AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GOODLAND KS 845 AM MST SUN MAR 10 2002 SOUTHERLY WINDS INCREASING QUICKLY OVER THE THE EASTERN CWA WITH KHLC GUSTING TO NEAR 30 MPH. LATEST RUC SUGGESTS THE WINDS WILL STAY AS SURFACE TROUGH TO THE WEST CONTINUES TO DEVELOP AND SURFACE HIGH OVER THE CENTRAL U.S. KEEPS THE GRADIENT FAIRLY TIGHT. OTHER THAN THAT...BUMPED UP THE NORTHEAST ZONE GROUPINGS (KMCK) TO ADVERTISE HIGHS NEAR 60 GIVEN 850 PROJECTIONS AND THEIR NOTORIOUS TREND TO BE WARMER THAN PROJECTED DESPITE THE CIRRUS DECK. NO OTHER CHANGES MADE. .GLD...NONE. THEDE ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1045 PM EST SUN MAR 10 2002 MAIN FCST CONCERNS INCLUDE LINGERING LES OVER THE NE CWA AND POTENTIAL FOR -SN SW BY DAYBREAK WITH INCOMING CLIPPER. WV IMAGERY AND RUC ANALYSIS INDICATED RISING HGTS WITH MID/UPR LVL FLOW BECOMING MORE ZONAL ACRS THE NRN PLAINS INTO THE WRN LAKES AS ERN NOAM TROF CONTINUES TO LIFT TO THE NE. UPSTREAM...A SHEARED SHRTWV STRETCHED FROM SW SASK INTO NE ND WHILE A STRONGER SHRTWV MOVE FROM UT INTO CO. AT THE SFC...NW FLOW LINGERED OVER THE ERN 2/3 OF LK SUPERIOR DOWNSTREAM FROM RDG WHICH EXTENDED FROM NRN MN TOWARD THE CNTRL OH VALLEY. KMQT 88D INDICATED SHSN INTO FAR NE PORTION OF CWA HAD CONTINUED TO DIMINISH AND SHIFT SLOWLY TO THE NORTH IN RESPONSE TO BACKING WINDS. WEAKENING GRADIENT AS RDG APPROACHES HAS ALSO ALLOWED WINDS TO SLACKEN. SO...HAVE DROPPED WINTER STORM WARNING FOR ALGER-LUCE WITH SHSN FROM PICTURED ROCKS TO KERY LIFT TO THE NORTH. EVEN THROUGH LK-H8 DELTA/T REMAINS NEAR 20C AND INVERSION HGTS REMAIN NEAR 4K FT...GRADUAL SHIFT OF BEST 950 CONVERGENCE...PER ETA...SHOULD KEEP ADDITIONAL AMOUNTS TO AROUND 2 INCHES ALONG THE SHORE WITH LESSER AMOUNTS TO THE SOUTH. WAA/ISENTROPIC LIFT WAS INCREASING TO THE WEST WITH THICKENING MID/HI CLD. SO FAR...NO SFC -SN REPORTS DESPITE INCREASING RADAR RETURNS...PER KDLH 88D. WHILE VERY DRY CONDITIONS BLO 650 MB...PER KINL/KGRB SNDGS...WILL INHIBIT DEVELOPMENT OF -SN AT THE SFC...ETA/RUC 280K-295K LYR AND RADAR TRENDS SUGGEST AT LEAST SOME -SN WILL MOVE INTO SW UPR MI BY DAYBREAK. HOWEVER...ANY ACCUMULATION SHOULD BE NOT MUCH MORE THAN A DUSTING BEFORE 12Z. THICKENING CLOUDS SHOULD LIMIT RADIATIONAL COOLING. SO...HAVE NUDGED MIN TEMPS UP SLIGHTLY. .MQT...GALE WARNING EAST HLF LK SUPERIOR. JLB mi SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 940 PM EST SUN MAR 10 2002 TWO AREAS OF CLOUDINESS TO AFFECT SOUTHEAST MICHIGAN OVERNIGHT. FIRST AREA OF THE RESIDUAL LAKE EFFECT CLOUDS OVER SOUTHWEST LOWER. THESE LOW CLOUDS HAVE PULLED AWAY FROM LAKE MICHIGAN AND APPEAR TO BE DISSIPATING A LITTLE AS THEY MOVE TOWARDS SOUTHEAST MICHIGAN. THE NEXT BATCH OF CLOUDS TO AFFECT US WILL THE WARM ADVECTION MID AND HIGH CLOUDS MOVING OUT ONTO LAKE MICHIGAN FROM WISCONSIN. THE 18Z ETA AND THE 00Z RUC BOTH SHOW THESE CLOUDS MOVING INTO SOUTHEAST MICHIGAN AFTER 06Z WITH THE THICKER CLOUDS MOVING INTO THE NORTH HALF OF THE FORECAST AREA. BASED ON THE ON THE MOVEMENT OF THESE CLOUDS WILL HAVE BECOMING MOSTLY CLOUDY IN THE FORECAST FOR ALL OF SOUTHEAST MICHIGAN. TEMPERATURES SHOULD CONTINUE TO FALL THROUGH 06Z AND THEN HOLD STEADY AS THE CLOUDS INCREASE ACROSS THE REGION. OVERNIGHT LOWS OF 10 TO 15 STILL LOOK OK FOR THE NORTHERN COUNTIES... WHILE LOWS AROUND 15 SHOULD WORK FOR THE SOUTHERN COUNTIES. .DTX...GALE WARNING...TONIGHT...LAKE HURON. KEYES mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 930 PM EST SUN MAR 10 2002 ...UPDATED TO INCREASE LOWS OVERNIGHT SOUTHERN CWA... BIGGEST QUESTION OVERNIGHT IS JUST HOW COLD WILL IT GET? TO ANSWER THAT QUESTION WE HAVE TO ANSWER THE QUESTION OF WHAT WILL HAPPEN TO THE WARM ADVECTION CLOUDS OVER WISCONSIN AND THE REMAINING LAKE CLOUDS OVER SOUTHWEST LOWER... BETWEEN I-96 AND I-94? THE 00Z RUC SHOWS THE CONDENSATION PRESSURE DEFICITS FALL TO BETWEEN 30 AND 50 MB OVER THE CENTRAL AND NORTHERN CWA BETWEEN 09Z AND 12Z. THIS IS DUE TO A COMBINATION OF JET ENTRANCE REGION LIFT AND ISENTROPIC LIFT AHEAD OF THE WARM FRONT OVER SOUTHERN IOWA TO NRN NE AT 02Z. AS FOR