ZCZC SPCSWODY1 ALL ACUS01 KWNS 201644 SPC AC 201644 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1144 AM CDT WED AUG 20 2003 VALID 201630Z - 211200Z THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 25 ESE ANJ 55 NNE MTW 40 W MMO 20 N ALN 45 W STL 20 SW IRK 30 ENE ICT 35 N P28 25 E RSL 45 ESE HSI 30 NNW OMA 20 WSW SPW 15 SSE ATY 40 SW FAR 30 NE RRT GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM DRT 60 E JCT 15 WSW TYR 35 N PRX 35 WSW FYV 40 SSW JLN 25 WNW TUL 25 NW OKC 20 W CDS 55 W MRF ...CONT... 45 S EHA 35 NNE GCK 25 SSE BUB 30 ENE ANW 70 WNW CDR 25 ESE RIW 30 NNW RKS 45 SSE RKS 20 SSE LAR 40 E FCL 25 SSE RTN 45 S EHA ...CONT... 10 NNE SBA 15 SE MER 45 E RBL 60 NNW WMC 30 SE SUN 45 W 3HT 60 ENE CTB ...CONT... 50 SE OSC 45 SSW SBN 20 WSW MTO 10 SW EVV LUK 30 S HLG 30 E MGW 10 SSE SHD 30 ESE LYH 45 S RIC ORF GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM BOS 30 W GFL MSS ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE UPR MS VLY AND UPR GRT LKS.... ...SYNOPSIS... ERN SD UPPER LOW EXPECTED TO EJECT NE ACROSS MN/LK SUPERIOR THIS PERIOD AS UPSTREAM IMPULSE NOW OVER CNTRL MT CONTINUES E TO MN...AND RIDGES PERSIST OVER THE CNTRL RCKYS AND APPALACHIANS. ELSEWHERE... WEAK IMPULSES WILL MOVE WWD ALONG THE CNTRL GULF CST...NWD ACROSS NV AND E/SE ACROSS KS. AT LOWER LEVELS...COLD FRONT NOW OVER MT SHOULD MOVE E INTO THE DAKOTAS...PRECEDED BY A SERIES OF WARM FRONTAL SEGMENTS/WEAK OUTFLOW BOUNDARIES OVER THE UPR MS VLY/UPR GRT LKS. ...UPR MS VLY/UPR GRT LKS... COMPLEX SURFACE PATTERN OVER THE N CNTRL STATES RESULTING FROM RECENT AND ONGOING CONVECTION WILL COMPLICATE CONVECTIVE EVOLUTION OVER REGION TODAY. MAIN CORRIDOR FOR ORGANIZED/SUSTAINED STORM DEVELOPMENT EXPECTED TO BE FROM NE IA/SE MN NEWD INTO CNTRL/NRN WI AND POSSIBLY UPR MI...ALONG SRN EDGE OF DIFFUSE OUTFLOW BOUNDARY LEFT FROM EARLY MORNING MCS. COMBINATION OF SURFACE HEATING AND CONTINUED NE MOTION OF SD UPPER TROUGH SHOULD RESULT IN 100 MB MLCAPE OF 1500-2000 J/KG BY AFTERNOON. DEEP SHEAR WILL BE MORE THAN AMPLE FOR SUPERCELLS...WITH 25-30 KT SSW LOW LEVEL JET VEERING TO 35-40 KT SW FLOW AT 500 MB. GIVEN POTENTIAL FOR STORMS TO MOVE PARALLEL TO BOUNDARY FOR SOME PERIOD OF TIME AND AVAILABILITY OF RICH BOUNDARY LAYER MOISTURE...THREAT WILL EXIST FOR A COUPLE TORNADOES IN ADDITION TO HAIL AND BOWING SEGMENTS WITH HIGH WIND. OTHER STORMS MAY FORM FARTHER W ACROSS MN AS SURFACE HEATING DESTABILIZES REGION IMMEDIATELY AHEAD OF SD UPPER VORT BY MID/LATE AFTERNOON. THESE STORMS WILL LIKELY SPREAD E INTO PARTS OF WI/UPR MI THIS EVENING...AND POSE A CONTINUED THREAT FOR HAIL/WIND. ...DAKOTAS... CONVERGENCE ALONG STRONG WIND SHIFT/COLD FRONT NOW ENTERING WRN ND MAY INITIATE ONE OR TWO STORMS AS THE FEATURE CONTINUES E ACROSS THE REMAINDER OF THE DAKOTAS LATER TODAY. WHILE ENVIRONMENT OVER REGION WILL BE FAVORABLE FOR DAMAGING WIND GUSTS...UNCERTAINTY REGARDING COVERAGE OF SUSTAINED ACTIVITY PRECLUDES AN UPGRADE TO SLIGHT RISK ATTM. ...CNTRL PLNS/LWR MO VLY... SCATTERED STORMS/STORM CLUSTERS EXPECTED TO DEVELOP SWD ALONG TRAILING LOW LEVEL CONFLUENCE ZONE INTO PARTS OF SE NEB/KS AND MO LATER TODAY...WHERE DEEP MIXED ENVIRONMENT AND MODEST DEEP SHEAR WILL EXIST. MAIN SEVERE THREAT WILL BE DAMAGING WIND LATE THIS AFTERNOON/EARLY TONIGHT. ...NRN NEW ENGLAND... A FEW STRONG STORMS MAY AFFECT NH AND ME LATER TODAY...WHERE AXIS OF WEAK CONFLUENCE WILL PERSIST BENEATH MODERATE NW FLOW ALOFT. SLOWLY RISING HEIGHTS AND WEAKNESS OF CONVERGENCE SUGGEST ONLY A LIMITED THREAT FOR SEVERE. ...GRT BASIN... SCATTERED DIURNAL STORMS WITH GUSTY WINDS/HAIL WILL LIKELY DEVELOP OVER THE GRT BASIN...ON NRN AND WRN FRINGE OF CLOUD SHIELD ASSOCIATED WITH YESTERDAY'S ACTIVITY. ..CORFIDI/TAYLOR.. 08/20/2003 ...NOTICE... FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3. THE INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED. $$ |