AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 830 PM EDT FRI OCT 13 2006 .DISCUSSION... OVERNIGHT...WATERVAPOR AND I.R. SAT IMAGERY SHOW A LARGE SWATH OF HIGH LEVEL MOISTURE/CLOUDS STREAMING EWD FROM THE GOMEX THIS EVENING. RUC ANLYS SWATH OF HIGH LEVEL RH IN DIVGT FLANK OF 120KT E-W ORIENTED JTSTRK CTRD ALONG THE NERN GULF COAST. PREFERRED GFS H25 RH/ WIND/DIVG PROGS INDICATE THESE CLOUDS SHOULD CONTINUE TO PRODUCE A HIGH BKN-OVC DECK OVER MUCH OF THE PENINSULA...PERHAPS THINNING SOME OVER THE SRN THIRD CWA. PLAN TO BUMP UP CLOUD COVER TO SHOE CONSIDERABLE HIGH CLOUDS...AND NUDGE MIN TEMPS UP A FEW DEGS SUCH THAT ALL BUT THE FAR NWRN CWA WILL SHOW M-U60S. && .MARINE...CURRENT WINDS AOB 10KT ACROSS THE ENTIRE MARINE AREA. ALL THE S/R GUIDANCE SHOWS A 15-20KT NRLY SURGE PUSHING THROUGH AT LEAST THE FLG-COF LEG 06Z-12Z. THIS SHOULD RESULT IN SEAS GETTING UP TO AROUND 5FT THERE...POSSIBLY A FT HIGHER IN THE GULF STREAM. PLAN TO GO WITH A CAUTIONARY STMT FOR THE GULF STREAM NORTH OF COF OVERNIGHT AND TWEAK SEA HGHTS UP A BIT AFT 06Z. && .AVIATION...VFR WITH A HIGH BKN-OVC DECK MOST OF THE NIGHT. && .FIRE WEATHER...ISSUED SHORT FUSE LATE AFTN RFW TO COVER PRECIPITOUS RH DROP ACROSS THE NRN INTR COS. RFW CONTINUES FOR THE NRN INTR FOR SAT AFTN...AND LATEST MAV GUIDANCE SUGGESTS THIS MAY NEED TO BE NUDGED CLOSER TO THE COAST (INTO WRN SECTIONS OF COASTAL VOLUSIA/NW BREVARD COS). && .MLB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING SATURDAY AFTERNOON FOR INTERIOR VOLUSIA/LAKE/ SEMINOLE/ORANGE/NORTHWEST OSCEOLA COS. && $$ SEDLOCK/CRISTALDI fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 956 PM EDT FRI OCT 13 2006 .UPDATE...DEEP VERTICALLY STACKED LOW CONTINUES TO SPIN NE OF LAKE SUPERIOR LATE THIS EVENING. PROLONGED ENHANCED LAKE EFFECT EVENT CONTINUES ACROSS NRN MICHIGAN...DRIVEN BY STRONG OVER-LAKE INSTABILITY (DELTA T'S AROUND 20 C) COMBINED WITH STRONG SYNOPTIC SUPPORT VIA A POTENT SHORT WAVE ROTATING THRU THE BASE OF THE UPPER LOW. LARGE AREA OF MODERATE TO HEAVY PRECIP THAT IMPACTED THE TIP OF THE MIT AND NW LOWER MICHIGAN DURING EARLY EVENING IS SHOWING A GRADUAL DOWNWARD TREND IN COVERAGE AS THE SYNOPTIC SUPPORT BEGINS TO WANE WITH THE DEPARTURE OF THE SHORT WAVE. HOWEVER...ANOTHER EVEN STRONGER SHORT WAVE IS FAST ON ITS HEALS...WITH THE LATE FEW FRAMES OF KAPX 88D SUGGESTING ANOTHER INCREASE IN MID LEVEL MOISTURE AND SYNOPTIC SUPPORT ACROSS NW SECTIONS OF THE CWA. LOW LEVEL FLOW REMAINS W/SW...BUT WILL GRADUALLY SHIFT W/NW OVERNIGHT AS THE STACKED LOW BEGINS TO EXIT NW AWAY FROM MICHIGAN. HOWEVER... INCREASING SYNOPTIC SUPPORT WILL PRECLUDE THE DEVELOPMENT OF DISCRETE LAKE EFFECT BANDING...BUT WILL INSTEAD FAVOR ANOTHER INCREASE IN AREAL COVERAGE AND INTENSITY OF ONGOING LAKE ENHANCED SNOW TARGETING FAVORED WESTERLY FLOW AREAS (I.E. FAR NRN AND NW LOWER MICHIGAN). WILL MAINTAIN CATEGORICAL POPS FOR THESE AREAS OVERNIGHT...TAPERING TO SCT POPS FOR THE FAR SE CWA NEAR SAGINAW BAY. SNOW/BLOWING SNOW HEADLINES WILL REMAIN IN TACT...AS WILL THE WIND ADVISORY FOR LAKESHORE AREAS FROM MANISTEE TO THE LEELANAU PENINSULA AND THE GALE WARNINGS FOR ALL NEARSHORE AREAS. ADDITIONAL SNOW AMOUNTS SHOULD STAY JUST UNDER WARNING CRITERIA DUE TO PARTIAL MELTING/COMPACTING OF THE SNOW AS TEMPS STAY AT OR JUST ABOVE FREEZING. HIGHER TERRAIN AREAS WILL SEE THE GREATEST ADDITIONAL ACCUMULATION...WITH ANOTHER 2 TO 4 INCHES EXPECTED OVERNIGHT ON TOP OF THE INCH OR TWO RECEIVED THIS EVENING. .PREV DISCUSSION...ISSUED 408 PM EDT FRI OCT 13 2006 SHORT TERM DISCUSSION...19Z SURFACE/SATELLITE/RUC ANALYSIS SHOWS 507DM 500MB LOW...AND ASSOCIATED 980MB SURFACE LOW ROTATING JUST NORTH OF LAKE SUPERIOR. SEVERAL EMBEDDED SHORTWAVES ROTATING AROUND PARENT MID LEVEL CIRCULATION...ONE WHICH IS JUST PASSING EAST OF THE REGION WITH ANOTHER ROTATING SOUTHWEST ACROSS WESTERN ONTARIO. TEMPERATURES REMAIN WELL BELOW SEASONAL NORMALS THROUGHOUT THE COLUMN WITH 12Z 850MB RAOB ANALYSIS SHOWING -6C TO -7C ACROSS THE GREAT LAKE REGION AND SURFACE TEMPERATURES IN THE 30S TO LOWER 40S. AS EXPECTED...LAKE EFFECT MACHINE STILL GOING ACROSS THE NORTHERN LAKES...ALTHOUGH SOMEWHAT LESS IMPRESSIVE THAN EARLIER THIS MORNING WITH LOSS OF MID LEVEL SUPPORT AND DIURNAL DISRUPTION. MOST LOWER ELEVATION AREAS HAVE CHANGED OVER TO A RAIN OR RAIN/SNOW MIX THIS AFTERNOON WITH THE WARMING BOUNDARY LAYER. ELEVATED AREAS HAVE REMAINED PREDOMINATELY SNOW...ALTHOUGH WITH LITTLE ADDITIONAL ACCUMULATION AS EVEN THERE TEMPERATURES HAVE GONE ABOVE FREEZING. MANY FORECAST CONCERN TONIGHT WITH REGARDS TO ADDITIONAL SNOWFALL AMOUNTS...ONGOING MARINE AND WINTER HEADLINES...AND WIND ISSUES ALONG LAKE MICHIGAN. TONIGHT...AFTER BRIEF OVERALL LULL IN THE ACTIVITY THIS EVENING...EXPECT LAKE EFFECT TO ONCE AGAIN RAMP UP AS ONTARIO SHORTWAVE AND ASSOCIATED POCKET OF 700MB-500MB DIVQ APPROACH THE REGION. IN ADDITION TO ABOVE SUPPORT...OTHER PARAMETERS REMAIN VERY FAVORABLE FOR CONTINUATION OF LAKE EFFECT. OVER WATER INSTABILITY REMAINS EXTREME WITH DELTA T/S REMAINING AROUND 20C...900MB-700MB RELATIVE HUMIDITY ABOVE 70 PERCENT...LITTLE WIND SHEAR IN THE CBL...AND INVERSION HEIGHTS AT NEARLY 15KFT. SO LITTLE DOUBT LAKE EFFECT WILL CONTINUE THROUGH THE NIGHT. PRIMARY CONCERNS CENTER ON PRECIPITATION TYPE AND PLACEMENT OF HEAVIER PRECIPITATION. WINDS WILL CONTINUE TO VEER THIS EVENING...EVENTUALLY COMING AROUND TO 270 DEGREES BY 06Z ACROSS THE NORTHERN LOWER AND ABOUT 280 DEGREES OVER THE EASTERN UPPER. GIVEN EXPECTED WIND FIELD...AREAS GENERALLY ALONG AND WEST OF I-75 IN THE NORTHERN LOWER AND NEAR WHITEFISH POINT IN EASTERN UPPER MICHIGAN SHOULD BEAR THE BRUNT OF THE LAKE EFFECT. AS FOR PRECIPITATION TYPE...RAIN AND SNOW SHOWERS THIS EVENING SHOULD GRADUALLY TRANSITION TO PREDOMINATELY SNOW...ESPECIALLY OVER ELEVATED AREAS...AS THE BOUNDARY LAYER COOLS. GIVEN MODIFIED AIR MASS...FEEL WARM LAKE INFLUENCES WILL HAVE MORE OF AN AFFECT..LEADING TO SOME MIX NEAR THE COASTS THROUGH THE NIGHT. HIGH LIQUID WATER CONTENT OF THE SNOW WILL HELP KEEP TOTAL ACCUMULATIONS DOWN SOMEWHAT TONIGHT. STILL EXPECTING SEVERAL MORE ADDITIONAL INCHES IN THE HIGHER TERRAIN AREAS OF NORTHERN LOWER MICHIGAN WITH A COUPLE INCHES POSSIBLE ACROSS WHITEFISH POINT. WILL THEREFORE EXTEND THE SNOW AND BLOWING SNOW ADVISORY FOR CURRENT AREA AND ADD IN CRAWFORD COUNTY THROUGH 12Z SATURDAY. ADDITIONAL ACCUMULATIONS SHOULD BE IN THE 2 TO 4 INCH RANGE WITH SOME ISOLATED HIGHER AMOUNTS POSSIBLE. WILL ALLOW ALL WINTER STORM WARNINGS TO EXPIRE. WILL EXTEND THE WIND ADVISORY FOR AFFECTED COUNTIES NEAR THE LAKE MICHIGAN SHORE THROUGH 06Z AS TIGHT PRESSURE GRADIENT AND OVER WATER INSTABILITY SUPPORTS 45 MPH GUST POTENTIAL. BY LATER TONIGHT...PRESSURE GRADIENT WILL BEGIN TO RELAX RESULTING IN DECREASED WIND SPEEDS. MARINE...WILL CONTINUE ONGOING GALE WARNINGS FOR ALL NEARSHORE WATERS...EXCLUDING WHITEFISH BAY AND THE SAINT MARYS RIVER...THROUGH 09Z. PRESSURE GRADIENT AND INSTABILITY OVER THE LAKES CONTINUES TO SUPPORT 35 KNOT GUST POTENTIAL. MSB SATURDAY AND SATURDAY NIGHT...DEEP/STACKED/BAROTROPIC LOW WILL BE CENTERED OVER HUDSON BAY EARLY SAT. AS AFOREMENTIONED SHORT WAVE ROTATES AROUND SRN PERIPHERY OF UPPER LOW AND LIFTS NE...THIS WILL ALLOW UPPER LOW TO FINALLY LOOSEN ITS GRIP ON THE REGION. HOWEVER... WITH 850 MB TEMPS STILL HOVERING AROUND -6C AND PERSISTENT WNW WINDS...LAKE CLOUDS/PRECIP WILL CONTINUE TO BE A CONCERN -- ESPECIALLY DURING THE DAY SATURDAY. IMPACT OF DEPARTING UPPER LOW SHOWS UP IN MODEL SOUNDINGS...WITH INVERSIONS LOWERING TO AROUND 6.5 KFT BY AFTERNOON (STILL VERY RESPECTABLE). HOWEVER...WITH 850-500 MB RH FALLING FROM 90% AT 1200 UTC TO AROUND 60% BY 0000 UTC...PRECIP WILL GRADUALLY BECOME LESS ORGANIZED AND WIDESPREAD BY EVENING. SURFACE BASED MELTING LAYERS ON MODEL SOUNDINGS SUGGEST MAINLY SNOW OVER INTERIOR AREAS EARLY...GIVING WAY TO MIXED RAIN/SNOW BY AFTERNOON. NEAR THE SHORELINES...A MIX EARLY WILL CHANGE TO ALL RAIN AS MELTING LAYERS EASILY EXCEED 1200 FT. ACCUMULATIONS OF AROUND AN INCH POSSIBLE OVER HIGHER TERRAIN OF NRN LOWER AND NEAR WHITEFISH BAY...MAINLY BEFORE NOON. LAKE EFFECT CLOUDS WILL HANG ON SAT NIGHT. EXPECT WIDELY SCATTERED LIGHT RAIN/SNOW SHOWERS TO BE MAINLY CONFINED TO THE FIRST PART OF THE NIGHT...AS MODEL SOUNDINGS SUGGEST THAT LIFTED PARCELS WILL HAVE AN INCREASINGLY TOUGH TIME REACHING -10C. SUNDAY...LAKE CLOUDS WILL BREAK UP...AND SKIES WILL BECOME PARTLY SUNNY AS WEAK HIGH PRESSURE RIDGE BUILDS INTO THE WRN GREAT LAKES AND PROMOTES SUBSIDENCE...LOW LEVEL DIVERGENCE...AND DRYING. HIGHS WILL PEAK IN THE 40S TO LOWER 50S. MONDAY...WAA WILL COMMENCE AS RIDGE PUSHES E. AT 850 MB...TEMPS WILL MODERATE FROM AROUND +2C AT 1200 UTC TO NEAR +8C BY 0000 UTC TUE. SIMILARLY...850 MB DEW POINTS WILL RISE TO NEAR +6C. INCREASING MOISTURE IN RETURN FLOW WILL SUPPORT A RISK FOR LIGHT RAIN BY MON AFTERNOON MOST AREAS...THOUGH LARGE-SCALE JET SUPPORT APPEARS LIMITED. REMAINDER OF FORECAST (TUESDAY THROUGH FRIDAY)...MORE UNSETTLED WEATHER APPEARS TO BE IN THE OFFING FOR THE MIDDLE AND END OF NEXT WEEK. UNFORTUNATELY...MEDIUM RANGE MODELS ARE IN POOR AGREEMENT REGARDING THE DETAILS. GFS/ECMWF AGREE THAT UPPER TROUGHING WILL CONTINUE TO DEVELOP OVER THE WRN U.S. AS DOWNSTREAM HEIGHTS RISE OVER THE ERN CONUS. HOWEVER...WHILE THE ECMWF LIFTS A SURFACE LOW QUICKLY FROM THE CENTRAL PLAINS INTO ONTARIO BY LATE TUES...THE GFS KEEP ONLY AN INVERTED SURFACE TROUGH OVER THE GREAT LAKES THROUGH WED BEFORE LIFTING A MUCH MORE INTENSE SURFACE LOW INTO THE REGION BY THUR. THE GEM GENERALLY APPEARS MORE SIMILAR TO THE ECMWF. WITH ALL THIS UNCERTAINTY...WILL LEAN TO NCEP MANUAL PROGS. WILL RELUCTANTLY KEEP A CHANCE OF RAIN IN FORECAST FOR TUE THROUGH FRI PERIOD...GIVEN PROXIMITY OF INVERTED TROUGH...WAA (ESPECIALLY EARLY IN PERIOD)...SW FLOW ALOFT...AND RISK THAT INVERTED TROUGH MAY ACTUALLY GIVE WAY TO CYCLOGENESIS (WHICH LATEST GFS STILL SUGGESTS MAY HAPPEN). SMITH && .APX...WATCHES/WARNINGS/ADVISORIES...SNOW AND BLOWING SNOW ADVISORY...TONIGHT...MIZ016-017-019-021-022-026-027-028- 032-033. GALE WARNING...TONIGHT...LMZ323-341-342-344-LHZ345>349. WIND ADVISORY...THROUGH 06Z TONIGHT...MIZ020-025-031. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 935 PM EDT FRI OCT 13 2006 .DISCUSSION... LATEST WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSES CONTINUE TO SHOW THE EXPANSIVE UPPER LOW CENTERED JUST NORTH OF THE GREAT LAKES. A POTENT SHORTWAVE CAN BE SEEN ROTATING AROUND THE UPPER LOW...CURRENTLY MAKING ITS WAY INTO THE MINNESOTA ARROWHEAD AND WESTERN LAKE SUPERIOR. THE LOCAL LAPS/WRF-ARW AND NAM SHOW A GOOD SHOT OF 850-500MB Q-VECTOR CONVERGENCE OUT AHEAD OF THIS FEATURE...ALONG WITH SOME UPPER DIVERGENCE WHICH SHOWS UP NICELY ON THE 2PVU SURFACE OF THE GFS. THIS LARGE SCALE FORCING HAS HELPED RAISE INVERSION HEIGHTS AND MOISTEN THE COLUMN OVER THE PAST FEW HOURS...WHICH HAS IN TURN ALLOWED FOR THE EXPANSION AND INTENSIFICATION OF LES ACROSS THE CWFA. 500MB TEMPERATURES DROP TO AROUND -34C WITH THE SHORTWAVE...STEEPENING LAPSE RATES CONSIDERABLY. WINDS HAVE BACKED AHEAD OF THE SHORTWAVE...AND WILL VEER AFTER IT PASSES BY. LES BANDING CURRENTLY SEEN ON RADAR IS LIKELY RESULTING IN SOME INCH/HR SNOWFALL RATES...ALTHOUGH THE BANDS ARE SHIFTING A BIT SO MOST LOCATIONS ARE NOT STAYING UNDER THE HEAVIEST RETURNS FOR AN EXTENDED PERIOD OF TIME. BY 06Z THE SHORTWAVE AXIS SHOULD BE THROUGH MOST OF THE CWFA...WITH GOOD SUBSIDENCE AND MID LEVEL DRYING ADVERTISED BEHIND IT. THE 00Z CWPL SOUNDING SHOWS THINGS HAVE DRIED OUT SUBSTANTIALLY WITH SOME WARMING NOTED IN THE MID LEVELS. THE FORMATION OF A SUBSIDENCE INVERSION ALONG WITH THE DRYING MID LEVELS AND ARRIVAL OF Q-VECTOR CONVERGENCE SHOULD HELP MITIGATE THE LES QUITE A BIT DURING THE OVERNIGHT HOURS. IN ADDITION...WITH BOUNDARY LAYER WINDS BECOMING MORE NORTHWESTERLY...TRAJECTORIES OVER WESTERN LAKE SUPERIOR WILL BE MUCH SHORTER...HELPING TO FURTHER LIMIT LES INTO THAT AREA. HOWEVER...THE NORTHWESTERLY WINDS COULD HELP BOOST LAKE EFFECT PCPN FOR A SHORT TIME OVER THE EASTERN CWFA UNTIL THE ARRIVAL OF DRIER AIR LATER TONIGHT. THE CURRENT HEADLINES ARE SET TO EXPIRE AT MIDNIGHT...WHICH SHOULD STILL WORK OUT OKAY. THE PCPN WON/T STOP...BUT THERE SHOULD BE A GENERAL DIMINISHING TREND AFTER MIDNIGHT WITH LIGHTER ACCUMULATIONS. THE GOING ZONE FORECAST HAS GOOD HANDLE ON THINGS...SO DO NOT PLAN TO MAKE UPDATES TO THE ZONE TEXT...AND WILL ONLY MAKE MINOR ADJUSTMENTS TO FORECAST GRIDS. TRH && .PREV DISCUSSION... 