THE LOW CLOUDS... THE RUC SUGGESTS AN AREA OF 60 TO 65 PCT RH HANGS IN THERE BETWEEN I-94 AND I-96 THROUGH 09Z. THAT IS THE AREA WHERE THE LOW CLOUDS CONTINUE AS OF 02Z. THIS SEEMS TO BE A COMBINATION OF THE CONVERGENCE OF THE AIR STREAM COMING IN FROM WI AND THE WARMER AIR STREAM MOVING IN FROM IL. SINCE IT IS CURRENTLY MOSTLY CLEAR OVER ALL OF THE NRN CWA AND WINDS HAVE BECOME LIGHT FROM THE SOUTHWEST... I WILL GO WITH INCREASING CLOUDINESS WITH LOWS NEAR 15F BY THE LAKE SHORE AND IN THE SINGLE NUMBER INLAND (SIMILAR TO THE GOING FORECAST). BY 2 TO 4 AM... CLOUDS SHOULD BE THICK ENOUGH TO STOP THE TEMPERATURE FROM FALLING FARTHER. OVER THE SRN CWA... I WENT WITH VARIABLE CLOUDINESS SINCE THE LOW CLOUDS ARE CURRENTLY SCT TO BROKEN AND IT SEEMS THEY WILL INCREASE AND DECEASE SOME OVER THE NEXT FEW HOURS... BUT NOT REALLY GO AWAY. NOT ONLY THAT... BUT THOSE SAME MID AND HIGH CLOUDS FROM WI WILL BE MOVING IN. BY 4 TO 5 AM THEY SHOULD BE THICK ENOUGH TO STOP THE TEMP FROM FALLING. THUS I INCREASED THE LOWS ABOUT 10F... TO LOWS IN THE TEENS. ALL OF THIS BLENDS NICELY INTO MONDAYS MOSTLY CLOUDY FORECAST. .GRR...NONE. WDM mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 405 PM EST SUN MAR 10 2002 12Z RAOBS/LATEST WV LOOP AND RUC ANAL SHOW VIGOROUS BUT RATHER PROGRESSIVE UPR TROF MOVG E THRU SE CAN...WITH ASSOCIATED SFC LO NR JAMES BAY DOWN TO 970MB. STRG NW CYC FLOW CONTS OVR THE UPR GRT LKS WITH SHARP PRES DIFF BTWN LO AND 1040MB HI PRES OVR THE MID MS VALLEY. 12Z INL RAOB INDICATES H5 WND OF 100KT...WITH H7 WNDS AS HI AS 80KTS OVR IL AND H85 WND UP TO 60KTS AT PROFILER IN SW WI. STRG UNIDIRECTIONAL WNDS WITH PRESENCE OF H85 THERMAL TROF (NO MORE CAD) AND TEMPS ARPCHG -25C CAUSING NMRS WIND PARALLEL LES BANDS INTO THE ERN ZNS. INGEST OF DRIER AIR DEPICTED ON THE 12Z INL SDNG AND SFC DWPTS NR -10F OVR THE MN ARROWHEAD AND SW ONTARIO HAS DIMINISHED LES OVR THE W WITH SHORTER FETCH AND LIMITED RESIDENCE TIME. ACTIVITY OVR THE E NOT PARTICULARLY HVY EITHER AS DEEP UPR MSTR HAS PULLED NE WITH UPR TROF. MAX REFLECTIVITY DEPICTED ON THE MQT REFLECTIVITY DOWN TO ARND 20DBZ. BUT GUSTY WNDS THIS AFTN STILL CAUSING SHARPLY REDUCED VSBY IN BLSN OVR ALGER/LUCE/NRN SCHOOLCRAFT. NR BLIZZARD CONDITIONS EARLIER IN PLACES OVR THE E...WITH VSBY EVEN AT ERY CONSISTENTLY DOWN NR 1/4SM INTO EARLY AFTN. BUT VSBY AT ERY HAS IMPROVED TO 3/4SM. WNDS JUST TO THE SW CLOSER TO RDG AXIS DCRSG... WITH ASX WND AT 17Z GUSTING TO 22 MPH. QUITE A BIT OF HI CLD SPRDG E QUICKLY INTO WRN MN INTO RDG AXIS IN WAD AHD OF SW TROF MOVG E THRU MT OVR UPR RDG IN THE ROCKIES. ANOTHER SHRTWV MOVG THRU THE CNTRL ROCKIES...BUT A MORE POTENT SHRTWV NOW APRCHG PAC NW COAST. MAIN FCST CONCERNS THIS PACKAGE ARE LES/WND TRENDS AND GOING HEADLINES EARLY...THEN IMPACTS OF PARADE OF CLIPPERS ON MON INTO WED. USED A MIX OF MODELS AS NOTED IN TEXT TO PREPARE TDAYS FCST. MODELS IN GOOD AGREEMENT SHOWING PRES GRADIENT SLACKENING THIS EVNG AS JAMES BAY LO PRES CONTS NE AND RDG TO W MAKES PROGRESS EWD. BUT 12Z ETA SHOWS SOME PERSISTENT H95 CNVGC NR LK SUP OVR ERN ALGER AND NRN LUCE COUNTY THRU 03Z. WND WL LIKELY STILL BE NR ADVY LVL THIS EVNG AS WELL...SO HAVE OPTED TO MAINTAIN A WINTER STORM WRNG THIS EVNG FOR ALGER/LUCE. DCRS IN WND SPEED MAY ALSO ALLOW BANDS TO MORE FULLY DVLP WITH INCRSG RESIDENCE TIME OF PARCELS OVR WATER. LES CHART SUGS 4"/6 HRS FOR XPCTD CONDITIONS...SO WL USE THIS ACCUM AS AN UPR LIMIT ON SN. OTRW...MODELS SHOW ISENTROPIC LIFT ON 280K TO 290K SFCS OVRSPRDG CWA W-E TNGT AS PRES GRADIENT SLACKENS WITH APRCH OF SFC RDG AXIS IN WAKE OF DEPARTING LO. AVN APPEARS TO HAVE BEST HANDLE ON INCRSG CLDS OVR THE NRN PLAINS...AND ITS RH PROGS SUG THICKENING MID/HI CLDS OVR THE W DURG THE EVNG AND OVR THE E OVRNGT. BUT LEADING EDGE OF CLD SHUD INITIALLY ERODE AS IT MOVES INTO DRIER AIR. ETA GENERATES QPF OVR THE WRN HALF OF CWA OVRNGT...BUT PREFER DRIER NGM/ETA/CAN DUE TO ABUNDANCE OF DRY LLVL AIR AND TREND FOR BETTER DYNAMICS TO REMAIN S AND PRES TO REMAIN HIER OVR CWA. WL PERSIST -SHSN OVR KEWEENAW THRU NGT AS ETA SHOWS PERSISTENT H95 