AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1010 PM EST TUE OCT 31 2001 ...UPDATED TO DECREASE WINDS INLAND AND ADD SHOWERS TO THE NW CWA... TWO QUESTIONS FOR THE SHORT TERM FORECAST. FIRST IS WILL THE 25 TO 40 DBZ SHOWERS OVER LAKE MICHIGAN AND EASTERN WISCONSIN BE ABLE TO RESULT IN SHOWERS ON THE GROUND IN OUR NW CWA? THE SECOND QUESTION IS WHAT TO DO WITH THE WINDS INLAND? WE HAD BREEZY WORDING IN THE OVERNIGHT ZONES... AND GIVEN THE 35 TO 50 KNOTS SHOWN BY 00Z DTX/APX AND GRB SOUNDINGS...PLUS THE VAD WIND BETWEEN 1000 AND 3000 FT ABOVE GROUND LEVEL...THAT MAKES SOME SENSE. HOWEVER MOST INLAND STATIONS HAVE WINDS BELOW 20 MPH. AS FOR THE FIRST QUESTION...THE SHOWERS OVER THE NW CWA TONIGHT... THE DTX/GRB AND APX SOUNDINGS ARE RATHER DRY BELOW 750 MB. HOWEVER... APX AND GRB ARE VERY MOIST ABOVE THAT LEVEL. THE 00Z RUC AND ETA BOTH SHOW STRONG ISENTROPIC ASCENT OVERNIGHT. THE AREA OF BEST ASCENT IS OVER NRN LK MICHIGAN AND NRN LWR MICHIGAN. THAT IS ASSOCIATED WITH A WEAK SHORTWAVE TROUGH FROM THE CANADIAN BORDER TO MO. ALSO AT 00Z... ERN WI...NRN LK MICHIGAN AND NRN LWR MI WERE IN AN AREA OF STRONG UPPER DIFFLUENCE... BETWEEN THE DEPARTING POLAR JET OVER QUEBEC AND THE INCOMING SOUTHERN STREAM JET FROM THE CENTRAL PLAINS. THIS ALSO HAPPENS TO BE NEAR THE UPPER RIDGE AXIS. IF THERE WERE ANY SIGNIFICANT AMOUNT OF MOISTURE BELOW 700 MB... SOME OF THOSE SHOWERS OVER LAKE MICHIGAN WOULD LIKELY REACH THE GROUND AND RESULT IN SHOWERS OVER OUR NW CWA. HOWEVER... THE CONDENSATION PRESSURE DEFICITS ARE ABOVE 100 MB (THROUGH 700 MB) OVER MOST OF THE CWA OVERNIGHT. EVEN WITH THE IMPRESSIVE ASCENT GOING ON OVER NRN LAKE MICHIGAN THOSE SHOWERS WILL HAVE A HARD TIME REACHING THE GROUND THROUGH THAT. THE 1000/700 MEAN RH STAYS BELOW 40 PERCENT OF MOST OF THE CWA THROUGH 12Z THURSDAY. THE EXTREME NW CWA DOES SEE 50 TO 60 PCT 1000/700 MEAN RH VALUES BY 12Z. HOWEVER... BY THEN... THE AREA OF UPPER DIVERGENCE AND BEST ISENTROPIC ASCENT HAS MOVES OFF TO THE EAST OF THE GRR CWA. IT SHOULD ALSO BE NOTED THAT THE LAPSE RATES IN THE MOIST LAYER ARE ABOVE 6C/KM. ALL OF THIS LEADS ME TO BELIEVE THE SHOWERS WILL MOSTLY NOT REACH THE GROUND OVER THE GRR CWA OVERNIGHT. HOWEVER... THEY ARE TO CLOSE FOR COMFORT SO I PUT A 30 PERCENT CHANCE IN THE NW CWA ANYWAY. AS FOR THE WIND ISSUE... WE HAVE WARM ADVECTION GOING ON OVERNIGHT. NOT ONLY THAT... LOOKING AT THE SOUTH BUOY... THE AIR TEMPERATURE AT THE BUOY WAS WARMER THAN THE LAKE TEMPERATURE (00Z). THUS THE WINDS ARE NOT MIXING DOWN WELL. I DO NOT SEE THEM MIXING DOWN WELL EITHER... EVEN THOUGH THE GRR VAD SHOWED 50 KNOTS AT 3000 FT AROUND 0300Z. THERE IS A CHANCE... OVER THE NRN CWA... WERE THE SHOWERS ARE MOSTLY ALOFT...THAT SOME OF THAT COULD MIX DOWN IN A DOWNBURST... THAT WILL HAVE TO BE WATCHED. .GRR...NONE. WDM mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1015 PM EST WED OCT 31 2001 00Z RAOBS/LATEST WV LOOP AND RUC ANAL SHOW LOW AMPLITUDE...NRLY ZONAL FLOW ACROS NRN TIER OF CONUS WITH TENDENCY FOR RDGING IN THE E AND TROFFING OUT W. A SHRTWV APRNT OVR THE NRN PLAINS...AND THERE IS 992MB SFC LO PRES MOVG INTO NW MN. PACIFIC COLD FNT EXTENDS S FM SFC LO INTO THE SCNTRL PLAINS. TEMP CONTRAST ACRS THIS BNDRY IS MINIMAL...SO FNT IS ALMOST MORE OF A PRES TROF. A STRG PRES GRADIENT BTWN THE LO AND HI PRES OVR THE ERN