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP CLOSED LO OVER ONTARIO JUST N OF LK SUP MOVING VERY SLOWLY TO THE S AS A PAIR OF SHRTWVS ON ITS WRN FLANK ARE ROTATING TO THE S. THE FIRST OF THESE SHRTWVS IS NOW MOVING INTO WRN LK SUP AND HAS CAUSED A GOOD DEAL OF SHSN...MIXED WITH RA NR LK SUP/LOWER ELEVATIONS...OVER MAINLY THE WRN CWA IN AREAS FVRD BY MOIST CYC WNW FLOW. CALUMET AND A LOCATION NR PELKIE ALG THE BARAGA/CMX COUNTY LINE REPORTED THE MOST SN OVERNGT ACRS THE FA...6.0 INCHES. LOCAL 12Z RAOBS SHOW HI RH THRU THE DEPTH OF THE TROP. HOWEVER...MID LVL TEMPS ARE HIER AT INL THAN GRB/APX IN WAKE OF INITIAL SHRTWV EVEN THOUGH HIER RH LINGERS. ALTHOUGH THE STRONGEST H5-H3 WINDS HAVE SHIFTED TO THE E SIDE OF THE UPR LO...A SECOND RATHER IMPRESSIVE-LOOKING SHRTWV ROTATING TO THE SW ACRS NW ONTARIO/NE MANITOBA PER WV IMAGERY. STEADY SN WITH VSBY AOB 1 MILE FALLING ACRS NW ONTARIO IN ADVANCE OF THIS SHRTWV. MAIN FCST CONCERNS THIS PACKAGE ARE LES TRENDS/GOING HEADLINES. ALTHOUGH SHSN MAY DIMINISH A BIT LATE TDAY AS SOMEWHAT WARMER MID LVL TEMPS AT INL/DNVA/H85-5 QVECTOR DVGC IN WAKE OF INITIAL SHRTWV MOVE OVHD WITH H85 TEMPS ARND ONLY -7C...SUSPECT ACTIVITY WL PICK UP AGAIN FOR A TIME THIS EVNG WITH APRCH OF SECOND SHRTWV FCST TO DIG NR INL BY 00Z SAT AND ACCOMPANYING DPVA/H85-5 QVECTOR CNVGC. THE HEAVIEST SN WL FALL OVER HIER TERRAIN FM IWD AND MARENISCO-ROCKLAND AND KENTON-WATTON...PELKIE AND PAINESDALE WHERE NAM/GFS SHOW SHARPEST H95 CNVGC IN LLVL WNW FLOW. ALTHOUGH H95 CNVGC FCST TO SHARPEN NR LK SUP E OF PICTURED ROCKS OVER THE E...LONG FETCH ACRS THE WARM WATERS OF LK SUP IN CONCERT WITH ONLY MARGINALLY CHILLY H85 AIR SHOULD MAINTAIN AT LEAST A MIX WITH RA IN THESE AREAS THAT WOULD BE SEEING SN IF THIS STORM WERE OCCURRING IN NOV-DEC. ONCE THE SHRTWV PASSES AND MOVES TO NRN LWR MI BY 12Z SAT...SN/RA INTENSITY WL DIMINISH SGNFTLY OVER THE W AFT 06Z WITH ARRIVAL OF DNVA/H85-5 QVECTOR CNVGC/LOSS OF DEEP MSTR. HOWEVER...WL CONT HI POPS EVEN AFT ARRIVAL OF THESE NEGATIVE DYNAMICS AS GFS/NAM FCST SDNGS SHOW LINGERING MSTR IN CYC FLOW DEEP ENUF TO KEEP -10C ISOTHERM IN THE MOIST LYR UNTIL ALMOST 12Z SAT. GOING WRNGS OVER THE W APPEAR IN ORDER...BUT WL GO WITH AN ADVY FOR NRN CMX COUNTY THRU MIDNGT AS WELL TO TAKE INTO ACCOUNT HEAVIER SN OVER HIER TERRAIN S OF CMX. THE REMAINDER OF THE KEWEENAW SHOULD SEE LESSER AMTS WITH MORE NW FLOW/ WEAKER CNVGC. WSHFT TO THE NW FOLLOWING SHRTWV PASSAGE MAY ALSO CAUSE LK EFFECT PCPN TO MOVE FARTHER INLAND OVER THE E. HOWEVER... PCPN TYPE ISSUES AS WELL AS LIMITED WINDOW OF OPPORTUNITY (NO MORE THAN 3-6 HRS) OF COINCIDENT DYNAMICS/LK ENHANCEMENT/FVRL FLOW SHOULD LIMIT SN ACCUMULATIONS OVER THE E EVEN WELL INLAND OF LK SUP ENUF TO AVOID NEED FOR HEADLINE. ALTHOUGH GFS/NAM HINT ANOTHER WEAK SHRTWV/SOME DPVA AND H85-5 QVECTOR CNVGC WL ROTATE ARND THE UPR LO AND OVER THE FA ON SAT... THESE MODELS AND UKMET ADVERTISE A 12HR H5 HGT RISE OF AOA 100M DURING THE DAY AS RIBBON OF HIER H5-3 WINDS ON THE E SIDE OF UPR TROF PRESENT THIS MRNG LIFT THE SYS TO THE N. SO EVEN THOUGH THERE MAY BE SOME BRIEF ENHANCEMENT OF THE SHRASN ON SAT AS A RESULT OF THIS SHRTWV PASSAGE IN AREAS MOISTENED/DESTABILIZED BY FCST 290 WIND...LARGER SCALE WEAKENING OF THE CYC CIRCULATION SHOULD RESULT IN DIMINISHING PCPN OVERALL WITH RISING MID LVL TEMPS/DRYING. DAYTIME HI TEMPS WL RECOVER TOWARD 45 OVER THE SE ZNS WHERE WNW FLOW DOWNSLOPES PER MIXING TO H85 ON GFS FCST SDNGS. SLOW H5 HGT RISES FCST ON SAT NGT AS VORTEX LIFTS SLOWLY TO THE N. WITH LOWERING SUBSIDENCE INVRN/GRDLY WEAKENING CYC FLOW...EXPECT LINGERING LK EFFECT PCPN TO WIND DOWN AND END OVER ALL BUT THE KEWEENAW/FAR ERN ZNS NR LK SUP BY 12Z SUN AS FLOW BACKS TO NEARLY DUE W. SINCE INVRN LOWERS SO MUCH THAT MOIST LYR WARMS ABV -10C... ANY LINGERING PCPN SHOULD BE ON THE LGT SIDE. SKIES WL CLR OVER THE SCNTRL...WHERE TEMPS SHOULD FALL WELL BLO 32. BOTH NAM/GFS SHOW LLVL WINDS REMAINING FAIRLY STEADY...SO TEMPS SHOULD NOT REALLY NOSEDIVE. SUN SHOULD BE THE MOST PLEASANT DAY IN THE NEAR FUTURE WITH RDG OF HI PRES DOMINATING UNDER CONFLUENT RISING HGTS BTWN DEPARTING TROF IN SE CAN AND DVLPG TROF IN THE PAC NW. MIXING TO H85 ON GFS FCST SDNGS YIELDS HI TEMPS RISING TOWARD 50 ACRS THE SCNTRL. LOOK FOR LO TEMPS SUN NGT TO OCCUR RELATIVELY EARLY AT NGT BEFORE WAD CLD DOWNSTREAM OF TROFFING IN THE NRN ROCKIES ROLLS IN LATER. THE MEDIUM/EXTENDED RANGE PORTION OF THE FCST WL FEATURE A DEEPENING TROF OVER THE W EARLY IN THE WEEK THAT TRANSITIONS TO A HI AMPLITUDE UPR TROF ACRS CNTRL NAMERICA BY WEEK'S END SANDWICHED BTWN RDGS OFF THE W AND E COASTS AND ANOTHER OVER GREENLAND. WAD TO THE E OF THE DEEPENING TROF WL SUPPORT A CHC OF RA ON MON INTO WED. QUESTIONS REMAIN AS TO THE INTENSITY OF A SFC LO FCST TO MOVE ACRS THE UPR GRT LKS ON TUE. ECMWF SHOWS THE DEEPEST SOLN/STORM TRACK FARTHER W WHILE 06Z GFS SHOWS THE WEAKEST LO WITH A NUMBER OF UNPHASED SHRTWVS RIDING THRU THE GENERAL TROFFINESS DVLPG TO THE W. GFS DVLPS A DEEPER SFC LO NEXT THU. NCEP MANUAL GUIDANCE USED A BLEND OF THESE SOLNS THAT LOOKS MORE LIKE THE MIDDLE-OF-THE-ROAD UKMET. WL FOLLOW THIS GUIDANCE GIVEN THE GENERAL LACK OF AGREEMENT ON FCST DETAILS AMONGST THE OPS MODELS. THE NCEP FCST WOULD SUG RA CHCS INTO WED FOLLOWED BY THE ARRIVAL OF COLDER AIR AND A CHC OF SHRASN BEFORE A DRIER DAY NEXT FRI AS WEAK HI PRES RDG BLDS INTO THE UPR LKS. NEGATIVE NAO PATTERN FEATURING TROF IN CNTRL NAMERICA/BLOCKING RDG OVER GREENLAND SUGS GENERALLY BLO NORMAL TEMPS FOR THE FORSEEABLE FUTURE. COORDINATED WITH APX/GRB/DLH. KC && .MQT WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL MIDNIGHT EDT MIZ002-009. LAKE EFFECT SNOW WARNING UNTIL MIDNIGHT EDT MIZ004-084. LAKE EFFECT SNOW ADVY UNTIL MIDNGT EDT MIZ003. GALE WARNING LAKE SUPERIOR. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 408 PM EDT FRI OCT 13 2006 .SHORT TERM DISCUSSION...19Z SURFACE/SATELLITE/RUC ANALYSIS SHOWS 507DM 500MB LOW...AND ASSOCIATED 980MB SURFACE LOW ROTATING JUST NORTH OF LAKE SUPERIOR. SEVERAL EMBEDDED SHORTWAVES ROTATING AROUND PARENT MID LEVEL CIRCULATION...ONE WHICH IS JUST PASSING EAST OF THE REGION WITH ANOTHER ROTATING SOUTHWEST ACROSS WESTERN ONTARIO. TEMPERATURES REMAIN WELL BELOW SEASONAL NORMALS THROUGHOUT THE COLUMN WITH 12Z 850MB RAOB ANALYSIS SHOWING -6C TO -7C ACROSS THE GREAT LAKE REGION AND SURFACE TEMPERATURES IN THE 30S TO LOWER 40S. AS EXPECTED...LAKE EFFECT MACHINE STILL GOING ACROSS THE NORTHERN LAKES...ALTHOUGH SOMEWHAT LESS IMPRESSIVE THAN EARLIER THIS MORNING WITH LOSS OF MID LEVEL SUPPORT AND DIURNAL DISRUPTION. MOST LOWER ELEVATION AREAS HAVE CHANGED OVER TO A RAIN OR RAIN/SNOW MIX THIS AFTERNOON WITH THE WARMING BOUNDARY LAYER. ELEVATED AREAS HAVE REMAINED PREDOMINATELY SNOW...ALTHOUGH WITH LITTLE ADDITIONAL ACCUMULATION AS EVEN THERE TEMPERATURES HAVE GONE ABOVE FREEZING. MANY FORECAST CONCERN TONIGHT WITH REGARDS TO ADDITIONAL SNOWFALL AMOUNTS...ONGOING MARINE AND WINTER HEADLINES...AND WIND ISSUES ALONG LAKE MICHIGAN. TONIGHT...AFTER BRIEF OVERALL LULL IN THE ACTIVITY THIS EVENING...EXPECT LAKE EFFECT TO ONCE AGAIN RAMP UP AS ONTARIO SHORTWAVE AND ASSOCIATED POCKET OF 700MB-500MB DIVQ APPROACH THE REGION. IN ADDITION TO ABOVE SUPPORT...OTHER PARAMETERS REMAIN VERY FAVORABLE FOR CONTINUATION OF LAKE EFFECT. OVER WATER INSTABILITY REMAINS EXTREME WITH DELTA T/S REMAINING AROUND 20C...900MB-700MB RELATIVE HUMIDITY ABOVE 70 PERCENT...LITTLE WIND SHEAR IN THE CBL...AND INVERSION HEIGHTS AT NEARLY 15KFT. SO LITTLE DOUBT LAKE EFFECT WILL CONTINUE THROUGH THE NIGHT. PRIMARY CONCERNS CENTER ON PRECIPITATION TYPE AND PLACEMENT OF HEAVIER PRECIPITATION. WINDS WILL CONTINUE TO VEER THIS EVENING...EVENTUALLY COMING AROUND TO 270 DEGREES BY 06Z ACROSS THE NORTHERN LOWER AND ABOUT 280 DEGREES OVER THE EASTERN UPPER. GIVEN EXPECTED WIND FIELD...AREAS GENERALLY ALONG AND WEST OF I-75 IN THE NORTHERN LOWER AND NEAR WHITEFISH POINT IN EASTERN UPPER MICHIGAN SHOULD BEAR THE BRUNT OF THE LAKE EFFECT. AS FOR PRECIPITATION TYPE...RAIN AND SNOW SHOWERS THIS EVENING SHOULD GRADUALLY TRANSITION TO PREDOMINATELY SNOW...ESPECIALLY OVER ELEVATED AREAS...AS THE BOUNDARY LAYER COOLS. GIVEN MODIFIED AIR MASS...FEEL WARM LAKE INFLUENCES WILL HAVE MORE OF AN AFFECT..LEADING TO SOME MIX NEAR THE COASTS THROUGH THE NIGHT. HIGH LIQUID WATER CONTENT OF THE SNOW WILL HELP KEEP TOTAL ACCUMULATIONS DOWN SOMEWHAT TONIGHT. STILL EXPECTING SEVERAL MORE ADDITIONAL INCHES IN THE HIGHER TERRAIN AREAS OF NORTHERN LOWER MICHIGAN WITH A COUPLE INCHES POSSIBLE ACROSS WHITEFISH POINT. WILL THEREFORE EXTEND THE SNOW AND BLOWING SNOW ADVISORY FOR CURRENT AREA AND ADD IN CRAWFORD COUNTY THROUGH 12Z SATURDAY. ADDITIONAL ACCUMULATIONS SHOULD BE IN THE 2 TO 4 INCH RANGE WITH SOME ISOLATED HIGHER AMOUNTS POSSIBLE. WILL ALLOW ALL WINTER STORM WARNINGS TO EXPIRE. WILL EXTEND THE WIND ADVISORY FOR AFFECTED COUNTIES NEAR THE LAKE MICHIGAN SHORE THROUGH 06Z AS TIGHT PRESSURE GRADIENT AND OVER WATER INSTABILITY SUPPORTS 45 MPH GUST POTENTIAL. BY LATER TONIGHT...PRESSURE GRADIENT WILL BEGIN TO RELAX RESULTING IN DECREASED WIND SPEEDS. MARINE...WILL CONTINUE ONGOING GALE WARNINGS FOR ALL NEARSHORE WATERS...EXCLUDING WHITEFISH BAY AND THE SAINT MARYS RIVER...THROUGH 09Z. PRESSURE GRADIENT AND INSTABILITY OVER THE LAKES CONTINUES TO SUPPORT 35 KNOT GUST POTENTIAL. MSB SATURDAY AND SATURDAY NIGHT...DEEP/STACKED/BAROTROPIC LOW WILL BE CENTERED OVER HUDSON BAY EARLY SAT. AS AFOREMENTIONED SHORT WAVE ROTATES AROUND SRN PERIPHERY OF UPPER LOW AND LIFTS NE...THIS WILL ALLOW UPPER LOW TO FINALLY LOOSEN ITS GRIP ON THE REGION. HOWEVER... WITH 850 MB TEMPS STILL HOVERING AROUND -6C AND PERSISTENT WNW WINDS...LAKE CLOUDS/PRECIP WILL CONTINUE TO BE A CONCERN -- ESPECIALLY DURING THE DAY SATURDAY. IMPACT OF DEPARTING UPPER LOW SHOWS UP IN MODEL SOUNDINGS...WITH INVERSIONS LOWERING TO AROUND 6.5 KFT BY AFTERNOON (STILL VERY RESPECTABLE). HOWEVER...WITH 850-500 MB RH FALLING FROM 90% AT 1200 UTC TO AROUND 60% BY 0000 UTC...PRECIP WILL GRADUALLY BECOME LESS ORGANIZED AND WIDESPREAD BY EVENING. SURFACE BASED MELTING LAYERS ON MODEL SOUNDINGS SUGGEST MAINLY SNOW OVER INTERIOR AREAS EARLY...GIVING WAY TO MIXED RAIN/SNOW BY AFTERNOON. NEAR THE SHORELINES...A MIX EARLY WILL CHANGE TO ALL RAIN AS MELTING LAYERS EASILY EXCEED 1200 FT. ACCUMULATIONS OF AROUND AN INCH POSSIBLE OVER HIGHER TERRAIN OF NRN LOWER AND NEAR