CNVGC OVR THE PENINSULA. WL TEND A BIT LWR THAN MOS GUIDANCE OVR INLAND AREAS IN THE WCNTRL FOR MINS AS THERE SHUD BE SVRL HRS OF MCLR SKIES WITH DIMINISHING WNDS BEFORE THE ARRIVAL OF THICKER MID CLDS IN VERY DRY LLVL AIR AND TREND TOWARD HIER PRES. MODELS HAVE TRENDED WEAKER AND FARTHER S WITH CLIPPER COMING IN ON MON...WITH MORE EMPHASIS ON LWRG PRES FARTHER S AHD OF SHRTWV MOVG E FM THE CNTRL ROCKIES...RESULTING IN EVEN LESS OF A MOISTURE FEED INTO SYS MOVG TOWARD THE CWA. ALTHOUGH BEST DYNAMICS STAY S OF CWA...COMBINATION OF ISENTROPIC LIFT ON 280-290K SFCS...CYC FLOW THRU DAY AND AXIS OF H85-7 FRONTOGEN JUST TO THE N SUG AT LEAST A HI POP/LO QPF EVENT. MODEL QPFS 0.05 TO 0.15" APPEAR RSNBL GIVEN 1-2G/KG AVBL BTWN 700 AND 750MB AND SUPPORT GOING FCST OF 1-2 INCHES ACCUM. ARRIVAL OF DRIER AIR OVR THE W DURG THE AFTN SUG PCPN WL TAPER OFF THERE DURG THAT TIME. MOS FCST MAX CONSISTENT WITH GOING FCST AND LOOK RSNBL. SHRTWV RESPONSIBLE FOR MON -SN SHEARS OFF TO THE E OVRNGT WITH UPR DRYING IN THE WAKE OF DEPARTING DYNAMICS MOVG OVR LINGERING WEAK CYC FLOW OVR THE CWA DURG THE EVNG...WHICH DEGENERATES INTO A WEAK RDG UNDER NVA/H85-5 QVECTOR DVGC LATER ON. WL CARRY CHCY POPS EARLY ACRS THE E AND NR LK SUP...BUT THEN DRY EVERYWHERE. ETA FCST SDNGS INDICATE LWRG INVRN HGT WITH DRY AIR WORKING IN UNDER INVRN...BUT NLY FLOW OFF LK SUP SUGS LO CLDS WL PERSIST AT LEAST ACRS NRN TIER THAT UPSLOPE OFF LK. FARTHER INLAND...XPCT PARTIAL CLRG WITH TEMPS FALLING BLO MOS GUIDANCE IN LGT WND REGIME UNDER RDG. TEMPS AOA MOS NR LK SUP. MODELS IN GOOD AGREEMENT SHOWING NXT CLIPPER SYS MOVG E IN ZONAL FLOW ALF...WITH SFC LO REACHING NR LK WINNIPEG BY LATE TUE AND THEN INTO NRN LK SUP OR SRN ONTARIO BY WED MRNG. FAIRLY TIGHT PRES GRADIENT DVLPS BY LATE TUE...AND ETA FCST SHOWS AVN MOST PROLIFIC GENERATING QPF OVR CWA (AOA 0.25") LATE TUE-TUE NGT WITH 40KT H85 WNDS ADVTCG PW OVR 0.5" INTO NW GRT LKS AND CAUSING FAIRLY SHARP H7 UVV. SINCE LO PRES/BEST DYNAMICS PASSING TO N...ETA FCST SDNGS SHOW QUITE A BIT OF DRY AIR ARND H85 TO BE OVERCOME...AND GLFMEX CONNECTION ABSENT...PREFER LWR QPF ETA/CAN FCST. MODELS SHOW H85 TEMPS RISING ABV 0C IN THERMAL RDG AHD OF THIS SYS ACRS AT LEAST THE SRN TIER... BUT ETA (WHICH FCSTS HIEST H85 TEMP UP TO 3C) FCST SDNGS SHOW WBZ IN WARMEST LYR AOB BLO 0C...SO ANY ACCOMPANYING PCPN SHUD BE SN. PASSAGE OF LO PRES AND COLD FNT DURG THE MRNG WED SUGS SOME SUN WL RETURN. H85 TEMPS PROGGED TO FALL NO LWR THAN -10C IN NWLY FLOW IN WAKE OF SYS...SO LES DOES NOT APPEAR TO BE A BIG PROBLEM. RETURN OF SUN AND ARRIVAL OF ONLY MARGINALLY COLD AIRMASS SUGS TEMPS WL REBOUND TO OR ABV NORMAL...ESPECIALLY FM MQT-ESC-MNM WHERE NWLY FLOW DOWNSLOPES. EXTENDED MODELS CONT TREND OF TURNING ZONAL FLOW AT MID WEEK INTO MORE OF A WRN TROF/ERN RDG SCENARIO BY LATE WEEK. OPERATIONAL MRF... WITH SUPPORT FM ITS MEAN ENSEMBLE SOLN...CONTS TO BE THE WEAKEST ON INTENSITY AND FARTHEST SE OF ALL THE MODELS WITH LOW PRES PROGGED TO RIDE NE TOWARD THE GRT LKS ON FRI/SAT ALG A STRG FNTL BNDRY BTWN CONTD ARCTIC AIR OVR NRN PLAINS AND BLDG BERMUDA HI OFF SE COAST. CONSIDERING THE STRENGTH OF THE SE RDG DEPICTED BY THE MRF ENSEMBLE MEAN...FAVOR A FARTHER NW POSITION OF THIS FNTL BNDRY AND TRACK OF THE SFC LO PER THE ECMWF/UKMET/CAN SOLNS. SO POPS HIER THAN MEX GUIDANCE FOR FRI/SAT AFTR A DRY DAY ON THU. CAN ENSEMBLE FCSTS FOR SUN INDICATE SUPPORT FOR A BIT MORE UPR TROFFING OVR NW GRT LKS ON SUN...SO WL GO WITH CHC OF SHSN. TEMPS AOB NORMAL THRU THE PD WITH ARCTIC HI PRES UNDER UPR CONFLUENCE S OF IN CAN FEEDING COLD AIR S. COORDINATED WITH APX/GRB/YQT. .MQT...WINTER STORM WRNG THIS EVNG MIZ006-007. GALE WRNG E1/2 LK SUP THIS EVNG. KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 330 PM EST SUN MAR 10 2002 THE WINTER WEATHER ADVISORY THAT WAS IN EFFECT FOR OUR ENTIRE CWA THROUGH 4 PM WILL BE ALLOWED TO EXPIRE. WINDS WILL CONTINUE TO GRADUALLY SUBSIDE TONIGHT AS THAT INTENSE AREA OF LOW PRESSURE MOVES FARTHER AWAY FROM OUR REGION. THE CLOUD AND MIN TEMP FORECAST TONIGHT IS VERY CHALLENGING. THE RUC 1000-850 MB RH