AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI 830 PM EDT MON SEP 2 2002 CONVECTIVE BAND ASSOCIATED WITH LOW LEVEL TROUGH TRAILING SOUTHWEST FROM EDOUARD...EXTENDS INTO FLORIDA EAST COAST JUST NORTH OF LAKE OKEECHOBEE. RADAR/SATELLITE INDICATE THIS BAND IS TRACKING SOUTH AT 10 TO 15 KNOTS AND MAY AFFECT PALM BEACH COUNTY BEGINNING AROUND 10 PM. RUC40 MODEL INDICATES THAT ISOLATED-SCATTERED SHOWERS/THUNDERSTORMS MAY EVEN OCCUR ACROSS EASTERN BROWARD AND MIAMI-DADE COUNTIES UNTIL AROUND 2AM...SO WILL REWORD ZFP. SURFACE WIND SHIFT ASSOCIATED WITH TRAILING TROUGH WILL TEMPORARILY CHANGE WIND DIRECTION OVER PALM BEACH COUNTY TO NORTHWEST BUT WILL GRADUALLY BECOME SOUTHEAST AGAIN LATER TONIGHT. .MIA...NONE. $$ fl FLORIDA KEYS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KEY WEST FL 955 AM EDT MON SEP 2 2002 CURRENTLY... 12Z KEY WEST SOUNDING IS VERY MOIST...2.22 INCHES PW AND BALLOON DID NOT SEEM TO ASCEND THROUGH A SHOWER. ESE FLOW STILL RUNS FROM SURFACE UP TO 14 THSD FT. SATELLITE AND RADAR SHOWS NO ORGANIZED SHOWER ACTIVITY IN THE AREA...ONLY A SLIGHTLY ENHANCED STREAM OF SCATTERED SHOWERS/ISOLATED TSTMS MOVING WITH LOW LEVEL FLOW FROM SOUTH OF ANDROS ISLAND, ACROSS THE STRAITS TO THE MIDDLE KEYS. THIS ACTION FLARED-UP DURING FAVORED LATE NIGHT-EARLY MORNING TIME. THE TROPICAL WAVE THAT HAS BEEN MOVING WEST OVER CARIBBEAN AND GREATER ANTILLES...IS BARELY DISCERNIBLE IN MORNING QUIKSCAT PASS AS A WEAK CYCLONIC TURN IN SURFACE WINDS EAST CUBA SOUTH OVER JAMAICA, WHILE CONVECTION WITH THE FEATURE HAS GREATLY DIMINISHED. WAVE VAPOR AND GOES SOUNDER SHOW VERY DRY AIR ALOFT POKING WEST FROM THE ATLANTIC NORTH OF THE WAVE AXIS...AND ENTERING THE NORTHERN BAHAMAS. KEYS WINDS HAD A TEMPORARY PICK-UP LAST NIGHT ACCORDING TO THE MID-SHIFT FORECASTER, BUT LAST FEW HOURS ESE WINDS HAVE SETTLED DOWN TO NEAR 10 KT...EXCEPT FOR GUTSINESS AT SOMBRERO KEY IN THOSE SHOWERS. THIS AFTERNOON... THE RUC LOOKS STRANGE WITH ERRATIC WINDS AROUND THE AREA...AND SHOWING A HUGE SHIFT WESTWARD FROM 10 AM TO 11 AM IN THE DRY AIR ALOFT SLOT FROM THE NORTHERN BAHAMAS ALL THE WAY TO THE UPPER KEYS. LOOKS TOO MUCH FOR ONE HOUR. 06Z MESOETA AND 06Z AVN BOTH KEEP AN AXIS OF HIGH MOISTURE OVER THE KEYS THROUGH TODAY, BUT WITHOUT MUCH IN THE WAY OF SYNOPTIC LIFT. SO...CURRENT PUBLIC ZONES LOOK FINE WITH 40 PCT POPS THROUGH THE DAY. MID-LATE AFTERNOON MAY SEE TCU/CB LINES OFF THE KEYS...SPECIALLY LOWER KEYS...WITH SHOWERS/FEW TSTMS AND POSSIBLE WATERSPOUTS...AFFECTING MAINLY WATERS ON NORTH SIDE OF THE KEYS. COASTAL WATERS CONTAINS NO CHANGES AT 1030 AM ISSUE. .EYW...NONE. C.B. fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 900 PM CDT MON SEP 2 2002 AIRMASS IS UNSTABLE BUT STRONGLY CAPPED TONIGHT. DVN AND ILX 00Z SOUNDINGS BOTH HAVE 700MB TEMPS AROUND +11C. FRONT CURRENTLY LOCATED IN ERN IA TO NCNTRL MO AT 01Z WITH LINE OF CU COUPLE OF HOURS AHEAD OF FRONT...AND MOVING INTO VERY MOIST AIRMASS IN IL. FRONT STILL FCST TO BE NEAR I-55 AROUND 12Z AND THEN PUSH THROUGH REMAINDER OF CWA BY EARLY AFTERNOON. INCOMING 00Z RUC CONTINUES TO SUPPORT THAT FCST. CURRENT FCST HAS 40 POPS IN NORTH AND CENTRAL FOR TONIGHT. BELIEVE THERE IS STILL SLIGHT CHC OF SOME DEVELOPMENT ALONG FRONT LATER TONIGHT...AFTER WINDS DECOUPLE FROM SFC AND LOW LEVEL JET KICKS IN. HAVE SEEN THIS HAPPEN BEFORE IN CAPPED ENVIRONMENTS. THEREFORE WILL ONLY LOWER POPS TO 30 PCT FOR TONIGHT. GOOD RULE OF THUMB TO GO BY IS: NO DRY FROPA IN SUMMER. THANKS CHI. COORD WITH DVN...LSX...AND LOT. .ILX...NONE. $$ AUTEN il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 824 PM CDT MON SEP 2 2002 00Z DVN SOUNDING SAYS IT ALL...CAPE 3536...CIN 56. MULTIPLE CAPPING INVERSIONS PREVENTING ANY CONVECTION FROM STARTING. DVN 88D SHOWS A FEW CELLS STARTING BUT DYING OUT AS FAST AS THEY START ACROSS THE NORTHERN CWFA. SATELLITE TRENDS INDICATE ENHANCED CU/TCU ALONG THE PRE-FRONTAL TROF WITH NO ACTIVITY ALONG THE COLD FRONT. 02/21Z RUC INDICATED BEST FORCING/FRONTOGENESIS STARTS FALLING APART BETWEEN 00-03Z. 00Z RUC HAS YET TO ARRIVE. IF 03/00Z RUC CONTINUES TREND OF 02/21Z RUC WILL EITHER PULL ALL POPS OR DROP THEM DOWN TO A SLIGHT CHANCE. REGARDLESS...CID/DBQ ZONE GROUP AND IOW ZONE GROUP WILL BE DRY AS PRE-FRONTAL TROF ALREADY THROUGH THERE WITH ACTUAL COLD FROPA LAGGING BEHIND BY 2 HOURS AND IS HALFWAY THROUGH THOSE GROUPS. .DVN... IA...NONE. IL...NONE. MO...NONE. 86 il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 317 PM CDT MON SEP 2 2002 FOCUS CHALLENGE CENTERS MAINLY ON FIRST PERIOD THUNDERSTORM CHANCES WITH COLD FRONTAL PASSAGE...THEN AMOUNT OF COOL DOWN WITH TEMPERATURES AS HIGH PRESSURE DROPS DOWN THROUGH MIDWEEK. AT 19Z THE SURFACE COLD FRONT WAS FROM CENTRAL MN TO ABOUT ALGONA IA...TO OMAHA. FRONT HAS SHOWN CONSISTENT EASTWARD PUSH SO FAR TODAY AND WITH 3 HR PRESSURE RISES IN 4 MB RANGE IN SD AND NEB...EXPECT IT TO CONTINUE TO PROGRESS EASTWARD THIS EVENING. ASSOCIATED MID LEVEL SHORTWAVE EXTENDED FROM MAIN VORT EAST OF LAKE WINNEPEG INTO NW IA. SEVERAL BANDS OF ELEVATED CONVECTION SEEN ON VISIBLE SATELLITE AND FROM ABOUT KDBQ TO KAWG WITH 88D SHOWING SOME OCCASIONAL SHOWERS ON NORTHERN END. TSRA COMPLEX THAT MOVED THROUGH EASTERN IA AND NW IL OVERNIGHT AND LINGERED UNTIL MIDDAY HAS LAID OUT AN OUTFLOW BOUNDARY OBVIOUS ON VISIBLE SATELLITE IN EAST CENTRAL IL CURVING UP TOWARD QUAD CITIES...WHERE IT BECOMES WEAKLY EVIDENT ON 88D IMAGERY JUST NORTH OF KDVN MOVING NORTH. SHORT TERM MODELS IN BASIC AGREEMENT WITH LARGE SCALE FEATURES. ETA AND UK HAD BEST 18Z FRONT POSITION AND TRENDED SLOWER THAN AVN WITH PASSAGE THROUGH CWA AND GENERALLY FOLLOWED. BEST UPPER FORCING AND JET LEVEL DIVERGENCE WELL TO NORTH...BUT SOME INFLUENCE EXTENDS SOUTH INTO NORTHERN ZONES BETWEEN 00Z AND 06Z TONIGHT. USUAL POOR AGREEMENT WITH QPF FIELDS WITH AVN ONLY MODEL EXTENDING ANY PRECIP SOUTH OF FAR NE IA/NW IL. RUC40 QPF TRENDS CLOSEST TO MY THINKING WITH THUNDERSTORMS DEVELOPING MID TO LATE AFTERNOON AT PEAK HEATING AHEAD OF FRONT AND MOVING THROUGH FORECAST AREA BEFORE MIDNIGHT. TEMPERATURES IN 80S TO AROUND 90 AND DEWPOINTS IN 70S HAVE PUSHED LAPS SB CAPES INTO 35-40 KJ/JG RANGE WITH WEAKEST CAP OVER NE IA. SPECIAL 18Z DVN SOUNDING INDICATED CONSIDERABLE 0-3 KM DIRECTIONAL SHEAR...WHICH WOULD BE MAXIMIZED ON ANY EXISTING BOUNDARIES. BEST SEVERE POTENTIAL WILL BE GREATEST MAINLY NORTH OF HIGHWAY 30 EARLY THIS EVENING AND WILL RESTRICT SEVERE WORDING TO THOSE ZONES WITH SOME MENTION OF LOCALLY HEAVY RAINFALL WITH HIGH PRECIP H20...BUT SHOULD NOT BE A SIGNIFICANT HYDRO EVENT