WHITEFISH BAY...MAINLY BEFORE NOON. LAKE EFFECT CLOUDS WILL HANG ON SAT NIGHT. EXPECT WIDELY SCATTERED LIGHT RAIN/SNOW SHOWERS TO BE MAINLY CONFINED TO THE FIRST PART OF THE NIGHT...AS MODEL SOUNDINGS SUGGEST THAT LIFTED PARCELS WILL HAVE AN INCREASINGLY TOUGH TIME REACHING -10C. SUNDAY...LAKE CLOUDS WILL BREAK UP...AND SKIES WILL BECOME PARTLY SUNNY AS WEAK HIGH PRESSURE RIDGE BUILDS INTO THE WRN GREAT LAKES AND PROMOTES SUBSIDENCE...LOW LEVEL DIVERGENCE...AND DRYING. HIGHS WILL PEAK IN THE 40S TO LOWER 50S. MONDAY...WAA WILL COMMENCE AS RIDGE PUSHES E. AT 850 MB...TEMPS WILL MODERATE FROM AROUND +2C AT 1200 UTC TO NEAR +8C BY 0000 UTC TUE. SIMILARLY...850 MB DEW POINTS WILL RISE TO NEAR +6C. INCREASING MOISTURE IN RETURN FLOW WILL SUPPORT A RISK FOR LIGHT RAIN BY MON AFTERNOON MOST AREAS...THOUGH LARGE-SCALE JET SUPPORT APPEARS LIMITED. REMAINDER OF FORECAST (TUESDAY THROUGH FRIDAY)...MORE UNSETTLED WEATHER APPEARS TO BE IN THE OFFING FOR THE MIDDLE AND END OF NEXT WEEK. UNFORTUNATELY...MEDIUM RANGE MODELS ARE IN POOR AGREEMENT REGARDING THE DETAILS. GFS/ECMWF AGREE THAT UPPER TROUGHING WILL CONTINUE TO DEVELOP OVER THE WRN U.S. AS DOWNSTREAM HEIGHTS RISE OVER THE ERN CONUS. HOWEVER...WHILE THE ECMWF LIFTS A SURFACE LOW QUICKLY FROM THE CENTRAL PLAINS INTO ONTARIO BY LATE TUES...THE GFS KEEP ONLY AN INVERTED SURFACE TROUGH OVER THE GREAT LAKES THROUGH WED BEFORE LIFTING A MUCH MORE INTENSE SURFACE LOW INTO THE REGION BY THUR. THE GEM GENERALLY APPEARS MORE SIMILAR TO THE ECMWF. WITH ALL THIS UNCERTAINTY...WILL LEAN TO NCEP MANUAL PROGS. WILL RELUCTANTLY KEEP A CHANCE OF RAIN IN FORECAST FOR TUE THROUGH FRI PERIOD...GIVEN PROXIMITY OF INVERTED TROUGH...WAA (ESPECIALLY EARLY IN PERIOD)...SW FLOW ALOFT...AND RISK THAT INVERTED TROUGH MAY ACTUALLY GIVE WAY TO CYCLOGENESIS (WHICH LATEST GFS STILL SUGGESTS MAY HAPPEN). SMITH && .APX...WATCHES/WARNINGS/ADVISORIES...SNOW AND BLOWING SNOW ADVISORY...TONIGHT...MIZ016-017-019-021-022-026-027-028- 032-033. GALE WARNING...TONIGHT...LMZ323-341-342-344-LHZ345>349. WIND ADVISORY...THROUGH 06Z TONIGHT...MIZ020-025-031. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 335 PM EDT FRI OCT 13 2006 .DISCUSSION... 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP CLOSED LO OVER ONTARIO JUST N OF LK SUP MOVING VERY SLOWLY TO THE S AS A PAIR OF SHRTWVS ON ITS WRN FLANK ARE ROTATING TO THE S. THE FIRST OF THESE SHRTWVS IS NOW MOVING INTO WRN LK SUP AND HAS CAUSED A GOOD DEAL OF SHSN...MIXED WITH RA NR LK SUP/LOWER ELEVATIONS...OVER MAINLY THE WRN CWA IN AREAS FVRD BY MOIST CYC WNW FLOW. CALUMET AND A LOCATION NR PELKIE ALG THE BARAGA/CMX COUNTY LINE REPORTED THE MOST SN OVERNGT ACRS THE FA...6.0 INCHES. LOCAL 12Z RAOBS SHOW HI RH THRU THE DEPTH OF THE TROP. HOWEVER...MID LVL TEMPS ARE HIER AT INL THAN GRB/APX IN WAKE OF INITIAL SHRTWV EVEN THOUGH HIER RH LINGERS. ALTHOUGH THE STRONGEST H5-H3 WINDS HAVE SHIFTED TO THE E SIDE OF THE UPR LO...A SECOND RATHER IMPRESSIVE-LOOKING SHRTWV ROTATING TO THE SW ACRS NW ONTARIO/NE MANITOBA PER WV IMAGERY. STEADY SN WITH VSBY AOB 1 MILE FALLING ACRS NW ONTARIO IN ADVANCE OF THIS SHRTWV. MAIN FCST CONCERNS THIS PACKAGE ARE LES TRENDS/GOING HEADLINES. ALTHOUGH SHSN MAY DIMINISH A BIT LATE TDAY AS SOMEWHAT WARMER MID LVL TEMPS AT INL/DNVA/H85-5 QVECTOR DVGC IN WAKE OF INITIAL SHRTWV MOVE OVHD WITH H85 TEMPS ARND ONLY -7C...SUSPECT ACTIVITY WL PICK UP AGAIN FOR A TIME THIS EVNG WITH APRCH OF SECOND SHRTWV FCST TO DIG NR INL BY 00Z SAT AND ACCOMPANYING DPVA/H85-5 QVECTOR CNVGC. THE HEAVIEST SN WL FALL OVER HIER TERRAIN FM IWD AND MARENISCO-ROCKLAND AND KENTON-WATTON...PELKIE AND PAINESDALE WHERE NAM/GFS SHOW SHARPEST H95 CNVGC IN LLVL WNW FLOW. ALTHOUGH H95 CNVGC FCST TO SHARPEN NR LK SUP E OF PICTURED ROCKS OVER THE E...LONG FETCH ACRS THE WARM WATERS OF LK SUP IN CONCERT WITH ONLY MARGINALLY CHILLY H85 AIR SHOULD MAINTAIN AT LEAST A MIX WITH RA IN THESE AREAS THAT WOULD BE SEEING SN IF THIS STORM WERE OCCURRING IN NOV-DEC. ONCE THE SHRTWV PASSES AND MOVES TO NRN LWR MI BY 12Z SAT...SN/RA INTENSITY WL DIMINISH SGNFTLY OVER THE W AFT 06Z WITH ARRIVAL OF DNVA/H85-5 QVECTOR CNVGC/LOSS OF DEEP MSTR. HOWEVER...WL CONT HI POPS EVEN AFT ARRIVAL OF THESE NEGATIVE DYNAMICS AS GFS/NAM FCST SDNGS SHOW LINGERING MSTR IN CYC FLOW DEEP ENUF TO KEEP -10C ISOTHERM IN THE MOIST LYR UNTIL ALMOST 12Z SAT. GOING WRNGS OVER THE W APPEAR IN ORDER...BUT WL GO WITH AN ADVY FOR NRN CMX COUNTY THRU MIDNGT AS WELL TO TAKE INTO ACCOUNT HEAVIER SN OVER HIER TERRAIN S OF CMX. THE REMAINDER OF THE KEWEENAW SHOULD SEE LESSER AMTS WITH MORE NW FLOW/ WEAKER CNVGC. WSHFT TO THE NW FOLLOWING SHRTWV PASSAGE MAY ALSO CAUSE LK EFFECT PCPN TO MOVE FARTHER INLAND OVER THE E. HOWEVER... PCPN TYPE ISSUES AS WELL AS LIMITED WINDOW OF OPPORTUNITY (NO MORE THAN 3-6 HRS) OF COINCIDENT DYNAMICS/LK ENHANCEMENT/FVRL FLOW SHOULD LIMIT SN ACCUMULATIONS OVER THE E EVEN WELL INLAND OF LK SUP ENUF TO AVOID NEED FOR HEADLINE. ALTHOUGH GFS/NAM HINT ANOTHER WEAK SHRTWV/SOME DPVA AND H85-5 QVECTOR CNVGC WL ROTATE ARND THE UPR LO AND OVER THE FA ON SAT... THESE MODELS AND UKMET ADVERTISE A 12HR H5 HGT RISE OF AOA 100M DURING THE DAY AS RIBBON OF HIER H5-3 WINDS ON THE E SIDE OF UPR TROF PRESENT THIS MRNG LIFT THE SYS TO THE N. SO EVEN THOUGH THERE MAY BE SOME BRIEF ENHANCEMENT OF THE SHRASN ON SAT AS A RESULT OF THIS SHRTWV PASSAGE IN AREAS MOISTENED/DESTABILIZED BY FCST 290 WIND...LARGER SCALE WEAKENING OF THE CYC CIRCULATION SHOULD RESULT IN DIMINISHING PCPN OVERALL WITH RISING MID LVL TEMPS/DRYING. DAYTIME HI TEMPS WL RECOVER TOWARD 45 OVER THE SE ZNS WHERE WNW FLOW DOWNSLOPES PER MIXING TO H85 ON GFS FCST SDNGS. SLOW H5 HGT RISES FCST ON SAT NGT AS VORTEX LIFTS SLOWLY TO THE N. WITH LOWERING SUBSIDENCE INVRN/GRDLY WEAKENING CYC FLOW...EXPECT LINGERING LK EFFECT PCPN TO WIND DOWN AND END OVER ALL BUT THE KEWEENAW/FAR ERN ZNS NR LK SUP BY 12Z SUN AS FLOW BACKS TO NEARLY DUE W. SINCE INVRN LOWERS SO MUCH THAT MOIST LYR WARMS ABV -10C... ANY LINGERING PCPN SHOULD BE ON THE LGT SIDE. SKIES WL CLR OVER THE SCNTRL...WHERE TEMPS SHOULD FALL WELL BLO 32. BOTH NAM/GFS SHOW LLVL WINDS REMAINING FAIRLY STEADY...SO TEMPS SHOULD NOT REALLY NOSEDIVE. SUN SHOULD BE THE MOST PLEASANT DAY IN THE NEAR FUTURE WITH RDG OF HI PRES DOMINATING UNDER CONFLUENT RISING HGTS BTWN DEPARTING TROF IN SE CAN AND DVLPG TROF IN THE PAC NW. MIXING TO H85 ON GFS FCST SDNGS YIELDS HI TEMPS RISING TOWARD 50 ACRS THE SCNTRL. LOOK FOR LO TEMPS SUN NGT TO OCCUR RELATIVELY EARLY AT NGT BEFORE WAD CLD DOWNSTREAM OF TROFFING IN THE NRN ROCKIES ROLLS IN LATER. THE MEDIUM/EXTENDED RANGE PORTION OF THE FCST WL FEATURE A DEEPENING TROF OVER THE W EARLY IN THE WEEK THAT TRANSITIONS TO A HI AMPLITUDE UPR TROF ACRS CNTRL NAMERICA BY WEEK'S END SANDWICHED BTWN RDGS OFF THE W AND E COASTS AND ANOTHER OVER GREENLAND. WAD TO THE E OF THE DEEPENING TROF WL SUPPORT A CHC OF RA ON MON INTO WED. QUESTIONS REMAIN AS TO THE INTENSITY OF A SFC LO FCST TO MOVE ACRS THE UPR GRT LKS ON TUE. ECMWF SHOWS THE DEEPEST SOLN/STORM TRACK FARTHER W WHILE 06Z GFS SHOWS THE WEAKEST LO WITH A NUMBER OF UNPHASED SHRTWVS RIDING THRU THE GENERAL TROFFINESS DVLPG TO THE W. GFS DVLPS A DEEPER SFC LO NEXT THU. NCEP MANUAL GUIDANCE USED A BLEND OF THESE SOLNS THAT LOOKS MORE LIKE THE MIDDLE-OF-THE-ROAD UKMET. WL FOLLOW THIS GUIDANCE GIVEN THE GENERAL LACK OF AGREEMENT ON FCST DETAILS AMONGST THE OPS MODELS. THE NCEP FCST WOULD SUG RA CHCS INTO WED FOLLOWED BY THE ARRIVAL OF COLDER AIR AND A CHC OF SHRASN BEFORE A DRIER DAY NEXT FRI AS WEAK HI PRES RDG BLDS INTO THE UPR LKS. NEGATIVE NAO PATTERN FEATURING TROF IN CNTRL NAMERICA/BLOCKING RDG OVER GREENLAND SUGS GENERALLY BLO NORMAL TEMPS FOR THE FORSEEABLE FUTURE. COORDINATED WITH APX/GRB/DLH. && .MQT WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL MIDNIGHT EDT MIZ002-009. LAKE EFFECT SNOW WARNING UNTIL MIDNIGHT EDT MIZ004-084. LAKE EFFECT SNOW ADVY UNTIL MIDNGT EDT MIZ003. GALE WARNING LAKE SUPERIOR. && $$ KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1115 AM EDT FRI OCT 13 2006 .UPDATE... CONCERN ON UPDATE IS CONTINUING WINTER STORM WARNING OVER HOUGHTON AND KEWEENAW COUNTY INTO THIS EVENING. BASED ON SPOTTER REPORTS...SFC OBS AND WEBCAM IMAGES DOESN'T LOOK LIKE MUCH OF ANYTHING IS HAPPENING OVER THE KEWEENAW PENINSULA OTHER THAN FLURRIES AT THIS TIME. WARMER BOUNDARY LYR TEMPS...MID-LVL DRYING AS NOTED ON NAM FCST SNDGS BY 18Z ALONG WITH A PERIOD OF Q-VECT DIV SHOULD MAINTAIN QUIET WX THROUGH MUCH OF THE AFTERNOON. AND WHILE THERE IS A ANOTHER SHORTWAVE POISED TO MOVE ACROSS THE AREA LATER IN THE DAY AND EVENING...THE BRIEF ENHANCEMENT FROM THIS SHORTWAVE SHOULD RESULT IN ACCUMULATIONS OF GENERALLY LESS THAN THE ADVISORY CRITERIA OF 4 INCHES. SO HAVE ELECTED TO DROP THE WINTER STORM WARNING FOR THESE COUNTIES. ELSEWHERE...WILL KEEP WSW HEADLINES GOING FOR THE REST OF THE WRN COUNTIES TODAY AS THERE COULD STILL BE SOME ACCUMULATION OF SNOW DURING THE DAY TODAY AS WELL AS LAKE ENHANCED SNOW THIS EVENING. && .DISCUSSION... MAIN FCST CONCERNS ARE LES TRENDS/PCPN TYPE AND HEADLINES. WATER VAPOR IMAGERY/RUC ANALYSIS AND 00Z RAOBS SHOW AN ANOMALOUSLY DEEP MIDLEVEL LOW FOR THIS TIME OF YEAR CENTERED OVER ONTARIO TO THE N OF LAKE SUPERIOR. 500MB HEIGHT IS AROUND 505DM AT THE CENTER... WHICH IS AROUND 3.5 STANDARD DEVIATIONS BELOW NORMAL. MOST PROMINENT SHORTWAVE OF CONCERN WITHIN CIRCULATION IS LOCATED OVER NRN ONTARIO TO FAR SW HUDSON BAY. AIRMASS AROUND THE W AND S SIDE OF CIRCULATION HAS MODIFIED AS WARMER AIR CONTINUES TO WRAP AROUND THE SYSTEM. 850MB TEMPS AT CWPL/KINL HAVE RISEN FROM -11C/-10C AT 12Z/12OCT TO -5C/-6C AT 00Z. THIS WARMING AND RESULTING ISENTROPIC ASCENT HAS ENHANCED THE DEEP MOISTURE THAT IS ROTATING AROUND THE MIDLEVEL LOW. 00Z KINL SOUNDING SHOWED A NEARLY SATURATED COLUMN TO 300MB...AND THIS IS REPRESENTATIVE OF THE AIRMASS THAT IS STREAMING OVER UPPER MI. ALTHOUGH 850MB TEMPS HAVE RISEN...LAKE ENHANCEMENT HAS IMPROVED DUE TO THE ARRIVAL OF DEEP MOISTURE. AT THE SFC...DEEP 974MB LOW LOCATED NEAR CWPL AT 00Z HAS ROTATED S TO NEAR LAKE NIPIGON AS OF 07Z. NAM/GFS ARE IN GOOD AGREEMENT IN WOBBLING CENTER OF MIDLEVEL LOW TO THE SE TODAY...PASSING VERY NEAR THE NE SHORE OF LAKE SUPERIOR. DESPITE THIS...500MB HEIGHTS ARE TO RISE ABOUT 70M ACROSS UPPER MI BTWN 12Z AND 00Z. SO IN GENERAL...SYNOPTIC FORCING WILL DIMINISH TODAY UNTIL THERE IS A SHOT OF BETTER FORCING TIED TO AFOREMENTIONED SHORTWAVE OVER NRN ONTARIO. MODELS SHOW THIS SHORTWAVE APPROACHING THE AREA LATE THIS AFTN AND REACHING LWR MI IN THE 06-12Z TIME FRAME. DEEP LAYER QVECTOR FIELDS (850-300MB) SHOW THE EXPECTED CHANGE IN SYNOPTIC FORCING NICELY WITH A PERIOD OF QVECTOR DIVERGENCE DEVELOPING TODAY...AND THEN A PERIOD OF QVECTOR CONVERGENCE ASSOCIATED WITH PASSING SHORTWAVE LATE AFTN THRU TONIGHT. SNOW INTENSITY TRENDS WILL FOLLOW THIS PATTERN. AS FOR THERMAL PROFILE AND PCPN TYPE...850MB TEMPS TODAY ARE PROGGED TO REMAIN NEAR CURRENT READINGS...AROUND -6/-7C...AND THEN FALL A DEGREE OR SO TONIGHT WITH PASSAGE OF SHORTWAVE. FCST SOUNDINGS INDICATE A SLIGHT INCREASE IN SFC BASED ABOVE FREEZING LAYER TODAY AS WOULD BE EXPECTED WITH DAYTIME HEATING. TEMPS ARE ALREADY IN THE 36-41F RANGE AT KP59 AND AT THE UPPER ENTRANCE OF PORTAGE CANAL...AND WRN BUOY SHOWS AN AIR TEMP OF 41F. CAN PROBABLY SAFELY ASSUME THAT PCPN TYPE HAS CHANGED OR IS CHANGING TO MAINLY RAIN ALONG THE LAKESHORE. PTYPE SHOULD