WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 151 PM MDT SUN SEP 8 2002 ...FLOODING REMAINS A CONCERN FOR THE SOUTHERN TWO THIRDS OF THE FORECAST AREAS THIS AFTERNOON AND TONIGHT... MOIST SOUTHWEST FLOW CONTINUES OVER THE CWA WITH JET SPEED MAX SLIDING NNE OVER WCNTRL UTAH. FAVORABLE JET QUAD FOR CONVECTION REMAINS OVER XTRM SCNTRL AZ. MESOETA AND RUC SLIDE THIS AREA DUE EAST...BUT TSTMS CURRENTLY DVLPG BENEATH IT ARE EDGING NE...AS ARE TSTMS FORMING OVER ERN MOGOLLON RIM. DESCENT SHEAR PROFILE EXISTS OVER MUCH OF THE AREA AS WELL. WITH CONVECTION SPROUTING IN THE CWA AND CLOSE BY AND MANY SENSITIVE AREAS RECEIVING SIGNIFICANT RAIN YESTERDAY...NOT MUCH RAIN IN A SHORT PERIOD WILL BE ENOUGH FOR MORE MUD AND ROCK SLIDES AND FLASH FLOODING...ESPECIALLY IN AREAS THAT WERE BURNED OVER BY WILDFIRES EARLIER THIS SUMMER. TROUGH OVER GREAT BASIN AND SWRN U.S. NOT YET SHOWING THE NE MOVEMENT PROGGED BY MODELS...THROUGH WV SATELLITE SHOWS KICKER APPROACHING FROM PACNW. BLV NRN HALF OF TROF WILL BEGIN SHEARING OUT...THOUGH BLV LIFT MUCH MORE TO THE NORTH...NOT SLIDING EAST AS QUICKLY AS ETA AND AVN SHOW. WILL MAKE XTRM NW PORTION PCLDY MON...BUT THEN MOISTURE AND CLDS SHOULD INCREASE AGAIN MON NGT AS MORE LOW AND MID LVL MOISTURE IS INJECTED INTO THE MIX FROM NW MEXICO AND BAJA. REMNANTS OF FAY PROGGED TO GET INFUSED INTO THIS FLOW TUE AND WED. SO AFTER A BRIEF PARTLY CLOUDY PERIOD FOR THE NWRN HALF OF THE CWA MONDAY...WILL THEN BRING IT BACK TO THE PERSISTENT MOSTLY CLOUDY AND MOIST CONDITIONS WITH A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH WED. BOTH ETA AND AVN GUIDANCE TEMPS WERE IN THE BALL PARK TODAY. CJC EXTENDED PERIOD...THURSDAY THROUGH SUNDAY...LOOKS LIKE THE LAST WAVE OF ENERGY TO MOVE ACROSS FRIDAY AS WE SHIFT TO A NORTHWEST FLOW. STILL PLENTY OF MOISTURE AROUND FOR DAILY CONVECTION THROUGH SATURDAY. WILL SLOW THE DRYING TREND KEEP SOME WEATHER IN FRIDAY AND SATURDAY. DC .GJT...FLASH FLOOD WATCH THROUGH 1000 PM MDT TODAY FOR SOUTHEAST UTAH AND SOUTHWEST COLORADO. co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 504 PM MDT SUN SEP 8 2002 ADDED STORMS TO WESTERN ZONES TONIGHT AS LINE OF THUNDERSTORMS FROM MESO-LOW ABOUT 30 MILES SOUTHWEST OF AKRON COLORADO NORTHEAST AND A SCATTERED TO BROKEN LINE EXTENDING SOUTH FROM IT. RUC HAS PATTERN OF STORMS OKAY BUT IS ABOUT 60 MILES TOO FAR EAST. HAVE ADJUSTED ZONES TO RUN A 40 POP IN YUMA COUNTY WITH 10 POPS IN KIT CARSON AND CHEYENNE COUNTIES IN COLORADO AND IN DUNDY COUNTY IN NEBRASKA. .GLD...NONE. ENTWISTLE ks AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GOODLAND KS 830 AM MDT SUN SEP 8 2002 WINDS PICKING UP AGAIN THIS MORNING AS MIXING DEVELOPS WITH SUNRISE. WITH SURFACE TROUGH TO OUR WEST AND HIGH PRESSURE TO OUR EAST WINDS WILL AGAIN BE IN THE WINDY CATEGORY ACROSS ALL BUT THE NORTHWEST CORNER OF THE CWA WHERE PROXIMITY TO TROUGH SHOULD KEEP THEM LOWER. ALSO UPDATED SKY COVER GIVEN CURRENT SATELLITE PICS AND MODEL TENDENCY TO BE OVERDOING CLOUD COVER GRIDS OF LATE. MAY UPDATE LATER THIS MORNING TO INCLUDE SOME ISOLATED THUNDERSTORMS OVER THE COLORADO COUNTIES. MOISTURE WILL BE CHANNELED INTO THAT PART OF THE FORECAST AREA TODAY. RUC/ETA SUGGEST SOME MEAGER CAPE BUT LITTLE CIN. NSSL MM5/ETA KAIN-FRITSCH ALSO INDICATE A FEW STORMS DEVELOPING ACROSS FAR EASTERN COLORADO. GIVEN WARM 500 TEMPS OF AROUND -5/-6 LOCAL RESEARCH SAYS CHANCES OF BEING SEVERE VERY LOW. WILL AWAIT NEW MODEL RUN BEFORE MAKING ANY CHANGES. .GLD...NONE. DDT ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 945 PM EDT SUN SEP 8 2002 00Z RAOBS/WV LOOP AND RUC ANAL SHOW HI AMPLITUDE AND VERY WARM/DRY UPR RDG DOMINATING THE GRT LKS DOWNWND OF UPR TROF OVR THE W. SWLY FLOW ARND SFC HI PRES IN THE MID ATLANTIC STATES BROUGHT ANOTHER ROUND OF RECORD WARMTH TO THE CWA TDAY UNDER CLR SKIES...AND SKIES REMAIN CLR THIS EVNG WITH FNTL BNDRY ON RIM OF HI PRES STILL OUT IN THE NRN PLAINS AND ACRS ONTARIO. 00Z GRB/APX SDNGS DEPICT RELATIVELY DRY AND STABLE PROFILE OVR THE NW GRT LKS. 01Z TEMPS RANGE FM 72 DOWNWND OF LK MI TO 82 OVR THE NW ZNS THAT DOWNSLOPE WITH SSW FLOW. ALTHOUGH ACYC SWLY FLOW PRESENT AGAIN THIS EVNG...PRES GRADIENT WEAKER THAN LAST EVNG. DWPTS LWR AS WELL...MAINLY 60 TO 65. MAIN FCST CONCERNS TNGT ARE MIN TEMPS/POTENTIAL FOR FOG. LATEST RUC AND 18Z ETA/AVN SHOW UPR RDG/DRY AIR REMAINING IN PLACE OVR THE NW GRT LKS TNGT...BUT RUC IS MOST AGGRESSIVE AT MOVG COLD FNT IN NRN PLAINS E TNGT INTO FAR WRN LK SUP BY SUNRISE WITH RESULT INCRSG PRES GRADIENT/SW FLOW OVR ESPECIALLY THE WRN ZNS LATE. THINK RUC TOO QUICK PUSHING FNT E INTO DOMINATING RDG GIVEN UPR FLOW PARALLEL TO THIS BNDRY WITH CLOSEST SHRTWV OVR SRN SASKATCHEWAN TENDING TO LIFT NE. BUT EVEN 18Z ETA SHOWS SHARPER PRES GRADIENT OVR THE WRN ZNS OVRNGT. WITH STRGR SWLY FLOW THESE AREAS...HIEST MINS WL OCCUR ACRS DOWNSLOPE AREAS FM IWD-P59-DOWNTOWN MQT. SINCE GRADIENT IS WEAKER AND SFC DWPTS SVRL DEGREES LWR THAN LAST NGT...AREAS ACRS THE SCNTRL AND E SHUD DECOUPLE WITH WEAKER GRADIENT PROGGED TO PERSIST ALL NGT. THINK TEMPS WL FALL THRU DWPT THESE AREAS WITH MINS BOTTOMING OUT SVRL DEGREES LWR THAN CURRENT DWPTS...PROBABLY AS LO AS 60. SETUP ALSO CONDUCIVE FOR FOG DVLPMNT THESE PLACES. BUT STRGR SWLY GRADIENT FLOW ACRS THE NW WL PREVENT FOG FORMATION. AFDMQT FM DAYSHIFT FOR LATER PDS: MONDAY INTO TUESDAY...12Z ETA COMING MORE IN LINE WITH YESTERDAY'S RUN OF AVN...PERHAPS A BIT SLOWER EVEN...WHILE NEW AVN AND NGM QUICKER THAN ETA. GIVEN STRENGTH OF RDG AND LTL TO NO MVMT OF CDFNT THUS FAR...HAVE OPTED WITH SLOWER SOLN. MODEL QPF STILL SUGGESTS POST FRONTAL PCPN WITH CAP REMAINING AHEAD OF THE FRONT...THUS HAVE BACKED OFF ON TIMING OF SCT SHRA/TSRA EVEN MORE. WL ONLY MENTION OF SHRA/TSRA 4 WRN COUNTIES LATE AFT MON...WITH SCT SHRA/TSRA SPREADING TO CNTRL AND ERN ZONES LATER IN EVNG. WITH SLOWER ARRIVAL OF CDFNT...LOOK FOR HIGHS MON TO REACH CLOSE TO SUNDAY READINGS (MID 80-S TO LOW 90S) OVR CNTRL AND ERN ZONES WITH 850 MB THERMAL RDG OF 20-21C OVRHD PER ETA. MODELS NOW IN BETTER AGREEMENT SHOWING RIGHT ENTRANCE FORCING/UPR DIV LATE MON NIGHT INTO TUE MORNING AS 140+ KT ANTICYCLONICALLY CURVED 3H JET MAX STREAKS ACROSS JAMES BAY INTO QUEBEC. THIS FORCING ALG WITH HIGH PWATS OF AROUND 1.6 INCHES AND SLOW MVMT OF CDFNT...THE POTENTIAL EXISTS FOR POST FRONTAL HEAVY RAINFALL LATE MON NIGHT INTO TUE MORNING WITH TSRA. RDGG THEN BUILDS IN OVR AREA MON AFT WITH DRYING AND SUBSIDENCE ALF PER ETA FCST SNDGS...LOOK FOR END TO PCPN BY THEN. .EXTENDED...MODELS STILL IN GOOD AGREEMENT WITH COOL CANADIAN SFC HIGH HOLDING FIRM OVR AREA FOR WED. MORE UNCERTAINTY EXISTS WITH MEDIUM RANGE MODELS THU INTO SUN. MODELS STILL HINT AND GLANCING BLOW FM WKR SHRTWV/CDFNT LATE THU INTO FRI BUT GIVEN THAN AVN AND ETA EXT SHOW CDFNT WASHING OUT NORTH OF GREAT LAKES AND MSTR LACKING ...DECIDED TO PULL SHRA MENTION FOR ERY FRI. ALSO PLENTY OF MODEL UNCERTAINTY WITH ARRIVAL AND STRENGTH OF STGR SYSTEM FOR WEEKEND. HWVR...MOST OF MODELS (UKMET/MRF/ECMWF) HINT AS MORE AMPLIFIED TROF DIGGING INTO SRN CANADA AND NRN PLAINS BY WEEKEND WITH MUCH COLDER AIR (ANYWHERE FM 0-4C AT 850 MB TEMPS) TO MOVE IN BEHIND SFC CDFNT ESPECIALLY FOR SUN INTO MON. MRF MOST AMPLIFIED WITH WHILE ECMWF LEAST AMPLIFIED...QUICKER AND NOT AS COLD WITH SYSTEM MOVG THRU. WITH LACK OF CLR PICTURE ON TIMING WL INCLUDE CHC OF SHRA/TSRA FOR BOTH SAT AND SUN...AND TREND WITH GRADUAL COOLING TREND INTO WEEKEND. .MQT...NONE. KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 450 PM EDT SUN SEP 8 2002 MAIN FCST CONCERNS WILL BE CONTINUED RECORD WARMTH INTO MONDAY ...THEN FROPA/PRECIP TIMING LATE MONDAY INTO TUESDAY. WV IMAGERY AND RUC ANALYSIS SHOWS TROF OVER THE WRN CONUS WITH BROAD WARM RDG OVR OH VALLEY AND GRT LAKES. AT THE SFC...LO PRES REMAINS OVR SD WITH AN INVERTED TROF/FRONT EXTENDING INTO NW MN AND WRN ONTARIO. STRENGTH OF RDG AND ASSOCIATED CAPPING...PER KINL/KMPX SNDGS CONTINUES TO KEEP SHRA/TSRA BEHIND CDFNT OVER SRN MANITOBA INTO WRN ONTARIO...IN PROXIMITY TO 850 MB FRONT. TONIGHT...SSW WINDS (5 TO 15 KT) TONIGHT WILL REMAIN STRONG ENOUGH TO KEEP BNDRY LYR MIXED AND TEMPS SLIGHTLY ABV ABOVE NORMAL...IN THE LOW TO MID 60S INLAND TO AROUND 70 F IN DWNSLP LOCATIONS NR LAKE SUPEPIOR. WITH WARM MOIST FLOW OVR LAKE MI...HAVE INCLUDED SOME PATCHY FOG LATE OVR 4 ERN COUNTIES. HAVE ALSO INCLUDED PATCHY FOG OVR MORE SHELTERED LOCATIONS OF SCNTRL UPR MI AS KIMT RADIATED TO DWPNT AND REPORTED FOG LATE LAST NIGHT. SUSPECT COULD BE SAME SITUATION LATE TONIGHT. MONDAY INTO TUESDAY...12Z ETA COMING MORE IN LINE WITH YESTERDAY'S RUN OF AVN...PERHAPS A BIT SLOWER EVEN...WHILE NEW AVN AND NGM QUICKER THAN ETA. GIVEN STRENGTH OF RDG AND LTL TO NO MVMT OF CDFNT THUS FAR...HAVE OPTED WITH SLOWER SOLN. MODEL QPF STILL SUGGESTS POST FRONTAL PCPN WITH CAP REMAINING AHEAD OF THE FRONT...THUS HAVE BACKED OFF ON TIMING OF SCT SHRA/TSRA EVEN MORE. WL ONLY MENTION OF SHRA/TSRA 4 WRN COUNTIES LATE AFT MON...WITH SCT SHRA/TSRA SPREADING TO CNTRL AND ERN ZONES LATER IN EVNG. WITH SLOWER ARRIVAL OF CDFNT...LOOK FOR HIGHS MON TO REACH CLOSE TO SUNDAY READINGS (MID 80-S TO LOW 90S) OVR CNTRL AND ERN ZONES WITH 850 MB THERMAL RDG OF 20-21C OVRHD PER ETA. MODELS NOW IN BETTER AGREEMENT SHOWING RIGHT ENTRANCE FORCING/UPR DIV LATE MON NIGHT INTO TUE MORNING AS 140+ KT ANTICYCLONICALLY CURVED 3H JET MAX STREAKS ACROSS JAMES BAY INTO QUEBEC. THIS FORCING ALG WITH HIGH PWATS OF AROUND 1.6 INCHES AND SLOW MVMT OF CDFNT...THE POTENTIAL EXISTS FOR POST FRONTAL HEAVY RAINFALL LATE MON NIGHT INTO TUE MORNING WITH TSRA. RDGG THEN BUILDS IN OVR AREA MON AFT WITH DRYING AND SUBSIDENCE ALF PER ETA FCST SNDGS...LOOK FOR END TO PCPN BY THEN. .EXTENDED...MODELS STILL IN GOOD AGREEMENT WITH COOL CANADIAN SFC HIGH HOLDING FIRM OVR AREA FOR WED. MORE UNCERTAINTY EXISTS WITH MEDIUM RANGE MODELS THU INTO SUN. MODELS STILL HINT AND GLANCING BLOW FM WKR SHRTWV/CDFNT LATE THU INTO FRI BUT GIVEN THAN AVN AND ETA EXT SHOW CDFNT WASHING OUT NORTH OF GREAT LAKES AND MSTR LACKING ...DECIDED TO PULL SHRA MENTION FOR ERY FRI. ALSO PLENTY OF MODEL UNCERTAINTY WITH ARRIVAL AND STRENGTH OF STGR SYSTEM FOR WEEKEND. HWVR...MOST OF MODELS (UKMET/MRF/ECMWF) HINT AS MORE AMPLIFIED TROF DIGGING INTO SRN CANADA AND NRN PLAINS BY WEEKEND WITH MUCH COLDER AIR (ANYWHERE FM 0-4C AT 850 MB TEMPS) TO MOVE IN BEHIND SFC CDFNT ESPECIALLY FOR SUN INTO MON. MRF MOST AMPLIFIED WITH WHILE ECMWF LEAST AMPLIFIED...QUICKER AND NOT AS COLD WITH SYSTEM MOVG THRU. WITH LACK OF CLR PICTURE ON TIMING WL INCLUDE CHC OF SHRA/TSRA FOR BOTH SAT AND SUN...AND TREND WITH GRADUAL COOLING TREND INTO WEEKEND. .MQT...NONE. VOSS mi SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE GREAT FALLS MT 330 PM MDT SUN SEP 8 2002 .SHORT TERM...POSITIVELY TILTED UPPER TROUGH WILL MOVE THROUGH THE NRN PORTIONS OF THE FORECAST AREA TONIGHT WHILE THE SRN PORTION WILL NOT MOVE THROUGH THE SRN ZONES UNTIL MON. MEANWHILE UPSTREAM UPPER RIDGE WILL BUILD INTO PAC NW MON THEN FURTHER BUILD AS IT MOVES INTO CENTRAL MT MON NIGHT. WEAK SW FLOW ALOFT WILL THEN BE OVER THE AREA THE REMAINDER OF THE SHORT TERM. MAIN POTENTIAL FORECAST PROBLEMS ARE IN THE FAR SRN ZONES TONIGHT THEN AGAIN THERE TUE INTO WED. FOR TONIGHT IN THAT AREA...EARLIER THINKING WAS THAT A FEW SHOWERS/THUNDERSTORMS COULD OCCUR THIS EVENING. LATEST RUC INDICATES A STABLE AIRMASS IN THE AREA AND NO LONGER HAS ANY QPF THERE. CURRENT SURFACE OBSERVATIONS ALSO INDICATE A STABLE AIRMASS SO HAVE DROPPED THE MENTION OF CONVECTION. FOR TUE THROUGH WED AVN HAS A SHORTWAVE OVER THE FAR SRN ZONES. BUT CHECK OF TIME/HEIGHT CROSS SECTIONS SHOWS A RELATIVELY DRY AIRMASS EVEN THOUGH LIFTED INDICES MAY APPROACH ZERO. WILL GO DRY FOR NOW. BLANK .EXTENDED...MEDIUM RANGE MODELS IN DECENT AGREEMENT. WILL GO WITH A GENERALLY DRY FORECAST. UPPER RIDGE OVER THE AREA DAY 4. RIDGE AXIS SHIFTS EAST DAY 5 AS AN UPPER TROF MOVES ACROSS SOUTHERN CANADA. ASSOCIATED SURFACE LOW PROVIDES GOOD DOWNSLOPE GRADIENT. NORTHWEST FLOW ALOFT DAY 6 WITH SURFACE HIGH PRESSURE PUSHING ACROSS THE AREA. THOUGH SURFACE GRADIENT IS UPSLOPE...LACK OF MOISTURE SHOULD KEEP IT DRY. DAY 7 REMAINS DRY WITH NORTHWEST FLOW ALOFT. TEMPERATURES SLIGHTLY ABOVE NORMAL EARLY IN THE EXTENDED PERIOD WITH TEMPERATURES DROPPING OFF BY THE END OF THE PERIOD. .CCF NUMBERS GTF BU 040/072 044/081 048 04000 UBBBB 080/045 078/045 076/050 053/044 061 00000000111 CTB BU 039/069 040/078 044 04000 UBBBB 077/042 074/040 072/043 049/043 059 00000000111 HLN BU 041/073 042/082 045 04000 UBBBB 081/046 080/046 073/047 056/043 061 00000000111 BZN BU 036/070 036/080 039 04110 UBBBB 080/040 079/040 074/049 059/045 062 00000000111 WEY BU 030/064 030/074 033 04110 BBBBB 074/031 066/032 066/048 059/043 056 11100000111 DLN BU 036/071 036/078 040 04000 UBBBB 078/038 074/039 073/049 064/046 063 ---00000111 HVR BU 040/076 044/085 047 04000 UBBBB 084/045 080/044 077/049 051/045 060 00000000111 LWT BU 039/070 041/078 045 04000 UBBBB 077/043 079/042 074/050 050/042 058 00000000111 .TFX...NONE mt SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE GREAT FALLS MT 930 AM MDT SUN SEP 8 2002 UPDATES FOR ZONES AND STATE .SHORT TERM...POSITIVELY TILTED UPPER TROUGH FROM NRN ID TO SE OREGON WILL BE MOVING THROUGH THE PLAINS ZONES TODAY AND SW MT THIS EVENING. BACK EDGE OF MOISTURE ASSOCIATED WITH THE UPPER LEVEL JET WAS MOVING THROUGH THE FAR ERN ZONES AT MID-MORNING. AIRMASS HAS DRIED QUITE A BIT TO ITS WEST AND AHEAD OF THE UPPER TROUGH. MAIN FOCUS TODAY WAS ON THE POSSIBILITY OF CONVECTION IN THE SW. LATEST MESO KEEPS QPF E OF THE AREA AS AIRMASS OVER SW MT IS FORECAST TO BE STABLE. RUC ON THE OTHER HAND HAS SOME QPF OVER SW MT AS THEY HAVE AIRMASS WEAKLY UNSTABLE. CHECK OF SOUNDINGS SHOWS MESOETA MAY HAVE LOW LEVEL DEWPOINTS TOO LOW AND HENCE AIRMASS TOO STABLE. BOTH MODELS HAVE SOME LOW LEVEL CONVERGENCE OVER FAR SW MT AND UPPER TROUGH WILL STILL HAVE TO MOVE THROUGH THE AREA. WILL LEAVE IN THE SLIGHT CHANCE