ZNS...AND THE STRG SW WND HAS ADVCTD UNSEASONABLY MILD AIR INTO THE CWA S OF WARM FNT STRETCHING ACRS NCNTRL LK SUP. TEMPS AT 02Z MAINLY THE MILD 50S. MPX/GRB RAOBS SHOW 32KT WNDS AS LOW AS 2K FT MSL/59KTS AT 5K FT MSL. BUT LLVL STABILITY IN WAD PATTERN PREVENTING FULL MIXING OF WNDS TO SFC AS H85 TEMPS 11C/13C AT GRB/INL...GUSTS TO ARND 20KTS. SFC OBS/IR SAT PIX INDICATE ABUNDANT MID/HI IN SWLY FLOW AHD OF PLAINS LOW PRES...BUT VERY DRY AIR IN THE SFC-7 LYR PER 00Z RAOBS HAS KEPT LOW CLD/PCPN NRLY NON EXISTANT. IN FACT...SFC DWPTS GENERALLY IN MID 40S ACRS CWA ATTM...BUT FALL TO THE UPR 30S/LO 40S IN UPSTREAM AREAS OF SRN WI. ONLY NRBY RPRTS OF RA LAST FEW HRS N OF SFC WARM IN MN ARROWHEAD AND ACRS NE WI UNDER A BIT HIER REFLECTIVITY RETURNS WHERE LATEST RUC MODEL SHOWS A PATCH OF HIER H7 RH. AIR EVEN DRIER ACRS THE PLAINS...WHERE MID/HI CLD THINS OUT OVR PACIFIC COLD FNT. MAIN FCST CONCERNS TNGT ARE PSBL WNDS/-SHRA/TEMPS. 00Z RUC MODEL SHOWS SFC LO CONTG NE OVRNGT AND DEEPENING TO 986MB AS IT REACHES SW ONTARIO TOWARD DAWN. PACIFIC COLD FNT PROGGED TO PASS IWD JUST BEFORE 12Z. H5 SHRTWV WL MOVE INTO MN OVRNGT. ASSOCIATED PRES FALLS NW OF CWA IN ADVANCE OF SHRTWV/LO SHARPEN PRES GRADIENT OVR CWA...AND H925 WNDS INCREASE TO 40 KTS OVRNGT. ALTHOUGH LLVL STABILITY WL PREVENT FULL MIXING...XPCT WNDS TO INCRS ENUF TO JUSTIFY FCST OF BECMG BREEZY. RUC SHOWS DCRSG MEAN H85-5 RH OVRNGT WITH SFC-H7 DRY ADVCTN/MSTR DVGC GREATLY WEAKENING ISENTROPIC LIFT IN WARM SECTOR. ONLY WEAK MSTR CNVGC NOTED ALG COLD FNT THAT REACHES IWD LATE. UPR DVGC AHD OF SHRTWV WEAK AS WELL AS CWA FALLS INTO UNFVRBL RIGHT EXIT OF SUPPORTING H3 JET MAX. RUC GENERATES QPF ONLY OVR SE ZNS IN ADVANCE OF HIER MSTR AREA NOW CAUSING SOME -RA OVR NE WI AND SHOWS HIER H7 RH EXITING ERN CWA BY 09Z. QUICK LOOK AT 00Z ETA CONFIRMS THIS FCST. BOTTOM LINE IS THAT PCPN LOOKS UNLIKELY OVR THE NW. REMOVED MENTION OF -SHRA XCPT IN SE ZNS...WHERE HIER REFLECTIVITIES APRCHG. MADE SOME CHGS TO THE SECOND PD AS WELL BASED ON 00Z ETA FCST FOR WEAK SHRTWV IN CNTRL PLAINS REINVIGORATING HIER MSTR ACRS THE SE DURG THE MRNG BEFORE PULLING OFF IN THE AFTN. SO PULLED ALL MENTION OF PCPN FOR THE NW TMRW AS WELL WITH CHCY POPS ACRS THE SE. WITH INCRSG WND SPEED...XPCT LTL DROPOFF IN PRESENT TEMPS OVRNGT EVEN WITH WEAK DRY ADVCTN. HAVE MADE MINOR ADJUSTMENTS UP FOR MINS BASED ON CURRENT RDGS AND INCRSG WND. AFDMQT FM DAYSHIFT FOR LATER PDS: PROBABLY MORE SIGNIFICANT WILL BE THE WINDS AS LOW PRES MOVES INTO WESTERN ONTARIO AND DEEPENS TO 983 MB BY THU AFTN. GRADIENT SFC WINDS SHOW 15 TO 25 KNOTS...WITH BL WINDS 20 TO 30 KNOTS DEVELOPING AS LOW DEEPENS. CONCERN HERE IS THAT INITIALLY TMRW MORNING THRU EARLY AFTN...WINDS WILL NOT BE ABLE TO MIX DOWN DUE STABLE LAYER AS H8 TEMPS WARM TO +9C. HOWEVER...AFTER COLD FRONT MOVES THROUGH THU AFTERNOON CAUSING DRY AIR ADVECTION AND CAA...WINDS COULD BE ABLE TO MIX DOWN...ESPECIALLY OVER THE LAKE AND OVER THE KEWEENAW PENINSULA AS H8 TEMPS RAPIDLY DROP TO 0C AND BELOW BY FRI MORNING. WITH THE SOUTHWEST WINDS...THE WESTERN LAKE AND KEWEENAW WILL BE THE FAVORABLE AREAS FOR WINDY CONDITIONS WITH CHANELLING OVER WESTERN LAKE AND THE CHANELLING NR THE KEWEENAW. WILL THEREFORE GO WINDY OVER KEWEENAW AND KEEP REMAINDER OF FA BREEZY. MAY HAVE TO GO WINDY OVER GOG/ONT ZONE...IF INVERSION DOES NOT