DUE TO FAST FRONTAL MOVEMENT. STAYED WELL ABOVE GUIDANCE POPS AND PLACED LIKELY IN NORTH...40 CENTRAL AND 30 PERCENT FOR SOUTH FOR MAINLY EVENING. EXPECTING FRONTAL PASSAGE ACROSS MISS RIVER ABOUT 05Z...THEN EAST OF CWFA BY 08Z WITH SKIES THEN CLEARING. HIGH PRESSURE OVER HIGH PLAINS MOVES INTO WESTERN IA TUESDAY FOR PLEASANT DAY AND GUIDANCE HIGHS IN UPPER 70S TO LOWER 80S REASONABLE. RIDGE MOVES OVERHEAD TUESDAY NIGHT WITH MODELS APPEARING TO DROP DEWPOINTS AND THUS TEMPERATURES TOO LOW...ESPECIALLY IN NORTH. SHOULD STILL GET IN 50S IN MOST AREAS WITH CLEAR SKIES...LONGER SEPT NIGHT AND SUBSIDENCE. UPPER RIDGE REBOUNDS OVER AREA WED AND THU FOR DRY AND SEASONABLY WARM CONDITIONS. SOME HINT OF PRECIP POTENTIAL FOR THURSDAY AS WAVE TOPS RIDGE AND WARM AIR ADVECTION PATTERN RETURNS...BUT NOT ENOUGH CONFIDENCE TO INCLUDE AT THIS TIME. IN EXTENDED...RAISED TEMPERATURES FOR FRIDAY AND SATURDAY AS UPPER RIDGE DOMINATES CENTRAL CONUS. PATTERN BEGINS TO BREAK DOWN SUNDAY WITH COLD FRONT POSSIBLY BRINGING FROPA IN LATE SAT NIGHT/SUN TIMEFRAME AND ADDED TSRA CHANCES TO SUNDAY. .DVN... IA...NONE. IL...NONE. MO...NONE. DLS il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 200 PM MDT MON SEP 2 2002 FORECAST CONCERNS ARE PRECIPITATION CHANCES LATE TUESDAY INTO EARLY WEDNESDAY...AND WINDS/TEMPS THROUGH THE SHORT TERM PERIODS. A WEAK COLD FRONT MOVED OVER THE AREA THIS MORNING KEEPING TEMPS DOWN AND BRINGING DRIER AIR INTO THE AREA. THROUGH EARLY AFTERNOON NORTH/NORTHEAST WINDS WERE SUSTAINED AT 15 TO 20 MPH WITH GUSTS TO AROUND 30 MPH. EXPECT THE WINDS TO VEER AND DIMINISH BRIEFLY BY EVENING. LATEST RUC/MESO ETA DEVELOP A DESCENT LOW LEVEL JET DURING THE EVENING HOURS...WILL LEAN AWAY FROM COLD MAV GUIDANCE AS INCREASING MOISTURE/MIXING ALLOW TEMPS TO STAY UP. CURRENT THINKING IS UPPER 50S WEST TO THE LOW TO MID 60S WEST. WILL REMOVE MENTION OF PCPN IN THE EAST. ON TUESDAY/TUESDAY NIGHT...EXPECT BREEZY TO WINDY CONDITIONS ACROSS THE AREA AS THE PRESSURE GRADIENT REMAINS TIGHT WITH SURFACE HIGH PRESSURE GRADUALLY MOVING EAST AWAY FROM THE AREA. MESO ETA 850 MB TEMPS SUPPORT HIGHS IN THE UPPER 80S NORTHWEST TO MID 90S EAST...WHICH IS VERY SIMILAR TO MOS GUIDANCE. A MID LEVEL TROUGH APPROACHES LATE ON TUESDAY...WILL KEEP A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE CENTRAL AND WESTERN CWA LATE TUESDAY AND INTO THE OVERNIGHT HOURS. BY WEDNESDAY...THE MID LEVEL TROUGH MOVES NORTHEAST...HOWEVER THE PRESSURE GRADIENT REMAINS TIGHT WITH SURFACE LOW PRESSURE LOCATED NORTH OVER THE WESTERN DAKOTAS...WILL ADD BREEZY WORDING THROUGH WED NIGHT. HIGH PRESSURE WILL DOMINATE THE WEATHER THROUGH THE REMAINDER OF THE WEEK. THE PRESSURE GRADIENT WILL INCREASE AGAIN ON FRIDAY AHEAD OF A COLD FRONT WHICH WILL BRUSH THE NORTHERN COUNTIES LATE SATURDAY. WILL KEEP A SLIGHT CHANCE OF PCPN ON SAT/SUN AND KEEP MONDAY DRY AS RETURN FLOW SETS UP ONCE AGAIN. WITH UPPER RIDGING OVERHEAD...TEMPS WILL LIKELY REMAIN WELL ABOVE NORMAL. .GLD...NONE. MWM ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 935 PM EDT MON SEP 2 2002 STRONG COLD FRONT HAD ADVANCED THROUGH WESTERN LAKE SUPERIOR... THE WESTERN UP AND N/W WISCONSIN. WELL AHEAD OF THE FRONT...SHOWERS ARE FAIRLY WIDESPREAD. HOWEVER...INTENSE THUNDERSTORMS ARE FOCUSED IN DYNAMIC FORCING REGIME ACROSS THE CENTRAL UP...AND ACROSS EAST CENTRAL WISCONSIN...PROPAGATING ESE INTO REGION WHERE LOW LEVEL MOISTURE CONVERGENCE COINCIDES WITH AXIS OF GREATEST SURFACE BASED INSTABILITY (CAPES EXCEEDING 2000 J/KG). BETWEEN THESE REGIMES...UPSTREAM RADARS DEPICT SIGNIFICANT WEAKENING/DECREASED COVERAGE OF RETURNS...WITH FEW REMAINING THUNDERSTORMS. WATER VAPOR IMAGERY AND LATEST MESOETA/RUC GUIDANCE SUGGEST THAT STRONGEST DYNAMIC FORCING IS LIFTING NE ACROSS LAKE SUPERIOR... AND MOST INTENSE THUNDERSTORMS ARE FOLLOWING SUIT...WHILE CURRENT TRENDS SUGGEST THAT STRONGEST THUNDERSTORMS IN FAVORABLE THERMODYNAMIC ENVIRONMENT OVER E CENTRAL WI MAY CLIP OR EVEN MISS EXTREME SW COUNTIES OF THE FORECAST AREA. IN BETWEEN...PRECIPITATION HAS PUSHED WELL AHEAD OF SURFACE FRONT...WHERE SURFACE MOISTURE DIVERGENCE IS OCCURRING...AND 0Z APX SOUNDING DEPICTING CAPES BELOW 1000 J/KG AND NEGATIVE AREA EXCEEDING 200 J/KG SUGGESTS THAT ENVIRONMENT IS UNFAVORABLE FOR A RESURGENCE OF CONVECTION...DESPITE EXCELLENT WIND SHEAR DEPICTED BY KAPX SOUNDING/VAD WIND PROFILE. IN FACT...CURRENT LIKELY POPS ARE IN DOUBT...ESPECIALLY ACROSS THE NORTHERN HALF OF NORTHERN LOWER MICHIGAN. GIVEN GUSTY WINDS/NE PROGRESS OF POST FRONTAL PRESSURE RISE CENTER UPSTREAM...WILL BUMP OVERNIGHT WINDS UP A BIT ACROSS THE EASTERN UP. ALSO...SATELLITE TRENDS SUGGEST SKIES WILL BECOME MAINLY CLEAR IN THE WAKE OF THE FRONT...ESPECIALLY ACROSS THE N/W...OVERNIGHT. .APX...NONE. ROWLEY mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 425 PM EDT MON SEP 2 2002 12Z RAOBS/LATEST WV LOOP AND RUC ANAL SHOW POTENT SHRTWV OVR SCNTRL CAN/NRN PLAINS PLOWING E INTO RDG ACRS ERN NAMERICA...WITH 992MB SFC LO JUST N OF LK WINNIPEG AND ATTENDANT OCCLUDED/COLD FNT XTNDG S INTO WRN MN/ERN SD AT 15Z. SHRTWV INTENSIFYING WITH 110KT H3 JET MAX/50KT H7 JET MAX DIGGING INTO SHRTWV FM SW CAN. IMPRESSIVE H3 HGT RISE/FALL COUPLET OF +110M/-130M NOTED ACRS SHRTWV...WITH WELL DEFINED DIFFLUENT UPR FLOW AND STEEP H85-5 LAPSE RATES PER 12Z INL/ MPX SDNGS IN ADVANCE OF SYS AND ACCOMPANYING H5 THEMAL TROF. AREA OF SHRA/TSRA UNDER THIS UPR DIFFLUENCE OVR NRN HALF OF MN AND DRIVING E. DLH HAS ALREADY ISSUED WRNGS FOR THE STRONGEST STORMS WITHIN THE COMPLEX...WITH RPRTS OF LARGE HAIL. DESPITE DYNAMICS CNVCTN APPEARS A BIT LIMITED AS OF 15Z BECAUSE WARM/MOIST SURGE IN ADVANCE OF SYS SO FAR IS WEAK...WITH ACYC FLOW IN WAKE OF SHRTWV NOW IN CNTRL LKS THAT CAUSED LAST NGTS PCPN STILL IN PLACE AND DISRUPTING THE RETURN FLOW INTO INCOMING SHRTWV. LATER OBS SUG MSTR IS SURGING N AS LLVL WNDS INCRS AND DWPTS ARPCH 70 ACRS THE S. DRIER AIR SURGING E BEHIND SHRTWV OVR THE DAKOTAS ON THE HEELS OF THE STRG H85-7 WLY WNDS IN WAKE OF SYS. GUSTINESS APPEARS LIMITED BY TRAJECTORY OF MAX PRES RISES WELL S THRU SD/NB. MAIN FCST CONCERNS THIS PACKAGE INCLUDE TIMING/SEVERITY OF CNVCTN AHD OF VIGOROUS SHRTWV/COLD FNT THIS EVNG...THEN STRENGTH OF WNDS IN WAKE OF SYS LATE TNGT AND TUE. 12Z MODELS IN GOOD AGREEMENT SHOWING POTENT SHRTWV REACHING WRN LK SUP BY 00Z WITH SFC COLD FNT MOVG THRU THE ERN CWA BY 06Z. CWA PROGGED IN DIFFLUENT UPR FLOW IN LEFT EXIT OF SUPPORTING 100KT H3 JET MAX AT 00Z AS COLD FNT BLASTS THRU W TO E. GIVEN STRENGTH OF UPR SHRTWV...SURPRISED TO SEE MAGNITUDE OF