OF PRECIPITATIONFOR THIS EVENING BUT ALSO INCLUDE LATER THIS AFTERNOON. EARLIER UPDATED TO MENTION SOME PATCHY VALLEY FOG IN THE SW AND ALSO TO DO SOME ADJUSTING OF CLOUDS AND PRECIPITATION IN THE NORTH. MAY MAKE A FURTHUR TWEAK HERE AND THERE. BLANK .EXTENDED...A FLAT UPPER LEVEL HIGH PRESSURE RIDGE WILL BE OVER THE ZONES ON WEDNESDAY. THIS WILL CAUSE DRY CONDITIONS. THE RIDGE CONTINUES TO BUILD ON THURSDAY. A WEAK SHORT WAVE MOVES THRU THE AREA ON FRIDAY...HOWEVER IT WILL BE QUITE WEAK AND WILL HAVE A HARD TIME GENERATING ANY PRECIP. THE PASSAGE OF THE SHORT WAVE SHOULD HELP DEVELOP BREEZY CONDITIONS FRIDAY AND SATURDAY...AND TEMPERATURES WILL ALSO COOL SLIGHTLY BEHIND THE SHORT WAVE ON SATURDAY. ZELZER .CCF NUMBERS GTF BB 068/040 072/044 077 13100 BBBBB 045/073 045/072 045/070 048/070 0000022111 CTB BB 065/039 069/040 074 13100 BBBBB 040/069 042/068 040/066 044/066 0000011111 HLN BB 069/041 074/043 079 131-0 BBBBB 044/075 046/073 046/071 049/072 0000022111 BZN BB 068/036 074/038 076 13110 BBBBB 040/072 040/070 040/069 051/070 0000022111 WEY BB 060/028 065/030 067 13110 BBBBB 031/068 031/067 032/066 050/066 0000022111 DLN BB 067/035 073/039 077 13110 BBBBB 040/070 038/070 040/069 054/070 0000022111 HVR BB 070/040 075/044 080 13100 BBBBB 042/074 045/073 044/070 047/072 0000022111 LWT BB 066/040 070/042 073 13110 BBBBB 040/071 043/070 042/068 045/070 0000022111 .TFX...NONE mt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 1019 AM EDT SUN SEP 8 2002 NATL HRCN CNTR WILL BE INITIATING ADVISORIES ON SUBTROPICAL DEPRESSION EIGHT NORTHEAST OF THE BAHAMAS THIS MORNING. IR SATELLITE SHOWS CONVECTIVE CLOUDS ALMOST ENCIRCLING THE CENTER WITH A BROAD CIRCULATION EMCOMPASSING MOST OF THE WESTERN ATLC. SEE FORTHCOMING NHC PRODUCTS FOR A FULLER DISCUSSION OF THIS FEATURE. STRENGTHENING NE WINDS ON THE NW PERIPHERY OF THE CIRCULATION ARE AFFECTING THE COASTAL CAROLINAS THIS MORNING. PATCHES OF SHALLOW CONVECTIVE CLOUDS/SHRAS MOVING OFF THE WATER WILL AFFECT MAINLY THE COASTAL COUNTIES. PTCLDY SHOULD BE FINE FOR SKY COVER...WILL UPDATE INLAND SXNS SINCE THEY APPEAR TO BE CLOUDING UP AS WELL. AFTN MAXES WILL BE COOLEST ALONG THE COAST WITH THE NE FLOW... CURRENT LOW 80S COAST LOOK FINE...WILL KNOCK INLAND DOWN TO 80-85. MARINE: APPEARS THE ADJACENT MARITIME AREAS WILL BE AFFECTED BY THE INTENSIFYING LOW NE OF THE BAHAMAS AND TO WHAT DEGREE IS UNKNOWN AT THIS TIME. MORE DETAILS WILL COME IN THIS AFTERNOON/S DISC. IN THE MEANTIME...SEEING SOLID NE 20 KTS SINCE 06Z WHILE SEAS ARE RECENTLY RUNNING AROUND 5 FT. EXPECT THE PRES GRAD TO SLOWLY PINCH BETWEEN THE RIDGE ACROSS THE MID-ATLC AND SOUTHEAST STATES AND THE INTENSIFYING LOW NE OF THE BAHAMAS. AS A RESULT I WILL BUMP SPEEDS UPWARD IN LINE W/ THE RUC FOR THIS AFTERNOON. NO CHANGES TO THE SMALL CRAFT ADVISORY. ALSO W/ A NE WIND DIR...SEAS WILL BE LOWER NEAR SHORE FROM CAPE FCSTID = 9 ILM 81 69 80 71 / 20 20 30 30 LBT 83 64 85 67 / 0 0 20 20 FLO 84 65 85 68 / 0 0 20 20 MYR 83 68 81 71 / 20 20 30 30 .ILM... NC...SCA SURF CITY TO LITTLE RIVER INLET SC...SCA LITTLE RIVER INLET TO S SANTEE RIVER TRA/SRP nc WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 225 AM MDT MON SEP 9 2002 UPPER TROUGH OVER THE WEST IS SHEARING APART EARLY THIS MORNING WITH THE FORECAST AREA REMAINING IN A VERY MOIST SOUTHWEST FLOW. WATER VAPOR CURRENTLY SHOWS A SHORTWAVE MOVING ACROSS CENTRAL UTAH. THIS IN COMBINATION WITH SOME UPPER JET SUPPORT IS RESPONSIBLE FOR THE BATCH OF RAIN AND EMBEDDED THUNDERSTORMS CURRENTLY MOVING ACROSS THE NORTHERN PORTION FORECAST AREA. THE RUC LIFTS THIS WAVE INTO WESTERN WYOMING BY 12Z WITH THE ASSOCIATED QPF MOVING OUT OF THE AREA. THIS LOOKS REASONABLE BASED ON SATELLITE AND RADAR TRENDS. ANOTHER WAVE IS LOCATED OVER THE LOWER COLORADO RIVER VALLEY AND WILL APPROACH THE FOUR CORNERS LATER TODAY. AS THE TROUGH CONTINUES TO SHEAR...THE UPPER JET AXIS SHIFTS FURTHER EAST TODAY WITH THE MODELS SHOWING SOME DRIER AIR MOVING INTO NORTHEAST UTAH AND EXTREME NORTHWEST COLORADO. HOW MUCH DRYING WILL ACTUALLY OCCUR IS IN QUESTION BUT THIS IDEA LOOKS REASONABLE AND WILL FOLLOW GUIDANCE. MODELS FORECAST THE WAVE OVER THE LOWER COLORADO RIVER TO REACH THE FOUR CORNERS BY 00Z. THIS IN ADDITION TO THE JET OVERHEAD SHOULD PROVIDE ENOUGH FORCING FOR SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS MUCH OF THE AREA. WILL TAPER POPS TODAY FROM HIGH CHANCE ALONG THE DIVIDE TO SOUTHEAST UTAH...TO SLIGHT CHANCE ACROSS NORTHEAST UTAH AND EXTREME NORTHWEST COLORADO. LITTLE CAPE FORECAST ACROSS THE AREA THIS AFTERNOON WITH THE BEST INSTABILITY ACROSS THE SAN JUANS. THREAT OF THUNDERSTORMS AND LOCALLY HEAVY RAIN LOOKS LIKE IT WILL BE HIGHEST IN THIS AREA. SUFFICIENT MOISTURE AND INSTABILITY FOR A CONTINUED THREAT OF SHOWERS AND THUNDERSTORMS TUESDAY AND WEDNESDAY. THE TAIL END OF THE UPPER JET REMAINS OVER THE AREA WITH SOME HANG BACK ENERGY FROM THE BASE OF OLD LONGWAVE TROUGH REMAINING OVER THE DESERT SOUTHWEST. THE DRYING OVER NORTHEAST UTAH AND NORTHWEST COLORADO WILL BE BRIEF AS SOUTHERLY FLOW PUSHES MOISTURE BACK INTO THAT AREA. TEMPERATURES TRENDS WILL BE TRICKY THE NEXT FEW DAYS. WILL FAVOR THE ETA TEMPS FOR THIS PACKAGE. LINDQUIST EXTENDED PERIOD...THURSDAY THROUGH SUNDAY...LOOKS LIKE THE LAST WAVE OF ENERGY TO MOVE ACROSS FRIDAY AS WE SHIFT TO A NORTHWEST FLOW. STILL PLENTY OF MOISTURE AROUND FOR DAILY CONVECTION THROUGH SATURDAY. WILL SLOW THE DRYING TREND KEEP SOME WEATHER IN FRIDAY AND SATURDAY. DC .GJT...NONE. co AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE DES MOINES IA 224 AM CDT MON SEP 9 2002 UPDATE... 88D AND IR IMAGERY PICKING UP BAND OF ELEVATED CONVECTION DEVELOPING FROM NEAR KFSD NE INTO WEST CENTRAL MN. THIS IS WITHIN LLJ AXIS AND ON THE REAR SIDE OF 850 THETA-E ADVECTION. LAST 30 MINUTES OF IR IMAGERY ALSO SHOWING ISOLD AC CU/AC DEVELOPMENT BETWEEN MCW AND ALO. LATEST RUC ACTUALLY HINTS UPON THIS VERY AREA FOR CONVECTION NEXT SEVERAL HOURS TO MY SURPRISE. THIS AREA AGAIN IS ON S PERIPHERY SOME WEAK THETA-E ADVECTION, LIKELY DUE TO THE LLJ NOCTURNAL MAX. WILL CLOSELY MONITOR. SHORT TERM... MAIN FORECAST ISSUE FOR TODAY IS TEMPERATURES, WITH A SECONDARY CONCERN OF EARLY MORNING FOG. WIDESPREAD MVFR VISIBILITY NOW OVER LARGE PORTION OF IL AND WI, BEGINNING TO SPREAD INTO EASTERN IA. SURFACE TRAJECTORIES ARE FROM MO INTO OUR FORECAST AREA WHERE DEW POINTS ARE A FEW DEGREES LOWER. TEMPS HAVE EXCEEDED MY EXPECTATIONS LAST COUPLE OF DAYS, SO AM INCLINED TO STAY WITH THE WARMER ETA MOS AGAIN FOR TODAY, WITH HIGHS AROUND 90 MOST AREAS. NOT SURE WHY MCW AND ALO REACHED 2-3 DEGREES HIGHER ON SUNDAY THAN THE REST OF THE FORECAST AREA. ONLY EVIDENCE I SEE IS THE META INITIALIZED A BIT WARMER AT 850 MB IN NC/NE IA. MORE CU AGAIN TODAY, ESPECIALLY EASTERN IA WITH MODERATE INSTABILITY. HAD 2 OR 3 SMALL SHRA/TSRA SUNDAY EVENING, AND AGAIN NOT OUT OF THE QUESTION TODAY. STILL LACKING A TRIGGER MECHANISM TO LATCH ONTO BESIDES WEAKENING VORT IN EASTERN IA. LONGER