SET UP LIKE MODEL SOUNDINGS AND BUFKIT SUGGESTS. FOR NOW...WILL KEEP BRZY. OTHER THAN THE WIND...IT SHOULD BE MOSTLY CLR WITH FA IN DRY SLOT BEHIND SHORT WAVE. ON FRIDAY AND FRIDAY NIGHT...WINDY/BREEZY CONDITIONS SHOULD START TO SUBSIDE LATE AS LOW PRES FILLS AND MOVES NORTHEAST. WILL BE SOME CLDS AROUND AS UPR GREAT LAKES SEES SOME WRAP AROUND MOISTURE IN CCB. NO MODEL IS INDICATING ANY UVM OR ISENTROPIC LIFT IN WRAP AROUND AREA THIS FAR SOUTH...SO WILL KEEP FA DRY. H8-LAKE DELTA-T VALUES RISE TO NEAR 10C...NOT ENOUGH TO GET PCPN BUT PROBABLY ENOUGH TO GET SOME CLDS. BIG CHANGE WILL BE THE SIGNIFICANT COOLDOWN FROM THURSDAY AS TEMPS WILL STRUGGLE TO REACH 50 ON FRI IN CAA REGIME. ETA MIGHT BE OVERDOING THE CAA JUST A BIT WITH 850MB TEMPS LOWERING TO -4C. LIKE AVN H8 TEMPS BETTER ESPECIALLY SINCE FLOW WILL REMAIN SOMEWHAT ZONAL. HAVE ALSO BACKED OFF COLD TEMPS OVERNIGHT FRI AS WIND SHOULD KEEP LOWER ATMOSPHERE SOMEWHAT MIXED. EXTENDED MODELS CONTINUE TO POINT TOWARD A ZONAL FLOW DEVELOPING ACROSS THE N CENTRAL U.S. STARTING THE BEGINNING OF NEXT WEEK AS TROUGH DEVELOPS ALONG THE EAST COAST. MRF/AVN CONTINUE TO SHOW A BRIEF INTRUSION OF COLDER AIR ACROSS THE UPR GREAT LAKES WITH ANTICYCLONE CENTERED OVER CENTRAL PLAINS. SPAGHETTI CHARTS FROM PSU ENSEMBLE WEB PAGE SUGGEST THAT COLD INTRUSION WILL BE FAST WITH MODEST HEIGHT RISES BY MONDAY. 850MB-LAKE DELTA-T VALUES LOWER TO 13C PER MRF...SUGGEST THAT THERE COULD BE A LITTLE LAKE ENHANCED PCPN LATE SAT NIGHT AND SUN MORNING AS SHORT WAVE MOVES THROUGH THE AREA. SYSTEM WILL BE MOISTURE STARVED...SO ANY PCPN WILL BE ON BACK SIDE OF SFC FRONT WITH THE THERMAL TROUGH AND ANY LK ENHANCEMENT. NO SIGNIFICANT CHANGES TO REMAINDER OF THE EXTENDED. WILL KEEP MONDAY DRY AS MRF/AVN/CAN MODELS ALL POINT TO WEAK RIDGE BUILDING OVER UPR MS VALLEY. THIS WILL BE SHORT LIVED IN ZONAL FLOW AS ANOTHER WEAK SHORT WAVE RIDES TO THE NORTH OF THE FA. HOWEVER...ANOTHER MOISTURE STARVED FRONT WILL MOVE THROUGH LATE MONDAY...WITH BEST MOISTURE ON THE BACK SIDE. ZONAL FLOW CONTINUES THROUGH WED AS ANOTHER SYSTEM...THIS ONE WITH A LITTLE BETTER MOISTURE AND DYNAMICS...MOVES THROUGH THE AREA WED. WILL KEEP MILD TEMPS THRU THE PERIOD WITH ZONAL FLOW CAUSING COLD AIR TO BE TRAPPED IN NRN CANADA WITH NO MECHANISM TO BE PULLED SWD. COLDEST AIR FOR THE NEXT TEN DAYS LOOKS TO BE BEHIND THE SFC FRONT ON THU. OVERALL...NO SIGNIFICANT WARM-UPS OR COOL-OFFS DUE TO PROGRESSIVE NATURE OF LOW AMPLITUDE FLOW. COORD WITH APX...THANKS. .MQT...NONE. KC mi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mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1030 AM EST WED OCT 31 2001 ILL-DEFINED WARM FRONT WAS LOCATED ACROSS LAKE SUPERIOR AND NORTHERN LAKE HURON LATE THIS MORNING. IR SATELLITE LOOP SHOWS THE COLDEST CLOUD TOPS ASSOCIATED WITH THE BEST WAA/ISENTROPIC ASCENT LIFTING NE OUT OF THE AREA. THIS IS CONSISTENT WITH CURRENT RADAR TRENDS...AND ALSO WITH THE LATEST ETA/RUC MODEL PRECIPITATION OUTPUT. BASED ON EXTRAPOLATION OF RADAR ECHOES...WHICH INCLUDE SOME NEWLY DEVELOPED SHOWERS OVER E WI AND LAKE MICHIGAN -- HAVE UPDATED ZONES TO DELAY THE ENDING OF THE SHOWERS SLIGHTLY. THESE NEW SHOWERS TO THE WEST APPEAR HIGHLY CONVECTIVE -- BASED ON RADAR...SATELLITE...AND FACT THAT A FEW LIGHTNING STRIKES HAVE BEEN DETECTED OVER NORTHERN LAKE MICHIGAN! THEY