SWLY H85 WNDS INCRS ONLY TO 30 KT. MODIFIED ETA FCST SDNGS SHOW CAPE UP NR 3500J/KG AT IWD (DWPT IN MID 60S WITH ASSUMPTION RETURN FLOW WL NOT BE STRG ENUF TO ADVCT 70 DEGREE DWPTS INTO CWA WITH WARM FNT MARKED BY LO CLD IN NRN WI ROBBING MSTR). GIVEN STRENGTH OF UPR WNDS FCST (70KT AT H5 AND 45KT AT H7) AND RATHER UNIDIRECTIONAL WSWLY FLOW AS WELL AS APRCH OF H5 THERMAL TROF/DRY PUNCH ALF...DAMAGING WNDS AND LARGE HAIL PRIMARY HAZARD. ETA BUFKIT SHOWS MULTICELLS MOST LIKELY FORM OF CNVCTN. TSRA SHUD BE ONGOING OVR WRN ZNS BY FCST ISSUANCE WITH ACTIVITY EXITING ERY ARND MIDNIGHT. SPC ISSUING WATCH FOR ENTIRE CWA AND LK SUP JUST BEFORE ZN ISSUANCE. XPCT FAIRLY RAPID CLRG BEHIND TSRA LINE/COLD FNT AS DRIER AIR IN THE NRN PLAINS SPEEDS EWD. ALTHOUGH WNDS MAY BE GUSTY RIGHT AS THE FNT PASSES...MODELS INDICATE A SOMEWHAT WEAKER PRES GRADIENT MOVES IN SOON AFTR. SINCE SUN WL BE DOWN TO MINIMIZE MIXING AND INITIAL PRES RISE MAX PASSES TO S...THINK WNDS WL REMAIN TAME MOST OF NGT. AVN MUCH MORE AGGRESSIVE WITH LLVL CAD BEHIND BNDRY AND IS PREFERRED BECAUSE OF STRENGTH OF SHRTWV. PER OVRNGT MINS UPSTREAM...XPCT TEMPS TO FALL NR 50 AT IWD...BUT ONLY 60 OVR FAR E BY DAWN. MODELS SHOW SHARPER PRES GRADIENT/CYC FLOW WL REDVLP OVR THE NRN TIER LATE TNGT AND TMRW WITH TIGHTEST PRES GRADIENT OVR EXPOSED KEWEENAW PENINSULA. DESPITE IMPRESSIVE STRENGTH OF FCST WND SPEEDS (H85 WNDS NRLY 50KT AT 12Z TUE PER ETA/AVN)...COMPLETION OF HI WND CHKLIST SUGS ADVY CRITERIA WL NOT BE MET. WL INCLUDE GUSTS UP TO 40 MPH OVR KEWEENAW. LACK OF WELL DEFINED PRES RISE MAX AND STRG LO LVL CAD (WITH ARRIVAL OF SHARPER PRES GRADIENT WELL AFTR MAIN FROPA) AS WELL AS CHANNELLED H5 VORTICITY CENTER AND LO SUBSIDENCE INVRN WL BE LIMITING FACTORS PER CHKLIST. ALTHOUGH ETA FCST SDNGS SUG LTL IN THE WAY OF SC...PREFERRED LWR AVN H85 TEMPS ARND 7C UNDER FCST SUBSIDENCE INVRN SUG MORE IN THE WAY OF SC IN CYC FLOW OVR NRN TIER. HOWEVER...SINCE MODELS ALL SHOW MAIN UPR JET AXIS SHIFTING N OF CWA DURG DAY...WL NOT GO AS PESSIMISTIC ON CLD COVER AS MIDNGT SHIFT... MORE SCT-BKN. FEWER CLDS ACRS THE S...ESPECIALLY MNM-ESC WHERE XPCT WNWLY FLOW DOWNSLOPES. TEMPS NR LWR NGM/AVN MOS GUIDANCE ACRS THE N AND W...BUT HIER ACRS THE SE. AS HI PRES RDG BLDS OVHD TUE NGT...XPCT WNDS TO DIMINISH AND LINGERING SC TO CLR. ETA HINTS AT PASSAGE OF SECONDARY TROF OVRNGT AND SC...BUT WITH RISING HGTS ALF WL NOT INCLUDE MORE THAN PTCHY SC IN FCST. XPCT LOWEST MINS DOWN INTO THE 40S ACRS THE W INTERIOR WHERE PRES GRADIENT SLACKENS THE MOST BY DAWN. ERN AND NCNTRL ZNS SHUD MAINTAIN ENUF GRADIENT TO PREVENT TEMPS FM FALLING LWR THAN 50. THEN MOSUNNY AND PLEASANT DAY ON WED OVR SW UNDER BLDG RDG. BUT ETA FCST SDNGS FOR THE ERN ZNS SHOW MSTR BECMG TRAPPED UNDER STRENGTHENING SUBSIDENCE INVRN...SO WL CALL THE DAY PSUNNY HERE. TEMPS AOA MOS GUIDANCE OVR THE SW WITH H85 TEMPS RECOVERING TO 15C...BUT TEMPS AOB MOS OVR THE E AND NCNTRL. AS HI PRES RDG SLIDES OFF TO E AND SLY RETURN FLOW DVLPS...MODELS HINT AT WARM FRONTOGEN OVR THE 4 WRN ZONES BY 12Z THU WITH PWAT INCRSG OVR 1 INCH. HAVE BROUGHT IN PTCHY CLD HERE ON WED NGT AND KEPT MINS 5 TO 10 DEGREES HIER THAN FARTHER E CLOSER TO DRIER... MORE STABLE HI. ETA GENERATES SOME LGT QPF ON THU AS WEAK SHRTWV MOVES THRU BLDG RDG...BUT RISING HGTS SUPPORT A DRY FCST ATTM. 00Z EXTENDED MODELS CONT TREND OF DEEPENING WRN TROF AND BLDG ERN RDG AFTR PERSISTENT ERN RDG GETS BATTERED DOWN EARLY TO MID WEEK. BUT THERE IS CONSIDERABLE DISAGREEMENT AMONG MODELS ON EVOLUTION OF MSLP FIELD. IN AGREEMENT WITH 12Z MODELS...OPERATIONAL MRF/CNDN/ ECMWF APPEAR TO PUSH WARM FNT THRU CWA ON THU WITH FA IN WARM SECTOR ON FRI/SAT BEFORE COLD FNT ASSOCIATED WITH LIFTING AND WEAKENING SHRTWV FM WRN TROF LIMPS THRU ON SAT NGT/SUN. UKMET IS MUCH LESS AGGRESSIVE WITH SFC WRMG AND ACTUALLY BLDS A STRG SFC HI IN CNTRL CAN ON FRI AS W COAST TROF DEEPENS AND SINKS SO FAR S THAT UPR CONFLUENCE STRENGTHENS IN CAN DOWNSTREAM OF RDG THAT DVLPS IN NRN ROCKIES. ECMWF HAS TRENDED IN THIS DIRECTION AS WELL WITH NEW F120 SHOWING MSLP QUITE A BIT HIER IN CNTRL CAN AND WARM FNT PUSHING LESS FAR N. NO MRF ENSEMBLES AVBL THIS MRNG...BUT CNDN ENSEMBLE MEMBERS SHOW QUITE A BIT OF VARIABILITY WITH ALL SOLNS SUGD BY DIFFERENT OPERATIONAL MODELS DEPICTED. GIVEN GREAT UNCERTAINTY IN OUTCOMES AND 12Z AVN SUPPORT FOR OPERATIONAL MRF/CNDN SOLN...WL MAINTAIN CONTINUITY WITH PREVIOUS FCST AND MAINTAIN DRY WARMUP ON FRI WITH TEMPS WELL ABV NORMAL...THEN A CHC OF SHRA/TSRA OVR THE WEEKEND WITH COLD FROPA AND TREND TOWARD MORE NORMAL TEMPS. COORDINATED WITH APX. .MQT...SVR TSRA WATCH IN EFFECT FOR LK SUP/MIZ001>007-009>014 TIL 03Z. KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1025 AM EDT MON SEP 2 2002 UPPER AIR PATTERN CONSISTS OF A SHORTWAVE TROUGH ACROSS NEW ENGLAND AND A STRONG SHORTWAVE TROUGH ACROSS THE NORTHERN U.S. WITH SHORTWAVE RIDGING ACROSS THE PACIFIC NW. WATER VAPOR SHOWING IMPRESSIVE AND STRONG SHORTWAVE WITH STRONG DARKENING MOVING ACROSS ND AND THIS SYSTEM IS VERY WOUND UP WITH STRONG CYCLONIC SPIN JUST NORTH OF THE MANITOBA/ND BORDER. OTHER STRONG DRYING ON WATER VAPOR OVER IA/SOUTHERN NEBRASKA AND SW WISCONSIN WITH MORE CONVECTION OVER EASTERN IA AND SOUTHERN WISCONSIN. BOTH OF THESE SHORTWAVES WILL CONTINUE TO MOVE EAST TODAY WITH THE ONE OVER ND THE NEXT MAIN WEATHER MAKER TODAY AND TONIGHT. IMPRESSIVE DYNAMICS WILL BE MOVING INTO CWA THIS AFTERNOON. 12Z RAOBS SHOWING 250 MB JET STREAM WIND SPEEDS OF 120 KT AT KGGW AND CWEC. 300 MB SHOWS 105 KT WINDS AT KGGW AND 100 KT AT CWEC. KBIS HAS 75 KT AT 500 MB AND 80 METER HEIGHT FALLS AT KBIS AND KUNR. 12Z RUC SHOWING 100 KT 300 MB JET STREAK MOVING FROM ND AT 12Z TO NORTHERN MN BY 00Z WHICH WOULD PUT CWA IN LFQ OF UPPER LEVEL JET. RUC ALSO SHOWING 850-500 MB Q-VECTOR CONVERGENCE INCREASING IN STRENGTH THIS AFTERNOON AND BECOMING STRONG CONVERGENCE AFTER 21Z ACROSS CWA. 12Z RUC SHOWING 5200 J/KG CAPE POKING INTO SOUTHERN GOGEBIC COUNTY AT 21Z AND LOOKING AT KIWD SOUNDING FROM THAT TIME...RUC IS USING A 79 TEMPERATURE WITH A DEW PT OF 71 TO ARRIVE AT THIS FIGURE. THIS SEEMS WAY TO HIGH FOR THE DEW POINT...BUT THE TEMP LOOKS OKAY AND USING A 65 DEW PT GIVES ME A SFC BASED CAPE VALUE OF 2700 J/KG WHICH SEEMS MORE REASONABLE WITH NO SFC BASED CIN. BASICALLY...AGREE WITH PREVIOUS SHIFTS THINKING. NOT MUCH TIME TOO LOOK AT MUCH. WILL BE UPDATING THE FORECAST TO REMOVE MORNING WORDING AND TEMPS LOOK ON TRACK AND WILL NOT CHANGE. WITH THIS DYNAMIC OF A SYSTEM COMING IN...LOOKS LIKE IT COULD BE AN ACTIVE AFTERNOON AND