TERM... FRONTOGENETIC ZONE ACROSS WY/SD/NW MN IS AND WILL CONTINUE TO BE FOCUS FOR MORE CONVECTIVE DEVELOPMENT. THIS IS WITHIN MOIST PLUME WHICH STILL YIELDS PWATS 180-200 PERCENT OF NORMAL AT 00Z. WILL MAINTAIN A CONSISTENT FORECAST AS MODELS ARE IN CONTINUED AGREEMENT OF WEAKENING FRONTOGENETICAL FORCING AS ASSOCIATED JET DEPARTS QUICKLY. STILL SHOULD BE SOME CONVERGENCE AND DPVA TO HELP MAINTAIN SHRA/TSRA BAND INTO NORTHERN IA LATE TONIGHT. HAVE TRIMMED POPS FURTHER N HOWEVER GIVEN SLOWER FRONTAL TIMING. MID LEVEL INSTABILITY STILL LACKING (SHOWALTERS ONLY 0 TO -1), BUT ENOUGH TO KEEP THUNDER MENTION GOING. WIDE DISPARITY ON TEMP GUIDANCE, BUT SINCE I'M FAVORING LESS PRECIP AND CLOUDS WITH TIME ON TUESDAY, MAV LOOKS TOO COOL, BUT ETA TOO WARM. THEREFORE A COMPROMISE NEAR FWC IS BEING USED. ONLY OTHER CHANGE WAS A SLIGHT ADJUSTMENT UPWARD FOR WEDNESDAY'S HIGHS AS COLD ADVECTION CEASES. LATE WEEK CHANCES STILL LOOK GOOD. .DSM...NONE KULA ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 140 AM EDT MON SEP 9 2002 ...HEAT WAVE MHT-ASH-LWM-BVY-FIT THRU TUE WITH RER 95F HEAT TDY AND LIKELY AGAIN TUE AT MOST SNE SITES... RERS FOLLOW BOS BDL PVD ORH MQE 9/9 91-1971 91-1971* 91-1971 90-1915 88-1959 9/10 95-1931 95-1931 94-1983 91-1931 90-1930 AND 1989 CEF SHORTER TERM PERIOD OF RECORD RERS BLO. 9/9 88-1959 9/10 93-189 TDYS 91 RER AT BDL WAS SET IN YRS PRIOR TO 1971 AS WELL. MOS: MAX TEMPS WILL B RAISED ABV THE AVBL NCEP MOS GUIDANCE TDY AND TUE BY 2 TO 5F BOTH DAYS ALL OF SNE! MARINE: THINKING POTENTIAL GALE GUSTS WEDNESDAY IN STG CAA. LAG IN SUBISIDENCE OF SEAS BLO 5FT FOR OUTER WATERS TIL THU AFTN? GUSTAV: ITS IN TPC/MPC HANDS. SPSBOX: WB REISSUED FOR RER HEAT AND BRIEF COMMENT ON GUSTAV. TDY: FOR THE SEASON SEARING (LIGHT WIND) HEAT. BRILLIANT SS. ONLY ORH IS UP FOR GRABS ON RER TIEING EVENT OTRW MAX TEMPS PER STUNNINGLY ACCURATE 15-21Z ETA 2M TEMP FCST YDY WILL BE APPLIED AGAIN TDY. ONE SOURCE TO SEE THIS NCEP MODEL HRLY ETA DATA IS VIA A COOP PROJECT BTWN NWS AND PSU WWW.EMS.PSU.EDU/WX/ETATS.HTML. THIS DAYTIME DATA HAS TROUBLE VERIFYING IN SEA BRZ OR NON- IDEAL DOWNSLOPE WIND (FOR INSTANCE BDL MAXES ON W OR WNW SFC WIND) WHEREAS DOWNSLOPE FOR OTHER LOCATIONS CAN BE AN E WIND OR OTHERWISE. THIS DATA HRLY AT NIGHT HAS TROUBLE VERIFYING WHERE MIXING OCCURS. IN ANY CASE: FOLLOWING THIS GUIDANCE ALMOST VERBATIM IN GRIDS AND FCST THRU TUESDAY WITH COASTAL PLAIN AND VLY NON-MARINE INFLUENCED MAX TEMPS 93-96F. FOR WHAT ITS WORTH TAQ EXP HAS 90 AT 15Z NR NZW AND FM BOS-PSM! THESE HEAT EVENTS SOMETIMES ARE FAVORED IN THE SURROUNDING SUBSIDENCE DERIVED FROM TROPICAL SYSTEMS. OTHER FACTORS MAY BE INVOLVED. FEEBLE TOO LATE C BREEZES E MA COAST DVLPG 18-21Z PER WKNG WLY GRAD AND TAQ EXP RUC HAS IT. WE'LL SEE IF IT MATERIALIZES. HINTS OF SAME IN NGM MRPCWN GUIDANCE FOR 013 AND IOS. UPPER CAPE COD GETS HOT TOO. TNGT: WHERE WIND BLOWS W ALL NITE IN THE URBAN CTRS LOW TEMP MAY GO NO LWR THAN 75. BLV ODDS FAVOR BOS CLOSE TO THAT VALUE PER ADDITIONAL BL SUPPORT...BUT WIND MUST BLOW >8 KTS ALL NIGHT AND NOT GO SSW (BLOW FROM THE SUBURBS). TUE: SEARING START THEN HI CLOUDS POSSIBLE TO CAP BUT FCSTG CLOSE TO 95F AGAIN WITH MAYBE LESS CHC OF ANY FEEBLE NARR BAY E MA COAST C BREEZES. A MORE WDSPRD HEAT EVENT FOR CAPE COD. TUE NITE: DEBATING QPF AREAS AND CLOSER TO MOS FOR LOWS. UKMET IS A REALLY NICE PREDICTOR OF QPF ARD HERE IN ITS AREAL INCLUSION AND AWAITING THIS 00Z RUN FOR ITS ASSISTANCE. NNE WIND G TO 29 KTS MAY START ARD 10Z AT BOS-BVY. WED: STG CFP AND BURST OF 30-38 KT WINDS LIKELY WITH MDT-STG NLY CAA SCT OR BKN CVRG SHWRS ASSTD WITH VERY STG SW PASSAGE. PROB FCST 50 PCT SW OF AFN-ORH-WLY AND 60-70 PCT E OF THAT LINE. AMTS LIGHT. 00Z UKMET AGAIN TO BE APPLIED FOR POP ADJUSTMENTS OF THE NCEP ETA/GFS. THU AM: CUD B A LIGHT TOUCH OF FROST IN SW NH AND NW MA PROTECTED VALLEYS WITH SFC TDS FCST NR 32F AND WIND BCMG LIGHT. RAD MAY NOT START SOON ENOUGH 9/6 (FRI AM) BARRE FALLS DAM MA HAD 33 AND MARLOW NH 35F FRI-SUN: WARMING BACK UP AS 12Z/8 EC AND 00Z/9 GFS PUMP THE RDG BACK UP ALONG THE E COAST. 567+ K DVLPS AND RIGHT NOW GFS MAKES IT RAIN HERE NEXT SUNDAY... IF IT DOESNT...WE MAY B SEEING TEMPS BACK INTO THE MID 80S CT RVR VLY THIS WKND. .BOX... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. DRAG ma AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 445 AM EDT MON SEP 9 2002 MAIN FCST CONCERNS THIS PACKAGE INCLUDE TIMING/COVERAGE OF PCPN THIS AFTERNOON THROUGH TUE MORNING. WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPR LVL RDG DOMINATING THE ERN CONUS AND A TROF OVER THE INTERMTN WEST. PERSISTENT PATTERN WAS SHOWING SIGNS OF DEAMPLIFICATION AS JET MOVES INTO WRN CANADA AND PIECES OF THE WRN TROF LIFT OVER AND FLATTEN THE RDG. ONE SIGNIFICANT SHRTWV WAS LOCATED OVER MANITOBA WHILE ANOTHER WAS LIFTING NE OUT OF UT/WY. AT THE SFC...FRONT WHICH EXTENDED FROM NEAR KINL INTO ERN SD CONTINUED TO MAKE SLOW PROGRESS TO THE SE WITH MODEST 1-2 MB 3 HR PRES RISES BEHIND THE FRONT. SHRA/TSRA OVER NRN MN WERE SUPPORTED BY UPR LVL DIV WITH RIGHT ENTRANCE OF UPR LVL JET. WHILE MOST OF THE PCPN WAS LOCATED BEHIND THE FRONT STRONG LOW LVL THETA-E INFLOW (40 KT AT 925 MB...PER PROFILER) SUPPORTED SOME ELEVATED CONVECTION OVER SW MN AHEAD OF THE FRONT. OVER UPR MI...WARM SRLY FLOW PREVAILED. HOWEVER...WHERE WINDS HAVE DECOUPLED...SHALLOW FG HAS DEVELOPED NEAR KIMT AND KESC. MDLS WERE IN REASONABLE AGREEMENT WITH TIMING OF FROPA OVER UPR MI AND WITH MASS FIELDS. ETA/AVN HAVE TRENDED TOWARD A DEEPER AND SLIGHTLY SLOWER SHRTWV MOVING INTO THE UPR MS VALLEY AND WRN LAKES TONIGHT AND EARLY TUESDAY. TODAY...WITH FRONT MOVING INTO THE WEST THIS AFTERNOON AND INTO CNTRL UPR MI...MAINLY AFTER 21Z...ABUNDANT SUNSHINE WILL PUSH TEMPS AGAIN INTO THE MID AND UPPER 80S F...SUPPORTED BY H8 TEMPS TO AROUND 19C. DESPITE CAPE VALUES OF 1-2 KJ/KG...CAPPING REMAINS STRONG ENOUGH TO PRECLUDE CONVECTION IN ABSENCE OF FORCING MECHANISM AHEAD OF THE FRONT SHOULD PRECLUDE CONVECTION. LATE THIS AFTERNOON THROUGH EARLY TUESDAY...MDLS SUGGEST CONVECTION WILL DEVELOP BY EVENING ALONG AND BEHIND THE FRONT WITH INCREASING LOW LVL CONVERGENCE AND SUPPORT FROM WEAK SHRTWV AND MODEST 900-700 FRONTOGENETICAL FORCING. EXPECT BETTER COVERAGE LATE TONIGHT INTO EARLY TUESDAY AS MAIN SHRTWV APPROACHES. MDLS SUGGEST PCPN WILL EXPAND AS MOISTURE AVBL ALONG AND SOUTH OF THE BNDRY (PWAT NEAR 1.6 INCHES) COMBINE WITH SUPPORT FOR UPWARD MOTION FROM DPVA/DEEP LYR QVECTOR CONVERGENCE AND SUPPORT FROM UPR LVL DIV WITH JET RIGHT ENTRANCE. WHILE MUCH OF THE PCPN MAY BE NON-CONVECTIVE...PROXIMITY OF NEG SHOWALTER INDICES OVER NRN WI MAY BRING SOME EMBEDDED ELEVATED CONVECTION ACRS UPR MI. DIFFERENCES ARISE IN QPF DEPICTION AS 00Z ETA/AVN SHOW HEAVIEST PCPN AXIS OVER NRN WI INTO SRN UPR MI WHILE CANADIAN/UKMET SHOW BAND FARTHER NW OVER WRN UPR MI AND LK SUPERIOR (06Z ETA HAS TRENDED IN THIS DIRECTION). SO...HAVE KEPT NMRS/LIKELY POPS INTO WEST HLF OF UPR MI OVERNIGHT AND ACRS AREA