ARE LIKELY THE RESULT OF DIFFERENTIAL DRYING WITHIN A LAYER OF ISENTROPIC ASCENT...WHICH IS CAUSING AN INCREASE/RELEASE OF ELEVATED POTENTIAL INSTABILITY. WILL FRESHEN UP FORECAST ONCE AGAIN TOWARD NOON TO REFLECT PRECIPITATION TRENDS...AND ALSO TO ADDRESS AFTERNOON TEMPERATURES (THOUGH GOING HIGH TEMPERATURE FORECASTS GENERALLY LOOK IN LINE). .APX...NONE. SMITH mi AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL/NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA NATIONAL WEATHER SERVICE ABERDEEN SD 915 AM CST WED OCT 31 2001 MID AND HI CLOUDS CONTINUE STREAMING FROM WEST TO EAST ACROSS THE NRN PLAINS THIS MORNING IN ADVANCE OF A PAC SHORT WAVE AND ASSOCIATED SFC FNT. LATEST RUC AGREES WITH PREVIOUS MODEL RUNS IN MOVING FNT ACROSS THE CWA BY LATE THIS AFTERNOON/EARLY THIS EVENING. SHORT WAVE SHOULD CROSS THE REGION LATER TONIGHT WITH ZONAL FLOW DVLPG IN ITS WAKE. CURRENT FORECASTS HAVE WINDS INCREASING AS THE FNT PASSES WITH TEMPS WARMING JUST AHEAD OF AND WITH FNT. THIS SEEMS REASONABLE GIVEN POTENTIAL MIXING AND ADIABATIC WARMING. WILL NEED TO MAKE SOME MINOR ADJUSTMENTS AND CLEAN UP WIND WORDING A BIT THOUGH. .ABR...NONE FAUCETTE sd SOUTHEAST TEXAS FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 1136 AM CST WED OCT 31 2001 UPDATED DISC... CONVECTION ASSOCIATED WITH THE COASTAL TROUGH IS A BIT MORE ACTIVE FURTHER INLAND THAN EARLIER THOUGHT. UPDATED THE FORECAST TO INCLUDE ISOLATED SHOWERS IN COUNTIES ADJACENT THE COASTAL AREAS. PREV DISC... COASTAL TROUGH WAS AFFECTING SE TX THIS MORNING...WITH SOME PATCHY FOG TO THE NORTH OF THE TROUGH AND ISOLATED SHOWERS ALONG AND SOUTH OF THE BOUNDARY. FORECAST CHALLENGE EARLY CONCERNS TIMING OF THE FOG LIFTING...OTHERWISE LOOKING AT THE RAIN CHANCES ALONG THE COAST AND AFTERNOON SKY CONDITIONS AND TEMPERATURES. COASTAL WATERS ARE LOOKING AT SWELLS CAUSED IN PART FROM THE DEVELOPING TROPICAL DEPRESSION 15 OVER THE CARRIBEAN. 12Z CRP AND LCH SOUNDINGS INDICATE THE FOG SHOULD DISSIPATE WITHIN THE NEXT COUPLE OF HOURS. WITH THE COASTAL TROUGH IN PLACE FEEL ISOLATED SHOWERS ARE STILL POSSIBLE OVER THE COASTAL COUNTIES... CURRENT RUC KEEPS THIS FEATURE IN PLACE TODAY. TEMPERATURES SHOULD GET A BIT WARMER THAN YESTERDAY AND FEEL THE CURRENT FORECAST IS ON TRACK IN THAT REGARD. WILL UP THE COASTAL WATERS TO SCEC BEYOND 20 NM TO DEAL WITH THE SWELLS...MAY NEED TO UP TO A SCA LATER TODAY. WILL NOT MAKE ANY UPDATES TO THE PUBLIC FORECAST. PL-40 43 .HGX...SCEC 20 TO 60 NM HIGH ISLAND TO THE MATAGORDA SHIP CHANNEL. PRELIMS... CLL BB 080/060 083/063 085 000 IAH BB 079/061 082/064 085 -00 GLS BB 075/068 079/070 081 100 tx DEEP SOUTH TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 1045 AM CST WED OCT 31 2001 SHORT TERM...ISOLD SHOWERS HAVE PROGRESSED NW INTO THE BRO VICINITY THIS MORNING. THESE SHOWERS APPEAR TO FIRING IN THE RETURNING LOW LEVEL MOISTURE ADVECTING NW IN THE LOW LEVEL SE FLOW. IN ADDITION...RUC DATA FROM THIS MORNING SHOWS 5H RIDGING PREVAILING OVER THE BIG BEND AREA WITH A CLOSED LOW LOCATED OVER CENTRAL MEXICO. MEANWHILE FURTHER EAST...BROAD UPPER LEVEL TROUGHING IS IN PLACE OVER THE CENTRAL GULF COAST AND THE WESTERN GULF OF MEX. A POCKET OF 5H VORTICITY REMAINS ELONGATED ALONG THE MEXICAN COASTLINE AND ONE LOBE OF THE VORTICITY EXTENDS NORTHWARD ALONG THE LOWER TX COASTLINE. AS A RESULT