LAKE EFFECT CLOUD PROG HAS A GOOD HANDLE ON OUR LAKE CLOUDS. IT INDICATES CLEARING WILL MOVE IN ACROSS OUR CWA FROM SOUTHWEST TO NORTHEAST LATE THIS AFTERNOON AND EVENING. THIS COULD ALLOW TEMPS TO TAKE QUITE A DIVE AFTER SUNSET... ESPECIALLY CONSIDERING WE HAVE A SNOW COVER AGAIN. WE WILL ALSO BE COMING OFF A COLD AFTERNOON AND TEMPS ALL DAY HAVE BEEN RUNNING A FEW DEGREES COLDER THAN FWC/MAV GUIDANCE HAD FORECAST. SO WE ARE GOING TO UNDERCUT GUIDANCE MIN TEMP FORECASTS TONIGHT. WE WILL GO FOR LOWS AROUND 10 DEGREES FOR OUR LAKESHORE COUNTIES AND IN THE SINGLE DIGITS INLAND. ETA TIME HEIGHT RH PROGS INDICATE MID AND HIGH CLOUD COVER WILL MOVE IN FROM THE WEST NORTHWEST LATE TONIGHT. RATHER THAN TRY TO GET TOO CUTE WITH CLOUD WORDING WE WILL JUST WORD THINGS AS PARTLY CLOUDY... ESPECIALLY SINCE THAT MID AND HIGH DECK MAY BE SCT-BKN BUT NOT OVC. THE NEXT WEAK WEATHER SYSTEM OUT IN THE PLAINS MONDAY WILL INITIALLY HAVE VERY LITTLE MOISTURE TO WORK WITH. HOWEVER AS HIGH PRESSURE SLIDES OFF THE EAST COAST SOUTHERLY FLOW WILL DEVELOP OFF THE GULF OF MEXICO. OUR LOW AND MID LEVEL WINDS WILL BACK TO THE SSW AND 850 MB SW WINDS OF AROUND 40 KTS ARE FORECAST BY 18Z. THIS WILL HELP TO ADVECT MOISTURE BACK INTO OUR REGION. AS FOR PRECIPITATION CHANCES MONDAY AFTERNOON... 12Z ETA GUIDANCE KEEPS OUR CWA DRY. MEANWHILE... 12Z AVN GUIDANCE BRINGS SOME LIGHT SNOW IN DURING THE AFTERNOON... MAINLY ACROSS OUR NORTHERN CWA. OUR GOING FORECAST CALLS FOR A 30 PERCENT CHANCE FOR SNOW IN THE AFTERNOON AND THAT STILL LOOKS FINE. A BETTER CHANCE FOR A LITTLE LIGHT SNOW WILL COME MONDAY NIGHT AS THE SYSTEM MOVES INTO OUR REGION AND MOISTURE WITH IT CONTINUES TO INCREASE. WE WILL KEEP A 50 PERCENT CHANCE FOR LIGHT SNOW GOING MONDAY NIGHT. ETA BUFKIT ONLY SPITS OUT A FEW HUNDREDTHS OF AN INCH OF LIQUID EQUIVALENT PCPN. THE CANADIAN LOOKS QUITE DRY AND VERY SIMILAR TO THE ETA. AVN GUIDANCE PROGS AROUND A TENTH TO QUARTER OF AN INCH OF LIQUID EQUIVALENT PCPN ACROSS OUR CWA. WE BELIEVE THE AVN IS OVERDONE IN TERMS OF IT/S QPF SO WE WILL GO WITH THE MUCH DRIER ETA/CANADIAN SOLUTIONS. IN FACT WE DO NOT ANTICIPATE ANY SNOW ACCUMULATIONS MONDAY AFTERNOON OR MONDAY NIGHT. FLOW WILL GO BRIEFLY NORTHWEST BEHIND THAT SYSTEM TUESDAY MORNING... BUT QUICKLY BACK TO THE SOUTHWEST OUT AHEAD OF A CLIPPER WHICH WILL APPROACH OUR REGION TUESDAY NIGHT. SKIES WILL BE MOSTLY CLOUDY TUESDAY ALTHOUGH A FEW BREAKS IN CLOUD COVER ARE POSSIBLE... ESPECIALLY EARLY IN THE DAY. THIS SYSTEM WILL NOT HAVE MUCH IN THE WAY OF MOISTURE TO WORK WITH AND ANY PCPN ASSOCIATED WITH IT WILL REMAIN TO OUR NORTH AND WEST TUESDAY NIGHT AND HOLD OFF ACROSS OUR AREA UNTIL WEDNESDAY MORNING. LAURENS EXTENDED FORECAST TIMING AND STRENGTH OF SYSTEMS IN THE EXTENDED PERIOD A LITTLE TRICKY AS ZONAL UPPER FLOW MAKES A GRADUAL TRANSITION TO SOUTHWEST FLOW AHEAD OF A DEVELOPING WESTERN U.S. LONGWAVE TROUGH. LATEST GUIDANCE INDICATES THAT THIS WESTERN TROUGH MAY REMAIN ANCHORED THERE FOR SEVERAL DAYS ONCE IT BECOMES ESTABLISHED...WHICH WOULD IMPLY MORE ACTIVE WEATHER BY THE END OF THE WEEK. IN TERMS OF THE DAILY WEATHER...WILL CARRY A CHANCE OF MORNING RAIN SHOWERS WEDNESDAY AS WEAKENING COLD FRONT TRAILING SOUTH FROM A LOW NORTH OF LK SUPERIOR SLIPS THROUGH. A DECENT OVERRUNNING SITUATION APPEARS POSSIBLE AT SOME POINT LATE THURSDAY OR FRIDAY...BUT AGAIN TIMING/TRACK/STRENGTH OF SHORTWAVES APPROACHING FROM THE SOUTHWEST IS VERY UNCERTAIN AT THIS TIME. SNOW CANNOT BE RULED OUT... ESPECIALLY IN THE NORTHERN COUNTIES...BUT GUIDANCE POINTS TOWARD PRIMARILY A RAIN EVENT AT THIS POINT. ECMWF/MRF/CANADIAN ALL SUGGEST THAT A WAVE WILL BE PULLING AWAY ON SATURDAY AND THERE WILL BE A BREAK IN THE PCPN CHANCES BEFORE THINGS RECHARGE BACK TO THE SOUTHWEST. WILL BE BOLD AND ADVERTISE A DRY DAY SATURDAY...BUT OF COURSE THIS WILL BE VERY SUBJECT TO CHANGE AS PATTERN EVOLVES. MEADE .GRR...NONE. mi WEST CENTRAL TEXAS FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE SAN ANGELO TX 944 PM CST SUN MAR 10 2002 850 MB MOISTURE CONTINUES TO STREAM NORTH ACROSS WEST CENTRAL TEXAS...AND