REMAIN MAINLY LIQUID THERE TODAY/TONIGHT WITH NO MEANINGFUL CAA. THIS LEAVES INLAND AREAS FOR AN EXTEMELY CHALLENGING SNOW ACCUMULATION FCST. FIRST...IT WILL BE TOUGH TO DETERMINE JUST HOW FAR INLAND/HOW HIGH UP THE TERRAIN RAIN WILL MIX WITH SNOW TODAY...AND SECOND...FORCING WILL BE DIMINISHING TODAY...RESULTING IN DECREASING PCPN INTENSITY. THEN THERE SHOULD BE A PERIOD OF INCREASED PCPN INTENSITY LATE AFTN/EVENING WITH PASSAGE OF SHORTWAVE. EXPECT SIGNIFICANT PORTION OF SNOW ACCUMULATION TODAY TO OCCUR THIS MORNING BEFORE DEEP LAYER FORCING DIMINISHES. SUBJECTIVE MODIFICATION OF LES DECISION TREE FOR DIMINISHED FORCING AND POSSIBLE MIX WITH RAIN LEADS TO A 2-5 INCH ACCUMULATION RANGE AS BEST ESTIMATE OVER THE HIGHER TERRAIN. NEXT SHIFT WILL NEED TO WATCH PCPN TYPE CHANGES CLOSELY THRU THE MORNING/AFTN. NOT OUT OF THE QUESTION THAT RAIN WILL MIX WITH SNOW EVEN AT SOME OF THE HIGHER ELEVATIONS AND CUT ADDITIONAL SNOW ACCUMULATIONS. ALREADY DURING THE OVERNIGHT...RAIN HAS MIXED WITH THE SNOW IN THE HOUGHTON VCNTY PER KCMX OB AND REPORT FROM HOUGHTON COUNTY SHERIFF. WITH ALL THAT SAID...NO CHANGES PLANNED ATTM FOR ONGOING HEADLINES WITH THIS FCST ISSUANCE...BUT WOULD NOT BE SURPRISED IF SOME HEADLINES MAY NEED TO BE DOWNGRADED IN THE AFTN...DEPENDING ON HOW MUCH RAIN MIXES WITH THE SNOW. HAVE ISSUED A WIND ADVY FOR DELTA COUNTY...MAINLY FOR THE STONINGTON/GARDEN PENINSULAS WHICH ARE EXPOSED TO STRONG WSW WINDS BLOWING ACROSS THE NRN BAY OF GREEN BAY. SUSTAINED WINDS TO 30 MPH WITH GUSTS TO 45 MPH LOOK LIKE A GOOD BET THERE THIS MORNING. APPROACH OF SHORTWAVE LATE AFTN/EVENING WILL LEAD TO AN INCREASE IN PCPN INTENSITY AND POSSIBLY A SHORT PERIOD OF MDT/HVY SNOW OVER THE HIGHER TERRAIN OF WRN UPPER MI. PRONOUNCED SUBSIDENCE FOLLOWING THE SHORTWAVE SHOULD THEN BRING A VERY QUICK DIMINISHING TREND TO SNOW BEGINNING LATE EVENING AND THRU THE OVERNIGHT. EXPECT EVENING ACCUMULATIONS TO BE IN THE 2-4 INCH RANGE. TO THE E OF MARQUETTE... WINDS VEERING TO THE NW WILL BRING LAKE EFFECT PCPN FIRMLY INTO THAT AREA. HOWEVER...PTYPE ISSUES AND THE VERY SHORT PERIOD OF SYNOPTIC FORCING CORRESPONDING WITH THE MORE FAVORABLE WIND DIRECTION SUGGEST NO HEADLINES ARE NECESSARY. WITH LONGER FETCH OVER THE 50F WATER... LAKESHORE LOCATIONS (AU TRAIN/MUNISING/GRAND MARAIS ETC) SHOULD SEE MAINLY RAIN TONIGHT...AND RAIN WILL PROBABLY MIX WITH SNOW FOR A GOOD DISTANCE INLAND. IN ANYCASE...DAYSHIFT WILL STILL NEED TO EXAMINE THE OUTSIDE POSSIBILITY OF AN ADVY INLAND. WITH PASSAGE OF SHORTWAVE TONIGHT...HEIGHTS RISE SUBSTANTIALLY SAT (100-160M AT 500MB) AND MIDLEVEL LOW RECENTERS ITSELF NEAR THE SW SHORE OF HUDSON BAY. AIRMASS SAT WILL STILL BE PLENTY COLD ENOUGH (850MB TEMPS AROUND -7C) TO SUPPORT LIGHT LAKE EFFECT -SHRA/-SHSN. LOW-LEVEL WINDS BACK WRLY THRU THE DAY...PUSHING PCPN AREAS TO MAINLY N OF KIWD ON THE W END AND TO MAINLY ALONG THE LAKESHORE E OF MUNISING BY LATE IN THE DAY. LIGHT LAKE EFFECT PCPN WILL CONTINUE TO WIND DOWN SAT NIGHT WITH CONTINUED WAA. QUITE WEATHER EXPECTED SUN/SUN NIGHT INTO MON MORNING BEFORE PATTERN CHANGES AS TROF AMPLIFICATION OCCURS OVER THE WRN CONUS WITH SW FLOW DEVELOPING INTO THE GREAT LAKES. IN RESPONSE...MAY SEE RAIN BREAK OUT AS EARLY MON AFTN. && .MQT WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL MIDNIGHT EDT FRI MIZ002-009. LAKE EFFECT SNOW WARNING UNTIL MIDNIGHT EDT FRI MIZ004-084. GALE WARNING LAKE SUPERIOR. && $$ VOSS (UPDATE) ROLFSON (PREV DISCUSSION) mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1050 AM CDT FRI OCT 13 2006 .UPDATE... CONCERN FOR TODAY CONTINUES TO BE BREEZY CONDITIONS AS 978 MB SURFACE LOW CONTINUES TO ROTATE NEAR THE NORTHERN SHORES OF LAKE SUPERIOR. DESPITE VERY TIGHT PRESSURE GRADIENT...WINDS ARE STRUGGLING TO APPROACH WIND ADVISORY CRITERIA ACROSS A GOOD PORTION OF THE AREA...MAINLY DUE A COUPLE OF FACTORS /LACK OF STRONG COLD AIR ADVECTION...INADEQUATE SUPERPOSITION OF THE UPPER JET AXIS...AND LACK OF STRONG ISALLOBARIC COMPONENT TO THE WIND/. AS A RESULT...HAVE TRIMMED THE WIND ADVISORY...LIMITING IT TO THE MINNESOTA RIVER VALLEY...WITH CLIMATOLOGY/NATURE OF THE GROUND COVER MORE FAVORABLE IN THIS REGION OF THE FORECAST AREA...IN ADDITION TO ATMOSPHERIC CONDITIONS MORE SUITABLE FOR MIXING. ONLY MINOR TWEAKS WERE REQUIRED TO THE REMAINDER OF THE SHORT TERM FORECAST...WITH CURRENT OBSERVATIONAL DATA AND LATEST MODEL DATA FAVORING THE GOING FORECAST FOR PRECIPITATION AND TEMPERATURES THROUGH THE EVENING. && .PREV DISCUSSION... /ISSUED 355 AM CDT FRI OCT 13 2006/ DISCUSSION... SHORT TERM...TODAY THROUGH SUNDAY NIGHT PRIMARY CHALLENGE FOR THIS FCST PACKAGE ARE WIND SPEEDS AND GUSTS TDY. POLAR VORTEX HAS RETROGRADED OVER THE PAST 12 HOURS AND NOW IS DRIFTING OVER NRN LAKE SUPERIOR. DEEPENING LOW PRESSURE AT 974 MB HAS DRIVEN A TIGHT MSLP GRDT INTO THE NRN FCST AREA THIS MRNG. H8 FLOW OF 55 TO 65 KT SEEN ON EVENING RAOBS NOW ATOP THIS AREA AND PROGGED BY THE RUC MODEL TO EVOLVE SW BEFORE DECREASING SLIGHTLY BY AFTN. THESE STRONG WINDS ALOFT HAVE MIXED DOWN IN GUSTS EXCEEDING 40 MPH ALREADY AND THINK POTENTIAL WILL INCREASE OVER REST OF MN FA TODAY...ESPECIALLY WHERE THERE WILL BE MORE SUN OVER SW MN. DRY ADIABATIC LAPSE RATES ON PROGGED SOUNDINGS UP TO 825MB SHOULD ALLOW FOR MIX DOWN OF GUSTS WELL UP TO ADVISORY CRITERIA. PURE GRADIENT OVER ERN MN NEAR TWIN CITIES METRO SHOULD ALSO ENABLE SUSTAINED SPEEDS IN THESE MORE CLOUDY PLACES TO STAY UP 30 TO 35 MPH INTO THE AFTN. OTHER CONCERN FOR TDY IS SHWR POTENTIAL. TWIRLING SYSTEM HAS WRAPPED STRONG MID AND UPPER LVL WINDS WITH PRESENT H3 DIVERGENCE BULLSEYE OVER NRN/WRN WI WHERE SNOW SHWRS HAVE BEEN TRAVERSING THRU THE EARLY MRNG. MID LVL WARM AIR IN THE WRAPAROUND JET ALSO INDICATED ON CANADIAN RAOBS LAST EVE HAS LED TO ISENTROPIC UPGLIDE INTO THIS AREA. RUC MDL CONTINUES THIS SUPPORT THRU LATE MRNG FOR FAR NE COUNTIES AND AN ADDITIONAL INCH IS POSSIBLE THERE. BY LATE MRNG SHWR ACTIVITY SHOULD BECOME MORE SCT AND POSSIBLY EXPAND BACK WESTWARD SLIGHTLY. MID LVL LAPSE RATES ARE NOT WHAT THEY WERE YESTERDAY SO COVERAGE SHOULD BE FAR LESS. MAX TEMPS TDY CLIMBING MORE WITH BUILDING THICKNESSES...ESPECIALLY IN SW FA. SHOWERS MAY POTENTIALLY LINGER INTO TONIGHT OVER WRN WI WITH ONE FINAL POTENT VORT LOBE ROTATING SWRD. BEST QG FORCING IS EAST OF FA THOUGH SO HAVE CHC POPS ONLY. ONE MORE CONCERN FOR THIS FCST PACKAGE IS RECORD COLD POTENTIAL TONIGHT OVER WRN AND SWRN FA AND FOR SAT NIGHT OVER CTRL AND ERN FA. BDL WINDS STAY UP TONIGHT BUT UPSTREAM TEMPS IN THE DAKOTAS THIS MORNING WERE NEAR 20F DESPITE THESE WINDS. HAVE NUDGED DOWN TEMPS TONIGHT NEAR THESE VALUES OUT WEST. IT APPEARS THE RECORD LOWS AT BOTH KAXN AND KRWF WILL BE IN JEOPARDY. ONLY A CHANCE FOR CIRRUS ON SAT NIGHT WITH FAR LIGHTER WINDS SO HAVE LEANED TOWARDS FAR COOLER MAV GUIDANCE. THIS WOULD BE NEAR OR AT RECORD LOW TEMPS FOR ERN MN AND WRN WI. LONGER TERM...MONDAY THROUGH FRIDAY TREND IS STILL THERE FOR A LOW PRESSURE TROUGH TO PASS OVER THE AREA MONDAY INTO TUESDAY. INITIAL SPLIT REGIME WITH AN UPPER LOW KICKING OUT TO OUR SE WILL KEEP MOST PRECIP EARLY PART OF MONDAY SE OF OUR AREA. SOMEWHAT OF AN INVERTED TROUGH WEST OF US WILL CAUSE SOME RAIN TO DEVELOP OVER DAKOTAS AND NW PART OF OUR CWA ON MONDAY AND BETTER CHANCE OVER ENTIRE AREA MONDAY NIGHT AND TUESDAY. ENSEMBLE POPS SIMILAR TO YESTERDAY WITH THIS DEVELOPMENT BUT HANGS ON TO HIGHER POPS THROUGH THURSDAY. THIS SEEMS A LITTLE OVERDONE AS BOTH GFS AND ECMWF SHOW A BREAK..WITH THE TROUGH MOVING THROUGH MOST OF THE AREA BY WEDNESDAY. THE SLIGHT CHANCE IS OK TUESDAY NIGHT AND WEDNESDAY FOR NOW..WITH A CHANCE OF RAIN AND SNOW MIX BEHIND THE TROUGH. MILDER TEMPS STILL LOOK GOOD FOR MONDAY AND TUESDAY...FAIRLY CLOSE TO NORMAL. ENSEMBLE 850 TEMP ANOMS LOOK COLDER AGAIN BY LATE IN THE PERIOD THOUGH. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WIND ADVISORY UNTIL 6 PM CDT THIS AFTERNOON FOR BLUE EARTH-BROWN- CHIPPEWA-DOUGLAS-FARIBAULT-FREEBORN-KANDIYOHI-LAC QUI PARLE- MARTIN-NICOLLET-POPE-REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT- WATONWAN-YELLOW MEDICINE COUNTY(IES). WI...NONE. && $$ MTF/JPR/KAT mn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE RALEIGH NC 1052 AM EDT FRI OCT 13 2006 .SHORT TERM /REST OF TODAY THROUGH TONIGHT/... LONGWAVE TROUGH EXTENDED LATE THIS MORNING FROM THE UPPER LOW OVER THE GREAT LAKES THROUGH THE OHIO AND TENNESSEE VALLEYS...WITH A MID-LEVEL SPEED MAX MOVING THROUGH KENTUCKY AND TENNESSEE AS INDICATED ON THE 12Z UPPER-AIR ANALYSES. JUST AHEAD OF THIS SPEED MAX A BAND OF MOSTLY MID CLOUDS EXTENDED FROM SOUTHEAST VIRGINIA THROUGH CENTRAL NORTH CAROLINA INTO SOUTH CAROLINA. GRADUAL CLEARING IS TAKING PLACE AS THE SPEED MAX SHIFTS EAST...WITH BOTH THE RUC AND THE LATEST NAM SUGGESTING THE MID-LEVEL MOISTURE PUSHING EAST OF CENTRAL NORTH CAROLINA BETWEEN 18Z AND 21Z. KGSO 12Z SOUNDING SHOWED THAT THE MOISTURE IS PRIMARILY CONFINED TO A NARROW LAYER BETWEEN 750MB AND 650MB. WITH SUBSIDENCE AND DIMINISHING 850MB AND 700MB THETA-E FORECAST...ANTICIPATE MOST OF CENTRAL NORTH CAROLINA...IF NOT ALL...ACHIEVING CONSIDERABLE SUN BY 21Z. TEMPERATURE FORECAST ON TRACK AND CHANGED LITTLE...NUDGED UP A DEGREE IN SOME SPOTS...AS MORNING LOWS COUPLED WITH 1000- 850MB THICKNESSES SUGGEST 60S SHOULD BE THE RULE...MAINLY LOWER 60S IN THE NORTHWEST AND MID TO UPPER 60S ELSEWHERE GIVEN ANTICIPATED SUN DEVELOPING THIS AFTERNOON. FROST ADVISORY CONTINUES IN THE NORTHWEST PIEDMONT AND AFTERNOON CONCERNS WILL BE ON POTENTIAL FOR EXPANSION. DEW POINT FORECAST SHOWS READINGS POSSIBLY FALLING INTO THE 20S OVERNIGHT IN MANY LOCATIONS. DRY AIR WILL BE IN PLACE...AND WINDS SHOULD BE LIGHT. WILL REVIEW LATEST GUIDANCE THIS AFTERNOON...BUT SOME OF THE 06Z MODEL RUN MOS HAD LOWS OF 35 AT RDU...RWI...AND VUJ. WILL REVIEW AFTERNOON DATA AND MAKE ANY MODIFICATIONS FOR THE AFTERNOON ZONE FORECAST ISSUANCE. THANKS TO GSP FOR MORNING COLLABORATION. GRIDDED AND WORDED AFTERNOON UPDATE ALREADY ISSUED. && .PREV DISCUSSION... (ISSUED 335 AM EDT FRI OCT 13 2006) SHORT TERM /TODAY THROUGH SUNDAY/... TODAY: Q-VECTOR FORCING AND A 50-60 KT MID LEVEL JETLET CONTINUE TO PRODUCE BROKEN ALTOCUMULUS OVER NORTHERN AL/GA... AND AS THIS JET ROUNDS THE TROUGH BASED AND PASSES OVER CENTRAL/EASTERN NC THIS MORNING WITH MODERATE Q-VECTOR CONVERGENCE OVER NC... EXPECT THE MID CLOUDS TO FILL IN FOR PARTLY TO MOSTLY CLOUDY SKIES OVER MUCH OF THE CWA... BUT MAINLY EASTERN SECTIONS... THROUGH MIDDAY. THE POLAR FRONT HAS BEEN DROPPING SLOWLY SOUTHEAST OVER THE LAST SEVERAL HOURS AND THIS PACE SHOULD CONTINUE THIS MORNING WITH SURFACE DEWPOINTS PLUMMETING. DESPITE THE MID LEVEL OMEGA... WITH SUCH A DRY SUBCLOUD LAYER THE CHANCES FOR MEASURABLE RAIN APPEAR SMALL AND WILL GO WITH JUST SCATTERED SPRINKLES THIS MORNING OVER ALL BUT THE NORTHWEST CWA. EXPECT INCREASING SUNSHINE IN THE AFTERNOON. HIGHS PRIMARILY IN THE LOWER-MID 60S ARE CONSISTENT WITH THE PREVIOUS FORECAST... LATEST MOS GUIDANCE... AND OUR LOCAL MAX TEMP TECHNIQUE WITH A LOW LEVEL DRY ADIABATIC PROFILE. TONIGHT THROUGH SUNDAY: A RELATIVELY QUIET PERIOD WITH THE MODIFYING POLAR HIGH BUILDING IN FROM THE WEST-SOUTHWEST. CONCERN EXISTS TONIGHT FOR SCATTERED FROST OVER THE NORTHWESTERN PIEDMONT WITH SURFACE WINDS DECREASING TO LESS THAN 5 KT AND LOW TEMPS IN THE MID 30S. LOW AND SHELTERED LOCATIONS ARE LIKELY TO BE A FEW DEGREES COLDER THAN URBAN LOCATIONS IN THE TRIAD REGION. SURFACE DEWPOINTS ARE PROJECTED