EARLY TUESDAY. HAVE ALSO GONE WITH ETA SCENARIO IN ENDING PCPN WEST AROUND 12Z AND ALL BUT THE FAR SE BY 15Z. REST OF TUESDAY INTO WEDNESDAY...DNVA...QVECTOR DIV AND DRY ADVECTION WITH ACYC NWRLY FLOW SHOULD BRING CLEARING SKIES AND COOLER AIR INTO UPR MI. FAVORABLE RADIATIONAL COOLING CONDITIONS SHOULD ALLOW TEMPS TO DIP INTO THE 40S WED MORNING. .MQT...NONE. JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 315 AM CDT MON SEP 9 2002 FORECAST CHALLENGES...TIMING OF CDFNT AND ASSOCIATED CHC -TSRA/-SHRA...AND TEMPS. SYNOPSIS/FORECAST...WSR-88D RADAR TRENDS SHOWING ECHOES SE SD TRYING TO GET GOING SINCE 05Z AND FINALLY A NICE BROKEN LINE WAS FORMING SINCE 06Z FM N OF ONL TO AROUND SANTEE...FSD..AND TO GRANITE FALLS MN. LINE OF ACCAS ON IR AND TSRA IN AREA OF HIGH PW/K INDEX VALUES OF 35+/ALONG H85 JET. H85 JET AREA SAGGING SE...HOWEVER...CLOUD ELEMENTS MOVING N. MORE FAVORED PWS/KINDEX VALUES SHIFTING N BY 12Z. IR STLT HAD CONVECTION OVR WRN NEB WEAKENING AND COMPLEX CNTRL SD MAINTAINING ITS STRENGTH. BETTER CONVECTION IN GENERAL AREA OF UVV/UPR LEVEL DIV ERN WY-SD AND SECONDARY MAX WRN WY. MOST ACTIVE AREAS PER STLT/LGTNG OVR MEXICO AND SRN TX WITH REMNANTS OF TS FAY. STLT/METARS ALSO PICKING UP ON ST FLOW FM TX/OK INTO DDC KS. A QUICK LOOK AT THE RUC80 INCREASES THE ST IN SW NEB...WELL TO THE W OF THE FCST AREA. THE OAX SOUNDING HAD A NICE MOIST LYR AT 770MB AND S FLOW THRU 550MB. NOT SURPRISED TO SEE A PATCH OF CLDS AT FNB. TOP WAS SATURATED AT 790MB AND HAD A PW OF 1.62 INCHES. DISTURBED AREA OF CLDS OVR MO/WHERE LAPSE RATES STEEP/WHERE THERE IS UVV. LATEST SFC MAP HAD THE COLD FNT THUR VTN AND PIR WITH 1-3MB PRES RISES AND DEWPOINTS POOLED IN THE AREA. SHORT RANGE MODELS IN GOOD AGREEMENT THAT THE FCST AREA WILL BE MAINLY DRY THIS MORNING...WITH INCREASING POPS NW COUNTIES TAF...CHC OF PRECIP SPREADING SE INTO TUE...THEN DRYING AND COOLER WED. AGAIN...THERE ARE DIFFERENCES IN THE QPF OUTPUT AND THE TREND HAS BEEN FOR LESS PRECIP FOR THE FCST AREA. UVV FIELDS LESS IMPRESSIVE THAN PREVIOUSLY ADVERTISED AND IS BEST W AND N OF THE FCST AREA. CURRENT POPS IN THE 30-60% RANGE INTO TUE. MID LVL RH RETURNS LATE WED NIGHT/THU PATTERN WARRANTS HIGHER POPS THAN ETA HAS. NGM MOS GUID HAS BEEN RUNNING 2-4 DEG TOO COOL LATELY AND ETA MOS 0-2 DEG TOO WARM. NEW GUID TRENDS CONTINUE TO SLOW DOWN PROGRESS OF PRE FRONTAL TROF AND CDFNT. H85 TEMPS ABOUT THE SAME AS SUN WITH A LITTLE LESS MIXING. FRONTAL TIMING HAS SLOWED DOWN TO AROUND 06Z AT OFK AND AFT 12Z AT FNB. WILL ADJUST CURRENT FCST TO AGREE WITH SLOWER FRONTAL PASSAGE. TEMPS WED AND THU MAINLY 70S. IN LATER PERIODS...A VARIETY ON MINOR SHORTWAVES TO AFFECT THE FCST AREA. TREND TOWARD AN UPR TROF OVR THE NATION/S MID SECTION WITH COOL TEMPERATURES. THE SFC FNT WILL RMN TO OUR S WITH HIGH PRESSURE DOMINATING. FMR GUID TEMPS FOR HIGHS IN THE LOWER 60S LOOK A BIT EXCESSIVE FOR SUN AT OMA. MEX HAS 70S...WHICH LOOKS MORE REASONABLE. NEWER MRF NOT A DEEP WITH THE UPR TROF AND SLOWER THEN THE ECMWF. .OMA...NONE. ZAPOTOCNY ne FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 320 AM CDT MON SEP 9 2002 FCST CONCERNS...CHC PCPN TODAY AND THEN TEMPS. CHECKED ISC GRIDDS FROM DLH/ABR AND WE DONT SEEM TOO FAR OFF. .CURRENT...COLD FRONT HAS MOVED ALL BUT FAR SE CWFA AT 08Z. FRONT IS BEING PROPELLED EASTWARD BY SHORT WAVE MOVING INTO WRN MANITOBA. SOME TSRA DEVELOPED AHEAD OF THIS FEATURE OVR NW MN AND SE MB AND THIS WILL EXIT FAR ERN ZONES EARLY THIS MORNING. OTHER TSRA DEVELOPING IN WCNTRL MN AND ERN SD ALONG SRN PART OF FRONT AS CAP IS FINALLY BROKEN. WELL DEFINED SHORT WAVE IN SW WYOMING WITH SATELLITE SHOWING CLOUDS AND RADARS SHOWING SOME SHRA/TSRA MOVING NNE THROUGH WYOMING INTO SCNTRL MT. IT IS THIS FEATURE WHICH WILL HAVE TO BE WATCHED. USED RUC FOR SHORT TERM AND ETA THRU 84HRS. .SHORT TERM... VORT MAX IN WYOMING WILL MOVE ENE AND BE IN ERN SD BY LATE TONIGHT. A LARGE AREA OF SHOWERS WILL EXPAND ENE AHD OF THIS FEATURE. MODELS IN AGREEMENT IN KEEPING MAJORITY OF PCPN IN SD....BUT HOWEVER WATER VAPOR AND SATELLITE SHOWS LIGHTNING STRIKES QUITE FAR NORTH IN WYOMING AND MID-UPR CLOUDS MOVING NORTH-NORTHEAST. THUS WILL MENTION SOME AFTN SHOWERS FOR MUCH OF ERN ND (EXCEPT DVL) AND NW AND WCNTRL MN TODAY AND THEN CONTINUE INTO THE EVENING FOR WCNTRL MN. WITH QUITE A BIT OF MID CLOUDS MOVING THRU...TEMPS WILL BE HELD IN CHECK WITH NOT MUCH VARIATION. WARMEST TEMPS MIGHT BE IN DVL ZONE WHERE BEST SHOT OF SUN IS. SKIES CLEAR OUT TONIGHT (EXCEPT SE ZONES) AND WITH LIGHT WINDS EXPECT LOWS MID 40S TO LOWER 50S. .LONGER RANGE... LARGE HIGH DROPS SOUTH INTO CNTRL PLAINS FOR TUE-WED WITH WARMING AND LIGHT WEST WINDS INVADING NRN PLAINS AHEAD OF DEVELOPING STORM IN NW CANADA. WENT WITH WARMER ETA 85H TEMPS TUE-WED AND WITH FULL SUN EXPECT HIGHS INTO THE 70S MOST AREAS. CHANGED THURSDAY TO DRY AS NEXT 50H SYSTEM WILL THRU JAMES BAY AND NOT AFFECT OUR REGION. NEXT LOW AND FRONT TO ARRIVE FRI NIGHT WITH COOLER WX SAT-SUN. MOVED UP MENTION OF SHOWERS TO FRI AFTN AND THEN CONTNIUED MENTION INTO SATURDAY UNDER COOL AIR ALOFT. PREV EXTENDED TEMPS SEEM TOO COOL SO RAISED THEM UP SOME. .FGF...NONE. RIDDLE nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SHREVEPORT LA 1000 AM CDT MON SEP 9 2002 VIS IMAGERY CONTINUING TO SHOW ABUNDANT CLOUD COVER ACROSS MOST AREAS THIS MORNING. AREA SOUNDINGS SHOWING DEEP MOISTURE ACROSS SOUTHERN AND WESTERN SECTIONS. PALESTINE WIND PROFILER SHOWS SOUTHEAST FLOW THROUGH A DEEP PORTION OF THE ATMOSPHERE...THUS EXPECT THE WESTERN TWO THIRDS TO KEEP CLOUD COVER ALL DAY. WILL LIKELY SEE SOME BREAKS IN THE EAST THIS AFTERNOON AS VERY DRY ATMOSPHERE NOTED AT 12Z JAN SOUNDING. LOW/MID LEVEL WINDS HAVE BACKED MORE ACROSS THE EAST AS NOTED ON WINNFIELD PROFILER...THUS EXPECT THIS DRIER AIR TO MAKE A GOOD PUSH INTO SOUTHERN ARKANSAS/NORTHEAST LA TODAY. LOCAL RADAR SHOWING SHOWERS CONTINUING ACROSS SE OK/PORTIONS OF SW AR WITH VERY LITTLE MOVEMENT INDICATED. LATEST RUC MODEL IN AGREEMENT WITH SHORT TERM PROGS IN KEEPING SHEAR AXIS ACROSS THIS REGION TODAY BUT UPPER LEVEL DIFFLUENCE WEAKENING BY AFTERNOON. MAY NEED TO REALIGN ZONE GROUPINGS A LITTLE FOR OUR UPDATE AND MAY DROP MORNING MODIFIER. MOISTURE AXIS REMAINS IN E TX TODAY BUT DOES GET SHOVED WEST WITH DRIER AIR INTRUDING FROM THE EAST. MAY LOWER POP JUST A LITTLE IN THE WEST BUT KEEP SLIGHT CHANCES IN THE EAST FOR THE POSSIBILITY OF DESTABILIZATION WITH BREAKS IN THE CLOUD COVER. TEMPS OVERALL LOOK PRETTY GOOD BUT WILL TAKE A LOOK AT 15Z TEMPS BEFORE MAKING ANY CHANGES. UPDATE PLANNED FOR 1100 AM...13. .SHV...NONE. la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 927 AM EDT MON SEP 9 2002 CLOUD SHIELD ASSOC WITH GUSTAV IS ALREADY ONSHORE AND CONTINUES TO SPREAD WEST. 00/06Z RUNS OF THE ETA PLUS THE 00Z NGM RUN ARE VERY DISCONCERTING WITH SUGGESTIONS OF A SOUTH CAROLINA LANDFALL PLACING OUR CWA SQUARELY UNDER THE GUN. 10 AM NHC CONF CALL WILL ANSWER MANY QUESTIONS CONCERNING ANY POSSIBLE TRACK