ZCZC SPCSWODY1 ALL ACUS01 KWNS 261243 SPC AC 261242 STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS. VALID 261300Z - 271200Z THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 45 SE ANJ 50 S ESC 20 S LSE 25 NW RST 25 NNW MSP 15 SSE DLH 60 ENE ELO. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 70 S GBN 20 N PRC 45 SSW P38 10 SW BIH 30 SSW TVL 30 ESE MHS 40 WSW MHS 25 WSW MFR 55 SW RDM 30 ESE ALW 65 ENE 63S ...CONT... 55 NNW GGW 30 NW MLS 35 S REJ 15 ENE 9V9 35 ENE AXN 15 W INL ...CONT... 20 NNE CAR 20 NNE LCI 30 SE UCA 20 ENE JHW TOL 10 ENE IRK 15 NNE MHK 20 WSW ICT 30 ENE OKC 30 WSW PGO 25 NNE PBF 55 SW BNA 25 SSE TRI 60 SW RIC 15 ESE ORF. ...UPPER MS VALLEY...GREAT LAKES THROUGH CNTRL PLAINS AREA... THE SHORTWAVE TROUGH AND ASSOCIATED MID/UPPER JET OVER MANITOBA WILL MOVE ESEWD INTO ONTARIO TODAY...SKIRTING THE UPPER MS VALLEY PORTION OF THE U.S. BORDER. AN UPPER RIDGE WILL PREVAIL FROM THE MID MS VALLEY WWD INTO THE CNTRL PLAINS. THIS MORNING A COLD FRONT EXTENDS FROM MANITOBA SWWD THROUGH CNTRL ND AND INTO SERN MT. WARM FRONT EXTENDS FROM A LOW IN SWRN MN EWD INTO WRN WI WITH A SURFACE TROUGH EXTENDING SWWD FROM THE LOW INTO SERN SD AND CNTRL NEB. EXTENSIVE ELEVATED CONVECTION OCCURING OVER GREAT LAKES IN ZONE OF WARM ADVECTION WILL SHIFT EWD AND SHOULD BEGIN TO DIMINISH BY EARLY AFTERNOON AS THE LOW LEVEL JET VEERS AND WEAKENS. THE ATMOSPHERE IS EXPECTED TO BECOME QUITE UNSTABLE FROM NEB NEWD INTO WI IN THE WAKE OF THIS ACTIVITY WITH MLCAPES FROM 2500 TO 3500 J/KG. MAIN LIMITING FACTORS FOR SEVERE WEATHER AGAIN TODAY WILL BE THE CAP AND WARM MID LEVEL TEMPERATURES. AS SHORTWAVE TROUGH MOVES ESEWD INTO ONTARIO... COLD FRONT WILL SHIFT SEWD AND BY LATE AFTERNOON EXTEND FROM NERN MN SWWD INTO NRN NEB. GIVEN STRONGER LIFT ACCOMPANYING SHORTWAVE TROUGH EXPECTED TO REMAIN N OF THE U.S. BORDER...ALONG WITH PRESENCE OF CAP...IT SHOULD BE INCREASINGLY DIFFICULT TO INITIATE SURFACE BASED STORMS WITH SWD EXTENT ALONG THE FRONT. MOREOVER... LOW LEVEL FLOW IS FORECAST TO VEER AND WEAKEN AS LEAD SHORTWAVE MOVES EWD INTO QUEBEC...AND THIS WILL TEND TO WEAKEN FRONTAL CONVERGENCE. THUS SLIGHT RISK IS SOMEWHAT CONDITIONAL. ISOLATED DAMAGING WIND WILL BE THE MAIN THREAT WITH ANY STORMS THAT DO DEVELOP SINCE VERY WARM AIR ALOFT WILL BE A LIMITING FACTOR FOR LARGE HAIL. FARTHER SW ALONG THE IA/NEB PORTION OF FRONT...THE CAP WILL ALSO POSE A PROBLEM FOR SURFACE BASED INITIATION. HOWEVER...ISOLATED STORMS MAY BE POSSIBLE WHERE STRONG SURFACE HEATING CAN OCCUR... MAINLY ACROSS PARTS OF WRN NEB WHERE DEEPER MIXING SHOULD RESULT IN A WEAKER CAP. ISOLATED DAMAGING WIND GUSTS WILL BE THE MAIN THREAT THROUGH EARLY EVENING IN THIS AREA. ..DIAL/BANACOS.. 07/26/03 NNNN |