE CENTRAL AND EASTERN LAKESHORE COUNTIES 925 AND 850MB WINDS ARE MORE SOUTHWEST AND SHOULD REMAIN SO THROUGH THE DAY AHEAD OF A RATHER STRONG SHORT WAVE DUE IN THIS EVENING. SHOWERS ARE VERY CLOSE TO THE SHORELINE AND EXPECT THAT SOME ACTIVITY WILL LIKELY SPREAD INLAND WITH THE BEST CHANCE OF THIS THROUGH THE FIRST HALF OF THE DAY ACCORDING TO BUFKIT WINDS. NOT CONFIDENT ENOUGH HOWEVER FOR TIMING AT THIS POINT. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... WILL ISSUE A LAKE EFFECT SNOW ADVISORY BEGINNING THIS EVENING AND CONTINUING THROUGH MONDAY AFTERNOON. BOTH TEMPERATURES ALOFT AND STEERING WINDS ARE NEAR CRITICAL VALUES SO IF WINDS VEER ANOTHER 10 TO 20 DEGREES AND TEMPS DROP ANOTHER COUPLE DEGREES THIS MAY NEED TO BE UPGRADED. FOR NOW HOWEVER MODELS SHOW A RATHER STRONG SHORT WAVE MOVING THROUGH THE AREA THIS EVENING ACCOMPANIED BY A SURFACE TROF. STEERING WINDS WILL BE PARALLEL TO THE LAKESHORE MUCH OF THE DAY BUT BEHIND THIS SYSTEM EXPECT WINDS TO VEER TO BETWEEN 260 AND 270 DEGREES AND CONTINUE FOR MUCH OF THE NIGHT ALLOWING FOR AN ONSHORE COMPONENT. AT THE SAME TIME 850MB TEMPS WILL DROP FROM AROUND -4C TODAY TO -6 TO -9C OVERNIGHT. CONDITIONS PERSIST INTO MONDAY ALTHOUGH THE MODELS SHOW THE SURFACE HIGH BUILDING IN. WINDS REMAIN FAVORABLE THROUGH THE DAY HOWEVER A SLOW DAYTIME SURFACE TEMPERATURE RISE SHOULD LIMIT ACCUMULATIONS. EXPECTING 1 TO 4 INCHES TONIGHT WITH ANOTHER 3 POSSIBLE MONDAY. MONDAY NIGHT WILL HOLD ONTO SCATTERED SNOW SHOWERS ACROSS THE NORTHEAST HOWEVER ELSEWHERE HIGH PRESSURE SHOULD BREAK CLOUDS FOR MUCH OF THE NIGHT. TUESDAY SHOULD TREND BACK TOWARD CLOUDY AHEAD OF LOW PRESSURE MOVING INTO THE MID MISSISSIPPI VALLEY. NAM AND GFS BOTH SHOW DEEP MOISTURE MOVING BACK INTO THE AREA FROM THE SOUTHWEST FOR THE AFTERNOON. TUESDAY NIGHT WILL BRING IN LOW CHC POPS FOR THE SOUTHWEST COUNTIES AFTER MIDNIGHT. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... WEDNESDAY WILL CONTINUE WITH CHC POPS ACROSS THE WEST AND SOUTHWEST COUNTIES BUT WILL HOLD ELSEWHERE TO SLIGHT CHANCE. MOISTURE CONTINUES TO DEEPEN ACROSS THE AREA ALTHOUGH MODELS SHOW ONLY LIMITED SURFACE OR UPPER SUPPORT...EVEN BUILDING A WEAK UPPER RIDGE ACROSS THE AREA WEDNESDAY AFTERNOON. THIS HOWEVER OCCURS AHEAD OF A DEEPENING UPPER TROF DIGGING INTO THE NORTHERN PLAINS AND UPPER MIDWEST WEDNESDAY NIGHT AND THURSDAY. WITH THIS DEVELOPING UPPER SUPPORT WILL INCREASE POPS TO HIGH CHANCE AND LIKELY WEDNESDAY NIGHT AND THURSDAY...CONTINUE WITH HIGH CHANCE THURSDAY NIGHT AND FRIDAY. COLDER AIR WILL SWING IN AGAIN FOR THE WEEKEND AS THE UPPER LOW CONTINUES TO DEEPEN...EVENTUALLY CLOSING OFF OVER THE AREA FRIDAY NIGHT. WILL BRING A MIX OF RAIN OR SNOW IN FOR FRIDAY NIGHT AND SATURDAY. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... WIDESPREAD MVFR CEILINGS ACROSS THE REGION THIS MORNING...BUT THERE WILL LIKELY BE PATCHES OF IFR DEVELOPING. LIGHT RAIN/DRIZZLE SPREADING FORM CLE/MFD EAST. EXPECT THIS REGION TO EXPAND IN AREA AS IT MOVES EASTWARD. THIS IS WHERE WE COULD HAVE SOME IFR. SREF PROBABILITIES DID SHOW THE BETTER CHANCES FOR IFR COMING THIS MORNING FOR YNG/CAK AND ALSO FOR TOL AREA. FORECAST SOUNDINGS INDICATE THAT PRECIP TYPE SHOULD BE ALL RAIN AS MOISTURE IS NOT THAT DEEP AND THEREFORE NO/LITTLE ICE CRYSTALS. HAVE NOT BEEN ABLE TO GET ANY TAMDAR SOUNDINGS YET THIS MORNING FOR REAL- TIME DATA. THIS IS THE FIRST BATCH OF PRECIP. NEXT WILL BE WITH UPSTREAM SIGNIFICANT TROUGH PRODUCING PRECIP ACROSS MI/IN. TRIED TO TIME THIS IN TO NORTHERN OHIO FOR LATER THIS MORNING. CEILINGS SHOULD RETURN TO ALL MVFR THIS MORNING. ALSO SNOW/RAIN MIX THREAT SHOULD BE OVER SHORTLY AFTER DAYBREAK...LEAVING JUST PLAIN RAIN FOR THE REST OF TODAY. HAVE A LOT OF VCSH FOR AFTERNOON AS TROUGH WILL BE IN THE AREA BUT CAN NOT HIT ANY CERTAIN TIME SLOTS FOR PREVAILING OR TEMPO WEATHER. SOME IMPROVEMENT OVERNIGHT TO VFR AWAY FROM THE SNOWBELT AREAS. TROUGH WILL TAKE WINDS TO THE WEST THIS EVENING. HAVE EMPHASIZED WITH A TEMPO GROUP RA/SNOW MIX FOR ERIE...TURNING ALL SNOW...AS WHAT WILL BE OUT OVER THE LAKE COMES INLAND WITH THE TROUGH PASSAGE AND WIND SHIFT. RA/SNOW MIX WILL LIKELY HAPPEN SOONER INLAND FROM THE LAKE..POSSIBLY BY LATE AFTERNOON. LAKE EFFECT A GOOD BET THROUGH END OF TAF PERIOD FOR ERIE. OUTLOOK...UPPER LOW WILL LIFT OUT ON MONDAY BUT IT MAY TAKE UNTIL LATER IN THE DAY FOR MVFR CONDITIONS TO IMPROVE TO VFR ACROSS NE OH/NW PA. TUESDAY MAY BE THE BEST DAY OF THE WEEK AS WE ARE BETWEEN SYSTEMS. CONDITIONS ARE LIKELY TO RETURN TO MVFR OR LOWER MID TO LATE WEEK...POSSIBLY AS EARLY AS WEDNESDAY AFTERNOON OR EVENING...AS A TROUGH DEEPENS ACROSS THE MIDWEST. && .MARINE... SMALL CRAFT CONDITIONS ON THE LAKE WILL CONTINUE THROUGH MONDAY. PERSISTENT WEST AND SOUTHWEST WINDS TO 30 KNOTS WILL CONTINUE AS LOW PRESSURE NEAR JAMES BAY MOVES LITTLE THROUGH MONDAY. THIS WILL ALSO CAUSE LOW WATER PROBLEMS FOR THE WESTERN BASIN OF LAKE ERIE AND A LOW WATER ADVISORY HAS BEEN ISSUED. SO FAR WATER LEVELS LOOK MARGINALLY LOW THROUGH MONDAY AND REMAIN CLOSE TO THE CRITICAL MARK. ONE LAST SIGNIFICANT TROUGH WILL ROTATE ACROSS THE LAKE TODAY AND THE LAKE EFFECT AND ENHANCED PRECIPITATION WILL CONTINUE ACROSS THE EAST HALF. MARINE WEATHER WILL BEGIN TO IMPROVE LATE MONDAY AFTER THE PASSAGE OF A WEAKER TROUGH...BUT ONE THAT WILL TURN WINDS MORE WEST-NORTHWEST. LAKE EFFECT WILL CONTINUE INTO MONDAY. HIGH PRESSURE BUILDS ACROSS OHIO FOR TUESDAY...BRINGING THE WINDS/WAVES DOWN AND ENDING THE LAKE EFFECT. THE HIGH WILL BE IN PLACE THROUGH WEDNESDAY. SOUTHEAST FLOW FOR THURSDAY AS A WEAKENING SOUTHERN STREAM SYSTEM MOVES INTO THE OHIO LOWER OHIO VALLEY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 4 PM EST MONDAY FOR PAZ002. MARINE...LOW WATER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LEZ142>144-162>164. SMALL CRAFT ADVISORY UNTIL 4 PM EST MONDAY FOR LEZ142>149. && $$ SYNOPSIS...TK NEAR TERM...TK SHORT TERM...TK LONG TERM...TK AVIATION...OUDEMAN MARINE...OUDEMAN