TO BE IN THE UPPER 20S TO NEAR 30... WHICH WILL RESULT IN ENOUGH SPREAD FOR MINIMAL FROST IN THE MILDER LOCATIONS... HOWEVER OUTLYING AREAS MAY SEE RELATIVE HUMIDITIES SUFFICIENT FOR PATCHY FROST. WILL ISSUE A FROST ADVISORY FOR THE NORTHWESTERN COUNTIES FOR LATE TONIGHT. LOWS 34-41 ACROSS THE CWA. THE LAST BIG BATCH OF VORTICITY SWINGS AROUND THE POLAR VORTEX BASE THROUGH THE ST. LAWRENCE VALLEY OVER THE WEEKEND. MOSTLY CLEAR SKIES ARE EXPECTED OVER NC INTO SUNDAY AS THE SURFACE HIGH BUILDS IN. MODEL THERMAL AND MOISTURE PROFILES DO SUGGEST POSSIBLE OROGRAPHICALLY ENHANCED HIGH CLOUDS LATE SATURDAY NIGHT INTO SUNDAY MORNING... AS A WEAK SURFACE TROUGH DROPS THROUGH THE REGION. HIGHS 65-70 SATURDAY... THEN LOWS 35-42 AND HIGHS 66-72 SUNDAY. DUE TO THE GFS'S MULTIPLE SUSPECT MID LEVEL PERTURBATIONS... PREFER THE NAM'S SLOWER INCREASE IN HIGH CLOUDS SUNDAY AFTERNOON AHEAD OF THE NEXT SYSTEM IN THE SOUTHERN STREAM. -GIH LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... VERY FEW CHANGES NEEDED. AGREEMENT BETWEEN THE GFS AND ECMWF ON THE EJECTION OF THE SOUTHERN STREAM VORTEX ISN'T PERFECT BUT IT'S IMPROVING COMPARED TO WHAT IT WAS EARLIER THIS WEEK. THE GULF OPENS UP STARTING MONDAY WITH A BRISK SOUTHERLY 850 MB FLOW. ISENTROPIC UPGLIDE PICKS UP IN EARNEST MONDAY NIGHT... AND HAVE BROUGHT IN THE HIGH CHANCE POPS ABOUT 6 HOURS EARLIER. THE GFS THEN KEEPS THIS VORTICITY MAX INTACT AS IT TRAVERSES NC... LIKELY OVERBLOWN DUE TO CONVECTIVE FEEDBACK... WHILE THE ECMWF DAMPENS THE WAVE AS IT ENCOUNTERS THE UPPER RIDGING OVER THE GULF. LATER SHIFTS MAY NEED TO RAISE POPS UP TO LIKELY OR HIGHER ONCE TIMING BECOMES MORE DEFINED... BUT FOR NOW WILL KEEP POPS AT HIGH CHANCES THROUGH TUESDAY. HAVE BUMPED TUESDAY MAX TEMPS DOWN A COUPLE OF DEGREES WITH SHOWERS AND CLOUDY SKIES. THEN MEAN RIDGING BUILDS FROM THE GULF UP THROUGH THE SOUTHEAST STATES WITH POSITIVELY TILTED MEAN TROUGHING FROM CENTRAL CANADA TO THE SOUTHWEST STATES... AND HAVE HELD ONTO THE TRANSITION TO DRY WEATHER FOR WEDNESDAY/THURSDAY WITH TEMPERATURES CLIMBING TO ABOVE NORMAL. -GIH AVIATION... ALTOCUMULUS/ALTOSTRATUS BEGINNING TO EXPAND ACROSS WESTERN INTO CENTRAL NC AT 300 AM. THIS JET INDUCED CLOUDINESS IS EXPECTED TO OVERSPREAD ALL OF CENTRAL NC THROUGH 12Z... THEN EXIT TO THE NE BETWEEN 14Z-19Z. OTHERWISE... VFR CONDITIONS EXPECTED THROUGH THE DAY INTO TONIGHT. -PWB && .RAH WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY FOR NCZ007-021>023-038-039 FROM 2 AM SATURDAY TO 7 AM SATURDAY. && $$ SHORT TERM...DJF nc AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GRAND FORKS ND 840 PM CDT FRI OCT 13 2006 FORECAST CHALLENGE CONCERNS TEMPERATURES/CLOUD TRENDS AND RESIDUAL PCPN CHANCES. HAVE JUST CANNED WIND/SNOW AND BLOWING SNOW ADVISORIES AS CONDITIONS IMPROVING AS PERSITENT LOW OVER S ONT LIFTS NE AND FILLS. LAST WAVE ROTATING SOUTHWARD THROUGH FA HAS PUSHED BACK EDGE OF CLOUD SHIELD WESTWARD INTO VALLEY REGION HOWEVER NO RETURNS SHOWING UP ON RADAR OR ANY INDICATION WITH METARS. CANADIAN RADARS CONTINUE TO SHOW -SN FEEDING INTO NE MN HOWEVER VSBY'S BETTER THAN 4 MILES OVER OUR NE FA SO ADDITIONAL ACCUMULATIONS NOT EXPECTED BUT WILL KEEP LOW RANGE POPS GOING. INTERESTING VORTICIES THIS AFTERNOON/EVENING FROM WATER VAPOR IMAGERY IN ZONE OF VERY DRY AIR OVER WESTERN FA. SURFACE DEWPOINTS DROPPED INTO SINGLE DIGITS FROM DVL-JMS WITH RUC SOUNDINGS INDICATING PRECIPITABLE H20 VALUES AT DVL < .20 INCH. WITH DRY AIR /SKC AND DIMINISHING WIND AM A LITTLE CONCERNED ABOUT MIN TEMPERATURES THIS AREA. MAY LOWER A FEW DEGREES TO BE SAFE AS CURRENT READINGS RUNNING BLO GUIDANCE. REMAINDER OF REGION SHOULD BE OK AS WINDS A LITTLE STRONGER/PERSISTENT WITH PATCHY CLOUD COVER AND NOT QUITE AS DRY. MINOR CHANGES PLANNED TO CURRENT FORECAST. $$ .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ VOELKER nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 905 AM CDT FRI OCT 13 2006 .CURRENT OBSERVATIONAL OVERVIEW... 14Z SURFACE ANALYSIS DEPICTED STRONG AREA OF LOW PRESSURE NORTH OF LAKE SUPERIOR WITH RESULTANT TIGHT CYCLONIC PRESSURE GRADIENT CONTINUING OVER CWFA. LATEST WATER VAPOR IMAGERY SHOWED VERY POTENT VERTICALLY STACKED LOW NORTH OF THE UPPER GREAT LAKES WITH SPOKES OF SHORTWAVE ENERGY I.E. CHANNELED VORTICITY ROTATING SOUTHEAST ACROSS THE DAKOTAS. BETTER LIFT/PIVA IN CONJUNCTION WITH LOW WAS FROM THE ARROWHEAD OF MN INTO THE UPPER GREAT LAKES. .FORECAST DETAILS... MAIN FORECAST CHALLENGE THIS AFTERNOON CONCERNS WHAT TO DO WITH CURRENT HEADLINES. 12Z RUC MODEL MAINTAINS WIND ADVISORY CRITERIA THROUGH THE DAY AS TIGHT PRESSURE GRADIENT PERSISTS. IN ADDITION MODEL MAINTAINS SOME WEAK LIFT FROM THE CENTRAL VALLEY INTO MINNESOTA THROUGH THE AFTERNOON IN RESPONSE TO S/W INTERACTION. WITH ADDITIONAL SNOW SHOWER ACTIVITY EXPECTED ACROSS THE NORTHEAST ZONES WILL LET SNOW/BLOWING ADVISORY CONTINUE UNTIL MIDDAY AND THEN RE-EVALUATE. BASED ON ABOVE NO UPDATE PLANNED FOR THE MORNING HOWEVER PLAN TO SEND SOME TYPE OF UPDATE EARLY THIS AFTERNOON TO EITHER EXTEND/EXPIRE SNOW/BLOWING SNOW ADVISORY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WIND ADVISORY UNTIL 4 PM CDT FRIDAY FOR NDZ006-NDZ007-NDZ008- NDZ014-NDZ015-NDZ016-NDZ024-NDZ026-NDZ027-NDZ028-NDZ029- NDZ030-NDZ038-NDZ039-NDZ049-NDZ052-NDZ053-NDZ054. MN...WIND ADVISORY UNTIL 4 PM CDT FRIDAY FOR MNZ001-MNZ002-MNZ003- MNZ004-MNZ007-MNZ013-MNZ014-MNZ015-MNZ016-MNZ022-MNZ023- MNZ024-MNZ027-MNZ028-MNZ029-MNZ030-MNZ031-MNZ032-MNZ040. SNOW AND BLOWING SNOW ADVISORY UNTIL 1 PM CDT FRIDAY FOR MNZ005- MNZ006-MNZ008-MNZ009-MNZ017. && $$ BERG nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 1200 PM CDT FRI OCT 13 2006 .AVIATION... 4000 FT CLOUD DECK CONTINUES ITS SLOW MOVE NORTH AND SHOULD BE AFFECTING KSJT BY TAF ISSUANCE. CLOUD DECK SHOULD SETTLE IN OVER SOUTH AND CENTRAL TEXAS THROUGH EARLY AFTERNOON BEFORE BREAKING UP. MOISTURE SURGING INTO TEXAS AHEAD OF A WEST COAST SYSTEM WILL BRING CEILINGS OVER BOTH TERMINALS DOWN TO THE 1K TO 2K FOOT LEVEL AFTER MIDNIGHT FOR KSJT AND BY DAYBREAK AT KABI. WINDS WILL REMAIN LIGHT SOUTHEASTERLY THROUGH THE NEXT 24 HOURS WITH NO THUNDERSTORM DEVELOPMENT IN THE AREA. && .PREV DISCUSSION... (ISSUED 1009 AM CDT FRI OCT 13 2006) UPDATE... WILL SEND AN UPDATE OUT SHORTLY PER CURRENT TRENDS...HAVE TWEAKED CLOUD COVER, TEMPS AND DP. THE LATEST RUC DEEPENS AND KEEPS THE UPPER LOW OFF THE SOUTHERN CALIFORNIA COAST THROUGH EARLY EVENING WITH SOME SHOWER ACTIVITY MOVING NORTH INTO THE SOUTHERN FORECAST AREA LATE THIS EVENING. FORECAST HANDLES THIS WELL - NO FURTHER CHANGES. PREV DISCUSSION... (ISSUED 617 AM CDT FRI OCT 13 2006) AVIATION... LOW CLOUDS JUST OUTSIDE OF MVFR AT 3800 FEET ARE AFFECTING THE KJCT AREA THIS MORNING. THESE CLOUDS APPEAR TO BE DEVELOPING SOUTH OF A MID LEVEL CLOUD LAYER...AND MAY HAVE SOME TROUBLE MOVING NORTHWARD FROM HERE...BUT WILL GO AHEAD AND INSERT A TEMPO INTO THE KSJT TERMINAL TAF FOR SOME LOW CLOUDS THIS MORNING. EXPECT THESE LOWER CLOUDS TO FILL IN BY THIS EVENING ACROSS MOST OF WEST CENTRAL TEXAS AS MOIST SOUTHWEST FLOW ALOFT INCREASES AHEAD OF AN UPPER LEVEL DISTURBANCE OVER COOL AIR AT THE SURFACE. SURFACE WINDS WILL VEER FROM NORTHEAST TO SOUTHEAST BY 00Z TO 03Z THIS EVENING. EXPECT PRECIPITATION CHANCES TO INCREASE BEYOND THE TAF FORECAST PERIOD. SHOULD SEE MAINLY VFR CONDITIONS THROUGH THE NEXT 6 HOURS AT BOTH KABI AND KSJT. 20 PREV DISCUSSION... (ISSUED 405 AM CDT FRI OCT 13 2006) SHORT TERM... WV IMAGERY INDICATING STRONG UPPER LEVEL LOW OFF THE SOUTHERN CALIFORNIA COAST WITH THE POLAR VORTEX LOCATED JUST NORTH OF THE GREAT LAKES. WEAK SURFACE HIGH PRESSURE OVER OKLAHOMA AND NORTHERN TEXAS AND COLD FRONT OVER DEEP SOUTH TEXAS. MID AND HIGH LEVEL CLOUD COVER TO INCREASE ACROSS CWFA TODAY AND TONIGHT. SOME LOW LEVEL MOISTURE RETURN AND WEAK UPPER SHORT WAVE ENERGY WILL YIELD TO ISOLD TO SCT SHRA ACROSS THE SOUTHERN CWFA TONIGHT. LONG TERM... MODELS SHOW DIFFERENCES IN MOVING SOUTHWEST US UPPER LEVEL LOW EASTBOUND. THE GFS IS FASTER MOVING AND OPENING SYSTEM ACROSS THE SOUTHERN PLAINS SUNDAY NIGHT AND MONDAY AND NAM IS SLOWER...HOLDING SYSTEM FURTHER BACK TO THE WEST OVER NORTHERN MEXICO BY MONDAY MORNING. LIKE THE SLOWER NAM SOLUTION DUE THE LOW BEING CURRENTLY CUT OFF FROM THE WESTERLIES...HOWEVER MAY END UP A LITTLE FURTHER EAST. ABUNDANT GULF MOISTURE WILL FLOW BACK TO THE NORTH ON LOW LEVEL JET THIS WEEKEND...ALONG WITH PW VALUES OF 1.5 TO 2 INCHES BY SUNDAY. MODELS INDICATING STRONG VERTICAL MOTION AND FAVORABLE JET DYNAMICS. LOOKS LIKE A WET WEEKEND WITH ROUNDS OF CONVECTION WITH WIDESPREAD QPF AMOUNTS OF 1 TO 2 INCHES POSSIBLE ACROSS WEST CENTRAL TEXAS. A FEW SEVERE STORMS POSSIBLE...ESPECIALLY IF BETTER SURFACE BASE INSTABILITY SETS UP. UPPER LEVEL LOW LIFTS OUT ACROSS SOUTHERN PLAINS MONDAY AFTERNOON AND NIGHT...WITH ONE LAST ROUND OF TSTMS. LOOKS LIKE DIRER WEATHER FOR TUESDAY...THEN UPPER LEVEL FLOW BACKS TO SOUTHWEST AND NEXT FRONT MOVES SOUTH INTO TEXAS. GOING WITH CHC POPS WEDNESDAY AND THURSDAY. SJT WATCHES/WARNINGS/ADVISORIES... NONE. SJT WATCHES/WARNINGS/ADVISORIES... NONE. $$ && .PRELIMINARY POINT TEMPS/POPS... ABILENE 57 74 64 79 / 20 60 80 60 SAN ANGELO 60 76 65 78 / 20 70 80 60 JUNCTION 62 76 67 82 / 30 70 80 60 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 15/99/99 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 1009 AM CDT FRI OCT 13 2006 .UPDATE... WILL SEND AN UPDATE OUT SHORTLY PER CURRENT TRENDS...HAVE TWEAKED CLOUD COVER, TEMPS AND DP. THE LATEST RUC DEEPENS AND KEEPS THE UPPER LOW OFF THE SOUTHERN CALIFORNIA COAST THROUGH EARLY EVENING WITH SOME SHOWER ACTIVITY MOVING NORTH INTO THE SOUTHERN FORECAST AREA LATE THIS EVENING. FORECAST HANDLES THIS WELL - NO FURTHER CHANGES. && .PREV DISCUSSION... (ISSUED 617 AM CDT FRI OCT 13 2006) AVIATION... LOW CLOUDS JUST OUTSIDE OF MVFR AT 3800 FEET ARE AFFECTING THE KJCT AREA THIS MORNING. THESE CLOUDS APPEAR TO BE DEVELOPING SOUTH OF A MID LEVEL CLOUD LAYER...AND MAY HAVE SOME TROUBLE MOVING NORTHWARD FROM HERE...BUT WILL GO AHEAD AND INSERT A TEMPO INTO THE KSJT TERMINAL TAF FOR SOME LOW CLOUDS THIS MORNING. EXPECT THESE LOWER CLOUDS TO FILL IN BY THIS EVENING ACROSS MOST OF WEST CENTRAL TEXAS AS MOIST SOUTHWEST FLOW ALOFT INCREASES AHEAD OF AN UPPER LEVEL DISTURBANCE OVER COOL AIR AT THE SURFACE. SURFACE WINDS WILL VEER FROM NORTHEAST TO SOUTHEAST BY 00Z TO 03Z THIS EVENING. EXPECT PRECIPITATION CHANCES TO INCREASE BEYOND THE TAF FORECAST PERIOD. SHOULD SEE MAINLY VFR CONDITIONS THROUGH THE NEXT 6 HOURS AT BOTH KABI AND KSJT. 20 PREV DISCUSSION... (ISSUED 405 AM CDT FRI OCT 13 2006) SHORT TERM... WV IMAGERY INDICATING STRONG UPPER LEVEL LOW OFF THE SOUTHERN CALIFORNIA COAST WITH THE POLAR VORTEX LOCATED JUST NORTH OF THE GREAT LAKES. WEAK SURFACE HIGH PRESSURE OVER OKLAHOMA AND NORTHERN TEXAS AND COLD FRONT OVER DEEP SOUTH TEXAS. MID AND HIGH LEVEL CLOUD COVER TO INCREASE ACROSS CWFA TODAY AND TONIGHT. SOME LOW LEVEL MOISTURE RETURN AND WEAK UPPER SHORT WAVE ENERGY WILL YIELD TO ISOLD TO SCT SHRA ACROSS THE SOUTHERN CWFA TONIGHT. LONG TERM... MODELS SHOW DIFFERENCES IN MOVING SOUTHWEST US UPPER LEVEL LOW EASTBOUND. THE GFS IS FASTER MOVING AND OPENING SYSTEM ACROSS THE SOUTHERN PLAINS SUNDAY NIGHT AND MONDAY AND NAM IS SLOWER...HOLDING SYSTEM FURTHER BACK TO THE WEST OVER NORTHERN MEXICO BY MONDAY MORNING. LIKE THE SLOWER NAM SOLUTION DUE THE LOW BEING CURRENTLY CUT OFF FROM THE WESTERLIES...HOWEVER MAY END