RADAR WIND PROFILES STILL SHOWING GOOD SOUTHERLY FLOW... LOW CLOUDS NOT GOING ANYWHERE FOR AWHILE. LATEST ETA AND RUC STILL SHOW THE MOISTURE PUSHING OFF TO THE EAST AFTER MIDNIGHT...BUT HIGH CLOUDS FROM AN APPROACHING SHORTWAVE WILL BE MOVING ACROSS. WILL LET THE MOSTLY CLOUDY SKIES GO ALL NIGHT. WITH 35 TO 40 KNOTS A COUPLE THOUSAND FEET UP AND WINDS ALREADY STAYING UP...ALSO UPPED WIND SPEEDS AS WELL. 07 ...240 PM CST SUN MAR 10 2002... SATELLITE IMAGERY INDICATES MID LEVEL SHORTWAVE MOVING ENE ACROSS RIO GRANDE VALLEY EARLY THIS AFTERNOON. ASSOCIATED MID TO HIGH CLOUDS SPREADING ACROSS WEST-CENTRAL AND SOUTHERN TX. EXPECT THESE CLOUDS TO EXIT OUR COUNTIES THIS EVENING...AND PLAN TO COVER TONIGHT SKY CONDITION WITH MOSTLY CLEAR WORDING. UPPER SHORTWAVE TO MOVE EAST ACROSS CENTRAL/SOUTHERN ROCKIES TONIGHT AND INTO CENTRAL/SOUTHERN PLAINS MONDAY. ASSOCIATED SURFACE TROUGH/WEAK PACIFIC COLD FRONT TO MOVE THROUGH OUR CWFA MON AFTERNOON AND EVENING. SURFACE HIGH PRESSURE RIDGE TO MOVE SOUTHEAST INTO TX BY TUESDAY MORNING...BEFORE SHIFTING EAST. NEAR ZONAL FLOW ALOFT TUESDAY THROUGH WEDNESDAY ACROSS OUR REGION...WITH DAYTIME TEMPERATURES WARMING TO 80 OR ABOVE IN OUR CWFA. UPPER TROUGH PROGGED TO TAKE SHAPE OVER THE WESTERN STATES THURSDAY...WITH LEAD SHORTWAVE EJECTING OUT INTO CENTRAL PLAINS BY EARLY FRIDAY. COLD FRONT TO SAG SOUTH TO RED RIVER/NORTH TX THURSDAY BEFORE STALLING...WITH DRYLINE SETUP OVER WEST TX. DRY AIR IS PROGGED TO HOLD IN OUR AREA...WITH GULF MOISTURE RETURN INTO CENTRAL AND EAST TX. LOOKS DRY AT THIS POINT FOR EXTENDED (DAYS 4-7)...BUT WILL MONITOR LATER MODEL RUNS FOR EVOLUTION OF WESTERN US TROUGH AND POSSIBILITY OF GULF MOISTURE RETURN. ABI 044/072/040/074 0000 SJT 041/074/040/077 0000 JCT 037/073/038/074 0000 .SJT...NONE. 19 tx WEST CENTRAL TEXAS FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE SAN ANGELO TX 540 PM CST SUN MAR 10 2002 QUICK UPDATE FOR CLOUD COVER...AS SATELLITE AND OBS SHOW 850 MB MOISTURE SURGING NORTHWARD INTO WEST CENTRAL TEXAS. CLOUDS NOW COVER MOST OF THE CENTRAL AND SOUTHERN ZONES...AND CONTINUE TO PUSH NORTH. LATEST RUC SUGGESTS THAT THESE LOW CLOUDS SHOULD START TO SHIFT EAST BY MIDNIGHT. THUS...HAVE WORDED FORECAST TO ACCOUNT FOR GRADUALLY CLEARING SKIES LATE. ...240 PM CST SUN MAR 10 2002... SATELLITE IMAGERY INDICATES MID LEVEL SHORTWAVE MOVING ENE ACROSS RIO GRANDE VALLEY EARLY THIS AFTERNOON. ASSOCIATED MID TO HIGH CLOUDS SPREADING ACROSS WEST-CENTRAL AND SOUTHERN TX. EXPECT THESE CLOUDS TO EXIT OUR COUNTIES THIS EVENING...AND PLAN TO COVER TONIGHT SKY CONDITION WITH MOSTLY CLEAR WORDING. UPPER SHORTWAVE TO MOVE EAST ACROSS CENTRAL/SOUTHERN ROCKIES TONIGHT AND INTO CENTRAL/SOUTHERN PLAINS MONDAY. ASSOCIATED SURFACE TROUGH/WEAK PACIFIC COLD FRONT TO MOVE THROUGH OUR CWFA MON AFTERNOON AND EVENING. SURFACE HIGH PRESSURE RIDGE TO MOVE SOUTHEAST INTO TX BY TUESDAY MORNING...BEFORE SHIFTING EAST. NEAR ZONAL FLOW ALOFT TUESDAY THROUGH WEDNESDAY ACROSS OUR REGION...WITH DAYTIME TEMPERATURES WARMING TO 80 OR ABOVE IN OUR CWFA. UPPER TROUGH PROGGED TO TAKE SHAPE OVER THE WESTERN STATES THURSDAY...WITH LEAD SHORTWAVE EJECTING OUT INTO CENTRAL PLAINS BY EARLY FRIDAY. COLD FRONT TO SAG SOUTH TO RED RIVER/NORTH TX THURSDAY BEFORE STALLING...WITH DRYLINE SETUP OVER WEST TX. DRY AIR IS PROGGED TO HOLD IN OUR AREA...WITH GULF MOISTURE RETURN INTO CENTRAL AND EAST TX. LOOKS DRY AT THIS POINT FOR EXTENDED (DAYS 4-7)...BUT WILL MONITOR LATER MODEL RUNS FOR EVOLUTION OF WESTERN US TROUGH AND POSSIBILITY OF GULF MOISTURE RETURN. ABI 044/072/040/074 0000 SJT 041/074/040/077 0000 JCT 037/073/038/074 0000 .SJT...NONE. 19 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 350 AM CST MON MAR 11 2002 PROBLEMS OF DAY...TIMING AND EXTENT OF SHOWER/TSTMS ASSOCIATE WITH SYSTEM TO CROSS AREA TODAY/TONIGHT/TUES AND CLEARING/WARM UP AFTER EXIT OF SYSTEM. MID LEVEL SHORTWAVE TROF CURRENTLY INDICATED BY LATEST WATER VAPOR IMAGERY/RUC ANALYSIS OVER NM/CO IS FORECAST BY MODELS TO DEEPEN AND APPROACH LOWER MS VALLEY REGION BY LATE TONIGHT. ELEVATED TSTMS ARE