EARLY EVENING ACROSS CWA. .MQT...NONE. MICHELS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 920 AM EDT MON SEP 2 2002 BKN TO OVC LOW CLOUDS COVER MUCH OF AREA THIS MORNING IN NE FLOW. DRIER AIR EVIDENT JUST SE OF AREA...OVER CLT...AND OVER W MTNS. BREAKS EXPANDING AT THIS TIME. EXPECT MIXING TO INCREASE BREAKS IN CLOUDS THIS AFTERNOON...SO PARTLY CLOUDY WORDING STILL ACCEPTED. RUC LOW LEVEL THICKNESS WITH CORRECTION REDUCED FOR CLOUDS YIELDED MAXIMUM TEMPERATURES WITHIN CURRENT FORECAST RANGE. NO UPDATE NEED AT THIS TIME. FCSTID = 7 GSP 85 66 89 68 / 10 0 10 20 AND 86 67 90 69 / 10 0 10 20 CLT 83 65 89 68 / 10 0 10 20 HKY 83 65 88 67 / 10 0 10 20 AVL 83 61 84 62 / 20 10 10 20 .GSP... GA...NONE. NC...NONE. SC...NONE. O7 sc AREA FORECAST DISCUSSION FOR CENTRAL/N-EAST SD AND W-CENTRAL MN...UPDATED NATIONAL WEATHER SERVICE ABERDEEN SD 1024 AM CDT MON SEP 2 2002 GRIDS NEEDED SOME AIR BRUSHING THIS MORNING IN TEMP AND DEWPOINT GRIDS...OTHERWISE GOING FORECAST LOOKS GOOD. LATEST RUC DEPICTING BEST LOW AND MID-LEVEL LAPSE RATES IN AREA EAST OF CWA WHERE ONGOING CONVECTION IS LOCATED. MID-LEVEL CLOUDINESS SHOULD HANG ON IN THE EAST THROUGH EARLY AFTERNOON. CAA PATTERN REALLY KNOCKING HIGHS DOWN EVERYWHERE TO LOW TO MID 70S...EXCEPT IN KPIR AREA...WHERE 80 MIGHT BE REACHABLE. DEWPOINTS TRENDING TOWARD SOME SIGNIFICANT DRYING TODAY AND LOWS IN THE 40S TONIGHT BECOMING EVER MORE ANTICIPATED. WINDS LATE THIS MORNING THROUGH EARLY EVENING SHOULD MAINTAIN HIGH END OF BREEZY TO WINDY WITH 30-45KTS AT 850 HPA EXPECTED TO MIX DOWN IN STRONG SUBSIDENCE AND TIGHT SURFACE PRESSURE GRADIENT PATTERN. WILL CONTINUE TO MONITOR FOR NEED TO CONSIDER A WIND HIGHLIGHT. .ABR...NONE. DORN sd AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 921 AM MDT MON SEP 2 2002 THE CURRENT FORECAST IS IN DECENT SHAPE WITH NO UPDATES PLANNED. THE MAIN CONCERN TODAY IS THE NORTHWEST WINDS. THE SURFACE PRESSURE RISE MAXIMUM HAS MOVED SOUTHEAST OF THE CWFA...WITH THE ISALLOBARIC WIND COMPONENT NOW OPPOSING THE GEOSTROPHIC FLOW. RUC BOUNDARY LAYER WINDS SUPPORT 15-30MPH SUSTAINED WINDS TODAY...WITH A GRADUAL DIMINISHING TREND IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS. .UNR...FIRE WEATHER WATCH NERN WY TUE AFTN AND EVNG. FIRE WEATHER WATCH ALL ZONES WED/THU AFTN AND EVNG. BUNKERS sd DEEP SOUTH TEXAS FORECAST DISCUSSION...COR TO CCF NATIONAL WEATHER SERVICE BROWNSVILLE TX 300 PM CDT MON SEP 2 2002 SHORT TERM...MSAS SURFACE ANALYSIS INDICATES A WEAK CIRCULATION OVER THE NORTHWEST GULF OF MEXICO THIS AFTERNOON BUT HARD TO DETERMINE BASED ON VISIBLE SATELLITE IMAGES. WATER VAPOR IMAGES INDICATE CIRCULATION OVER THE EXTREME WESTERN GULF ASSOCIATED WITH 200MB LOW ALONG THE MEXICAN COASTLINE. OVER THE EASTERN GULF 200MB RIDGE IN CONJUNCTION WITH THE 200MB OVER THE WESTERN GULF DRAWING TROPICAL MOISTURE NORTHWARD FROM THE YUCATAN PENINSULA ACROSS THE CENTRAL GULF WHERE RUC 1000-500MB ANALYSIS PLOTS AN INVERTED TROUGH AXIS. 12Z ETA PROGS THIS FEATURE OVER THE EXTREME WESTERN GULF TUESDAY AND MOVING ONSHORE THE MEXICAN AND LOWER TX COAST WEDNESDAY. WITH PRECIPITABLE WATER VALUES CONTINUE TO INCREASE OVER THE CWA AND THE AFTERNOON SEABREEZE BEING A FOCUS FOR CONVERGENCE...BELIEVE CHANCE POPS WARRANTED THE NEXT COUPLE OF DAYS WITH SCATTERED CONVECTION. WITH ADDITIONAL CLOUD COVER...MAX TEMPS TO BE CLOSER TO NORMAL FOR THIS TIME OF YEAR. EXTENDED...12Z AVN INDICATES TROPICAL MOISTURE TO PERSIST OVER THE WESTERN GULF THURSDAY THROUGH SATURDAY AS A 700MB LOW ENTERS THE NORTHEAST GULF OF MEXICO ASSOCIATED WITH THE POSSIBLE REMNANTS OF T.S. EDOUARD BUT WAY TOO EARLY TO SAY IF THIS SYSTEM WILL REMAIN OVER THE ATLANTIC OR EVENTUALLY DRIFT SOUTHWEST ACROSS FLORIDA BEYOND 72 HOURS. A SLIGHT CHANCE TO CHANCE OF SHOWERS AND THUNDERSTORMS LOOKS REASONABLE INTO NEXT WEEKEND AS EASTERLY FLOW OVER THE GULF PERSISTS UNDER THE 700MB RIDGE OVER THE CENTRAL AND EASTERN U.S. WITH WEAK TROPICAL WAVES MOVING WESTWARD ALONG THE SOUTHERN PERIPHERY OF THE RIDGE. MARINE...LAST 5 HOURS OF OBS FROM BUOY 020 INDICATED WINDS SHIFTING FROM NORTHEAST 10 KNOTS AT TO WEST AT 4 KNOTS WITH SEAS AT 3 FEET. EXPECT WINDS TO OSCILLATE BETWEEN LIGHT AND VARIABLE AT 5 KNOTS AND NORTHEAST AT 10 KNOTS AS THE WEAK SURFACE LOW... TROPICAL WAVE PUSHES WEST ONTO THE TEXAS COAST. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL OCCUR DAILY THROUGH THE WEEK. WINDS AND SEAS WINDS AND SEAS WILL REMAIN BELOW SCEC/SCA CRITERIA THROUGH THE WEEK. .PRELIMINARY NUMBERS... BRO EE 076/092 076/092 076 20/40/20/40/20 HRL EE 075/092 075/092 075 20/40/20/40/20 MFE EE 076/093 076/093 076 30/40/30/40/30 RGC EE 074/096 074/096 074 30/40/30/40/30 SPI EE 080/088 080/088 080 10/30/10/30/10 SYNOPTIC...CASTILLO.61 MESO-AVIATION-MARINE...BENNETT.53 INTERNET ADDRESS...WWW.SRH.NOAA.GOV/BRO .BRO...NONE. tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 330 AM CDT TUE SEP 3 2002 CONCERNS TDY ARE SLIM PRECIP CHANCES THIS AFTN AND TNGT AND TEMPS. SURFACE ANALYSIS SHOWS WEAK COLD FRONT FROM EAX-EMP-ICT WITH DRIER AIR WORKING INTO NW SECTIONS OF CWA. DO NOT EXPECT FRONT TO MAKE TOO MUCH MORE PROGRESS SOUTH AS BEST PRESSURE RISES OVER IOWA WITH NOT MUCH...IF ANY...PRESSURE FALLS SOUTH OF THE BOUNDARY. MESOETA/ETA VERY SIMILAR WITH FRONT STALLING OUT OVER SRN SECTIONS OF KS. SO WITH FRONT IN THE AREA AND GOOD INSTABILITY ACROSS THE AREA...IS ANY PCPN POSSIBLE. NOT MUCH IN THE WAY OF CONVERGENCE ALONG THE BOUNDARY...AS RUC/ETA DO SHOW SOME WAA OVER THE TOP OF THE BOUNDARY THIS AFTERNOON...BUT UPPER LEVEL SUPPORT HAS MOVED NE OF THE PLAINS INTO THE GRT LKS. FAIRLY STRONG CAP ALSO REMAINS IN THE MID LEVELS. SO PRECIP CHCS APPEAR TO BE SMALL TDY. AM HESITANT TO GO COMPLETELY DRY WITH A FRONTAL BOUNDARY NEARBY...BUT WITH ABOVE MENTIONED FACTORS NOT SUPPORTING PRECIP...WILL GO DRY ACROSS THE AREA. SO TEMPS WILL BE THE MAIN CONCERN TDY. DRIER AIR AND SOMEWHAT COOLER TEMPS ACROSS THE RGN...NORTH OF THE FRONT WILL KEEP TEMPS FROM REACHING YESTERDAYS VALUES...BUT AREAS SOUTH OF BOUNDARY COULD REACH UPR 90S AGAIN. ETA MOS NUMBERS SEEM TO HAVE THE RIGHT IDEA AND WILL FOLLOW. ETA/MESOETA SHOWS FRONT BEGINNING TO MOVE BACK TO THE NORTH TNGT AS A WARM FRONT WITH 850H WAA/MOIST CONVERGENCE INCREASING OVER EXTREME NWRN SECTIONS OF THE CWA. COULD SEE SOME ELEVATED TSRA IN THIS AREA TNGT AS BOUNDARY MOVES BACK TO THE NORTH...SO WILL KEEP A LOW POP IN FOR THIS CHC. AVN CONTINUES TO TRY TO MOVE A S/WV ACROSS THIS AREA WITH PCPN MORE EXTENSIVE ALONG THE FRONT...BUT HAVE DISCOUNTED THIS AS ETA/MESOETA MORE CONSISTANT. SO REST