UP A LITTLE FURTHER EAST. ABUNDANT GULF MOISTURE WILL FLOW BACK TO THE NORTH ON LOW LEVEL JET THIS WEEKEND...ALONG WITH PW VALUES OF 1.5 TO 2 INCHES BY SUNDAY. MODELS INDICATING STRONG VERTICAL MOTION AND FAVORABLE JET DYNAMICS. LOOKS LIKE A WET WEEKEND WITH ROUNDS OF CONVECTION WITH WIDESPREAD QPF AMOUNTS OF 1 TO 2 INCHES POSSIBLE ACROSS WEST CENTRAL TEXAS. A FEW SEVERE STORMS POSSIBLE...ESPECIALLY IF BETTER SURFACE BASE INSTABILITY SETS UP. UPPER LEVEL LOW LIFTS OUT ACROSS SOUTHERN PLAINS MONDAY AFTERNOON AND NIGHT...WITH ONE LAST ROUND OF TSTMS. LOOKS LIKE DIRER WEATHER FOR TUESDAY...THEN UPPER LEVEL FLOW BACKS TO SOUTHWEST AND NEXT FRONT MOVES SOUTH INTO TEXAS. GOING WITH CHC POPS WEDNESDAY AND THURSDAY. SJT WATCHES/WARNINGS/ADVISORIES... NONE. && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 15/99 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 900 AM CDT FRI OCT 13 2006 .DISCUSSION...THE COLD FRONT CONTINUES TO STRUGGLE SOUTHWARDS ACROSS THE NORTHERN TIER OF THE BRO CWA AND IS PRODUCING ISOLD TO SCT CONV FROM EASTERN BROOKS COUNTY OUT TO 60 TO 80 NM OFFSHORE OF KENEDY COUNTY. BOTH THE NAM AND THE GFS TAKE THEIR TIME MOVING THIS FEATURE THROUGH THE REGION AND CONSIDERING THE OVERALL RADAR TRENDS THIS SLOWNESS LOOKS OK. THE AIRMASS SOUTH OF THE FRONT IS PRETTY MOIST AND UNSTABLE WITH A PWAT AT THE 12Z BRO SOUNDING AROUND 2.2 INCHES AND A CAPE OF 5356 J/KG. DESPITE THE PRESENCE OF THE LOW LEVEL CONVERGENCE AHEAD OF THE FRONT...THE INSTABILITY AND DEEPER TROPICAL MOISTURE...THE ONE LIMITING FACTOR FOR SVR CONV DEVELOPMENT WILL BE THE MID AND UPPER LEVEL CLOUD COVER ALREADY IN PLACE OVER THE REGION. THIS WILL LIKELY LIMIT ANY SERIOUS AFTERNOON HEATING HELPING ENHANCE THE CONV. BECAUSE OF THIS AND THE SLOW MOVEMENT OF THE CELLS BELIEVE THE MAIN THREAT IN THE SHORT TERM WILL BE LOCALLY HEAVY RAINFALL. THE GFS APPEARS TO BE SUFFERING FROM SOME FEEDBACK PROBLEMS AS MENTIONED IN THE LATEST PMDHMD AND THE CORRESPONDING POPS SEEM TOO HIGH CONSIDERING THE CURRENT RADAR TRENDS. THE MORE CONSERVATIVE NAM AND RUC GUIDANCE LOOKS MORE REASONABLE AND WILL STICK WITH THESE IN THE SHORT TERM. CONSIDERING THE LIMITED AREAL COVERAGE OF THE CURRENT CONV...THE LACK OF INTENSITY AT THE MOMENT AND THE HIGHER OVERALL FFG...DO NOT BELIEVE THAT A FFA WOULD BE NEED AT THE MOMENT. BUT THIS SITUATION WILL STILL NEED TO BE MONITORED CLOSELY OVER THE NEXT 12 TO 24 HOURS. WILL MAKE ONLY SOME MINOR ADJUSTMENTS TO THE CURRENT ZFP FOR POPS...BUT THE OVERALL WORDING LOOKS OK. && .MARINE...BUOY020 REPORTED SSE WINDS AROUND 10 KTS AND SEAS NEAR 3 FEET. A COLD FRONT CONTINUES MOVING SOUTH IS EXPECTED TO PASS THE BUOY IN A COUPLE MORE HOURS. WINDS WILL BECOME NORTH AT 15 TO 20 KTS. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS MORNING AS THE FRONT MOVES SOUTH. WINDS WILL VEER TO EAST LATE FRIDAY...WITH BRIEF SCA CONDITIONS POSSIBLE OFFSHORE ON SATURDAY AS A COASTAL TROUGH TRIES TO FORM. SOUTHEAST WINDS WILL ALSO RETURN ON SATURDAY...WITH MODERATE SOUTH WINDS RETURNING BY EARLY NEXT WEEK. SEAS WILL BUILD TO NEAR 6 FEET OFFSHORE BY SAT WITH MODERATE SEAS PREVAILING INTO NEXT WEEK. && .AVIATION...A COLD FRONT...CURRENTLY OVER A LINE FROM CENTRAL ZAPATA THROUGH SRN KENEDY COUNTIES...WILL CONTINUE MVG S TODAY. ALTHOUGH THIS BOUNDARY IS WEAKENING IT WILL PROVIDE A FOCUS FOR SCT CONVECTION. SOUTH OF THE BOUNDARY...VFR CONDITIONS WILL PREVAIL WITH TEMPO MVFR TO IFR CONDITIONS IN ANY CONVECTIVE ACTIVITY. NORTH OF THE BOUNDARY...IFR CIGS WITH MVFR VIS IN BR WILL PREVAIL THIS MORNING BEFORE GRADUALLY IMPROVING TO MVFR CIGS/VFR VIS EARLY THIS AFTERNOON. && .BRO WATCHES/WARNINGS/ADVISORIES...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON OUR INTERNET WEB PAGE AT: HTTP://WWW.SRH.NOAA.GOV/BRO SYNOPTIC/GRIDS...60 MARINE/AVIATION...55 MESO...ABBOTT tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 355 AM MDT SAT OCT 14 2006 .SHORT TERM... (TODAY AND TONIGHT) ...POTENTIAL WET WEATHER MOVING IN THIS AFTERNOON AND TONIGHT... CURRENTLY...WATER VAPOR IMAGERY AND RUC MODEL UPPER AIR ANALYSES ANIMATION SHOWED CUTOFF CLOSED LOW SPINNING OVER SOUTHERN CA WITH TWO AREAS OF PRECIPITATION...NORTHEAST QUADRANT ACROSS SOUTHERN NV AND EAST AHEAD OF THE LOW ACROSS AZ INTO SOUTHERN UT. LIGHTNING CONTINUES TO BE GENERATED WITH THE TWO AREAS OF PRECIPITATION. MEANWHILE ACROSS THE CENTRAL ROCKIES...JUST SOME SCT-BKN CI/CS CLOUDS MOVING THROUGH THE AREA. SFC DEW POINTS HAVE CLIMBED INTO THE 40S ACROSS MUCH OF THE SOUTHEASTERN CO PLAINS...ESPECIALLY IN THE LOWER AR RIVER VALLEY. 50F DEW POINTS NOT TOO FAR ANY AND CURRENT ABOUT TO ADVECT INTO THE TX PANHANDLE. SOME PATCHY 3-5SM SHALLOW FOG AND IFR STRATUS CURRENTLY DEVELOPING IN THE LOWER AR RIVER VALLEY AND EASTERN CO PER METARS AND TOUGH TO SEE ON SATELLITE DUE TO THE HIGH CLOUDS MASKING THE LOWER CLOUDS. TODAY...06Z/14 WRF MODEL SHOWING THE POTENTIAL FOR SCT-BKN LIFR-IFR STRATUS TO DEVELOP ACROSS EASTERN CO AS SFC-H8 HUMIDITY INCREASES TO 90-95 PERCENT BETWEEN NOW AND 18Z/14. WILL ADD SOME "PATCHY" FOG ACROSS SOUTHEAST CO THIS MORNING. PROBABLY A COMBINATION OF RADIATIONAL AND MOISTURE ADVECTION FOG NEAR THE CO/KS BORDER. ANTICIPATING AFOREMENTIONED CUTOFF CLOSED LOW TO SLOWLY MOVE EASTWARD ACROSS SOUTHERN CO. MIDDLE AND UPPER LEVEL SOUTH TO SOUTHWEST WINDS SHOULD CONTINUE TO ADVECT MOISTURE INTO THE CENTRAL ROCKIES BY THIS AFTERNOON. H7-H5 SPECIFIC HUMIDITY VALUES ARE PROGGED TO INCREASE TO 4-5 G/KG...WHICH IS NOT TOO BAD FOR MIDDLE OCT IN THE CENTRAL ROCKIES. H7 TEMPERATURES ARE FORECAST TO BE +6C TO +8C AND H7-H5 STATIC STABILITIES BECOME MODERATELY UNSTABLE...8 C/KM...THIS AFTERNOON. ALSO...WRF AND GFS PROJECTING MIDLEVEL THETA-E ADVECTION...WHICH WILL HELP DESTABILIZE THE ATMOSPHERE. WILL PROBABLY SEE ISOLD-SCT SHOWERS DEVELOPING ACROSS WESTERN AND SOUTH CENTRAL CO LATER THIS MORNING AND AFTERNOON. INITIALLY...IT MAY TAKE A WHILE FOR THE PRECIPITATION TO REACH THE GROUND UNTIL THE LOWER LEVELS CAN BECOME MORE SATURATED. WRF MODEL HAS AN EMBEDDED SHORTWAVE TROUGH IN THE SOUTHWESTERLY FLOW... WHICH THE GFS MODEL DOES NOT...SO THE WRF IS DEVELOPING MORE PRECIPITATION THAN THE GFS THIS AFTERNOON. HARD TO FIND THAT IN THE WATER VAPOR RIGHT NOW...BUT THERE IS CURRENTLY NIGHTTIME PRECIPITATION GOING ON IN AZ...SO SOMETHING IS THERE. GIVEN THE MIDLEVEL INSTABILITY...LIGHTNING IS POSSIBLE THIS AFTERNOON. WENT AHEAD AN TWEAKED POPS UP A LITTLE AND MAINLY AROUND THE CONTINENTAL DIVIDE AND SOUTHERN CO-NM BORDER. MAXIMUM TEMPERATURES MIGHT BE A CHALLENGE...ESPECIALLY ACROSS SOUTHEAST CO. ANY POTENTIAL SNOW WOULD BE AROUND MOUNTAIN PEAKS AS FREEZING AND WET BULB ZERO LEVELS ARE RELATIVELY HIGH. WITH THE HIGH CLOUDS MOVING IN...LOWERING AND THICKENING...WILL NEED THE WIND AND MIXING TO PICK UP TO GET WARMER TEMPERATURES. IF WE CAN MIX TO H7...THEN LOWER 70S ARE POSSIBLE ACROSS SOUTHEAST CO. IF NOT...THEN THE LOWER AR RIVER VALLEY...INCLUDING PUB...MAY HAVE A TOUGH TIME WARMING WHICH IS TYPICAL IN THESE PATTERN. HOWEVER...ANY VIRGA COULD HELP WITH A "HEAT BURST" TO WARM TEMPERATURES UP AT PUB. TOUGH CALL. TONIGHT...MIDLEVEL SHORTWAVE TROUGH MOVES THROUGH THE CENTRAL ROCKIES THIS EVENING. 310K LEVEL ISENTROPIC UPGLIDE...IMPLIED LIFT...STRONGEST ACROSS SOUTHEAST CO...EASTERN NM...AND TX/OK PANHANDLES THIS EVENING AND THEN SHIFTS EASTWARD INTO THE CENTRAL AND SOUTHERN PLAINS OVERNIGHT. INCREASED POPS A CATEGORY OR TWO ACROSS MUCH OF THE CWFA THIS EVENING AND CONTINUED ACROSS EXTREME SOUTHEAST CO OVERNIGHT. THINK MUCH OF THE POTENTIAL PRECIPITATION SHOULD BE OVER AFTER MIDNIGHT ALONG AND WEST OF I-25 CORRIDOR...BUT MAINTAINED LOW POPS DUE TO UNCERTAINTY. IT COULD BE A RELATIVELY MILD NIGHT...ESPECIALLY ACROSS SOUTHEAST CO PLAINS...DUE TO CLOUD COVER AND SFC-PBL SOUTHERLY LOW LEVEL JET DEVELOPING. AGAIN...ANY POTENTIAL SNOWFALL WOULD BE AT THE HIGHER MOUNTAIN ELEVATIONS... GENERALLY AT AND ABOVE 10K FT MSL...BUT COULD LOWER DUE TO STRONG DIABATIC COOLING IN INTENSE PRECIPITATION CORES. METZE .LONG TERM... (SUNDAY THROUGH FRIDAY) ...MAIN CHALLENGE IS UPPER LOW ON SUNDAY... .SUNDAY...NAM...GFS AND EC AGREE THAT THE UPPER LOW WILL MOVE ACROSS NORTHERN NEW MEXICO AND ARIZONA OVER THE WEEKEND. BY SUNDAY AFTERNOON...A DRY SLOT WILL MOVE INTO THE MOUNTAINS WILL LESS CHANCES FOR PRECIPITATION. ON THE PLAINS...LOW LEVEL MOISTURE WILL BE MOST ABUNDANT IN THE SOUTHEAST CORNER...WHERE DEW POINTS MAY APPROACH 50F. NAM TENDS TO BRING MORE OF THE MOISTURE FURTHER WEST WHILE THE GFS DEVELOPS SURFACE LOW OVER BENT AND WESTERN KIOWA COUNTIES...KEEPING THE MOISTURE FURTHER EAST. MAJOR CHANGES TO GRIDS WERE TO INCREASE POPS OVER THE SOUTHEAST CORNER TO HIGH CHANCE CATEGORY...AND TO EXTEND ISOLATED POPS WESTWARD TO THE SOUTHEAST MOUNTAINS. BEST LIFT LOOKS TO BE OVER THE SOUTHEAST CORNER. BUT IF LOW LEVEL MOISTURE EXTENDS WESTWARD TO THE MOUNTAINS...IT WOULD NOT TAKER MUCH LIFT/INSTABILITY TO GET SOME SHOWERS. .MONDAY...A TROUGH CONTINUES TO DEVELOP OVER THE PACIFIC NORTHWEST. WESTERLY FLOW ALOFT DEVELOPS...WITH A LEE TROUGH DEVELOPING ON THE PLAINS. 700MB TEMPERATURES WARM TO 6 TO 8C WITH HIGHS WELL INTO THE 70S ON THE PLAINS. SOME MOISTURE MAY MOVE INTO THE MOUNTAINS BY THE EVENING FOR SOME SHOWERS IN THE CENTRAL MOUNTAINS. .TUESDAY THROUGH THURSDAY...TROUGH OVER THE PACIFIC NORTHWEST MOVES EASTWARD WITH A COLD FRONTAL PASSAGE FROM THE NORTH SOMETIME ON TUESDAY OR EARLY WEDNESDAY. I COOLED MAXIMUMS ON TUESDAY AND WEDNESDAY ESPECIALLY ON THE PLAINS WITH CLOUDY WEATHER LIKELY WITH THE UPSLOPE. IT IS TOO EARLY TO FINELY TUNE THE POPS...BUT IT DID ADD 20 POPS TO THE THE PLAINS ON WEDNESDAY WITH THE TROUGH PASSAGE OVER THE LOW LEVEL UPSLOPE. IN THE MOUNTAINS...A COOL NORTHWEST FLOW WILL DEVELOP...WITH BEST CHANCES FOR PRECIPITATION IN THE CENTRAL MOUNTAINS. .FRIDAY...EC AND OPERATIONAL GFS HAVE SOME SIGNIFICANT DIFFERENCES. EC HAS A TROUGH OVER THE PACIFIC NORTHWEST WITH A RELATIVELY MILD SOUTHWEST FLOW AHEAD OF THE SYSTEM. OPERATIONAL GFS HAS A RIDGE OVER THE PACIFIC NORTHWEST WITH A REINFORCING SURGE OF COLD AIR. SOME MEMBERS OF THE GFS ENSEMBLE HAVE THE TROUGH OVER THE PACIFIC NORTHWEST...SO THIS SOLUTION IS POSSIBLE. GRIDS LEAN TOWARD THE EC SOLUTION WITH POPS MAINLY IN THE CENTRAL MOUNTAINS. --PGW-- && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 17/06 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 424 AM EDT FRI OCT 13 2006 .DISCUSSION... MAIN FCST ISSUES ARE ENDING LAKE EFFECT PCPN WHICH IS NOW WINDING DOWN AND THEN ONSET OF PCPN MON AS SW FLOW DEVELOPS INTO THE GREAT LAKES DOWNSTREAM OF WRN CONUS TROF AMPLIFICATION. WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THE ANOMALOUSLY DEEP MIDLEVEL LOW THAT HAS DOMINATED THE WEATHER OVER UPPER MI THE LAST COUPLE OF DAYS FILLING AND DRIFTING NE. CENTER WAS LOCATED JUST TO THE SW OF JAMES BAY. ONE LAST VIGOROUS SHORTWAVE ROTATING THRU THE CIRCULATION HAS NOW PASSED SE OF THE FCST AREA. SHORTWAVE BROUGHT A BURST OF HEAVIER PCPN TO MUCH OF THE AREA LAST EVENING...ESPECIALLY ACROSS THE W AND N. PCPN HAS SINCE DIMINISHED IN SHARP SUBSIDENCE REGIME IN THE WAKE OF SHORTWAVE. SOME DRYING IN THE LOW/MID LEVELS PER 00Z CWPL SOUNDING IS ALSO HELPING THE DIMINISHING TREND. GREATEST CONCENTRATION OF PCPN IS OCCURRING OVER ALGER/NRN SCHOOLCRAFT/LUCE COUNTIES UNDER LONG FETCH NW LOW-LEVEL FLOW. MIDLEVEL LOW WILL REORGANIZE TOWARD SW HUDSON BAY TODAY WITH CORRESPONDING 500MB HEIGHT RISES OF 100M OR MORE ACROSS FCST AREA BTWN 12Z AND 