ADJUSTMENTS. WATER VAPOR IMAGERY AND LATEST RUC SHORT-TERM RUNS SHOW THE MID LEVEL RIDGE HOLDING STRONG FROM THE NORTHEASTERN U.S. SOUTHWEST DOWN THE MISSISSIPPI RIVER VALLEY. IF A WEAKNESS IS GOING TO DEVELOP AND TURN GUSTAV AWAY...IT WILL HOPEFULLY MANIFEST ITSELF SOON. PLAN ON TWEAKING THE ZFP TO ADJUST SKY COVER WITH THICKER CLOUDS ALREADY INTO THE AREA. WILL ALSO RAISE POPS THIS AFTN FOR PENDER AND NEW HANOVER COUNTIES WITH THE WESTERN EDGE OF THE RAIN SHIELD GETTING OMINOUSLY CLOSE ON RADAR. HIGH TEMPS MAY BE A TAD TOO HIGH - MAY ADJUST INTO A LOWER RANGE IN SPOTS. ANY CHANGES AFTER 10 AM CALL WILL BE DETAILED HERE IF NEEDED. MARINE: WIND/SEAS CONTINUE TO WORSEN AS GUSTAV NUDGES CLOSER TO THE CAROLINAS. FRYING PAN SHOALS SHOWING SPEEDS OF 30-35 KTS AND 7 TO 8 FT SEAS. FOR THE MOST PART THIS TREND IS IN LINE W/ THE CURRENT FCST SO AN UPDATE WILL BE REQUIRED TO MAINLY CLEAN UP THE EARLIER CONDITIONS. WILL UPDATE THE AFD IF NEEDED AFTER THE UPCOMING CONF CALL. FCSTID = 09 ILM 81 70 80 70 / 20 60 70 20 LBT 84 68 85 68 / 10 30 30 10 FLO 85 69 85 68 / 10 30 30 10 MYR 83 70 83 70 / 20 40 50 20 .ILM... .NC...TROPICAL STORM WARNING SURF CITY TO CAPE FEAR. SMALL CRAFT ADVISORY CAPE FEAR TO LITTLE RIVER INLET. .SC...SMALL CRAFT ADVISORY LITTLE RIVER INLET TO S SANTEE RIVER. PUBLIC: TRA MARINE: SRP nc DEEP SOUTH TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 1015 AM CDT MON SEP 9 2002 SHORT TERM...THE CIRCULATION EMBEDDED IN THE REMNANTS OF FAY IS EVIDENT ON VSBL SATL AND SURFACE OBS TO BE ROUGHLY NEAR COT WITH NO REAL MOVEMENT EVIDENT ATTM. THE MORNING CONV FROM EARLIER TODAY HAS DISSIPATED OVER THE BRO CWA WITH THE BULK OF THE CONV ASSOCIATED WITH FAY REMAINING CONCENTRATED OVER THE CRP AND EWX CWAS WHERE APPARENT SURFACE LOW LEVEL CONV CONTINUES TO ENHANCE THE CONV ACTIVITY. THE 12Z BRO AND CRP SOUNDINGS SHOW PLENTY OF TROPICAL MOISTURE IN PLACE OVER SOUTH TX WITH PWATS RANGING IN THE 2.4 TO 2.5 INCH RANGE. MODEL GUIDANCE AND QPF OUTLOOKS MAINTAIN THAT THE REMNANTS OF FAY WILL CONTINUE A SLOW SW DRIFT WHICH WILL MAINTAIN PWATS >2.0 INCHES IN THE SHORT TERM. RUC DATA MAINTAINS SEVERAL POCKETS OF 5H VORTICES ALONG AND JUST SOUTH OF THE RIO GRANDE RIVER VALLEY. THE MESO-ETA VORTICITY FIELDS SHOW A LITTLE DIFFERENT RESOLUTION MAINTAINING THE BULK OF THE 5H VORTICITY CENTERED NEAR AND JUST NORTH OF LRD. AT THE MOMENT...AM LEANING TOWARDS THE RUC VORTICITY FIELDS PORTRAYING THE CURRENT CONV MORE ACCURATELY WITH THE NORTHERN CONV LYING JUST NORTH OF THE STRONGEST PVA INDICATED BY THE RUC VORT FIELDS. MID LEVEL CLD COVER IS SLOWING DOWN THE USUAL DIURNAL HEATING TODAY...BUT BELIEVE THAT AFTERNOON CONV WILL BE ENHANCED SOMEWHAT LATER BY THE WARMING AFTERNOON TEMPS. DUE TO THE SCT NATURE OF THIS MORNINGS CONV AND THE RECENT BREAK IN THE ACTIVITY...WILL NOT ISSUE A FLASH FLOOD WATCH AT THE MOMENT AS CURRENT FLASH FLOOD GUIDANCE FROM THE WGRFC SHOWS 6 HR REQUIREMENTS RANGING FROM 5 TO 6 INCHES. WILL RE-EVALUATE THIS TREND THIS AFTERNOON TO SEE IF A WATCH WILL BE REQUIRED LATER TODAY AND TONIGHT. OVERALL WORDING OF THE CURRENT ZFP LOOKS OK. MARINE...CIRCULATION AROUND THE REMNANTS OF TROPICAL STORM FAY CONTINUES TO PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS OVER THE REGION. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED OVER THE LOWER TEXAS GULF WATERS FOR THE NEXT COUPLE OF DAYS...AS TROPICAL MOISTURE INTERACTS WITH LOW PRESSURE OVER SOUTH TEXAS. WINDS AND SEAS WILL BE HIGHER IN AND NEAR THUNDERSTORMS. EXPECT EXTENSIVE FEEDER BAND ACTIVITY OFF THE GULF TO SPREAD INTO THE COASTAL WATERS LATER TONIGHT. BOY020 HAS LIGHT SOUTHWEST WINDS...WITH SEAS DROPPING TO 5 FROM 6 FEET. EXPECT ONSHORE FLOW TO RESUME THIS AFTERNOON WITH THE DEVELOPMENT OF THE SEA BREEZE. DEEP LAYER HIGH PRESSURE WILL BUILD IN FROM THE NORTH BEGINNING ON WED...DRYING OUT THE WEATHER AND SHIFTING THE WINDS AROUND TO THE NORTH AND NORTHEAST. SYNOPTIC...60/AVIATION-MARINE...62/MESO...ABBOTT INTERNET ADDRESS...WWW.SRH.NOAA.GOV/BRO .BRO...NONE. tx NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER COLORADO 220 PM MDT MON SEP 9 2002 SHORT TERM DISCUSSION: LONGWAVE PATTERN FINALLY UNDERGOING A CHANGE WITH LOWER PORTION OF WESTERN LONGWAVE TROUGH BEGINNING TO FILL AND LIFT NEWRD TOWARDS THE GREAT BASIN. SHORT AND MEDIUM RANGE MODELS IN GENERAL AGREEMENT AS THEY ALL OPEN UP TROUGH AND TRAVERSE IT ACRS THE GREAT BASIN STATES ON TUESDAY. MEANWHILE MID/UPR LVL RIDGE OVER THE CNTRL/SRN PLAINS STATES WEAKENS AS ITS SLIDES SEWRD ACRS TX. CURRENT WATER VAPOR IMAGERY CONTINUES TO SHOW A STEADY/CONTINUOUS STREAM OF SUBTROPICAL MOISTURE UP ACRS THE DESERT SW AND CNTRL RCKY MTN STATES. EAST OF THE MTNS...A COLD FRONT WHICH SLID S THRU NERN CO ERLY THIS MRNG PROGD BY RUC AND ETA TO SLOW TO A CRAWL AS IT MOVES THRU SERN CO DURING EVE HRS. LOW LVL WND SHEAR AND FRONTOGENTIC FORCING SHOULD FOCUS MOST OF SHWR AND T-STORM COVERAGE ALONG THIS CONVERGENCE ZONE OVERNIGHT. HWVR RUC AND ETA SHIFT THIS BOUNDARY AXIS E AND JUST S OF OUR CWFA AROUND MIDNIGHT...SO FRONTAL INDUCED CONVECTIVE PCPN MAY ALSO SHIFT OUT OF OUR CWFA SOON AFTER. MEANWHILE WIND GRIDS SHOW UPSLOPE FLOW STRENGTHENING THRU THE EVE ALONG THE FRONT RANGE AS STG SFC HIGH NOSES SEWRD ACRS NEB OVRNGT. LATEST MM5 IS INDICATING FM A QUARTER TO HALF INCH OF RAIN IN AND NEAR THE FRONT RANGE NEXT 24 HRS WHERE OROGRAPHIC FORCING AT ITS STRONGEST. GREATEST PCPN LKLY TO OCCUR IN THE SRN FRONT RANGE FTHLS (ZONE 36) AND OVER HIGHER TRRN ALONG THE MONUMENT RIDGE (ZONES 41..46 AND 47) WHERE MM5 IS GIVING 24-HR RAINFALL AMTS UPWARDS OF AN INCH. EVEN HIGHER AMTS (IN EXCESS OF 2 INCHES) COULD ACCUMULATE IN LINCOLN CTY WHERE VRY HVY RAINS FELL LAST NIGHT. THUS A FLASH FLOOD WATCH WILL REMAIN IN EFFECT UNTIL 5 AM MDT FOR ZONES 36..46..47.. 49..50 AND 51. AS FOR REMAINDER OF CWFA CHANCES FOR MEASURABLE PCPN NEXT 24 HRS NOT LOOKING AS PROMISING WITH ATMOSPHERE PROBABLY TOO STABLE AND COOL FOR ANYTHING MORE THAN SCATTERED LIGHT SHWRS. OVERNIGHT TEMPS COOL ENOUGH FOR SNOW IN THE HIGH COUNTRY. AVN STILL CRANKING OUT A FEW INCHES AT ELEVATIONS GENERALLY ABV 10500 FT MSL. TUESDAY PRECIPITABLE WATER VALUES GO UP SOME AS ELY UPSLOPE FLOW STRENGTHENS/DEEPENS. STILL LOOKS LIKE A CLOUDY AND UNSEASONABLY COOL DAY WITH PRECIPITATION LIKELY ESPCLY IN THE MTNS...FTHLS AND ADJACENT HIGH PLAINS. INFLUX OF SUBTROPICAL MOISTURE FM OLD T.D. FAY AND VRY LGT S-SWLY FLOW ALOFT MAY AGAIN RESULT IN HVY RAIN PRODUCING SHWRS AND ELEVATED T-STORMS ALONG THE HIGHER TERRAIN. TEMPS ON THE PLAINS TUE WILL STRUGGLE TO CLIMB INTO THE 60S WITH HVY CLOUD CVR. LONG TERM: TUE NIGHT THRU THU...MODELS CONTINUE TO CIRCULATE QUITE A BIT OF MOISTURE UNDERNEATH THE RIDGE SLOWLY EXITING THE REGION. MEANWHILE UPR TROUGH LIFTING OUT OF THE DESERT SOUTHWEST IS PROGD TO MIGRATE SLOWLY EASTWERD ACRS THE NRN/CNTRL ROCKY MTN STATES BY ERLY FRI. PRIOR TO ITS PASSAGE AMS OVR THE N-CNTRL MTNS AND NERN PLAINS OF CO MAY SEE LITTLE DRYING OR WARMING. FRIDAY AND BEYOND...AREA GOES UNDER RELATIVELY DRY AND STABLE NWLY FLOW WITH UPR TROF MIGRATING ACRS THE UPR GREAT PLAINS. AFTER A GRDL REBOUND IN TEMPS UP THRU FRI...COULD SEE A SLIGHT DIG IN READINGS DURING THE WEEKEND FOLLOWING PASSAGE OF WK COLD FNT SAT ACCORDING TO THE GFS. BAKER .DEN...FLASH FLOOD WATCH UNTIL 5 AM MDT TUE...ZONES 36..46..47..49.. 