OF THE AREA SHOULD REMAIN DRY AS WARM FRONT QUICKLY RETREATS NORTH INTO NEB BY WED MORNING. TEMPS COULD BE A LITTLE TRICKY TNGT GIVEN FRONT ON THE MOVE. WIL GO WITH SLIGHTLY WARMER ETA/MAV NUMBERS WITH WARMER AIR RETURNING. WARM SW BREEZES DOMINATE THE WX PATTERN FOR WED-FRI AS UPPER TROF DIGS INTO THE WRN US WITH UPPER RIDGING ACROSS THE PLAINS...WITH SUMMERLIKE TEMPS AND DRY WX FOR KS. SAT-SUN: SAT-SUN BECOMES A LITTLE MORE UNCERTAIN. AS ECMWF CONTINUES TO HOLD ONTO UPPER TROF OVER THE WRN US KEEPING UPPER RIDGE IN PLACE ACROSS THE MIDWEST WITH DRY AND WARM WX. MRF KICKS OUT THE UPPER TROF INTO THE NRN PLAINS ON SUN... FLATTENING OUT THE RIDGE WHILE THE ECMWF HOLDS TIGHT WITH THE RIDGE. ECMWF HAS BEEN VERY CONSISTANT WITH THIS RIDGE HOLDING TIGHT AND WARM AND DRY WX CONTINUING FOR THE WEEKEND. SO PREFER ECMWF SOLUTION OF RIDGE HOLDING THRU THE WEEKEND. MON: ECMWF FINALLY KICKS THE TROF INTO THE ROCKIES ON MON...BUT SHEARS MOST OF THE ENERGY TO THE NE INTO THE NRN PLAINS NORTH OF KS. KEEPING LEE SIDE TROF WEST OF CEN KS. WITH MODEL INCONSISTENCY THIS FAR OUT WILL LEAVE MONDAY DRY FOR NOW...AND LET LATER SHIFTS INTRODUCE CHC IF NEEDED. FCSTID = 22 / KETCHAM ICT 93 69 94 68 / 10 10 10 10 HUT 91 68 95 67 / 10 10 10 10 EWK 92 68 94 67 / 10 10 10 10 EQA 93 69 93 68 / 10 10 10 10 WLD 94 69 93 68 / 10 10 10 10 RSL 89 66 96 67 / 10 20 10 10 GBD 90 66 96 67 / 10 10 10 10 SLN 89 67 94 67 / 10 10 10 10 MPR 92 68 94 67 / 10 10 10 10 CFV 94 69 93 68 / 10 10 10 10 CNU 93 69 92 68 / 10 10 10 10 K88 93 69 92 68 / 10 10 10 10 .ICT... KS...NONE. KETCHAM ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 225 AM CDT TUE SEP 3 2002 PRELIM DISCUSSION. CONCERNS TDY ARE SLIM PRECIP CHANCES THIS AFTN AND TNGT AND TEMPS. SURFACE ANALYSIS SHOWS WEAK COLD FRONT FROM EAX-EMP-ICT WITH DRIER AIR WORKING INTO NW SECTIONS OF CWA. DO NOT EXPECT FRONT TO MAKE TOO MUCH MORE PROGRESS SOUTH AS BEST PRESSURE RISES OVER IOWA WITH NOT MUCH...IF ANY...PRESSURE FALLS SOUTH OF THE BOUNDARY. MESOETA/ETA VERY SIMILAR WITH FRONT STALLING OUT OVER SRN SECTIONS OF KS. SO WITH FRONT IN THE AREA AND GOOD INSTABILITY ACROSS THE AREA...IS ANY PCPN POSSIBLE. NOT MUCH IN THE WAY OF CONVERGENCE ALONG THE BOUNDARY...AS RUC/ETA DO SHOW SOME WAA OVER THE TOP OF THE BOUNDARY THIS AFTERNOON...BUT UPPER LEVEL SUPPORT HAS MOVED NE OF THE PLAINS INTO THE GRT LKS. FAIRLY STRONG CAP ALSO REMAINS IN THE MID LEVELS. SO PRECIP CHCS APPEAR TO BE SMALL TDY. AM HESITANT TO GO COMPLETELY DRY WITH A FRONTAL BOUNDARY NEARBY...BUT WITH ABOVE MENTIONED FACTORS NOT SUPPORTING PRECIP...WILL GO DRY ACROSS THE AREA. SO TEMPS WILL BE THE MAIN CONCERN TDY. DRIER AIR AND SOMEWHAT COOLER TEMPS ACROSS THE RGN...NORTH OF THE FRONT WILL KEEP TEMPS FROM REACHING YESTERDAYS VALUES...BUT AREAS SOUTH OF BOUNDARY COULD REACH UPR 90S AGAIN. ETA MOS NUMBERS SEEM TO HAVE THE RIGHT IDEA AND WILL FOLLOW. ETA/MESOETA SHOWS FRONT BEGINNING TO MOVE BACK TO THE NORTH TNGT AS A WARM FRONT WITH 850H WAA/MOIST CONVERGENCE INCREASING OVER EXTREME NWRN SECTIONS OF THE CWA. COULD SEE SOME ELEVATED TSRA IN THIS AREA TNGT AS BOUNDARY MOVES BACK TO THE NORTH...SO WILL KEEP A LOW POP IN FOR THIS CHC. AVN CONTINUES TO TRY TO MOVE A S/WV ACROSS THIS AREA WITH PCPN MORE EXTENSIVE ALONG THE FRONT...BUT HAVE DISCOUNTED THIS AS ETA/MESOETA MORE CONSISTANT. SO REST OF THE AREA SHOULD REMAIN DRY AS WARM FRONT QUICKLY RETREATS NORTH INTO NEB BY WED MORNING. TEMPS COULD BE A LITTLE TRICKY TNGT GIVEN FRONT ON THE MOVE. WIL GO WITH SLIGHTLY WARMER ETA/MAV NUMBERS WITH WARMER AIR RETURNING. WARM SW BREEZES DOMINATE THE WX PATTERN FOR WED-FRI AS UPPER TROF DIGS INTO THE WRN US WITH UPPER RIDGING ACROSS THE PLAINS...WITH SUMMERLIKE TEMPS AND DRY WX FOR KS. SAT-SUN: SAT-SUN BECOMES A LITTLE MORE UNCERTAIN. AS ECMWF CONTINUES TO HOLD ONTO UPPER TROF OVER THE WRN US KEEPING UPPER RIDGE IN PLACE ACROSS THE MIDWEST WITH DRY AND WARM WX. MRF KICKS OUT THE UPPER TROF INTO THE NRN PLAINS ON SUN... FLATTENING OUT THE RIDGE WHILE THE ECMWF HOLDS TIGHT WITH THE RIDGE. ECMWF HAS BEEN VERY CONSISTANT WITH THIS RIDGE HOLDING TIGHT AND WARM AND DRY WX CONTINUING FOR THE WEEKEND. SO PREFER ECMWF SOLUTION OF RIDGE HOLDING THRU THE WEEKEND. MON: ECMWF FINALLY KICKS THE TROF INTO THE ROCKIES ON MON...BUT SHEARS MOST OF THE ENERGY TO THE NE INTO THE NRN PLAINS NORTH OF KS. KEEPING LEE SIDE TROF WEST OF CEN KS. WITH MODEL INCONSISTENCY THIS FAR OUT WILL LEAVE MONDAY DRY FOR NOW...AND LET LATER SHIFTS INTRODUCE CHC IF NEEDED. .ICT... KS...NONE. KETCHAM ks SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 340 AM EDT TUE SEP 3 2002 00Z RAOBS/WATER VAPOR LOOP SHOW UPPER LOW OVER WESTERN ONTARIO...WITH SHARP SHORTWAVE PUSHING ACROSS UPPER MICHIGAN. SURFACE ANALYSIS SHOWS LOW OVER NORTHERN ONTARIO...WITH COLD FRONT MAKING STEADY PROGRESS INTO NORTHERN AND WESTERN MICHIGAN. REGIONAL RADARS/SATELLITE SHOW SEVERE EVENING CONVECTION ACROSS WISCONSIN HAVING WEAKENED AS IT MOVED ACROSS LAKE MICHIGAN...BUT TRYING TO FLARE UP AGAIN AS IT CROSSES THE LOWER PENINSULA. MAIN WEATHER CONCERN OCCUPIES THE FIRST FEW HOURS OF THE FORECAST... UNTIL BIG BUBBLE OF HIGH PRESSURE BUILDS BACK ACROSS THE REGION. SHORTWAVE/+90KT 300MB JET SHIFT EAST THIS MORNING...FOCUSING THE BEST QG-FORCING NORTH OF THE CWA. HOWEVER BETTER MOISTURE IS FARTHER SOUTH ACROSS SOUTHERN WISCONSIN/LAKE MICHIGAN ALONG 50KT 850MB JET...WITH MAIN 850MB THETA-E AXIS AND 1000-700MB MOISTURE CONVERGENCE. 00Z RUC/ETA WEAKEN THE JET BY MORNING...BUT WITH THE MOIST AXIS STILL MAKING IT ACROSS SOUTHEAST MICHIGAN. EXPECT THE COLD FRONT TO CONTINUE TO MAKE DECENT PROGRESS EASTWARD THIS MORNING...AS WEST-NORTHWEST MID-LEVEL FLOW REMAINS NEARLY PERPENDICULAR TO THE BOUNDARY. THUNDERSTORMS WILL CLEAR THROUGH THE CWA THIS MORNING...GENERALLY FROM NORTHWEST TO SOUTHEAST. AGAIN WITH MAIN SHORTWAVE TRACKING ACROSS THE NORTHERN GREAT LAKES...THE STRONGEST SUBSIDENCE BEHIND IT WILL BE FOCUSED NORTH OF THE CWA. HOWEVER ABUNDANT DRY AIR UPSTREAM TO MOVE ACROSS THE REGION AS HIGH OVER THE CENTRAL PLAINS BUILDS TOWARD THE WESTERN GREAT LAKES. IR SATELLITE SHOWS SKIES QUICKLY CLEARING OUT BEHIND THE FRONT. LOOKS LIKE THE DRY AIR WILL WORK IN FASTER THAN THE COLD AIR...AND DO NOT EXPECT A RAPID CU-UP. COULD SEE A FEW CLOUDS...BUT STILL LOOKS LIKE BECOMING MOSTLY SUNNY WILL COVER IT. BLOCKED PATTERN DEVELOPS FOR THE REMAINDER OF THE WEEK. UPPER LOW OVER THE PACIFIC NORTHWEST DIGS INTO MORE OF A LONGWAVE TROUGH.... AND SIMILARLY UPSTREAM...ENERGY FROM THE ONTARIO LOW AMPLIFIES AND CUTS OFF OFF THE EAST COAST AS IT RUNS INTO RIDGE OVER THE ATLANTIC. RIDGE OVER THE HIGH PLAINS WILL SHIFT EAST TO THE GREAT LAKES. SURFACE HIGH BUILDS TOWARD THE GREAT LAKES...CROSSING THE REGION WEDNESDAY/THURSDAY...BEFORE HOLDING ALONG THE EAST COAST. PATTERN IS SIMILAR TO THE SETUP FROM LAST WEEK...ALTHOUGH DISPLACED A BIT SOUTHWARD. 