OF THIS LOBE OF VORTICITY...THESE SHOWERS WILL CONTINUE TO FIRE ALONG THE LOWER TX COASTLINE. THE CURRENT ZFP REFLECTS THIS PRETTY WELL WITH NO SIGNIFICANT CHANGES REQUIRED. MARINE...BUOY020 CURRENTLY IS REPORTING SWELLS FROM 6 TO 7 FT WITH A SE FLOW NEAR 10 KTS. THE LIGHT SE FLOW WILL CONTINUE THROUGH THE DAY WHICH WILL NOT BUILD SWELLS MUCH HIGHER. HAVE ADJUSTED THE CURRENT CWF TO REFLECT THE SHIFT IN WIND DIRECTION. SYNOPTIC-AVIATION-MARINE...60/MESO...WATKINS .BRO...NONE. tx SOUTHEAST TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 929 AM CST WED OCT 31 2001 COASTAL TROUGH WAS AFFECTING SE TX THIS MORNING...WITH SOME PATCHY FOG TO THE NORTH OF THE TROUGH AND ISOLATED SHOWERS ALONG AND SOUTH OF THE BOUNDARY. FORECAST CHALLENGE EARLY CONCERNS TIMING OF THE FOG LIFTING...OTHERWISE LOOKING AT THE RAIN CHANCES ALONG THE COAST AND AFTERNOON SKY CONDITIONS AND TEMPERATURES. COASTAL WATERS ARE LOOKING AT SWELLS CAUSED IN PART FROM THE DEVELOPING TROPICAL DEPRESSION 15 OVER THE CARRIBEAN. 12Z CRP AND LCH SOUNDINGS INDICATE THE FOG SHOULD DISSIPATE WITHIN THE NEXT COUPLE OF HOURS. WITH THE COASTAL TROUGH IN PLACE FEEL ISOLATED SHOWERS ARE STILL POSSIBLE OVER THE COASTAL COUNTIES... CURRENT RUC KEEPS THIS FEATURE IN PLACE TODAY. TEMPERATURES SHOULD GET A BIT WARMER THAN YESTERDAY AND FEEL THE CURRENT FORECAST IS ON TRACK IN THAT REGARD. WILL UP THE COASTAL WATERS TO SCEC BEYOND 20 NM TO DEAL WITH THE SWELLS...MAY NEED TO UP TO A SCA LATER TODAY. WILL NOT MAKE ANY UPDATES TO THE PUBLIC FORECAST. PL-40 43 .HGX...SCEC 20 TO 60 NM HIGH ISLAND TO THE MATAGORDA SHIP CHANNEL. PRELIMS... CLL BB 080/060 083/063 085 000 IAH BB 079/061 082/064 085 -00 GLS BB 075/068 079/070 081 100 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 410 AM CST THU NOV 1 2001 MAIN FORECAST CONCERNS ARE INCREASING WINDS AND SML THREAT OF -SHRA FIRST PD. PACIFIC TROUGH VCNTY OF KSTC TO KRWF MOVING SLOWLY EWD. SLY WINDS AHEAD OF TROUGH HAVE PULLED 50 TO 55 DEGREE DEWPTS IN SRN MN AND MSAS SHOWING INCREASING THETA-E RDG INTO FAR SRN MN...AND ISOLATED CELLS TO 35 DBZ SHOWING UP VCNTY OF KAEL LAST HOUR. -SHRA SPREADING NE...AIDED BY WEAK SYNOPTIC FORCING FM LEFT EXIT RGN OF 70 KT JET. FORCING ALSO AIDING PERSISTENT ISOLATED-SCT -SHRA OVR WEST CENTRAL MN...EXTENDING FM NEAR KLXL TO KMML. THIS AREA OF -SHRA LINING UP WELL WITH LOWER CONDENSATION PRES DEFICITS ON ETA 300 THETA SFC...BUT BOTH ETA/AVN/RUC SHOWING AREA DECREASING THRU 12Z. HOWEVER...IR IMAGERY SHOWING SLIGHT COOLING IN CLOUD TOPS OVR WEST CENTRAL MN...WHICH MAY BE HINTING AT -SHRA PERSISTING A BIT LONGER THAN EXPCD. HENCE WL ADD MENTION OF ISOLD -SHRA EARLY MOST CENTRAL/ERN ZONES AND REMOVE AS NECESSARY. AVN AGAIN SHOWING BETTER CONSISTENCY WITH RESPECT TO MID LEVEL FEATURES AT 24 HOURS WHILE ETA SLOWING UPPER LOW IN SRN CAN TO AVN SOLUTION. HOWEVER BOTH MODELS IN GENERAL AGREEMENT SO WENT WITH A BLEND FOR THIS FORECAST PACKAGE. SANGSTER WINDS UPSTREAM IN 25 TO 35 KT RANGE WITH 40KTS BEGINNING TO PUSH ACRS US/CAN BORDER INTO NRN MT IN ASSOCIATION WITH PUSH OF COLDER AIR ASSOCD WITH S/W CIRCULATION DEPICTED NICELY ON WV IMAGERY IN SERN SASK. 4 MB MSAS PRES RISES IMMEDIATELY BEHIND POLAR FRONT WHILE 2 MB PRES RISES IN DAKOTAS BEHIND PACIFIC FRONT. STRONGEST PRES RISES TO RMN IN SRN CAN NEXT THRU 00Z WITH WEAKER RISES INTO WRN PTNS