50 AND 51. co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 150 PM MDT MON SEP 9 2002 FORECAST CONCERNS ARE CHANCES OF LOCALIZED FLOODING TONIGHT. AT 20Z LINE OF SHOWERS AND A FEW THUNDERSTORMS EXTENDED FROM NORTH CENTRAL NEBRASKA SOUTHWEST THROUGH THE CO/KS LINE INTO SOUTHEAST COLORADO...BASICALLY ALONG THE FRONT. OVERLAYING VARIOUS MODEL QPF FORECASTS ON TOP OF THE RADAR MOSAIC SHOWS THE ETA/AVN/RUC HAVING A PRETTY GOOD HANDLE ON THIS PARAMETER. FOR THE FORECAST WILL SIDE TOWARD THE ETA GIVEN ITS CONSISTENCY IN PLACEMENT OF HEAVIEST RAINS THE PAST FEW DAYS. TONIGHT/TUESDAY...COLD FRONT SLOWLY MAKES IT MAY THROUGH THE FORECAST AREA TONIGHT. PLENTY OF MOISTURE AND LIFT ALONG THE FRONT TO GENERATE WELL ADVERTISED SHOWER AND THUNDERSTORM ACTIVITY. WITH PRECIPITABLE WATER VALUES OF 1.0-1.5 INCHES AND THE SLOW MOVEMENT OF THE FRONT LOCALLY FLOODING RAINS CAN BE EXPECTED OVER ALL BUT THE FAR EAST/SOUTHEAST CWA. IN COORDINATION WITH SURROUNDING OFFICES WILL WILL ISSUE A FLOOD WATCH FOR MUCH OF THE CWA. THIS WOULD MATCH THE DAY 1 EXCESSIVE RAINFALL OUTLOOK...ALBEIT A BIT FURTHER NORTHWEST. WILL BUMP UP THE POPS A BIT GIVEN MODEL CONSISTENCY AND AGREEMENT BETWEEN EACHOTHERS QPF OUTPUT. LOWS WILL RANGE FROM THE LOW 50S NORTHWEST TO THE LOW 60S SOUTHEAST. FOR TUESDAY...WINDS GRADUALLY TURN TO THE NORTHEAST AS HIGH PRESSURE BUILDS INTO THE AREA. SOME DRIER AIR WORKS INTO THE LOWER LEVELS BUT MID LEVELS REMAIN MOIST. GIVEN THE DRIER AIR WORKING IN FROM NORTHEAST TO SOUTHWEST WILL HAVE POPS ALSO IN THAT ORIENTATION. AS FAR AS TEMPS BOTH THE ETA/FWC MOS VALUES ARE CLOSE TO EACHOTHER. WITH CLOUDCOVER EXPECTED WONT DEVIATE FROM THESE TOO MUCH. TUESDAY NIGHT/WEDNESDAY...WILL GO CLOUDY BUT DRY TUESDAY NIGHT. MAY SEE SOME LIGHT PRECIP OVER THE SOUTHEAST CWA WHERE MINOR 500 VORT MAX APPROACHING THE AREA FROM THE SOUTHWEST. BOUNDARY LAYER MOISTURE HIGH ENOUGH THAT SOUTHWEST CWA COULD ALSO SEE SOME FOG. LOWS AGAIN NEAR ETA/FWC MOS VALUES...MID 40S NORTHWEST TO MID 50S SOUTHEAST. THE UPPER DISTURBANCE MOVES ACROSS THE AREA WEDNESDAY WITH RIGHT REAR QUAD OF UPPER JET TO OUR NORTHWEST. ACCOMPANIMENT OF SHOWERS AND MAYBE A THUNDERSTORM LOOKS PRETTY GOOD. IT WILL REMAIN CLOUDY WITH TEMPS NEAR MET/FWC MOS VALUES...GENERALLY IN THE LOW 70S NORTHWEST TO MID 70S EAST. WEDNESDAY NIGHT/THURSDAY...MAIN UPPER FLOW REMAINS NORTH OF THE UNITED STATES BUT LINGERING UPPER TROUGH REMAINS WEST OF THE AREA. DISTURBANCES EJECTING FROM THE TROUGH MOVE ACROSS THE AREA WITH ETA/AVN SHOWING SOME LIGHT PRECIP OVER THE AREA WHERE SURFACE TROUGH EXISTS. PRECIP CONTINUES PER ETA/AVN THURSDAY AS SURFACE LOW DEVELOPS OVER SOUTHEAST COLORADO. 700 VORT MAX AND ASSOCIATED TROUGH APPEAR TO BE RESPONSIBLE FOR THE UPWARD MOTION DEPICTED IN THE MODELS. LOW TEMPS WILL REMAIN IN THE 50S WITH HIGHS THURSDAY GENERALLY IN THE 70S. THURSDAY NIGHT...SOME LIGHT PRECIP CONTINUES AS THE ABOVE MENTIONED DISTURBANCE MOVES EAST AND COLD FRONT MOVES IN FROM THE NORTHWEST. LOWS A BIT COOLER AS HIGH BUILDS IN WITH READINGS IN THE 50S. IN THE EXTENDED (FRI-MON)...ONE UPPER TROUGH SWINGS ACROSS THE AREA FRIDAY WITH TROUGHY/NORTHWEST FLOW THROUGH MONDAY. AT THE SURFACE... TROUGH ALONG THE CO/KS BORDER MOVES EAST AS A COLD FRONT MOVES INTO THE AREA SATURDAY. HIGH PRESSURE REMAINS IN CONTROL ON SUNDAY BEFORE MOVING EAST ON MONDAY AS WINDS TURN TO THE SOUTH ON THE BACKSIDE OF THE HIGH AND DEVELOPING LEE TROUGH TO THE WEST. AS FAR AS PRECIP CHANCES...WILL KEEP A CHANCE FRIDAY AS UPPER TROUGH AND VORTICITY MAXIMA MOVE ACROSS THE AREA. ON SATURDAY SURFACE HIGH PUSHES INTO THE AREA BRINGING DRIER AIR WITH IT. WITH MUCH OF THE UPPER ENERGY TO OUR NORTH WILL GO AHEAD AND MAKE IT DRY. ON SUNDAY UPSLOPE FLOW CONTINUES AS SURFACE HIGH NEARLY OVERHEAD. ALTHOUGH 850 THTE-E AXIS MOSTLY SOUTH OF OUR AREA 700 AXIS RESIDES OVER THE AREA. WITH ANOTHER INCOMING AND A BIT STRONGER VORT MAX IN NORTHWEST FLOW WILL GO WITH A CHANCE OF PRECIP. ON MONDAY IT WILL BE DRY AS SOUTHEAST WINDS TRANSPORT HIGHER MOISTURE TOWARD THE FRONT RANGE ON THE BACKSIDE OF THE DEPARTING SURFACE HIGH. THANKS TO MY SURROUNDING OFFICES FOR COORDINATION. .GLD...FLOOD WATCH UNTIL MIDNIGHT MDT FOR YUMA COUNTY COLORADO. ...FLOOD WATCH UNTIL 6 AM MDT (7 AM CDT) WEST OF A LINE FROM NORTON KANSAS TO OAKLEY KANSAS TO CHEYENNE WELLS COLORADO. DDT ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 230 PM CDT MON SEP 9 2002 SWLY FLOW ALF HAS A HUSKY IMPULSE IN THE WRN DAKS SPAWNING A RATHER LARGE AREA OF SHWRS AND TSTMS. LOOKING AT THE FIRST 6-12 HOURS OF THE NEW MODEL RUNS, THE RUC AND MESOETA HAVE THAT PRETTY WELL NAILED AS COMPARED WITH THE ASSOCIATED 88D IMAGERY. THE VORT MAX AND 85H WAA ARE DVLPG SOME TSTMS JUST N OF THE WM FNT THERE. THE FNT AT 17Z RAN FM HURON SD TO THE BAYFIELD PENINSULA AND THE UPR LVL FLOW WL BE PARALLEL TO THIS MOIST BAROCLINIC ZONE FOR THE NEXT 12 TO 24 HOURS AND SHOULD NOT MOVE MUCH. SO AS THE VORT MAX IS EJECTED, THE ENERGY SHOULD MOVE THRU THE SERN PTN OF THE MN CWA AND MUCH OF NORTHWEST WIS, CLIPPING THE DLH AREA. ALL MODELS XCP THE NGM BRING A BIG OMEGA BULLEEYE OVR DLH AND IS WHY THE POPS ON THE MESOETA ARE IN THE LIKELY CATEGORY FOR ABOUT MIDNIGHT. THE UPR TROF IS OUT OF MN BY 12Z WED BUT LINGERS INTO WED MRNG IN WI. DRIER AIR THEN MIXES IN FM THE W. THAT IS A BIT SHORT LIVED AS WAA MOVES IN. SO WE'LL FOLLOW THE MESOETA QPF DEPICTION WHICH HAS BEEN QUITE GOOD. THAT BRINGS THE MAX PCPN SWATH FROM ABOUT BRD TO BAYFIELD OVRNGT. MESO ETA MOS IS ALSO ON TARGET AT 18Z. .DLH...NONE. CS mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 400 PM CDT MON SEP 9 2002 FORECAST CONCERN WILL BE TIMING ENDING OF SHOWER ACTIVITY AND THEN TEMPERATURES. NO MAJOR INITIALIZATION PROBLEMS NOTED WITH MODELS WHEN EXAMINING THIS MORNING RAOBS. ETA AND AVN IN GOOD AGREEMENT WITH UPPER LEVEL AND SURFACE FEATURES THROUGH THURSDAY. MAIN MODEL DIFFERENCE APPEARS TO BE STRENGTH OF LOW LEVEL THERMAL RIDGE WHICH DEVELOPS BEHIND LOW LEVEL RIDGE AXIS TOWARD WEDNESDAY AND THURSDAY. SHORT WAVE INFLUENCING CWA THIS AFTERNOON NOW LOCATED OVER NORTH CENTRAL WYOMING WITH RUC AND SATELLITE DATA SUGGESTING WAVE IS CONTINUING TO GET SHEARED OUT. AREA OF SHOWERS SLOWLY WORKING EASTWARD THIS AFTERNOON. KUNR RADAR INDICATING SHOWERS NEARLY COMING TO AN END ACROSS FAR WESTERN CWA AND WILL CARRY EARLY EVENING SHOWER MENTION IN FAR WEST. AREA OF PRECIPITATION IS BEING ENHANCED BY MID LEVEL BAROCLINIC AND UPPER DIVERGENCE ASSOCIATED WITH WEAK UPPER JET STREAK DOWNSTREAM OF AFOREMENTIONED WY TROUGH AXIS. RUC DATA ALSO INDICATING INCREASING MAGNITUDE TO MID LEVEL FLOW IN ADVANCE OF THIS WAVE CONTRIBUTING TO WEAK 700 HPA WAA