ERUPTING FROM NRN MX ALONG RIO GRANDE NWD TO WACO/LONGVIEW AREA... ABOVE VERY COOL/DRY BOUNDARY LAYER...INDICATIVE OF INCREASING DYNAMICS. CONFIDENCE AT THIS TIME IS LOW CONCERNING TIMING OF ONSET OF SHOWER/TSTM ACTIVITY FOR THE FORECAST AREA. MESOETA INDICATES DRY SUBCLOUD LAYER WILL INITIALLY THWART ATTEMT FOR PRECIP TO REACH GROUND. HOWEVER...THIS PATTERN SUPPORTS QUICKER PRECIPITATION AS RELATIVELY VEERED MID LEVEL FLOW WELL AHEAD OF MAIN SHORTWAVE FLOW MAY ADVECT HEAVIER CONVECTION OVER DRY BOUNDARY LAYER AND OVERCOME LARGE TEMP/DEWPOINT SPREADS. WILL KEEP CLOSE EYE ON TRENDS. SEVERAL FACTORS ARE PROGGED BY ETA/AVN TO COME TOGETHER FOR WIDESPREAD SHOWER/TSTM ACTIVITY FROM LATER TODAY INTO EARLY TUESDAY. IMPRESSIVE AGEOSTROPIC FLOW AND UPPER DIVERGENCE WILL DEVELOP IN LEFT EXIT REGION SUBTROPICAL JET LATER TODAY AND SUPPORT STRONG LOW LEVEL SOUTHERLY JET (~40 TO 50KTS) AND STRONG UPGLIDE IN 295K TO 305K THETA LAYER. ELEVATED TSTM ACTIVITY LOOKS LIKE A SURE BET GIVEN LATEST TRENDS AND AGREE WITH SPC DAY ONE OUTLOOK THAT HAIL WILL BE POSSIBLE...AND NOT QUITE WORTHY OF SVR TSTM MENTION IN ZONES AT THIS TIME. DO NOT EXPECT TSTM ACTIVITY TO BECOME SFC-BASED DESPITE STRENGTH OF WARM ADVECTION...GIVEN LITTLE TIME TO MODIFY BOUNDARY LAYER ALONG GULF. MODELS SUGGEST THAT LOW LEVEL SUPPORT WILL BEGIN TO OUTRUN MIDLEVEL SUPPORT EARLY TUESDAY WITH CONVECTIVE COMPLEX LIKELY TO BECOME SUPPRESSED TO COASTAL REGIONS. HOWEVER...CLOSED MID LEVEL CIRCULATION SHOULD PROVIDE ENOUGH DYNAMICS TO GENERATE SHOWERY CONDITIONS...ESPECIALLY OVER NORTH CENTRAL/NE COUNTIES MUCH OF DAY. CLEARING MAY NOT BE EASY BEHIND SYSTEM AS NOT MUCH SUBSIDENT MIXING COMES IN BEHIND IT. HAVE WORDED PARTLY CLOUDY FOR TUES NIGHT MOST ZONES...BUT THIS COULD BE OPTIMISTIC OVER ERN ZONES. SHOULD SEE SIGNIFICANT WARM UP WEDNESDAY GIVEN MOSTLY SUNNY SKIES. FOR THE WEEKEND...00Z MRF/UKMET CONTINUE TO INDICATE THAT A VERY ACTIVE PATTERN WILL BE SETTING UP OVER THE CNTRL US WITH SEVERAL ROUNDS OF RAINFALL LIKELY OVER THE FORECAST AREA. HAVE BROKEN OFF SAT AND SUN GROUP FROM FRIDAY IN EXTENDED...TO INTRODUCE TSTM CHANCES AS RATHER IMPRESSIVE SUBTROPICAL STREAM ENERGY IS PROGGED BY MRF TO HAVE INFLUENCE OVER THE LOWER MS VALLEY REGION. PRELIM NUMBERS... JAN 59/50/59/45/72 5+600 MEI 60/48/60/45/72 2+710 .JAN... AR...NONE. LA...NONE. MS...NONE. 43 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 310 AM CST MON MAR 11 2002 TEMPERATURES WILL REMAIN THE PRIMARY FCST CONCERN UNTIL WEDNESDAY. SHORTWAVE AND FRONT MOVING THROUGH WILL PRODUCE MID AND HIGH LEVEL CLOUDINESS...BUT PCPN SEEMS UNLIKELY. LATEST STLT IMAGERY SHOWED A BAND OF CS OVER MUCH OF THE AREA. CLOUDS WERE ORIENTED PRETTY CLOSE TO THE LOCATION OF WRMFNT /INVERTED TROF THAT EXTENDED NEWD FROM LOW PRES CENTER OVER SERN CO. COLDER AIR POISED TO THE N IN THE SD...WHERE HIGH YESTERDAY WERE MOSTLY IN THE 20S. LATEST RUC OUTPUT INDICATED THAT SFC LOW WILL TRACK TOWARD NRN OK INTO EARLY AFTN...WHILE WIND SHIFT MOVES E ACROSS OUR AREA. STRUGGLE TODAY WILL BE BETWEEN COOL LOW LEVEL AIRMASS...WARMER 850 MB TEMPS AND BOUNDARY LAYER MIXING. LOCALLY...HIGHS YESTERDAY RANGED FROM THE UPPER 20S NORTH TO LOWER 50S SOUTH. IT DOES NOT LOOK LIKE QUITE AS MUCH OF A RANGE TODAY...WITH DECENT MIXING THIS AFTN. EXPECT HIGHS FROM NEAR 40 NORTH TO MID 50S SOUTH. LOOKS LIKE A GOOD WARMUP ON TUE ALL AREAS. SNOWCOVER THAT IS STILL IN PLACE NOW SHOULD BE GREATLY REDUCED BY LATE THIS AFTN. SO...WITH MODELS INDICATING 850 MB TEMPS MAINLY FROM 4 TO 7 C... THINK THAT SRN ZONES WILL REACH THE LOWER TO MID 60S...WITH 50S ELSEWHERE. WEAK SYSTEM MAY PRODUCE A LITTLE RAIN OR SNOW IN THE FAR NRN ZONES TUE NGT. WILL KEEP SLGT CHANCE THERE. CLOUDINESS SHOULD INCREASE ON WED...WITH A CHANCE OF LIGHT RAIN BY AFTN. AVN AND ETA AGREE ON POSITION OF SFC LOW BY 12Z THU...OVER WRN OK BUT THERMAL AND QPF FIELDS DO NOT AGREE. FOR NOW WILL STAY CLOSE TO THE AVN SOLUTION. THIS KEEPS BEST CHANCE OF PCPN OVER THE CNTRL AND SRN ZONES. PATTERN THEN TO REMAIN ACTIVE INTO THE WEEKEND. GENLY WENT BELOW MRF MOS OUTPUT VALUES FOR HIGHS IN THE THU TO SAT TIMEFRAME WITH IDEA THAT THERE WILL BE CLOUDS AND PCPN TO KEEP THE DIURNAL RANGE DOWN. .OMA...NONE. MILLER ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1120 AM EST MON MAR 11 2002 WILL SEND A QUICK UPDATE TO REMOVE THE FLURRIES FROM THE FCST THIS AFTERNOON. 