00Z. MEANWHILE...850MB TEMPS WILL RISE A DEGREE OR TWO FROM CURRENT READINGS AROUND -7/-8C PER RUC ANALYSIS...STILL PLENTY COLD ENOUGH TO GENERATE SOME LAKE EFFECT -SHRA/-SHSN. MODELS HINT AT A WEAK SHORTWAVE STREAKING ACROSS THE AREA...BUT FORCING AS VIEWED IN DEEP LAYER QVECTOR CONVERGENCE FIELDS IS QUITE WEAK. IT MIGHT YIELD SOME INCREASE IN LAKE EFFECT PCPN COVERAGE...BUT PCPN WILL OVERALL REMAIN LIGHT. WINDS BACK FROM THE CURRENT NW DIRECTION TO A WNW TO W DIRECTION BY LATE AFTN WHICH WILL SHIFT PCPN AREAS CLOSER TO THE SHORE E OF MARQUETTE. TO THE W...WIND DIRECTION WILL FAVOR ONTONAGON/S HALF OF HOUGHTON/BARAGA COUNTIES FOR BEST COVERAGE. MAX TEMPS SHOULD BE NEAR HIGHS OBSERVED FRI SINCE THERE HAS BEEN LITTLE CHANGE IN AIRMASS. AS HEIGHTS CONTINUE TO RISE TONIGHT WITH MIDLEVEL FLOW BACKING... WAA GETS UNDERWAY. BY 12Z SUN...850MB TEMPS WILL RANGE FROM ABOUT -4C OVER WRN LAKE SUPERIOR TO -6C OVER THE E. -4C WILL BE ABOUT SUFFICIENT TO BRING AN END TO LINGERING LAKE EFFECT PCPN OVER THE W...WHERE PCPN SHOULD BE CONFINED TO MAINLY THE KEWEENAW PENINSULA BY LATE IN THE NIGHT AS LOW-LEVEL WINDS BACK ALMOST DUE W. EXAMINATION OF NAM/GFS FCST SOUNDINGS SHOW SOMEWHAT OF AN INVERTED-V LOOK AT KCMX WHICH SUGGESTS PCPN OVER THE W HAS A GOOD CHANCE OF ENDING COMPLETELY...PERHAPS AS EARLY AS MIDNIGHT. SO...WILL DROP PCPN MENTION DOWN TO JUST FLURRIES/SPRINKLES AFTER MIDNIGHT. SOME LIGHT PCPN WILL CONTINUE ALONG THE LAKESHORE E OF MUNISING THRU 12Z WITH LINGERING SUFFICIENT INSTABILITY. IN THE INTERIOR...LOSS OF OVERLAKE TRAJECTORIES SUGGESTS SKIES WILL BECOME PARTLY CLOUDY...MAYBE MOSTLY CLEAR. GFS MOS MINS LOOK REASONABLE WITH LOWS GENERALLY IN THE LOW/MID 20S. IF SOME OF THE AREAS OVER THE W THAT STILL HAVE A DECENT SNOW COVER CLEAR...TEMPS COULD EASILY DROP WELL DOWN INTO THE TEENS IN THE USUAL COLD SPOTS. IN FACT...GFS MOS COOP GUIDANCE HAS A MIN OF 17F AT CHAMPION. WILL GO WITH LOWEST TEMPS (UPPER TEENS) IN GOGEBIC/SRN ONTONAGON INTO SRN BARAGA/NW IRON COUNTIES. COULD BE QUITE A BIT COLDER IF LOW-LEVEL WINDS FIELDS JUST OFF THE SFC ARE LIGHTER. ANY LINGERING PCPN ALONG THE LAKESHORE E OF MUNISING WILL END SUN MORNING AS WARMING CONTINUES. OTHERWISE...SUN WILL BE A PLEASANT DAY IN COMPARISON TO RECENT DAYS AS TEMPS CLIMB BACK TOWARD MORE TYPICAL MID OCT READINGS UNDER AT LEAST PARTLY SUNNY SKIES. BASED ON NAM/GFS FCST SOUNDINGS FOR 12Z AND 18Z SUN...MOS GUIDANCE LOOKS A BIT TOO OPTIMISITIC WITH HIGH TEMPS. 50F LOOKS ABOUT AS WARM AS IT COULD GET AND WILL CONFINE THOSE TEMPS TO THE SCNTRL FCST AREA. OTHERWISE... MID/UPPER 40S SHOULD BE THE RULE. SUN NIGHT THRU TUE...PATTERN SHIFTS TO TROFFING FROM CNTRL CANADA TO THE SW CONUS. IN THE TRANSITION TO THIS NEW PATTERN...WAA PATTERN COMBINED WITH ONE OR MORE WEAK SHORTAVES MOVING TO THE UPPER MISSISSIPPI VALLEY/WRN GREAT LAKES WILL BRING THE FIRST POTENTIAL OF RAIN BEGINNING MON. DECENT SHOT OF ISENTROPIC ASCENT AND A STRONG PUSH OF GULF MOISTURE N INTO THE UPPER LAKES (PRECIPITABLE INCREASES TO AROUND 1 INCH OR 175-200PCT OF NORMAL) SUGGEST RAIN IS A GOOD BET MON...SPREADING FROM SW TO NE DURING THE DAY. HAVE ACCORDINGLY BUMPED UP POPS TO LIKELY. CONTINUED WAA/MOIST ISENTROPIC ASCENT WILL KEEP RAIN CHANCES GOING THRU MON NIGHT/TUE. COLD FRONT SHOULD MOVE ACROSS THE AREA TUE PER GFS/UKMET/CANADIAN. ECMWF IS A GOOD 12HRS SLOWER. THEN THERE IS PLENTY OF UNCERTAINTY MIDWEEK AS GFS FOR THE LAST 4 RUNS BRINGS ANOTHER WAVE NE INTO THE GREAT LAKES WITH SFC LOW TRACKING NE THRU LWR MI THU...SUGGESTING A POTENTIAL ACCUMULATING SNOW FOR PARTS OF THE FCST AREA. 00Z UKMET HAS TRENDED TOWARD THIS SOLUTION. ECMWF HAS NO WAVE...BUT BRINGS ANOTHER DEEP VORTEX INTO THE UPPER LAKES BY LATE THU. GIVEN THE UNCERTAINTY...NO CHANGES HAVE BEEN MADE TO FCST BEYOND TUE SINCE GENERAL TRENDS ARE CAPTURED. && .MQT WATCHES/WARNINGS/ADVISORIES... GALE WARNING E HALF OF LAKE SUPERIOR. && $$ ROLFSON mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 1126 AM CDT SAT OCT 14 2006 .FIRE WEATHER... RELATIVE HUMIDITIES HAVE BEEN WELL BELOW FORECAST VALUES THIS MORNING. HAVE UPDATED THESE BASED ON THE 12Z RUC AND NAM-WRF FORECAST OF A MIXED LAYER DEWPOINT. AS A RESULT...THIS HAS PUSHED US INTO THE VERY HIGH FIRE DANGER CATEGORY. WILL MAKE THE APPROPRIATE CHANGES IN THE HWO AS WELL. KRC && .PREV DISCUSSION... /ISSUED 313 AM CDT SAT OCT 14 2006/ DISCUSSION... MAIN FORECAST CONCERNS WILL DEAL WITH PRECIP CHANCES FOR LATE SATURDAY NIGHT INTO SUNDAY...FOLLOWED BY A MODERATE OCTOBER COOL DOWN FOR MID-WEEK WITH SOME LIGHT PRECIP CHANCES. TDY-TONIGHT WATER VAPOR IMAGERY SHOWS DEEP POLAR VORTEX OVER THE GREAT LAKES REGION FINALLY BEGINNING TO MIGRATE EASTWARD A BIT. MEANWHILE...UPPER LEVEL SYSTEM OVER SOUTHERN CALIFORNIA IS ON THE MOVE EAST AND SHOULD CONTINUE ITS SLOW EASTWARD TREK OVERNIGHT. DAYTIME HIGHS WILL BE NEAR NORMAL TODAY WITH PLENTY OF SUNSHINE AGAIN...BUT CIRRUS CLOUDS SHOULD GRADUALLY INCREASE DURING THE LATE AFTERNOON HOURS. SATELLITE IMAGERY SHOWS LEADING EDGE OF GULF MOISTURE OVER SOUTHWEST TEXAS EARLY THIS MORNING SURGING NORTHWARD. DEEP ISENTROPIC LIFT OF THIS MOISTURE WILL COMMENCE LATE TONIGHT WITH THE BULK OF ANY PRECIP ACTIVITY OCCURRING WELL AFTER MIDNIGHT. SUN-MON HIGHEST PRECIP CHANCES LOOK TO OCCUR ON SUNDAY INTO SUNDAY NIGHT AS MAIN UPPER WAVE APPROACHES THE TEXAS PANHANDLE REGION. DAYTIME TEMPS WOULD BE HELD IN CHECK ON SUNDAY DUE TO COOLING EFFECTS FROM OCCASIONAL PRECIP ACTIVITY AND CLOUDS. OTHERWISE...PESKY LOW CLOUDS COULD HANG AROUND FOR MUCH OF THE DAY ON MONDAY AS PRECIP CHANCES TAPER OFF...THUS WE LOWERED DAYTIME TEMPS ACROSS MAINLY EASTERN KS. EXTENDED: TUE-FRI A CANADIAN AIRMASS LOOKS TO INVADE KANSAS ON WEDNESDAY WITH SOME LIGHT PRECIP CHANCES COMING BACK INTO THE PICTURE AS WELL. MEDIUM RANGE MODELS ARE STILL IN PRETTY GOOD AGREEMENT WITH A STRONG CANADIAN COLD FRONT MOVING SOUTHWARD ACROSS THE STATE FOR TUESDAY NIGHT INTO WEDNESDAY. AGAIN TEMP FORECASTING WILL BE A CHALLENGE DUE TO POSSIBLE TIGHT THERMAL GRADIENT IN THE AREA. NONE THE LESS...CONFIDENCE IS HIGH FOR BELOW NORMAL TEMPS WITH THIS SURGE OF CANADIAN AIR FOR WEDNESDAY AND THURSDAY. THE GFS MODEL HAS A COLDER SOLUTION COMPARED TO THE ECM MODEL...AND THE COLDER GFS SOLUTION WOULD ACTUALLY GIVE WAY TO FROZEN PRECIP FOR CENTRAL KANSAS WEDNESDAY NIGHT...HOWEVER CLIMATOLOGICAL ODDS SUGGEST THAT THIS POSSIBILITY IS RATHER LOW FOR MID-OCTOBER SO WE WILL KEEP PRECIP TYPE IN THE LIQUID FORM AT THIS JUNCTURE. JAKUB && PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 70 54 63 55 / 10 60 80 70 HUTCHINSON 69 54 63 54 / 10 60 80 60 NEWTON 69 53 63 55 / 10 50 80 70 ELDORADO 69 53 63 56 / 10 50 80 70 WINFIELD-KWLD 71 55 63 56 / 10 60 80 70 RUSSELL 68 52 64 53 / 10 50 60 50 GREAT BEND 69 53 64 53 / 10 60 60 50 SALINA 68 52 63 53 / 10 50 70 60 MCPHERSON 68 53 63 54 / 10 50 80 60 COFFEYVILLE 73 53 63 57 / 10 40 80 80 CHANUTE 69 51 63 57 / 5 40 80 80 IOLA 68 50 63 56 / 5 40 80 80 PARSONS-KPPF 71 52 63 57 / 10 40 80 80 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 953 AM CDT SAT OCT 14 2006 .SYNOPSIS...A WAVY STATIONARY SURFACE BOUNDARY CONTINUES OUT OVER THE GULF EAST OF CORPUS. STRONG MOISTURE GRADIENT IS EVIDENT JUST OFF THE COAST WHERE CLOUDS WILL PERSIST AND COULD RETREAT BACK OVER LOWER SOUTHEAST TEXAS TODAY. VERY STRONG THERMAL PACKING IS ALSO EVIDENT FROM SOUTH LOUISIANA TO THE NEARSHORE WATERS WHERE A MODERATE EASTERLY FLOW IS SENDING A STRONG SIGNAL OF FRONTOGENISIS OR STRENGTHENING OF THE EXISTING BOUNDARY. FAVORABLE SURFACE WINDS EAST OF PADRE ISLAND ARE ALSO POINTING TOWARDS CYCLOGENISIS OR THE FORMATION OF A SURFACE LOW. IR IMAGERY PLACES A POSSIBLE DEVELOPING SURFACE LOW EAST OF TAMPICO MEXICO. && .UPDATE...EXPECTING ONE MORE DAY WITH RELATIVELY DRY AIR OVER THE AREA WITH THE EXCEPTION OF LOWER SE TX WHERE RUC H925 MOISTURE LOOKS TO BE MOVING BACK IN FROM THE GULF. SUBSIDENCE MAY BE WINNING THE BATTLE WITH WEAK COLD AIR ADVECTION AND AFOREMENTIONED CLOUD COVER IN THE BPT AREA SO TWEAKED TEMPS UP JUST A TAD. RIDGING AT ALL LEVELS, SO ZEROED OUT POPS INLAND. CURRENT FORECAST HAS ALREADY DONE THE HEAVY LIFTING AND THESE MINOR TWEAKS ARE STILL COVERED IN THE ZONES SO NO UPDATE NEEDED. && .MARINE...RUC ALSO HOLDING TRUE WITH SCA EASTERLY WINDS BEYOND 20 NM AND INCREASING MODERATE WINDS NEAR SHORE, SO NO CHANGES WILL BE MADE. && .PREV DISCUSSION... (ISSUED 508 AM CDT SAT OCT 14 2006) DISCUSSION...CURRENT SFC ANALYSIS SHOWS HI PRES CENTERED OVER THE LWR MISSISSIPPI VALLEY PROVIDING A RELATIVELY DRY ERLY FLOW OVER THE REGION. MEANWHILE THE CDFNT THAT CROSSED THE AREA LATE THU/EARLY NOW SITS OVER THE CNTL GULF. WATER VAPOR IMAGERY SHOWS TROFFING IN PLACE OVER THE ERN CONUS...A CUTOFF LO SPINNING ASHORE ALONG THE SRN CALIFORNIA CST...AND WEAK RIDGING BETWEEN EXTENDING FROM CNTL TX TO THE 4-CORNERS REGION. IR PIX SHOW GENERALLY SCT/BKN MID/UPR- LVL CLOUDS STREAMING OVER THE REGION. REGIONAL 88DS QUIET TNGT SAVE FOR SOME CONVECTION WELL OFF OUR CST...MAINLY E OF PADRE ISLAND. SO MUCH FOR OUR RUN OF NICE QUIET WX AS PLENTY OF THE WET STUFF LOOKS ON THE WAY FOR THE COMING DAYS. LO-LVL FLOW TO REMAIN OUT OF THE EAST TODAY WHILE MID/UPR-LVL FLOW BECOMES A BIT MORE SWRLY...RESULT OF WHICH SHOULD BE JUST A THICKENING OF MID/UPR-LVL CLOUDS AND NO PRECIP. POPS RETURN TO PARTS OF THE AREA TNGT THEN LINGER THRU MID-WEEK. MODELS IN GENERAL AGREEMENT ON UPCOMING PATTERN ALTHOUGH WENT CLOSER TO THE NAM DURING THE FIRST COUPLE OF DAYS OF THIS PACKAGE AS THE GFS STILL LOOKS A BIT OVERDONE W/ ITS STRENGTH OF S/WV ALOFT & SFC LO OVER THE WRN GULF REGION. THE SFC LO IS PROGGED TO MOVE TOWARD THE AREA TNGT INTO SUN WHILE S/WV ALOFT ALSO PUSHES UP THE TX CST IN SWRLY FLOW AHEAD OF SRN CA CUTOFF LO. W/ INCREASING MOISTURE AND INFLUENCE OF BOTH THE VORT & THE SFC LO...HAVE INTRODUCED A 20 POP FOR THE SWRN ZONES FOR TNGT. BY TMRW THE LO IS PROGGED TO HAVE MOVED INTO SE TX WHICH IN TURN WILL PULL THE FNT OVER THE GULF BACK NORTH AS A WMFNT. THROW INTO THE MIX SOME RIDICULOUS MOISTURE VALUES (ALTHOUGH THAT 2.6 TO 2.8 DEPICTED FOR SUN AFTN BY THE GFS MAY WELL BE OVERDONE LIKE THE REST OF ITS FEATURES)...A 40-50 KT LO-LVL JET AND GOOD DIVERGENCE DEVELOPING ALOFT AND THE RESULT LOOKS TO BE NUMEROUS TO WIDESPREAD RW/TRW FOR SUN AFTN. HAVE CAPPED POPS AT 70 PCNT ATTM BUT WOULDN'T BE SURPRISED TO SEE LATER SHIFTS BUMP THAT NUMBER HIGHER. FCST SOUNDINGS INDICATE EXCELLENT LO-LVL DIRECTIONAL & SPEED SHEAR W/ HIGH HELICITY VALUES AND THUS SPC HAS PUT THE AREA IN A SLGT RISK FOR TMRW. MAIN LIMITING FACTOR TO SVR WX COULD BE AVAILABLE INSTABILITY BASED ON PLENTIFUL CLOUD COVER KEEPING TEMPS DOWN DURING THE AFTN. KEPT LIKELY POPS IN THE FCST FOR SUN NGT AS WMFNT MAKES ITS WAY NORTH ACROSS THE FCST AREA AND STRONG SRLY LO-LVL WINDS PERSIST. GOOD LO-LVL SPEED CONVERGENCE NEAR THE CST SHOULD PROVIDE FOR CONTINUED CONVECTIVE DEVELOPMENT WHICH WILL SPREAD INLAND DURING THE NGT AND INTO THE MORNING ON MON. IN ADDITION WEAK RIPPLES IN THE SWRLY FLOW ALOFT WILL PROVIDE FOR ADDITIONAL LIFT DURING THIS PERIOD RESULTING IN CONTINUED WIDESPREAD RW/TRW DEVELOPMENT. ON MON THE S/WV WHICH WAS ONCE THE LO OVER SRN CA WILL PASS NW OF THE FCST AREA PROVIDING GOOD FORCING ALOFT. THIS WAVE WILL ALSO INDUCE SFC LO DEVELOPMENT OVER NRN LA PROVIDING FOR ADDITIONAL LO- LVL LIFT. AGAIN LIKELY POPS LOOK WARRANTED FOR THE DAY...W/ HIGHER POPS CONTINUING INTO THE EVE FOR THE SERN ZONES WHERE ACTIVITY SHOULD LINGER A LITTLE