ZCZC SPCSWODY1 ALL ACUS01 KWNS 280548 SPC AC 280445 STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS. VALID 281200Z - 291200Z THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 40 WNW SPI RFD 20 W SBN 25 SE LUK 25 WNW 5I3 35 NNW TYS 15 WNW BNA 40 SSW BLV 40 WNW SPI. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 E PIE 35 ENE ORL ...CONT... 20 SW CRE 20 ESE AGS 25 SSE AHN 45 E HSV MKL 20 SSE UNO 25 E UMN 30 ESE CNU 10 W EMP 15 NNE BIE 25 SW FRM 25 ENE STC 75 E ELO ...CONT... 70 NW GGW 75 NNE BIL 40 ENE SHR 60 WNW CDR 20 SSE SNY 35 NNE LAA 45 SSE LAA 30 S CAO 30 NW CVS 35 NNE CNM 25 SSE INK 25 WSW HDO 35 NE CRP ...CONT... 10 WSW IPL 25 ESE DAG 55 ESE FAT 70 NE MER 45 SSW NFL 25 SE BAM 55 WSW SUN 50 WSW 27U 35 WSW S06 45 NE 4OM ...CONT... 45 W 3B1 40 N AUG 20 NE PWM. ...SYNOPSIS... HIGH AMPLITUDE UPPER FLOW PATTERN WILL CONTINUE THROUGH MIDWEEK WITH COLD UPPER TROUGH SITUATED ACROSS THE ERN THIRD OF THE NATION AND A STRONG UPPER RIDGE REMAINING OVER THE WRN TWO THIRDS OF THE COUNTRY. A POTENT MIDLEVEL SHORTWAVE TROUGH TOPPING THE RIDGE WILL MOVE QUICKLY SEWD INTO THE MIDWEST TODAY AND TONIGHT. AT THE SURFACE...COLD FRONT WILL MOVE THROUGH THE GREAT LAKES-MIDWEST BY WEDNESDAY EVENING...WITH THE TAIL END OF THE FRONT WEAKENING OVER THE CNTRL PLAINS. THIS FRONT WILL BE THE FOCUS FOR POSSIBLE SEVERE TSTMS THIS AFTERNOON ACROSS THE MIDWEST AND LOWER OH VLY. ...MIDWEST/LOWER OH VLY... VAPOR IMAGERY SHOWS THE POTENT SHORTWAVE TROUGH STRENGTHENING OVER MN ATTM AND ASSOCIATED EXIT REGION OF THE 125 KT UPPER JET WILL SPREAD ACROSS THE MIDWEST/LOWER OH VLY DURING PEAK HEATING WEDNESDAY. BOUNDARY LAYER IN THE WARM SECTOR AHEAD OF THE FRONT WILL LIKELY HEAT CONSIDERABLY...BUT MAIN LIMITING FACTOR FOR SEVERE TSTM DEVELOPMENT WILL BE MEAGER MOISTURE RETURN. WSWLY LOW LEVEL TRAJECTORIES WILL LIKELY TAP INTO LOW-MID 50S DEW POINTS... CONTRIBUTING TO MLCAPES OF 500-1000 J/KG. TSTMS SHOULD INCREASE IN COVERAGE ALONG/E OF THE FRONT AND IN ZONE OF LARGE SCALE ASCENT. VERTICAL SHEAR WILL BE SUFFICIENT FOR SUPERCELLS WITH DAMAGING WIND AND HAIL...THOUGH WEAK INSTABILITY/MIDLEVEL LAPSE RATES MAY MITIGATE WIDESPREAD SEVERE. ANY TSTMS SHOULD QUICKLY TRANSITION INTO OUTFLOW DOMINATED LINES/BOWS WITH POTENTIAL DAMAGING WINDS. ACTIVITY SHOULD MOVE INTO THE LOWER OH VLY BY EVENING AND WEAKEN AFTER SUNSET. ...CNTRL/SRN ROCKIES... MIDLEVEL TEMPERATURE PROFILES HAVE WARMED GRADUALLY OVER THE PAST COUPLE OF DAYS AND CAP SHOULD BE EQUALLY STRONG OR STRONGER THAN TUESDAY ACROSS THE CNTRL/SRN ROCKIES. BOUNDARY LAYER MOISTURE SHOULD BE MAINTAINED ON LIGHT SELY UPSLOPE FLOW...WITH STRONGER DEEP LAYER SHEAR EXISTING ALONG THE FRONT RANGE EWD. ISOLD/WDLY SCATTERED COVERAGE OF TSTMS ARE POSSIBLE ALONG THE HIGHER TERRAIN OF SERN WY-CO-NM BY MID AFTERNOON. CONTINUED NNELY STEERING FLOW SUGGESTS THE STORMS WILL REMAIN ON/CLOSE TO THE MOUNTAINS AND MOVE SWD. ISOLD DAMAGING WINDS OR HAIL COULD ACCOMPANY THE STRONGER STORMS...BUT CAP SHOULD KEEP MOST STORMS SUB-SEVERE. ..RACY/TAYLOR.. 05/28/03 NNNN |