OF MN THIS AFTN. ETA BUFKIT DATA SHOWS LOWER PORTIONS OF SOUNDING AT KAXN NEARLY DRY ADIABATIC...TAPPING AIR UP TO 5K FT. POTENTIAL MOMENTUM TRANSFER OF 35 TO 38KTS THIS AFTN...POSSIBLY MEETING WIND ADVY CRITERIA IN WRN CWA. PER COORD WITH KABR/KFGF...WL HOLD OFF FOR NOW ON ADVY AND LET DAYTIME SHIFT TAKE SECOND LOOK AS STRONGEST WINDS EXPCD THIS AFTN. WL MENTION POTENTIAL WIND GUSTS TO 33KTS IN ZONES HOWEVER. POTENTIAL LOW CLOUDS AS A RESULT OF COLD AIR ADVECTION MAY BRUSH NRN AREAS TONIGHT...HOWEVER JET AXIS SHIFTS INTO CENTRAL MN TNGT INTO FRI WITH DRY AIR SETTLING INTO PLACE. HENCE M/S WORDING LOOKS GOOD. LEANING TWD SLIGHTLY WARMER MAV NUMBERS FOR FIRST PD WITH GUIDANCE NUMBERS IN BALLPARK IN LATER PDS. NO CHANGE TO EFP. .MSP...NONE. KAVINSKY mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 215 AM CST THU NOV 1 2001 FORECAST CONCERNS CENTER AROUND PRECIPITATION CHANCES TODAY THROUGH FRIDAY. PLENTY OF CLOUD COVER ACROSS THE REGION THIS MORNING. SOUTH WIND HAD REMAINED IN THE BREEZY CATEGORY...ESPECIALLY AT JOPLIN WHERE GUSTS TO 30 KNOTS CONTINUED THROUGH MIDNIGHT. RUC 500-300MB VORTICITY/WATER VAPOR LOOP SHOWED CHAIN OF VORTICITY LOBES FROM INTERNATIONAL FALLS MINNESOTA TO PHOENIX. 00Z MODELS ARE CONSISTENT WITH EACH OTHER AND PREVIOUS RUNS IN DEVELOPING AN AREA OF SHOWERS/EMBEDDED THUNDERSTORMS ACROSS THE FORECAST AREA LATE THIS AFTERNOON AND TONIGHT. LEANED HEAVILY ON THE MESOETA FOR GRIDDED DATABASE EDITS. STRANGE THING ABOUT THIS SYSTEM IS THAT THE INITIAL ELONGATED VORTICITY AREA WEAKENS AND MOVES NORTHEAST WELL BEFORE THE PRECIPITATION DEVELOPS. OVERLAY OF MESOETA 250 MB DIVERGENCE AND PRECIPITATION FIELDS IS ALMOST AN EXACT MATCH...SO IT LOOKS LIKE A COMBINATION OF THE UPSTAIRS DYNAMICS AND LOW LEVEL PREFRONTAL CONVERGENCE WILL BE RESPONSIBLE FOR RAIN PRODUCTION...WITH 500 MB TROUGH AXIS OVER THE WESTERN HIGH PLAINS. PREVIOUS FORECAST HAD SITUATION IN HAND...AND MADE ONLY MINOR EDITS. MAIN CONCERN WAS HOW LONG TO KEEP MENTION OF RAIN IN FOR FRIDAY. MODELS HAVE BEEN PERSISTENT IN MOVING THE RAIN AREA INTO NORTHERN ARKANSAS SHORTLY AFTER 12Z FRIDAY...SO WILL FOLLOW THEIR LEAD. MID LEVEL RIDGING DEVELOPS SATURDAY AND SUNDAY...SO DRY WEATHER PATTERN TO RETURN WITH TEMPERATURES RISING ABOVE SEASONAL NORMS. INCREASED HUMIDITIES AND DECREASED WINDS WILL PRECLUDE ANY THOUGHT OF RED FLAG WARNING TODAY. ISC GRIDS HAVE BEEN SENT. PRELIMINARY FORECAST GUIDANCE FOR COORDINATION PURPOSES ONLY. FCSTID = 8 SGF 73 59 68 49 / 20 60 30 0 JLN 74 59 69 49 / 10 40 30 0 UNO 73 61 68 53 / 10 70 60 0 VIH 74 56 68 47 / 20 60 30 0 .SGF... MO...NONE. KS...NONE. SUTTON mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBANY NY 100 AM EST THU NOV 1 2001 00Z KALY SOUNDING WAS SATURATED THRU LYR BTWN ABT H8.2 AND H5 WHILE CWMW WAS ABT THE SAME ONLY 100 MB CLOSER TO SFC...ALG WITH TEMP PROFILE SUPPORTIVE OF PE PRODUCTION. SOUNDING AT KPIT INDICATED CSDRBL DRYING. H3 POLAR JET OF 120 KT PER AIREP OVR SE NB AND RUC HAD BEST UPR DIV IN SRN QUE...WITH OTHER RGNS OVR WRN GRTLKS AND IN DRIER AMS THRU WV AND PA. WRMFNT APPEARS TO BE ALIGNED FM UPR MI- GEORGIAN BAY-CTSKLS AT 04Z AND RADAR SHOWS PCPN SHIELD HEADING ACRS ADRNDCKS...PTNS OF MHKVLY AND INTO SXNS OF NEW ENG. WRMFNT ADVANCES INTO ST LAWRENCE VLY AT 12Z THIS MRNG. MSTR INCRS AGAIN INVOF ERN GRTLKS BY 00Z FRI WITH PCPN