850MB THERMAL TROUGH CROSSES THE CWA TONIGHT. STILL HAVE SOMEWHAT OF A NORTHWEST GRADIENT...BUT WITH A DRY AIRMASS AS 1000-500MB RH AROUND 25 PERCENT. ETA/AVN BOTH DROP SURFACE DEWPOINTS INTO THE MID 40S TONIGHT...WHICH SEEMS TOO LOW GIVEN UPSTREAM READINGS. LEANING TOWARD LOWER 50S AS MORE REASONABLE...WITH SIMILAR OVERNIGHT LOWS. EXPECT A SUNNY DAY FOR WEDNESDAY...AND RELATIVELY NEAR NORMAL HIGHS AS WE MIX TO 850MB TEMPERATURES AROUND 13C. HIGH CENTER CROSSES THE CWA WEDNESDAY NIGHT...AND WITH THE COMBINATION OF CALM WINDS AND DRY ATMOSPHERE EXPECTING A COOL NIGHT WITH LOWS DIPPING INTO THE 40S. ETA FORECAST SOUNDINGS HINTING AT FOG DEVELOPMENT. AVN/ETA POINT TOWARD A DEEP WEAK WIND FIELD...PRETTY MUCH 10KTS OR LESS THROUGH 500MB. GIVEN THE PRIME RADIATIONAL COOLING EXPECTED AND THE DECENT SUBSIDENCE INVERSION DEPICTED BY THE ETA...AS WELL AS EXPERIENCES WITH FOG LAST WEEK DESPITE DRY CONDITIONS...WILL ADD A MENTION TO THE FORECAST. PIECE OF SHORTWAVE ENERGY TRIES TO TRACK ACROSS THE TOP OF THE RIDGE INTO THE WESTERN GREAT LAKES THURSDAY. DRY AIR AND HIGH PRESSURE SHOULD HOLD DOMINATE OVER SOUTHEAST MICHIGAN AND PREVENT ANY PRECIP...BUT WILL TREND TO PARTLY CLOUDY SKIES. .DTX...NONE. BRAVENDER mi SOUTHEAST IDAHO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE POCATELLO/IDAHO FALLS ID 935 AM MDT TUE SEP 03 2002 MAIN FEATURE OF CONCERN IN SHORT TERM IS STRONG S/WV ROTATION MOVING NNE FROM SW UTAH. THIS FEATURE SPREADING CLOUDS AND MOISTURE AHEAD OF IT WAS INITIALIZED TOO FAR SOUTH BY 12Z AVN/ETA RUNS AS COMPARED TO WV IMAGERY. CURRENT FCST HIGHLIGHTING INCREASING AFTERNOON CLOUDS FOR SOUTHERN AND EASTERN HIGHLANDS AND WILL GENERALIZE THOSE ZONES INTO BECOMING WORDING FOR PARTLY CLOUDY SKIES. PRECIP SHOULD REMAIN CLOSE TO THE CORE OF THIS FEATURE SO NOT EXPECTING ANYTHING INTO F/A FROM IT. WILL KEEP SLIGHT CHANCE OF DRY THUNDERSTORMS GOING IN UPPER SNAKE HIGHLANDS AND EXPAND THIS WORDING INTO CENTRAL MTN ZONES FOR THIS AFTN. THIN BAND OF CLOUD COVER THROUGH CENTRAL MTNS ALREADY PRODUCING VIRGA PER LONG TOM OBSERVER AND LATEST RUC40 CARRYING SFC-LIS OF -1 TO -3 ACROSS THAT REGION. WILL ALSO CARRY THIS WORDING INTO 2ND PERIOD. REST OF F/A WILL PROBABLY SEE SOME AFTN CU BUT LITTLE REAL DEVELOPMENT AND NO PRECIP WILL BE MENTIONED. DMH .KSFX...OPERATIONAL...VCP 32. BYI 89 56 82 00236 .PIH...NONE. PIH UB 090/053 082/053 074 12002 id AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1052 AM EDT TUE SEP 3 2002 SFC AND UPPER LEVEL LOWS ARE NORTH OF LAKE SUPERIOR WITH WRAP AROUND MOISTURE NOW OVER CENTRAL LAKE SUPERIOR. TRAJECTORIES AND SOUNDINGS UPSTREAM (KINL, KMPX AND KGRB) OF THE REGION SHOWS MOSTLY DRY AIR TO THE WEST OF N LOWER, WHILE E UPPER REMAINS A BIT OF QUESTION MARK. ETA AND RUC THIS MORNING WANT TO BRING SOME MOISTURE INTO E UPPER BY THE AFTERNOON, SO WILL GO WITH MOSTLY SUNNY EARLY...THEN PARTLY SUNNY AS THE CLOUDS ARE BEGINNING TO EXPAND OVER LAKE SUPERIOR. WITH THE SECONDARY 500MB TROUGH AXIS STILL OVER WESTERN LAKE SUPERIOR THINK THAT LIMITED SELF DESTRUCT SUNSHINE IS PROBABLE OVER THE U. P. OVER N LOWER, WILL GO MOSTLY SUNNY. .APX...NONE. LUTZ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1045 AM EDT TUE SEP 3 2002 12Z RAOBS/WV LOOP AND RUC ANAL SHOW POTENT SHRTWV THAT BROUGHT CNVCTN LAST NGT NOW MOVG THRU ONTARIO IN FAIRLY PROGRESSIVE ZONAL FLOW ACRS US/ CAN BORDER TO N OF RDG ACRS THE SRN CONUS. ASSOCIATED SFC LO NOW APRCHG JAMES BAY...AND ATTENDANT COLD FNT HAS PUSHED WELL E OF CWA. STRG CYC FLOW IN WAKE OF FNT EVIDENT SFC-H5 OVR NRN GRT LKS BEHIND FNT...BUT 12Z GRB/INL SDNGS SHOW AIRMASS QUITE DRY (KINX < 0 AT BOTH PLACES) WITH SUBSIDENCE INVRN ARND H8-85. SO SKIES COMPLETELY CLR OVR FA THIS MRNG. WINDS WITHIN SUB INVRN LYR AT INL AS HI AS 40 TO 45 KT WITH 2K FT AGL. ALTHOUGH SKIES CLR IN CWA... MORE WDSPRD LO CLD EVIDENT ACRS ONTARIO WHERE H85 TEMPS A BIT LWR CLOSER TO MAIN H5 VORTEX ON CYC SIDE OF UPR JET. 12Z RUC ANAL H85 TEMP/70 PCT RH COMPARE FVRBLY TO INL RAOB AND LOCATION OF SRN EDGE OF ONTARIO SC. MAIN FCST CONCERNS THIS UPDATE PACKAGE ARE WNDS/CLD TRENDS/MAX TEMPS WITH DRY AIR/SUBSIDENCE INVRN RULING OUT ANY PCPN. RUC SHOWS ONTARIO SHRTWV MOVG E TDAY WITH GRDLY RISING HGTS AND SLACKENING PRES GRADIENT DURG THE AFTN. UPR JET AXIS LIFTS SLOWLY ENE WITH CWA REMAINING ON MORE STABLE ACYC SIDE OF THIS FEATURE. RUC FCST H85 70 PCT RH LINE BRUSHES KEWEENAW PENINSULA AND LK SUP BORDER COUNTIES...SO WL ALTER GOING FCST TO SUNNY BECMG PSUNNY ACRS THE N WITH MOSUNNY ACRS THE S. EVALUATION OF HI WND CHKLIST SUGS HI WND ADVY CRITERIA WL NOT BE MET TDAY...EVEN OVR THE EXPOSED KEWEENAW PENINSULA DESPITE STRG WNDS OBSVD WITHIN THE MIXED LYR AT INL AT 12Z. WL CALL FOR GUSTS UP TO 40 MPH OVR THE KEWEENAW. MAX TEMPS YDAY RANGED FM ARND 70 TO THE MID 70S...AND 12Z INL SDNG SUPPORTS MAX OF 71 WITH MIXING UP TO INVRN BASE. XPCT THE COOLER READINGS OVR THE KEWEENAW PENINSULA...WITH SOMEWHAT HIER TEMPS 75 TO 80 OVR THE DOWNSLOPE AREAS FM MNM-ESC-ISQ. AFDMQT FM MIDNGT SHIFT FOR LATER PDS: THE UPR LVL RDG WILL MOV INTO MN AND W ONT...WHILE THE SFC RDG STARTS TO MOV INTO UPR GRTLKS RGN. SFC LOW IS OVR NW SD. ISENTROPIC ANLSY CONT TO SHOW MAINLY SUBSIDENCE ACRS THE RGN. PWAT REMAINS <.75 INCH. AND Q-VEC INDC DIVERGENCE ACRS THE AREA. THUS SKIES SHOULD REMAIN MOCLR. THE RDG OVR THE U P SHOULD KEEP SKIES MO CLR OVRNGT... AND THE WNDS LGT. MEANWHILE A SHRTWV IS DVLPG OVR CNTRL PLAINS...AND IS BEING PROPELLED TWRD THE FCST AREA. THE RDG WILL MOV OVR UPR GRTLKS ON WED. THE SHRTWV WILL CLIMB OUT OF THE CNTRL PLAINS INTO MN. THE SFC RDG WILL MOV OVR THE UPR GRTLKS AS WELL. A LOW WITH A DVLPG CDFNT WILL MOV INTO N PLAINS. ISENTROPIC ASCENT IS EVIDENT OVR MN AHEAD OF THE CDFNT. Q-VEC CONVERGENCE WILL BE FOCUSED WITH THE SHRTWV. ETA/AVN PLACE THE BEST CONVERGENCE OVR W ONT. PWATS OVR MN AND W ONT WILL INCR TO >1.25 INCH. FOR THE FCST AREA SKIES WILL REMAIN MO SUNNY YET. THE MSTR WILL SPREAD E WED NGT. THE SHRTWV WILL SLIDE INTO E MN AND W LK SUPERIOR. SFC LOW WILL REACH W ONT DRAGGING THE CDFNT INTO N MN. Q-VEC CONVERGENCE WILL STRENGTHEN OVR LK SUPERIOR AND ONT. ISENTROPIC ASCENT WILL INCR OVR FCST AREA AHEAD OF THE CDFNT. THE SHRTWV WILL MOV ACRS FCST AREA ON THU AS WELL AS THE ASSOC