ACROSS FAR EASTERN CWA. THIS HAS RESULTED IN DEVELOPMENT OF SHOWERS AND ISOLATED THUNDER JUST TO THE SOUTH OF CWA EXTENDING INTO FAR SOUTHEAST CWA. THIS AREA ALSO HAS WHAT LIMITED INSTABILITY REMAINS WITH LOW LEVELS STILL REMAINING SLIGHTLY WARMER. AS MID LEVEL FRONTOGENESIS AXIS MOVES THROUGH EASTERN CWA LATE THIS EVENING...WILL BEGIN TO SEE CLEARING TAKE PLACE ON THE COLD SIDE OF MID LEVEL BAROCLINIC ZONE ACROSS WESTERN HALF OF CWA...WORKING INTO FAR EASTERN CWA TOWARDS MORNING. TEMPERATURE FORECAST A BIT TRICKY TONIGHT DEPENDING ON HOW RAPIDLY CLEARING TAKES PLACE. WILL GO FOR UPPER 40S ACROSS NORTHWEST WHERE CLEAR SKIES WILL OCCUR LONGER AND NEAR 50 ACROSS FAR EAST. TUESDAY WILL BE UNEVENTFUL WITH MID LEVELS QUITE A BIT DRIER. PWATS BEHIND SHORT WAVE FALL TO AROUND 0.6 INCHES WITH DEEP LAYER LOW RH IN MODEL TIME SECTIONS. LOW LEVEL RIDGE AXIS WILL APPROACH FROM THE WEST KEEPING WINDS IN THE 10 MPH RANGE FROM THE NORTH ACROSS MOST OF CWA. UPPER RIDGE AXIS SETTLES INTO CWA ON WEDNESDAY MORNING AS WEAK SHORT WAVES FROM BAJA OF CALIFORNIA REGION EXPECTED TO RIDE OVER THE RIDGE. AT THIS TIME APPEARS STRONGEST LOW LEVEL WARM ADVECTION WILL BE JUST SOUTH OF CWA FROM WEDNESDAY INTO EARLY THURSDAY. HAVE REMOVED SHOWER MENTION FOR WEDNESDAY EVENING WITH LOW LEVELS STILL FAIRLY DRY. WILL GO WITH LOW POPS FOR THURSDAY AS BEGIN TO GET BETTER LOW LEVEL MOISTURE RETURN AND MORE SIGNIFICANT LOW LEVEL THERMAL RIDGING IN ADVANCE OF UPPER WAVE. HIGHS FOR LATE IN THE PERIOD REFLECT A COMPROMISE BETWEEN WARM ETA AND COOL AVN IN STRENGTH OF THERMAL RIDGING FOR THURSDAY. .EXTENDED DISCUSSION... MODELS HAVE FALLEN OUT OF GENERAL AGREEMENT THAT WAS ENJOYED PAST FEW DAYS. THE MOST CONSISTENT APPEARS TO BE THE CANADIAN...SO HAVE LEANED MORE TOWARD THIS SOLN. FIRST FRONT HAS PUSHED THROUGH CWA BY FRIDAY MORNING WITH HIGH PRESSURE BUILDING INTO REGION. THE AVN SLOWS THE FRONT DOWN BY NEARLY 12 HOURS...WHILE THE ECMWF IS A ROUGH COMPROMISE. WITH FRONT MORE PERPENDICULAR TO UPPER FLOW...AND UPPER FLOW MOVING THROUGH FAIRLY QUICKLY...THINK THAT QUICKER SOLN OF THE CANADIAN SEEMS REASONABLE. FOR SATURDAY AND SUNDAY...MODELS AGREE SOMEWHAT ON UPPER FLOW. SERIES OF UPPER LEVEL WAVES COME THROUGH...HELPING TO REINFORCE TROFING ACROSS UPPER MIDWEST. NO PARTICULAR WAVE STANDS OUT FROM THE OTHERS...AND NONE ARE IMPRESSIVE MOISTURE WISE. IF ANYTHING...THEY REINFORCE THE COOL AIR ALREADY PRESENT. THE CANADIAN IS SLIGHTLY WEAKER AT 5H THAN THE AVN WHILE THE ECMWF HAS STRENGTHENED THINGS GREATLY. ANY PCPN CHANCES WITH UPPER WAVES WOULD BE SLIGHT AT BEST...AND NOT WORTH THE MENTION CURRENTLY. HIGH PRESSURE BUILDS INTO THE REGION ON SUNDAY...BRINGING COOLISH TEMPERATURES AND DECREASING CLOUDS. HIGH PRESSURE REMAINS IN CONTROL FOR MONDAY AS UPPER FLOW TURNS MORE ZONAL. TEMPS SHOULD WARM SLIGHTLY ABOVE THE WEEKEND TEMPS AS THICKNESS VALUES AND 8H AND 7H TEMPS BEGIN TO WARM. .ABR...NONE MARSILI/HINTZ sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 340 PM CDT MON SEP 9 2002 FORECAST PROBLEMS...EVENING CONVECTION...TIMING/PRECIPITATION OF THE COLD FRONT CURRENTLY EXTENDING FROM KDLH-KFSD...TEMPERATURE COOL DOWN BEHIND THE FRONT. DATA ANALYSIS...UPPER LEVEL DISTURBANCE CONTINUES TO EXIT THE WEST...MOVING INTO THE HIGH PLAINS. NOTABLE BAROCLINIC LEAF OVER THE HIGH PLAINS ASSOCIATED WITH THIS DISTURBANCE. SATELLITE SHOWING SOME MOISTURE...ASSOCIATED WITH SOME OF THE TROPICAL DISTURBANCES WHICH HAVE BEEN MOVING OVER LAND INTO THE SOUTHERN PLAINS...MAKING ITS WAY INTO THE REGION. PROFILER DATA SHOWING THAT LOW LEVEL FLOW CONTINUES TO SUPPORT THE TRANSPORT OF THE MOISTURE INTO THE REGION. LAPS/RUC SHOW THE GREATEST INSTABILITY OVER THE EASTERN HALF OF THE FORECAST AREA...WITH SBCAPES OF 2500-4000 J/KG. TEMPERATURES IN THE LOWER 90S HAVE CAUSED THE CAP TO BREAK. VERY LITTLE SHEAR TO SUPPORT SUSTAINED UPDRAFTS. THUS...STORMS SHOULD DEVELOP...THEN WEAKEN QUICKLY. RADAR DETECTING THIS VERY THING. WILL INCLUDE ISOLATED CONVECTION THIS EVENING. ONCE AGAIN...09/12Z ETA/AVN BOTH IN GOOD AGREEMENT...AND BOTH SLOW THE FRONT DOWN FURTHER. PROFILERS HAVE SHOWN VERY LITTLE ADVANCEMENT OF UPPER LEVEL RIDGE. NOW...THE FRONT SHOULD BE DELAYED UNTIL TUESDAY. ETA PRESSURE DEFICITS AT 310K-320K LAYER SHOW THE AREA OF MOISTURE ON SATELLITE OVER THE PLAINS VERY WELL AT 18Z. AS THE DISTURBANCE MOVES EAST TONIGHT...MUCH OF THE FORCING WILL BE CARRIED NORTH OF THE FORECAST AREA. THIS KEEPS MUCH OF THE SATURATION NORTH OF THE AREA. HOWEVER...THERE SHOULD BE ENOUGH TO CAUSE CONVECTION ALONG THE FRONT AS THE SYSTEM MATURES AND MOVES THROUGH. AM STILL CONCERNED THAT THE MODELS WILL CONTINUE TO SLOW THE FRONT DOWN. THE LATEST RUC RUN DOES TREND THIS WAY...SO WILL KEEP SLIGHT CHANCE IN THE EVENING IN THE SOUTHERN AREAS. HIGH PRESSURE SETTLES IN THROUGH THURSDAY. JET STRUCTURE FAVORS KEEPING SYSTEMS WELL TO THE NORTH IN THE FAST FLOW...ALLOWING THE AIRMASS OVER THE FORECAST AREA TO MODIFY SOME EACH DAY. THEREFORE...WILL CONTINUE TO STICK WITH FORECAST ABOUT 5 DEGREES OVER CLIMATE. AMAZINGLY...MOS CONTINUES TO COME AROUND TO THIS SOLUTION. NEXT SYSTEM EXITS THE WEST...AND MOVES TOWARD THE REGION TOWARD NEXT WEEKEND. THAT FACT IS TRUE...BUT TIMING IS A CONCERN. BASED ON TREND TOWARD FAST FLOW...MODELS USUALLY HANDLE SYSTEMS TOO SLOW. WILL TREND THIS WAY IN THE EXTENDED FORECAST. NORTHWEST FLOW WILL DIP INTO THE REGION EARLY NEXT WEEK. FALL LIKE COOL DOWN EXPECTED. .LSE...NONE. KRC wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 315 PM CDT MON SEP 9 2002 PATTERN NOW UNDERGOING CHANGE AS THE RIDGE THAT HAS BEEN DOMINANT OVER THE EASTERN 2/3RDS OF THE COUNTRY BEGINS TO BREAK DOWN. TWO FEATURES WILL HAVE TO BE WATCHED FOR NEAR TERM FORECAST. AT THE SURFACE...A COLD FRONT NOW EXTENDS FROM NEAR DULUTH TO LOW OVER SOUTHEAST SD. ALOFT... SHORT WAVE NOW MOVING THROUGH THE NORTHERN PLAINS. SATELLITE AND OBS SHOWING LARGE AREA OF PCPN OVER THE DAKOTAS...ASSOCIATED WITH THE UPPER FEATURE. MODELS FAIRLY SIMILAR...AGAIN SLOWER THAN PREVIOUS RUN...BRINGING FRONT THROUGH THE GRB AREA AFTER 12Z TUE. CURRENTLY...FEW SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER SOUTHEASTERN ZONES...WHERE CAP IS WEAKER. RUC IS SHOWING POCKET OF SLIGHTLY LOWER 850 TEMPS IN THAT AREA. WILL ADD MENTION OF EARLY EVENING SHOWERS...THOUGH PUSH BACK THE BULK OF THE PCPN TO MATCH FRONTAL MOVEMENT. MAIN DYNAMICS ASSOCIATED WITH WAVE TO BE OVER THE NORTH AS RRQ OF JET MAX LIFTS INTO ONTARIO. BUFFY SOUNDINGS SHOW SIG INSTABILITY THROUGH THE NIGHT...STABILIZING BY AM TUE. LACK OF SIG SHEAR TO LIMIT SEVERE POTENTIAL WITH ANY STORMS THAT DEVELOPS OVERNIGHT. HIGH PRESSURE TO WORK IN LATER TUE WITH CLEARING SKIES. TEMPS EXPECTED TO RETURN TO NEAR NORMAL LEVELS. IN EXTENDED...PATTERN IS FLUID WITH STRONG WESTERLIES REMAINING JUST NORTH OF US BORDER. WILL KEEP NEXT CHANCE ON SAT INTO SUN. 5H HEIGHTS CONTINUE TO BE IN 570 RANGE INTO SAT...SO WILL CONTINUE TO BUMP MRF GUIDANCE TEMPS UP. .GRB...NONE. TE WWW.CRH.NOAA.GOV/GRB wi