AHEAD OF FNT RCHG INTO ADRNDCKS BEFORE THE NGT ENDS. MODELS ARE IN AGREEMENT THAT CDFNT RCHS WRN NY BY 00Z SAT. XPC MOST OF MEASURABLE PCPN RMNG NW OF KMSV-KPSF LN ON FRI...THEN CDFNT DROPS OVR DIST FRI NGT. AVN RUN KEEPS THINGS VERY UNSETTLED ERY NEXT WEEK WITH VERY BUSY VOT PAT IN MOIST NW FLOW. RDG LN RCHS SE ONTARIO TUE MRNG AND INTO NERN STATES WED. MCKINLEY/KDL .ALY...NY ERN/VT EXTRM SRN/MA EXTRM WRN/CT NW...NONE. ny SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO COLORADO 156 PM MST THU NOV 1 2001 MAIN CHALLENGES FOR THE NEXT 2 DAYS WILL BE MAX/MIN TEMPS WITH LITTLE OR NO PRECIPITATION EXPECTED. IN FACT...THIS COULD CARRY INTO DAYS 3-5 ALSO. CURRENTLY: LATEST WATER VAPOR IMAGERY/RUC 400MB ANALYSES SHOWED MID LEVEL SHORTWAVE TROUGH OVER NERN CO MIGRATING EWD INTO KS. FURTHER UPSTREAM...W-NWLY FLOW DEVELOPING. ALSO..."OLD" CYCLONE SPINNING IN THE PACIFIC OCEAN(33N, 128W)...SLOWING HEADING EWD TOWARD BAJA OF CA. LATEST LAPS SOUNDINGS REVEALED DRY ADIABATIC LAPSE RATE UP TO 650-600MB TDA...SO WITH THE LACK OF DEEP TURBULENT MIXING AND SLIGHTLY COOLER TEMPS ALOFT...TEMPS ARE A LITTLE COOLER THAN YDA. IR SATELLITE IMAGERY SHOWING LITTLE...IF ANY...CLOUD COVER IN GREAT BASIN/SW US. MAIN CLOUD COVER WAS OVER PACIFIC NW NEAR ONCOMING ULJS. TNGT-SAT: AGAIN...OVERALL SYNOPTIC SCALE FLOW FORECAST TO REMAIN W- NWLY. SYSTEM IN THE PACIFIC OCEAN IS VERY SLOW TO MOVE AND BARELY MAKES IT TO THE BAJA OF CA BY SUN. SHOULD SEE SKC TO FEW-SCT HIGH CLOUDS FOR THE NEXT 2 DAYS. WILL LIKELY BE A LITTLE MORE OPTIMISTIC WITH THE SKY CONDITION...RATHER THAN "PARTLY CLOUDY"...FOR TNGT/FRI. GOOD RADIATIONAL COOLING TNGT WITH TYPICAL THERMALLY DRIVEN DRAINAGE WINDS. COOLEST SPOTS WILL BE IN VALLEYS AND WILL LIKELY STAY CLOSE OR A LITTLE BELOW MOS. ON FRI...DEPTH OF MIXING AND MAX TEMPS THE MAIN CONCERN. SHOULD SEE PLENTY OF SUNSHINE. MESO-ETA GRIDS ARE FAIRLY CLOSE TO MOS...SO WILL STICK WITH IT ON FRI. FRI NGT...LOWER TROP WINDS PICK UP A LITTLE(SLY 10-15KTS) IN SERN CO WHICH COULD KEEP THINGS MIXED OVERNIGHT...BUT ALL IT TAKES IS 1 HOUR OF LIGHT WINDS FOR THE TEMP TO TANK. SLY FLOW DEVELOPS FRI NGT/SAT WITH BEST 850- 800MB AXIS PROJECT FURTHER S-E OF SERN CO. CURRENT VIS SATELLITE IMAGERY SHOWS ST/SC CLOUDS CONFINED OVER EXTREME SRN/ERN TX. BY SAT AFTN...LOWER TROP AIR MASS RELATIVELY DRY. SYSTEM IN THE PACIFIC OCEAN IS STILL WAY OFF THE CA/BAJA OF CA COASTLINE ON SAT/SAT NGT AND IS A NO PLAYER IN OUR WEATHER. MESO-ETA SUGGESTING SAT MAX TEMPS 68-73F ON THE SERN CO PLAINS...WHICH IS A LITTLE WARMER THAN CURRENT ZFP. MESO-ETA MAX TEMP GRIDS IN-LINE WITH CURRENT WARMER MOS(MAV/FWC). EVEN THE COOL BIAS MAV HAS 73F FOR PUB SAT. WILL MAINTAIN CURRENT ZFP...BUT WOULDN'T BE SURPRISE FOR IT TO A LITTLE WARMER ON SAT. SUN-THU: FOR SUN-TUE...LITTLE CHANGE IN THE OVERALL PATTERN. 84HR ETA AND 84-120HR AVN...SHOWING GENERALLY W-NWLY UPPER LEVEL FLOW OVER CO. DECAYING PACIFIC OCEAN SYSTEM FINALLY IS FORECAST TO COME ON-SHORE IN BAJA OF CA SUN/MON THEN MIGRATES...WELL...S OF FCST AREA ALONG THE US/OLD MEXICO BORDER(TRACK IS A NO PLAYER FOR US). AVN MAY BE WAY OVERDONE ON ITS LIGHT PRECIPITATION FOR SAT NGT-SUN-MON. 84HR ETA HAS NO QPF FOR SUN IN CO. CURRENT PLANS ARE NOT TO TOUCH SUN-TUE FORECAST...HOWEVER CLOUDS AND LOW POP UNCERTAINTY WORDING MAY BE OVERDONE. MRF IS FORECASTING ANOTHER