CDFNT. ISENTROPIC LIFT ASSOC WITH THE CDFNT AND THE Q-VEC WITH THE SHRTWV WILL ACT TOGETHER TO PRODUCE INSTABILTIY. LIMITING FACTOR WILL BE THE MSTR. PWAT WILL BE ARND 1.30 INCH. ETA/AVN KEEP THE STRONGEST Q-VEC CONVERGENCE OVR ONT. ON FRI EVE COND WILL AGAIN STABILIZE FOLLOWING THE FROPA AND THE FCST AREA FALLING UNDER THE INFLUENCE OF THE NVA. BY SR...ANOTHER WEAK SHRTWV WILL NAVIGATE ACRS THE FCST AREA. .MQT...NONE. KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 1008 AM EDT TUE SEP 3 2002 BAND OF LOW CLOUDS ACROSS FOOTHILLS AND PIEDMONT THIS MORNING. TEMPERATURES RUNNING BELOW PREVIOUS EXPECTATIONS...WHILE DEW POINT RUNNING ABOVE. EXPECT LOW CLOUD TO ERRODE...ALLOWING TEMPERATURES TO REACH POTENTIAL INDICATED BY RUC LOW LEVEL THICKNESS. NUDGED FORECAST MAX TEMPERATURES UP A BIT GMU/SPA AREA...AND WIDENED RANGE NC FOOTHILLS/PIEDMONT. MOUNTAIN FOG TO BURN OFF SOON. RUC SHOWING INSTABILITY OVER MOUNTAINS AND FAR E...BUT WITH LIMITED LOW LEVEL MOISTURE...WILL LEAVE ISOLATED THUNDER IN NC MOUNTAINS DUE TO TERRAIN EFFECTS...BUT EXTEND CONVECTION THERE INTO THIS EVENING. FCSTID = 7 GSP 89 67 91 68 / 10 10 30 30 AND 90 68 92 69 / 10 10 30 30 CLT 89 67 91 68 / 10 10 30 30 HKY 88 66 90 65 / 10 10 30 30 AVL 85 62 86 61 / 20 20 30 30 .GSP... GA...NONE. NC...NONE. SC...NONE. O7 sc SOUTHEAST TEXAS FORECAST DISCUSSION...CORRECTION TO ADV SXN NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 945 AM CDT TUE SEP 3 2002 VERY WEAK SFC LOW OVR WRN GULF NE OF BRO ATTM. MODELS SEEM TO TAKE NO INTEREST IN DEVELOPING THIS MUCH...BUT ARE IN AGREEMENT IN SLOWLY ADVECTING INCREASED MOISTURE INTO THE CWA NEXT 24-36 HRS. ETA FCST SOUNDING SHOWS PW VALUES OF 2.2" AT GLS BY DAYS END TDA WITH THE AVN INDC 2.4". AVN AND UKMET BRING UPR LVL ENERGY/H5 TROF AXIS ONSHORE THIS AFTN. ETA A LTL SLOER. AM COMFORTABLE WITH CURR NUMBERS IN THE ZFP AND WONT CHG MUCH EXCEPT MAYBE TO UP THEM A BIT COAST. JUST SOME MINOR WORD AND WIND ADJUSTMENTS. WILL ALSO ADD MENTION OF LCLY HVY RA COASTAL ZONES GIVEN HIGH MOISTURE LVLS. STM MOTIONS FCST TO BE 10 KT OR MORE...SO AM NOT EXPECTING FF PRODUCING TOTALS THIS AFTN. WIDESPREAD CONVECTION MAKE IT LESS THAN AN IDEAL DAY FOR RECREATIONAL BOATING. PLUS...RUC AND MESOETA SHOW SOME INCRG WIND OVR THE GULF WATERS THIS AFTN...AND HAVE DECIDED TO GO WITH AN SCEC THERE. 46/37/DO .HGX...SCEC GULF WATERS 0-60 NM. ----------------------------------------------------------- PREV DISC... THE INTERACTION BETWEEN THE UPPER HIGH OVER NE TX...THE UPPER LOW OVER NORTHEASTERN MEXICO...AND THE APPROACHING MID LEVEL WAVE OVER THE GULF WILL IMPACT SE TX INTO EARLY FRIDAY. MAIN FORECAST ITEM OF NOTE WILL BE POPS AND RAINFALL. MODEL DIFFERENCES WERE MOST NOTED ON THE MOISTURE FIELDS WITH THE ETA DRIER THAN THE AVN AND NGM. LIKE THE AVN ONCE AGAIN FOR ITS HANDLING OF THE PATTERN AND MOISTURE. AN INTERESTING NOTE...HOWEVER...IS THAT THE SATURDAY 500 MB FORECAST IS A BIT DIFFERENT THAN 24 HOURS AGO. PW/S OF GREATER THAN 2.0 WILL SNEAK ONSHORE THE COASTAL COUNTIES TODAY AND GET AS HIGH AS 2.5 FROM FREEPORT TO SOUTHERN LA. THIS IS ABOUT TWO STANDARD DEVIATIONS ABOVE NORMAL AND AS HIGH AS THE HISTORICAL GRAPH SHOWS FOR THIS TIME OF SEPTEMBER. FEEL THAT LIKELY POPS ARE IN ORDER OVER THE COASTAL COUNTIES TODAY AND TONIGHT...THEN OVER MOST OF SE TX WEDNESDAY AND THURSDAY. THE AVN SHOWS A DEFINITE DRYING TREND ONCE AGAIN FOR OVERNIGHT THURSDAY NIGHT INTO FRIDAY AS IT DID 24 HOURS AGO. FEEL THAT A HEAVY RAINFALL EVENT IS SHAPING UP FOR WEDNESDAY AND THURSDAY AS THE 700 MB WAVE AXIS MOVES SLOWLY INLAND AND WILL ISSUE AN SPS TO OUTLINE THIS POSSIBILITY. ITEMS CHANGED ON THIS FORECAST PACKAGE...WILL UP POPS COASTAL AREAS TODAY AND TONIGHT...ALL AREAS WEDNESDAY AND THURSDAY. WITH SUCH A HIGH PROBABILITY WILL THEN LOWER HIGH TEMPERATURES WEDNESDAY AND THURSDAY. PL-40 45 .HGX...NONE. PRELIMS... CLL BT 095/073 090/074 089 235 IAH ET 091/075 088/076 088 447 GLS TT 088/081 087/081 087 747 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHEYENNE WY 909 AM MDT TUE SEP 3 2002 SHORTWAVE TROUGH CENTERED OVER SOUTHWEST UTAH AT MID MORNING WILL MOVE NORTHEAST THROUGH TONIGHT. CURRENTLY THERE ARE A FAIR AMOUNT OF SHOWERS AND SOME THUNDERSTORMS IN EASTERN UTAH AND WESTERN COLORADO. THE SHORTWAVE HAS BEEN SLOW TO LIFT NORTHEAST SINCE MONDAY BUT APPEARS TO BE MOVING A BIT FASTER NOW. 12Z MESOETA SEEMED SLIGHTLY SLOW AT 15Z WITH THE POSITION OF THE FEATURE. EVEN THE 12Z ETA WAS SLOWER IN THE MOVEMENT OF THE SHORTWAVE TROUGH TO THE NORTHEAST THROUGH TONIGHT. MODELS ALSO STILL DEPICT A WEAKER SHORTWAVE TROUGH MOVING THROUGH THE CWA IN ADVANCE...THROUGH THE AFTERNOON. THE FEATURE WILL IMPACT THE CWA LATE THIS AFTERNOON AND EARLY TONIGHT WITH A SCATTERED COVERAGE OF SHOWERS AND STORMS. CURRENT FORECAST ON TRACK...BUT WITH MANY FAVORABLE PARAMETERS IN PLACE...ESPECIALLY IN THE EAST PART OF THE CWA...POPS MAY NEED TO BE RAISED A BIT. IN THE MOUNTAINS AND AREAS TO THEIR WEST...MOST OF THE ACTIVITY WILL PRODUCE STRONG WIND GUSTS. FURTHER TO THE EAST...THE AIRMASS WILL BE MORE UNSTABLE WITH CAPES FORECAST BY THE MESOETA AND 20KM RUC BETWEEN 1000 AND 2000 J/KG FROM 00Z TO 03Z. STORMS IN THE WESTERN NEBRASKA PANHANDLE MAY BE STRONG THIS EVENING AND MAY INCLUDE IN THE FORECAST WORDING...ALTHOUGH DO NOT EXPECT MUCH IN THE WAY OF SEVERE STORMS. FORECAST IS IN GOOD SHAPE WITH THE EXPECTED SHOWERS AND THUNDERSTORMS LATER TODAY...WARM TEMPERATURES AND BREEZY CONDITIONS IN THE NEBRASKA PANHANDLE. .CYS... WY...NONE. NE...NONE. WEILAND wy SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO COLORADO 203 PM MDT TUE SEP 3 2002 BIGGEST FCST CHALLENGE IS HOW LONG TO HOLD ONTO PRECIPITATION CHANCES...ALBEIT SMALL...THROUGH THE FCST PERIOD. CURRENTLY: LATEST WATER VAPOR/RUC UPPER AIR ANALYSES SHOWING A RATHER VIGOROUS SHORTWAVE TROUGH NOW ENTERING UT AND MIGRATING N-NEWD TOWARDS WY. ALSO...VERY MINOR SHORTWAVE TROUGH EXITING CNTRL NM INTO SERN CO. A FEW SHORT RANGE MODELS HAVE PICKED UP THIS FEATURE. THE AFOREMENTIONED WEAK SHORTWAVE HAS TOUCHED OFF ISOLD-SCT SHRA/TSRA ACROSS THE SANGRE DE CRISTO MTNS AND SRN FOOTHILLS...INCLUDING THE RATON MESA RGN. TNGT: SHORT RANGE MODELS APPEAR TO HAVE A VALID SCENARIO OF THE VIGOROUS SHORTWAVE OVER UT BRUSHING BY WRN CO AND HEADING TOWARDS NRN ROCKIES DURING THE NGT. THE WEAKER SHORTWAVE WILL CONTINUE TO MOVE ACROSS SERN CO THIS EVE AND THEN INTO THE CNTRL PLAINS. SHOULD SEE THE ISOLD-SCT SHRA/TSRA AND ASSOCIATED CONVECTIVE CLOUDS DISSIPATE AROUND OR AFTER SUNSET. 