ZCZC SPCSWODY1 ALL COR ACUS01 KWNS 061704 SPC AC 061704 COR...DIRECTION OF SLGT RISK ARROW IN IA/MN STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS. VALID 061630Z - 071200Z THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 SW HUM 30 SSE MCB 25 N LUL 50 E MEI 20 SW MGM 35 SSW TOI 25 W PFN. THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 25 ESE MSP 15 SE LSE 25 SE DBQ 15 SSE BRL 35 NW IRK 40 NW LWD 25 W FRM 35 NW MKT 25 ESE MSP. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 55 W 3B1 20 SSE MWN 25 NNW EEN 30 SSW ART ...CONT... 15 ENE MBS 25 NW LAN 20 E BEH 45 NNE LAF 10 SW IND 55 W LUK 30 ENE SBY ...CONT... 40 WSW FHU 40 N TUS 20 NNE PHX 60 WSW PRC 25 S IGM 35 NE IGM 10 E GCN 25 SSW GUP 30 ESE GNT 10 SE SAF 65 S ALS 25 ESE EVW 30 SSW MQM 15 SSW BTM 45 NE HVR. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 SW ABI 25 NNE AUS 20 ENE CLL 20 ENE PRX 35 SSE HRO 25 NE UNO 35 NE VIH 20 NE COU 40 ESE STJ 20 SE OMA 20 WSW OFK 20 N BBW 40 NE AMA 50 SW CDS 20 SW ABI. ...ERN IA/SRN MN... CLEARING IN WAKE OF MORNING CONVECTION WILL AID DESTABLIZATION THIS AFTERNOON AHEAD OF COLD UPPER SYSTEM AND ASSOCIATED SURFACE COLD FRONT MOVING FROM WEST TO EAST ACROSS THIS AREA. THOUGH SURFACE TEMPERATURES WILL LIKELY REMAIN COOL FOR THIS TIME OF YEAR...VERY COLD MID LEVEL AIR /H5 TEMPS TO -20C/ WILL MAINTAIN STEEP LAPSE RATES. IN ADDITION...SURFACE DEW POINTS IN THE UPPER 50S SHOULD SUPPORT MARGINAL TO MODERATE INSTABILITY THIS AFTERNOON WITH SBCAPE AROUND 1000 J/KG. LARGE SCALE ASCENT ALONG AND AHEAD OF APPROACHING COLD FRONT SHOULD THEREFORE SUPPORT SCATTERED THUNDERSTORMS INTO THE EARLY EVENING...WITH ATTENDANT THREAT OF ISOLATED LARGE HAIL/DAMAGING WINDS FROM THE STRONGER CELLS. REGION WILL REMAIN ALONG NRN PERIPHERY OF MID/UPPER LEVEL JET ASSOCIATED WITH APPROACHING UPPER LOW...SUGGESTING SHEAR WILL REMAIN SUFFICIENT FOR ORGANIZED STORMS...INCLUDING A SUPERCELL OR TWO. ...CENTRAL GULF COAST... INSTABILITY WILL REMAIN RATHER WEAK TODAY AS DEEP MOISTURE AND WARM TEMPERATURES ALOFT OVERSPREAD THE REGION. THOUGH MID LEVEL WIND SPEEDS ARE MARGINAL FOR SUSTAINED/ROTATING UPDRAFTS...LOW LEVEL SLY FLOW WILL LIKELY INCREASE IN RESPONSE TO WEAK SRN STREAM IMPULSE EJECTING TOWARDS THE LOWER MS RIVER VALLEY TODAY WITH H85 WINDS FROM 25-35 KT. IN ADDITION...ROBUST BOUNDARY LAYER MOISTURE/LOW LCLS SUGGEST BRIEF LOW LEVEL ROTATION AND AN ATTENDANT ISOLATED TORNADO THREAT WILL PERSIST OVER THE AREA. ...CENTRAL HIGH PLAINS... NEXT NRN STREAM UPPER LOW NOW OVER ERN MT WILL FOLLOW QUICKLY ON THE HEELS OF EJECTING SYSTEM MOVING INTO MN/IA THIS AFTERNOON. STRONGEST ASCENT AND SURFACE COLD FRONT ASSOCIATED WITH SSEWD DIGGING SYSTEM WILL SPREAD SWD ACROSS NERN CO DURING THE EARLY EVENING. THOUGH TEMPERATURES ALOFT REMAIN RATHER COLD /I.E. H5 TEMPS NEAR -16C OVER ERN CO/...LOW LEVEL MOISTURE APPEARS SPARSE WITH SURFACE DEW POINTS REMAINING IN THE LOWER TO MID 40S. DESPITE THE FORECAST OF ONLY MARGINAL INSTABILITY...STRENGTH OF UVV/S AND STEEP MID LEVEL LAPSE RATES WILL LIKELY SUPPORT SCATTERED THUNDERSTORMS LATER TODAY AND THIS EVENING. LOW LEVEL LAPSE RATES WILL REMAIN STEEP...AS SURFACE TEMPERATURES INCREASE TO AROUND 70F...SUGGESTING PRE-FRONTAL CONVECTION SHOULD PRODUCE ISOLATED STRONG/SEVERE WIND GUSTS. CONVECTION NEARER TO AND JUST BEHIND THE SURFACE FRONT MAY ALSO PRODUCE HAIL. ..EVANS/BANACOS.. 06/06/03 NNNN |