12Z SOUNDINGS REVEAL VERY DRY AIR BELOW 700 MB AND CEILING HEIGHTS ARE CURRENTLY AT OR ABOVE 10K FEET. THERE ARE SEVERAL BREAKS OR THIN SPOTS IN THE HIGH OVERCAST...AND AM TEMPTED TO BE A LITTLE MORE OPTIMISTIC WITH SKY FCST. HOWEVER WILL KEEP IT MOSTLY CLOUDY AS LATEST RUC MAINTAINS 80 PCT OR HIGHER RH OVER THE MAJORITY OF THE CWFA THROUGH 00Z. WILL NOT MESS TOO MUCH WITH GOING HIGH TEMPS ATTM...BUT DEPENDING ON HOW BRIGHT SKIES BECOME A FEW SPOTS COULD TOP 40 LATER ON. MEADE .GRR...NONE. mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 930 AM EST MON MAR 11 2002 ...UPDATING TO REMOVE MORNING WORDING... 12Z SURFACE/MSAS ANALYSIS SHOWS DOUBLE AREA OF HIGH PRESSURE EASING TOWARDS THE EAST COAST WITH SUBTLE TROUGH IN BETWEEN. LOW PRESSURE SYSTEM NEAR OKLAHOMA ORGANIZING WITH FRONT REACHING NORTH OF CHICAGOLAND AREA. RUC SHOWS RIDGING WILL CONTINUE AS THE HIGH EVENTUALLY SLIDES OFF THE ATLANTIC COAST THIS EVENING. LOW TO MID LEVEL SUBSIDENCE WILL ALLOW STRATOCU TO CONTINUE TO BREAK UP. VISIBLE/WATER VAPOR SATELLITE TRENDS DEPICT AREA OF HIGHER CLOUDS ASSOCIATED WITH WARM ADVECTION SLIDING ACROSS THE STATE TODAY...ESPECIALLY ACROSS THE NORTH. RUC THETA-E CROSS SECTIONS SHOW MIXING TO ABOUT 900 MB. TEMPERATURES WARM AT THIS LAYER FROM -8 TO -4 C TODAY. MIXING WILL YIELD HIGHS AVERAGING IN THE 36-38 F RANGE ACROSS MY CWA. WINDS WILL REMAIN LIGHT UNDER THE HIGH...WITH ONLY 15 KNOTS UP AT 900 MB...MAY SEE A COUPLE 10 MPH OBS FROM THE SOUTHWEST. WORK ZONES OUT AS PHLWRKMIS...REAL ZONES ON THE STREETS IN A FEW! .CTP...NONE. ROGOWSKI/GARTNER pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 1030 AM EST MON MAR 11 2002 PATCHES OF THICK CIRRUS CROSSING MUCH OF THE FORECAST AREA LATE THIS MORNING. SATELLITE LOOP SHOWING CLOUDS CONTINUING TO MOVE EASTWARD AND SHOULD MOVE OUT OF THE AREA OVER THE NEXT 3-4 HOURS. CLOUDS ASSOCIATED WITH WEAK SHORTWAVES PASSING THROUGH AREA AS DEPICTED BY LATEST RUC. MOSTLY SUNNY SHOULD STILL SUFFICE FOR THE AFTERNOON. WINDS ARE BECOMING MORE FROM THE EAST AND WILL WORD ACCORDINGLY IN THE ZONES. BECAUSE OF THE THICK CIRRUS...TEMPS HAVE NOT RISEN QUITE AS QUICKLY AS EARLIER FORECAST...SO WILL GIVE RANGE OF 60-65 FOR CENTRAL AND SOUTHERN COUNTIES THIS AFTERNOON. TEMPS FOR NORTHERN COUNTIES LOOK FINE. NO OTHER MAJOR CHANGES PLANNED. FCSTID = 22 CAE 64 44 55 50 / 0 40 90 70 AGS 64 44 60 50 / 0 50 90 70 SSC 64 43 57 51 / 0 30 90 70 OGB 64 43 60 51 / 0 30 90 70 .CAE... GA...NONE. SC...NONE. BC sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 252 PM EST MON MAR 11 2002 SYNOPSIS: WATER VAPOR IMAGERY AND RUC ANALYSES SHOW A SERIES OF WEAK SHORT WAVES MOVING ACROSS THE LOWER MS VALLEY WITH ATTENDANT MID/UPPER LEVEL CLOUDS APPROACHING THE CWFA FROM THE W. A STRONGER SHORT WAVE IS CLEARLY EVIDENT MOVING INTO WRN TX THIS AFTERNOON W/ THE ASSOCIATED SURFACE LOW NEAR THE TX PANHANDLE. SURFACE HIGH PRESSURE EXTENDS FROM THE MID ATLANTIC COAST SWWD TO NE FL. ABUNDANT SUNSHINE IS ALLOWING TEMPS TO RISE QUICKLY AND RH HAS DROPPED BELOW CRITICAL LEVELS ACROSS MOST OF OUR FL ZONES. MODEL DISCUSSION: MAIN SHORT WAVE PROGGED TO SWING ACROSS TX TONIGHT AND THEN SINK ESEWD INTO THE NRN GULF. THE VORT CENTER WILL CROSS OUR COASTAL WATERS TUE NIGHT WITH ASSOCIATED COLD POOL MOVING OVER THE CWFA AT THAT TIME. THE UPPER SYSTEM THEN MOVES E OF THE AREA 12-18Z WED. THE ETA SHOWS A JET STREAK MOVING FROM NRN MEXICO E ACROSS THE GULF TONIGHT AND TUE. THE CWFA IS IN THE FAVORABLE LEFT EXIT REGION OF THIS JET WITH A BULLS EYE OF UPPER DIVERGENCE NOTED AT 00Z WED. MODELS ALL SHOW THE ENTIRE CWFA GETTING INTO THE WARM SECTOR WITH DEW POINTS GETTING INTO THE LOWER 60S IN OUR FL ZONES. MINIMUM SURFACE LI/S RANGE FROM ABOUT -2 FROM THE ETA TO -5 FROM THE AVN. MAIN LIMITING FACTOR FOR SEVERE WX THREAT WOULD BE EXTENSIVE CLOUD