LONGER. THINGS LOOK TO QUIET DOWN A BIT FOR THE MIDDLE OF THE WEEK W/ MUCH LESSER RAIN CHANCES EXPECTED AS MID/UPR-LVL RIDGING ATTEMPTS TO DEVELOP OVER THE CNTL GULF CST REGION. MAIN TROF AXIS AND SFC CDFNT FINALLY CROSS THE AREA ON THU...ALLOWING THE AREA TO DRY OUT AND HAVE A DECENT END OF THE WEEK AND WEEKEND. MARINE...HAVE RAISED SCA FLAGS FOR THE OFFSHORE WATERS W/ THIS PACKAGE AS CRITERIA WINDS ARE EXPECTED TO DEVELOP SOMETIME THIS AFTN...TIMING OF WHICH COULD BE AN HOUR OR TWO OFF BUT CLOSE ENOUGH TO WARRANT ISSUANCE ATTM. ALSO INSERTED SCEC WORDING FOR THE NEAR SHORE WATERS ALTHOUGH SCA WILL LIKELY BE NEEDED IN THIS AREA BY THIS AFTN. STRONG SRLY WINDS LOOK TO PERSIST INTO MON BEFORE RELAXING. AVIATION...MAINLY VFR CONDITIONS TO CONTINUE. && .UPDATED POINT TEMPS/POPS... KLCH 83 65 77 73 / 0 20 60 70 KBPT 81 66 77 72 / 0 20 70 70 KAEX 82 58 78 70 / 0 10 50 70 KLFT 83 63 78 73 / 0 10 50 70 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 7 PM MONDAY FOR THE FOLLOWING ZONES: WATERS FROM CAMERON, LA TO HIGH ISLAND, TX EXTENDING FROM 20 NM TO 60 NM...WATERS FROM INTRACOASTAL CITY, LA TO CAMERON, LA EXTENDING FROM 20 NM TO 60 NM...AND WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY, LA EXTENDING FROM 20 NM TO 60 NM. && $$ 11 la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 312 PM MDT SAT OCT 14 2006 .SHORT TERM... MAIN SHORT TERM CONCERNS CONTINUE TO BE POPS ASSOCIATED WITH TRACK OF DESERT SW CUTOFF SYSTEM. CURRENT WATER VAPOR IMAGERY AND RUC UPPER AIR DATA INDICATING WEAK WEST TO SOUTHWEST FLOW ACROSS THE STATE WITH NORTHERN STREAM SHORT WAVE TROUGH MOVING ACROSS UPPER GREAT LAKES REGION AND SOUTHERN STREAM CUTOFF LOW PERSISTING ACROSS THE DESERT SW ATTM. WATER VAPOR ALSO INDICATING A SHORT WAVE EMBEDDED IN THE FLOW MOVING ACROSS WESTERN COLORADO ATTM. SATELLITE DATA AND REGIONAL RADARS INDICATING GENERALLY MOSTLY CLOUDY SKIES WITH ISOLATED TO NUMEROUS SHOWERS ACROSS THE REGION ATTM...WITH BEST COVERAGE ACROSS THE SW AND CENTRAL MTS ASSOCIATED WITH EMBEDDED WAVE. ACROSS THE LOWER ARKANSAS RIVER VALLEY...STUBBORN STRATUS FINALLY STARTING TO LIFT WITH TEMPERATURES VERY SLOWLY WARMING INTO THE 50S ATTM. HAVE GENERALLY FOLLOWED THE GFS SOLUTION FOR TONIGHT AND SUNDAY...AS IT HAS DONE WELL WITH PREVIOUS SYSTEM AND ALSO HAS SOME CONSENSUS WITH ECMWF SOLUTION. AT ANY RATE...UPPER LOW TO SLOWLY TRACK NORTH AND EAST ACROSS EAST CENTRAL ARIZONA BY 12Z SUNDAY AND THEN SLOWLY CONTINUES TO MOVE ACROSS CENTRAL NEW MEXICO THROUGH 00Z MONDAY. MOVEMENT OF SYSTEM KEEPS MOIST SOUTH TO SOUTHWEST FLOW ACROSS THE STATE THROUGH THE PERIOD...ALONG WITH BEST LIFT AND UPPER SUPPORT ACROSS NORTHERN NEW MEXICO AND INTO THE SOUTHERN REACHES OF THE STATE ASSOCIATED WITH DEFORMATION BAND. WITH LIFT AND MOISTURE ASSOCIATED WITH EMBEDDED WAVE...HAVE GONE WITH SCATTERED TO NUMEROUS POPS ACROSS THE THE HIGHER TERRAIN AND HIGH MT VALLEYS THIS EVENING KEEPING SCATTERED POPS OVERNIGHT WITH THE MOIST AND DIVERGENT FLOW ALOFT. WITH THE WARM AIR ALOFT...SNOW LEVELS TO RELATIVELY HIGH TONIGHT...AND HAVE 1 TO 3 INCHES POSSIBLE ACROSS THE HIGHER MT PEAKS. HAVE KEPT ISOLATED TO SCATTERED POPS ACROSS THE EASTERN MTS AND PLAINS THIS EVENING AND KEEPING BEST POPS ACROSS THE FAR SE PLAINS OVERNIGHT WITH WAA/ISENTROPIC LIFT AHEAD OF SYSTEM. WITH CLOUDS AND THE WARM AND MOIST SOUTHERLY FLOW ALOFT...OVERNIGHT LOWS TO BE RATHER MILD ACROSS THE REGION...WITH MVFR STRATUS LIKELY RE- DEVELOPING ACROSS THE FAR SE PLAINS. -MW .LONG TERM... (SUNDAY NIGHT THROUGH FRIDAY) UPPER TROUGH LIFTS INTO THE SOUTHERN PLAINS SUNDAY NIGHT...WITH SOME LINGERING PRECIP OVER OVER THE SAN JUANS AND FAR SOUTHEASTERN PLAINS IN THE EVENING. DRIER AND WARMER WEATHER STILL IN STORE FOR MONDAY...AS LEE TROUGH DEVELOPS OVER THE EAST IN RESPONSE TO MAJOR UPPER TROUGH DIGGING INTO THE WESTERN U.S. MODELS STILL SUGGEST FRONTAL PASSAGE SOMETIME TUESDAY AFTERNOON...THOUGH BETTER CHANCES FOR PRECIP WILL REMAIN MAINLY NORTH AND WEST OF THE AREA UNTIL TUESDAY EVENING. LATEST MODEL RUNS SHOW A LITTLE MORE UPSLOPE OVER THE EAST TUESDAY NIGHT INTO WEDNESDAY...WITH UPPER JET HOLDING BACK SLIGHTLY WEST OF PREVIOUS RUNS AS WELL. INCREASED POPS FOR MUCH OF THE AREA TUESDAY NIGHT...WITH SNOW LEVELS FALLING TO BELOW 5000 FEET BY WEDNESDAY MORNING. UPPER TROUGH REMAINS OVERHEAD DURING THE DAY WEDNESDAY...BUT WITH MAIN JET MIGRATING EAST AND UPSLOPE WANING...SUSPECT PRECIP WILL DECREASE BY AFTERNOON OVER MUCH OF THE AREA. EXCEPTION MIGHT BE THE CENTRAL MOUNTAINS WHERE NORTHWEST UPPER FLOW IS FAVORABLE FOR CONTINUED SNOW SHOWER PRODUCTION. GFS QPF FIELD HINTS AT THIS AS WELL...WITH DRYING NOTED ALONG THE I-25 CORRIDOR BY 00Z. MAIN CHANGE TO THE GRIDS WAS TO COOL MAX TEMPS WED AFTERNOON...WITH MOST AREA STRUGGLING INTO THE 30S AND 40S. STILL SOME BIG QUESTIONS REGARDING EVOLUTION OF THE UPPER PATTERN BEYOND WEDNESDAY...AS GFS DIGS THE NEXT UPPER JET INTO THE NRN PLAINS THURSDAY...VERSUS THE PACIFIC NORTHWEST 24 HOURS AGO. GFS THEN BRINGS ANOTHER SYSTEM OVER THE EPAC RIDGE OVER THE WEEKEND...WITH UPPER TROUGH AXIS SLOWLY RETROGRADING BACK TOWARD THE ROCKIES BY SUNDAY. 14/00Z ECMWF WAS MUCH DEEPER WITH THE WEEKEND WRN TROUGH THAN THE GFS...THOUGH QUICK LOOK AT THE 14/12Z RUN SUGGESTS A TREND BACK TOWARD THE GFS. MADE VERY FEW CHANGES TO GRIDS BEYOND WEDNESDAY...LIKING THE TREND OF MUCH COOLER THAN MEX GUIDANCE TEMPS CURRENTLY PORTRAYED. --PETERSEN && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 23/10 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 305 PM EDT SAT OCT 14 2006 .DISCUSSION... 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR VORTEX OVER ONTARIO BEGINNING TO LIFT STEADILY TO THE NE WITH 00Z-12Z H3 HGT RISES AOA 200M IN ITS WAKE FM INL-YPL. WV IMAGERY CLEARLY SHOWS DEEPER MSTR ROTATING S IN THE NLY FLOW TO THE W OF THE CLOSED LO CENTER BEGINNING TO PUSH MORE E THAN S. HOWEVER...12Z INL SDNG STILL SHOWS FAIRLY HI RH SFC-H75 OR SO WITH -10C ISOTHERM REMAINING WITHIN MOIST LYR...SO SOME SHSNRA STILL OBSVD OVER THE NRN TIER OF THE FA/OVER LK SUP IN THE PERSISTENT CYC WLY FLOW BTWN DEPARTING LO PRES OVER ONTARIO AND SFC-H85 RDG EXTENDING FM THE NRN PLAINS INTO THE LWR OH RIVER VALLEY. BUT MID LVL TEMPS AT INL HAVE RISEN STEADILY FM 00Z TO 12Z...WITH THIS INCRSD STABILIZATION CONSISTENT WITH VIGOROUS DNVA/SUBSIDENCE COINCIDENT WITH OBSVD HGT RISES. IN FACT...VSBL STLT IMAGERY SHOWS CLR-PCLDY SKIES OVER NW ONTARIO W OF YPL AND ACRS MUCH OF NRN MN WHERE SFC DWPTS AS LO AS THE UPR TEENS. SOME DIURNAL CU/SC REDVLPG IN THESE AREAS IN MOIST NR SFC LYR UNDER SUBSIDENCE INVRN BTWN H8-85 AS SHOWN ON 12Z INL SDNG/TAMDAR SDNG FM YQT. MAIN FCST CONCERNS IN THE SHORT TERM REVOLVE ARND LK PCPN/CLD TRENDS AND TEMPS. FOCUS FOR EARLY WEEK SHIFTS TO PCPN CHCS/TIMING ASSOCIATED WITH WAD PATTERN FCST TO DVLP E OF TROFFING IN THE NRN ROCKIES. FOR TNGT...GFS/NAM SHOW UPR LO OVER ONTARIO DRIFTING VERY SLOWLY TO THE N...WITH RISING MSLP/LOWERING SUBSIDENCE INVRN HGT OVER THE UPR GRT LKS COINCIDENT WITH APRCHG HGT RISES. ALTHOUGH SOME H95 CNVGC FCST TO REMAIN THRU THE NGT OVER THE NW AND ERN ZNS E OF MUNISING... GFS/NAM FCST SDNGS SHOW INVRN BASE LWRG SUFFICIENTLY THRU THE NGT SO THAT SUB INVRN LYR WARMS ABV -10C BY 06Z. POOR SN GROWTH MICROPHYSICS IN CONCERT WITH DCRSG OVERWATER INSTABILITY AND FCST DRYING OF THE SUB INVRN LYR AS AIRMASS NOW SUPPORTING CLR-PCLDY SKIES OVER NW ONTARIO/NRN MN ADVECTS TOWARD THE AREA...LOOK FOR LINGERING -SHSNRA THIS EVNG TO GIVE WAY TO NOTHING MORE THAN --SHSNRA OVRNGT BEFORE ENDING SUN MRNG. MEASUREABLE PCPN WL PROBABLY LINGER A LTL LONGER OVER THE E WITH LONGER FETCH/BETTER CHC FOR DEEPER MIXED LYR. WITH SKIES EXPECTED TO CLR TNGT...TEMPS HAVE THE POTENTIAL TO DROP QUICKLY OVER INLAND AREAS AFT RELATIVELY LTL RECOVERY TDAY... ESPECIALLY IN AREAS WITH SN COVER. HOWEVER... GFS/NAM SHOW FCST WIND SPEEDS ARND 20KT WITHIN 1K FT OF THE SFC...AND RUC13 PROGS SFC WIND SPEEDS GOING NO LWR THAN 7KT OR SO EVEN OVER THE INTERIOR W HALF. BUT HARD TO BELIEVE NR SFC LYR WON'T DECOUPLE AT THE MORE SHELTERED LOCATIONS UNDER CLRG SKIES OVER THE INTERIOR W HALF WITH RUC13 SHOWING WSW LAND BREEZE FLOW DVLPG OVERNGT...SO WL KEEP GOING FCST LO TEMPS IN THE UPR TEENS GOING IN THESE PLACES CONSISTENT WITH OBSVD DWPTS UPSTREAM. MIN TEMPS WL BE MUCH WARMER CLOSER TO THE LKSHORES WITH STEADY W WIND PERSISTING THERE. SUN LOOKS TO BE THE NICEST DAY IN RECENT MEMORY WITH SFC HI PRES RDG BLDG OVHD UNDER CONFLUENT WNW FLOW ALF/RISING HGTS. MIXING TO H85 ON GFS FCST SDNGS YIELDS TMAX IN THE 45 TO 50 RANGE. LATEST MODEL GUIDANCE SHOWS H5 RDG AXIS DOWNSTREAM OF DEEPENING TROF IN THE PAC NW/NORTHERN ROCKIES OVER THE FA LATE SUN NGT...SUGING A SGNFT INCRS IN HI CLD WL NOT OCCUR UNTIL LATER AT NGT AS SHOWN BY LACK OF SGNFT MOISTENING ON GFS F48 310K ISENTROPIC SFC. ALTHOUGH TEMPTED TO LOWER GOING FCST LO TEMPS...GFS/NAM HINT AT SURGE OF MOISTURE ON THE 290K SFC WITH INCRSG LLVL WINDS AFT 06Z. SO KEPT LO TEMPS...WHICH WL PROBABLY OCCUR RELATIVELY EARLY...THE SAME EXCEPT TO LOWER OVER THE INTERIOR E WHERE THIS LLVL MSTR WL ARRIVE LATEST. GFS/NAM/UKMET SHOW BAND OF RA WORKING N ACRS THE FA ON MON AS MSTR SURGE/H85-5 QVECTOR CNVGC IN DECENT ISENTROPIC LIFT ON THE 300K SFC (ARND H75) OVERSPREADS THE FA TO THE E OF DVLPG LO PRES TO THE E/ TROFFING OVER THE NRN ROCKIES. WL BUMP POPS UP TO CATEGORICAL IN THE AFTN/EARLY EVNG. ALTHOUGH SKY WL BE OVC...EXPECT HI TEMPS TO RISE SGNFTLY FM EARLY MRNG LOWS WITH LLVL SURGE OF MOIST AND WARMER AIR IN SLY FLOW TO THE E OF LO PRES. THINK PCPN CHCS WL DIMINISH MON EVNG AS GFS/UKMET SHOW MORE ACYC H85 FLOW DVLPG/LESS QPF OVERNGT WITH H85-5 QVECTOR DVGC/H7 SUBSIDENCE/MID LVL DRYING WITH BETTER DEFORMATION ZN AND ISENTROPIC LIFT SHIFTING TO THE N THEN AS WARM SECTOR OF LO TO THE W OVERSPREADS FA. WL CUT BACK TO CHC POPS S-N DURING THE NGT AND INTRODUCE AREAS OF FOG AS HIER DWPTS CONT TO FLOW N OVER GRND COOLED DURING RECENT COLD OUTBREAK. EXPECT RELATIVELY LTL DIURNAL DCRS IN TEMP MON NGT. THE MEDIUM/EXTENDED RANGE CHARTS CONSISTENT IN SHOWING DEEP TROF AMPLICATION OVER CNTRL NAMERICA UPSTREAM OF BLOCKING UPR RDG OVER GREENLAND/NATLANTIC. HOWEVER...SGNFT DIFFERENCES IN DETAILS OF DAY-TO-DAY WX REMAIN AMONG THE OPS MODELS LATER IN THE PD. THERE IS GOOD AGREEMENT SHOWING SFC LO TRACKING JUST TO THE NW ON TUE/WED WITH SFC COLD FNT CROSSING THE CWA TUE NGT AS NRN BRANCH SHRTWV TRACKS ACRS SRN CAN. ALTHOUGH OP GFS HAS CONSISTENTLY SHOWN THE DVLPMNT OF A DEEP LO PRES IN THE LOWER GRT LKS BEGINNING ON THU THAT WOULD CAUSE SGNFT SN OVER PORTIONS OF THE FA ON THU AS A SECOND SRN BRANCH SHRTWV MOVES ARND THE BASE OF THE CNTRL TROF... THIS MODEL REMAINS AN OUTLIER COMPARED TO THE OTHER MODELS/GFS ENSEMBLE MEAN. OTHER GUIDANCE INDICATES LO WL NOT DEEPEN SGNFTLY UNTIL THE CENTER MOVES TO THE N ON THU. 12Z GFS HAS TRENDED WEAKER/FARTHER SE WITH SFC LO...INCRSG CONFIDENCE IN NEGLECTING 00Z/06Z GFS. GIVEN EVIDENCE FOR THE NON- GFS SCENARIO...WL HOLD ON TO GOING FCST SHOWING RA/SHRA ON TUE GRDLY TRANSITIONING TO LES AFTER WEAK WAVE RUNS N ALG COLD FNT GIVES WAY TO NW FLOW ON THE SRN FLANK OF DEEPENING LO IN ONTARIO. WL MAINTAIN LES CHS ON FRI/SAT PER NCEP GUIDANCE/DEEPENING TROF/CONTD NW FLOW. TEMPS WL REMAIN PRETTY MUCH AOB BLO NORMAL FOR THE FORSEEABLE FUTURE WITH NEGATIVE NAO PATTERN/CNTRL NAMERICA TROF/ BLOCKING UPR RDG CENTERED NR GREENLAND IN PLACE. COORDINATED WITH APX/GRB/DLH. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ KC mi