30-45KT SLY LLJ DEVELOPS NR THE CO/KS BORDER WITH EXIT RGN LOCATED AROUND NE DURING THE NGT. ANY POTENTIAL NOCTURNAL MCS ACTIVITY WILL LIKELY BE FURTHER NE AND E LATER TNGT NEAR THE LLJ EXIT RGN AND ASSOCIATED THERMAL ADVECTIONS. WILL BUMP UP WINDS AND TEMPS TNGT IN SERN CO NEAR THE LLJ RGN. OTHERWISE...FCST GRIDS LOOK REASONABLE. WED-WED NGT: HARD PRESSED TO FIND ANY SYNOPTIC SCALE SYSTEM TO HELP ENHANCE DIURNAL CONVECTION PROCESS ON WED. CURRENT POPS OVER THE MTNS MAY BE OVERDONE. ETA NOW SUGGESTING SOME QPF IN SERN CO NEAR THE BETTER LOW LEVEL MOISTURE FEED JUXTAPOSED WITH A WEAK CYCLONIC SHEAR AXIS. PLAN TO HANG ONTO CURRENT FCST TO AVOID FLIP-FLOP ISSUE AND LET MID SHIFTS RE-ANALYZE THE SCENARIO. OTHERWISE...TEMPS STILL AOA EARLY SEP AVES. THU-THU NGT: SYNOPTIC SCALE PATTERN TO GO THROUGH A CHANGE...AS MID LEVEL HIGH PRESSURE BUILDS INTO CNTRL ROCKIES AND CNTRL PLAINS IN RESPONSE TO SIGNIFICANT W COAST SYSTEM DEVELOPING. ALSO...GULF OF MEXICO TROPICAL SYSTEM MIGRATES ELY INTO EXTREME SRN PLAINS. THIS PUTS CNTRL ROCKIES IN S-SWLY FLOW WITH SOME MID LEVEL MOISTURE REMAINING. TROPICAL SYSTEM IN ERN PACIFIC REMANENCE SHOULD REMAIN WELL W OF THE CONTDVD. LIKE WED...HARD PRESSED TO FIND ANYTHING TO HOLD ONTO LOW POPS FOR THE MTNS...BESIDES CLIMO. ETA/AVN PRINT OUT NO QPF FOR THU. WILL MAINTAIN CURRENT GRIDS FOR CONTINUITY. AGAIN...TEMPS SHOULD BE AOA EARLY SEP AVES. FRI-TUE: LITTLE CHANGE IN THE PATTERN...AT LEAST FRI-SUN. BIG MID LEVEL ANTICYCLONE BUILDS OVER THE CNTRL PORTION OF US IN RESPONSE TO UNSEASONABLY STRONG CYCLONE PROGGED TO DEVELOP OVER WRN US FRI-SUN OR MON. PERSISTENCE THE BEST WAY TO GO FOR FRI-SUN. POPS MAY BE OVERDONE IN SERN CO. AVN/GFS MODEL CONTINUOUSLY DEVELOPS DIURNAL H5 MOISTURE NEAR THE MODEL'S POOR RESOLUTION CONTDVD WHICH COULD BE IN RESPONSE TO THE CONVECTIVE PARAMETERIZATION. NOT READY TO BUY THE GFS' EJECTING OLD SYSTEM INTO CNTRL ROCKIES LATE MON INTO TUE. NONETHELESS...I AM PLANNING ON STICKING WITH LOW POPS THROUGH TUE GIVEN CLIMO. TEMPS SHOULD REMAIN AOA EARLY SEP AVES. .PUB...NONE. METZE co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 200 PM MDT TUE SEP 3 2002 FORECAST CONCERNS ARE PRECIPITATION CHANCES TONIGHT AND POSSIBLY INTO WEDNESDAY AND HIGH TEMPS THROUGH MUCH OF THE WEEK. LATEST WATER VAPOR/RUC ANALYSIS SHOWING SHORT WAVE TROUGH OVER THE ROCKIES SPREADING MID AND UPPER LEVEL MOISTURE OVER MUCH OF COLORADO/NORTHERN NEW MEXICO AND SOUTHWEST KANSAS. AT THE SAME TIME...THE SURFACE BOUNDARY THAT BROUGHT COOLER/DRIER AIR INTO THE REGION YESTERDAY CONTINUES TO LIFT NORTH WITH SOUTHEASTERLY WINDS TRANSPORTING HIGHER DEWPOINTS INTO WESTERN KANSAS...EASTERN COLORADO AND FAR SOUTHWEST NEBRASKA. CURRENT FORECAST HAS A SLIGHT CHANCE FOR THE OVERNIGHT PERIOD...NO CHANGES PLANNED AT THIS TIME. WITH BREEZY CONDITIONS EXPECTED TONIGHT...WILL KEEP TEMPS UP SEVERAL DEGREES FROM LAST NIGHTS LOWS. THE MID LEVEL TROUGH WILL BE REPLACED BY UPPER RIDGING LATE ON WEDNESDAY...THIS UPPER RIDGE WILL BE THE DOMINATE FEATURE THROUGH THE UPCOMING WEEK AND INTO THE WEEKEND. SUBSIDENCE WILL RESULT IN ABOVE NORMAL TEMPERATURES AND ABUNDANT INSOLATION. WILL EDGE TEMPS UP...ESPECIALLY OVER THE FAVORED HOT AREAS AS ETA/AVN 850 TEMPS SUPPORT HIGHS RANGING FROM THE LOWER 90S WEST TO THE UPPER 90S OR HIGHER IN THE EAST THROUGH THE WEEKEND. IN THE LONG RANGE...WILL REMOVE THE MENTION OF THUNDER ON SAT/SUN AND INCLUDE A SLIGHT CHANCE ON MON/TUE AS THE WEST COAST TROUGH EVENTUALLY KICKS THE UPPER RIDGE EAST OF THE AREA ALLOWING GULF MOISTURE TO BE TRANSPORTED NORTH WHILE AN UPPER TROUGH APPROACHES FROM THE WEST. .GLD...NONE. MWM ks DEEP SOUTH TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 300 PM CDT TUE SEP 3 2002 SHORT TERM...RADAR AND VISIBLE SATELLITE IMAGES INDICATE SEABREEZE FRONT MOVING INLAND OVER COASTAL COUNTIES OF THE CWA THIS AFTERNOON WITH AN OUTFLOW BOUNDARY OVER EXTREME SOUTHEAST PORTIONS OF DEEP SOUTH TX FROM EARLIER CONVECTION. SHOWERS AND ISOLATED THUNDERSTORMS ARE DEVELOPING ALONG SEABREEZE AND OUTFLOW BOUNDARY. MSAS SURFACE ANALYSIS CONTINUES TO INDICATE A WEAK SURFACE CIRCULATION OVER THE NORTHWEST GULF OF MEXICO. BUT MOST OF THE CONVECTION ALONG THE UPPER TX COAST AND LA COAST ASSOCIATED WITH MAX VORTICITY CENTER NORTHEAST OF THE 200MB TROUGH/LOW OVER THE LOWER VALLEY AND NORTHEAST MEXICO. RUC 1000-500MB STREAMLINE ANALYSIS INDICATES INVERTED TROUGH OVER THE WESTERN GULF WITH MOISTURE ADVECTING WESTWARD WITH THIS FEATURE. 12Z ETA PROGS 700MB TROUGH AXIS MOVING INLAND WEDNESDAY AND ACROSS THE UPPER PORTIONS OF THE VALLEY THURSDAY WITH VORT MAX CENTER MOVING ACROSS SOUTH TX TOWARDS THE WESTERN PORTIONS OF THE CWA. BELIEVE WITH SEABREEZE FRONT DEVELOPING...HIGHER CHANCE OF PRECIPITATION WEST THAN EAST DURING THE LATE AFTERNOON TO EARLY EVENING HOURS THE NEXT COUPLE OF DAYS. WILL INCREASE POPS SLIGHTLY THURSDAY WITH BEST CHANCE OF RAIN MAINLY WEST. MAX TEMPS TO BE CLOSER TO NORMAL WITH ADDITIONAL CLOUD COVER ESPECIALLY THURSDAY. EXTENDED...500MB RIDGE OVER THE SOUTH CENTRAL UNITED STATES TO SHIFT SLOWLY WESTWARD THROUGH SUNDAY AS 500MB LOW DROPS SOUTHWARD ALONG THE TROUGH OVER THE WESTERN U.S. COAST. 12Z AVN CONTINUES TO PROG 700MB LOW OVER THE EASTERN GULF OF MEXICO FRIDAY AS THE REMNANTS OF T.S. EDOUARD MOVE ACROSS FLORIDA. STILL TOO EARLY TO SAY WHAT HAPPENS WITH REMNANTS OF EDOUARD AFTER 72 HOURS. 700MB RIDGE OVER THE EASTERN U.S. TO CONTINUE TO PROVIDE AN EASTERLY FLOW ACROSS THE GULF OF MEXICO THROUGH THE WEEKEND. WITH MOISTURE OVER THE WESTERN GULF CONTINUING TO STREAM INTO SOUTH TX FRI...WILL CONTINUE CHANCE OF SHOWERS AND THUNDERSTORMS INTO SAT WITH SLIGHT CHANCE INTO EARLY NEXT WEEK. MARINE DISCUSSION...A LARGE TROPICAL WAVE WITH A BROAD AREA OF WEAK SURFACE LOW PRESSURE IS TRAVERSING THE WESTERN GULF OF MEXICO. THE BULK OF THE MOISTURE ASSOCIATED WITH THIS WAVE IS MOVING INTO LOUISIANA AND SOUTHEAST TEXAS. SURFACE WIND ANALYSIS INDICATES THE WEAK SURFACE LOW CENTER IS ABOUT 185 MILES EAST OF BROWNSVILLE. WINDS WILL BECOME LIGHT AND VARIABLE OVER THE NEXT 24 HOURS...AS THIS FEATURE TRACKS WEST TOWARD THE LOWER TEXAS COAST. IN ADDITION...MARINERS CAN EXPECT ISOLATED THUNDERSTORMS AND SCATTERED RAINS SHOWERS THROUGH FRIDAY. WINDS AND SEAS WILL REMAIN BELOW ADVISORY CRITERIA THROUGH SATURDAY. .PRELIMINARY NUMBERS... BRO BE 075/093 075/092 075 10/30/20/40/30 HRL BE 076/094 076/093 076 10/30/20/40/30 MFE ET 075/096 075/095 075 40/40/50/50/60 RGC ET 074/097 074/096 074 40/40/50/50/60 SPI BE 080/088 080/087 080 05/20/10/30/20 SYNOPTIC...61/AVIATION-MARINE-MESO...53 INTERNET ADDRESS...WWW.SRH.NOAA.GOV/BRO .BRO...NONE. tx