COVER AND STRATIFORM PRECIP AND THE FACT THAT THE BEST DYNAMICS ARE MOVING IN AT NIGHT WHICH WILL FURTHER LIMIT SURFACE INSTABILITY. MODELS SHOW ISENTROPIC UPGLIDE ALREADY IN PLACE, WITH ENOUGH MOISTURE MOVING IN TO MAKE IT RAIN FROM EARLY TUE MORNING INTO TUE NIGHT AHEAD OF THE MAIN DYNAMICS. FINALLY, SHEAR PROFILES LOOK FAIRLY WEAK. STILL, CANNOT RULE OUT ISOLATED SEVERE STORM NEAR THE COAST WHERE INSTABILITY WILL BE GREATEST. MAIN THREAT WOULD BE HAIL AND GUSTY WINDS. PUBLIC FORECAST: WILL ACCEPT LOW CHANCE MOS POPS FOR TONIGHT WITH ONSET OF PRECIP LATE/TOWARD MORNING. MOS POPS LOOK TOO LOW FOR TUE AND TUE NIGHT. WILL MAINTAIN CURRENT LIKELY TO CATEGORICAL POP FOR TUE. SEE NO REASON TO GO BELOW CATEGORICAL POPS TUE NIGHT ACROSS THE BOARD AS THE MAIN DYNAMICS COME THROUGH AND SURFACE COLD FRONT APPROACHES. WILL KEEP A RESIDUAL POP IN WED MORNING ERN ZONES ONLY. HOWEVER, MODEL QPF INDICATES THAT FLOOD THREAT SHOULD BE MINIMAL. MARINE: SE WINDS WILL VEER TO S ON TUE AND SW TUE NIGHT. NOT ANTICIPATING ANY HEADLINES AT THIS TIME. FIRE WX: CURRENT WARNING VERIFYING WELL ACROSS INLAND FL ZONES. OBVIOUSLY THERE WILL BE NO CONCERNS ON TUE. EXTENDED: IT NOW LOOKS AS IF THE SURFACE HIGH WILL SETTLE E OF FL AND BE STRONG ENOUGH TO HOLD OFF THE NEXT FRONTAL SYSTEM THIS WEEKEND WITH FRONTAL PASSAGE DELAYED UNTIL MONDAY. WILL THEREFORE PULL POPS FROM SAT/SUN FORECAST AND INCLUDE ON MON. PRELIM NUMBERS... TLH 52 72 54 74 2782 PFN 55 68 55 68 3881 DHN 55 68 55 71 488- ABY 54 68 55 70 3881 VLD 55 74 56 74 2782 .TLH... .AL...NONE. .GA...NONE. .FL...RED FLAG WARNING UNTIL SUNSET TODAY FOR INLAND ZONES. WOOL fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHEYENNE WY 159 PM MST MON MAR 11 2002 LOWERING HEIGHTS IN THE EASTERN PACIFIC AND A VERY STRONG 300 MB JET SIGNAL THE CHANGES IN THE WEATHER OVER THE CWA FOR THE REST OF THE WEEK. WESTERLY WIND FLOW ALOFT OVER AND TO THE NORTH OF THE CWA INCREASES TONIGHT AND TUESDAY AND WILL AID IN PRODUCING A VERY WINDY PERIOD OVER MUCH OF THE CWA. AT THE SAME TIME...PRESSURE GRADIENTS FROM THE SURFACE TO 700 MB TIGHTEN...WITH MESOETA AND RUC40 KCAG- KCPR GRADIENTS FAVORABLE BETWEEN 06Z AND 18Z. FOR THOSE REASONS... WILL UPGRADE THE PREVIOUSLY ISSUED HIGH WIND WATCH FOR THE MOUNTAINS AND SOME NEARBY AREAS TO A HIGH WIND WARNING 06Z TO 18Z. THAT SAME STRONG WESTERLY FLOW ALOFT WILL BRING CONSIDERABLE MID AND HIGH LEVEL CLOUDS OVER THE CWA ALONG WITH OROGRAPHIC LIGHT SNOW IN THE SNOWY RANGE STARTING BY MIDDAY TUESDAY. AS HEIGHTS LOWER...A COLD FRONT MOVES THROUGH THE CWA LATE TUESDAY AFTERNOON AND EARLY TUESDAY NIGHT. AHEAD OF THE FRONT...TEMPERATURES WILL BE MILD AND TEMPERED ONLY BY THE CLOUD COVER. HIGHS FOR WEDNESDAY WILL BE 10 TO 20 DEGREES COOLER IN THE COOLER AIR MASS BEHIND THE FRONT. BY WEDNESDAY TROUGH ALOFT DEEPENS OVER THE WEST COAST...WITH SOUTHWEST WIND FLOW ALOFT OVER THE CWA. BY WEDNESDAY AFTERNOON...LEFT FRONT QUADRANT OF THE 300 MB JET WILL PROVIDE ENOUGH LIFT OVER THE COLDER BOUNDARY LAYER COLDER AIR FOR LIGHT SNOW. MODELS SIMILAR IN THAT SCENARIO WITH THE SOUTH THIRD OF THE CWA HAVING THE MOST WIDESPREAD AND HIGHER QPF. SURFACE UPSLOPE WIND FLOW ENDS AROUND MID MORNING ON THURSDAY...WITH THE SNOW ENDING. GUIDANCE TEMPERATURES SEEM TO BE TOO WARM FOR WEDNESDAY AND WILL GO BELOW THOSE VALUES WITH THE READINGS STAYING COOL ON THURSDAY. .EXTENDED... RATHER COOL AND UNSETTLED PATTERN STILL ADVERTISED OVERALL BY THE WEEKEND INTO EARLY NEXT WEEK. MODELS DIVERGENT ON HOW MUCH ENERGY WILL DROP SE OUT OF CANADA INTO A WRN U.S. TROF. MRF SHOWING HIGHLY AMPLIFIED RIDGE DVLPG FROM THE PACIFIC TO ALMOST THE POLE BY FRIDAY. THIS SEEMS RATHER EXTREME. OTHER MODELS LESS AMPLIFIED AND MORE PROGRESSIVE. WILL FAVOR LESS AMPLIFIED SOLN BUT GO COLDER THAN GUIDANCE TEMPS. BEST CHC FOR PCPN LOOKS TO BE SAT AND SUNDAY AS SHORTWAVE ENERGY BEGINS TO MOVE ACROSS...BUT NO ORGANIZED SFC SYSTEM SHOULD KEEP PCPN MORE SCATTERED. .CYS... WY...HIGH WIND WARNING MOUNTAINS AND PLATTE COUNTY FROM LATE EVENING TONIGHT TO NOON TUESDAY. ZONES 62>64..66..67. NE...NONE. WEILAND/EMANUEL wy