SYSTEM TO COME THROUGH WED AND EXIT THU. NOGAPS IS WEAKER AND FURTHER N...CAN AND ECMWF HOLDS SYSTEM FURTHER W IN THE WRN US. THE UKMET DOESN'T HAVE A CLUE. IF MRF VERIFIES...METEOROLOGICAL CONCEPTUAL MODELS WOULD SUGGEST WINDY CONDITIONS AND POTENTIAL PRECIPITATION ALONG AND W OF CONTDVD. WITH MUCH UNCERTAINTY AND KNOWING EXTENDED MODELS WEAKNESSES AND PROPENSITY TO FLIP-FLOP...WILL JUST ADD THU TO WED. .PUB...NONE. METZE co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 130 PM EST THU NOV 1 2001 VISIBLE SATELLITE IMAGERY...RUC UPPER ANALYSIS AND SURFACE DATA SHOW HIGH PRESSURE FIRMLY ENSCONCED OVER THE SOUTHEASTERN U.S. WITH A DECENT CU FIELD DEVELOPING...MOSTLY SUNNY SKIES...MODERATE SURFACE WINDS...WARM TEMPERATURES AND MODERATELY HIGH AND INCREASING RH VALUES. PRESSURE GRADIENT IS FAIRLY TIGHT SO WINDS OVER LAND ARE UP SOMEWHAT AND BREEZY ON THE EAST SIDE. OVER WATER WINDS ARE UP SIGNIFICANTLY WITH SCEC IN EFFECT. MODELS/ZFP: MODELS SHOW THE UPPER WEAK RIDGE OVER THE EAST SLOWLY OVER THE FORECAST PERIOD GIVING WAY TO A WEAK UPPER TROUGH OVER THE EAST BY END OF FORECAST. THE UPPER LOW OVER THE SOUTHERN CANADIAN PLAINS WILL MOVE ALONG THE CANADIAN/U.S. BORDER TO SOUTHERN ONTARIO...THEN BEGIN TO LIFT NE ON SATURDAY. MODELS HAVE NOT CHANGED REGARDING THE TRAILING WEAK VORT LOBE PREVIOUSLY EXPECTED TO BECOME DRAPED ACROSS THE TN VALLEY AND INTO THE SOUTHERN PLAINS BY EARLY SATURDAY. THIS FEATURE IS FORECAST TO WEAKEN INTO SUNDAY AS IT APPROACHES THE CWA. AT THE SURFACE: MODELS ARE MORE IN LINE AS ETA NO LONGER SHOWS A WEAK INVERTED TROF ACROSS THE GULF COAST. IT DOES SHOW VERY MINOR AND TRANSIENT NORTHWARD-REACHING ANOMALIES IN THE MOISTURE FIELDS FRIDAY MORNING...NONE OF WHICH ARE EXPECTED TO PRODUCE ANY SENSIBLE WEATHER. MODELS STILL SHOW MOST OF THE PRECIP ASSOCIATED WITH MICHELLE OVER THE SOUTHERN FLORIDA PENINSULA AND THE SOUTHERN GULF WATERS THROUGH THE FORECAST PERIOD...WITH SMALL POSSIBILITY OF SOME PRECIP FRIDAY NIGHT AND SATURDAY DUE TO THE EASTERLY FLOW. LITTLE CONFIDENCE IN THIS FORECAST. COLD FRONTAL BOUNDARY WILL APPROACH THE CWA FROM THE NORTH...BUT WILL REMAIN NORTH BY LATE SATURDAY. INHERITED ZONE DISTRIBUTION LOOKS SOUND BASED ON MODEL SCENARIO SHOWN. MUCH DEPENDS ON ACTUAL TRACK OF MICHELLE. WITH TIME THIS TRACK LOOKS MORE AND MORE LIKE A SOUTH FLORIDA EVENT. TEMP GUIDANCE CLOSE AND GENERALLY ACCEPTED. POPS GUIDANCE SHOW A TREND OF DELAYING THE CHANCE FOR PRECIP. HAVE NO POPS TONIGHT...GRADUALLY INCREASED POPS TO 10% ACROSS THE BOARD BY SATURDAY NIGHT. MARINE: WINDS HAVE STAYED IN THE SCEC RANGE TODAY...SOMETIMES JUST BARELY...AND ARE EXPECTED TO CONTINUE SO THROUGH FRIDAY...BEGIN TO PICK UP FRIDAY NIGHT...POSSIBLY TO SCA CONDITIONS ON SATURDAY. FIRE WEATHER: NO REQUIREMENTS AS MIN RH VALUES WILL REMAIN WELL ABOVE CRITICAL THRESHOLDS. EXTENDED: BEHIND THE FRONT...NE TO E FLOW WILL PREVAIL OVER THE AREA AS SURFACE HIGH PRESSURE BECOMES REESTABLISHED OVER THE SOUTHEASTERN U.S. MICHELLE IS NOW EXPECTED TO TURN MORE EASTERLY BY MONDAY... MOVING ACROSS CUBA ENROUTE TO THE BAHAMAS. THIS TRACK WOULD TEND TO KEEP BOTH CLOUDS AND PRECIPITATION WELL TO THE SOUTH OF MY CWA. PRELIM NUMBERS: TLH 58 83 61 83 00-1 PFN 62 82 64 81 00-1 DHN 59 82 61 81 00-1 ABY 58 81 59 80 0--1 VLD 59 83 60 83 0111 .TLH... .AL...NONE. .GA...NONE. .FL...NONE. AFD fl