ZCZC SPCSWODY1 ALL ACUS01 KWNS 181310 SPC AC 181307 STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS. VALID 181300Z - 191200Z THERE IS A MDT RISK OF SVR TSTMS THROUGH THIS AFTERNOON / EVENING ACROSS CENTRAL AND ERN MO AND INTO ADJACENT AREAS OF W CENTRAL AND SWRN IL / NRN AR / FAR WRN KY / FAR NWRN TN. THE MDT RISK AREA IS TO THE RIGHT OF A LINE FROM 35 ENE IRK 20 SE UIN 10 W BLV 25 N PAH 35 SSW PAH 15 NE JBR 15 NNE HRO 40 S SZL 35 NE SZL 25 SSW IRK 35 ENE IRK. SURROUNDING THE MDT RISK AREA...THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 W SHD 10 SSE EKN 45 SE PKB 25 SW PKB HTS 30 WSW BLF 65 S TYS 20 W 0A8 30 NE ESF 35 ENE SHV 25 NNE JLN 25 ENE MKC 20 ENE P35 30 NE OTM 20 NNW DEC 25 SW HUF BMG 45 WNW LUK 40 NNE DAY 20 W MFD 35 SSE FKL 35 NW IPT 30 SSW BGM 30 NW EWR ACY 25 WSW WAL 40 WNW RIC 20 W SHD. THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 10 NNE RRT 10 SE TVF 30 E PIR 65 W YKN 25 SSE BUB 40 SSW EAR 30 ESE AKO 30 ENE FCL 15 NNE LAR 25 SE CPR 50 SSE SHR 40 ENE SHR 45 SE MLS 65 NNE ISN. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 40 SE DRT 45 S SEP 25 S PRX 25 SW PGO 50 ENE TUL 30 WNW EMP 45 N RSL 45 WSW GLD 25 WSW LHX 15 SW LVS 35 NW ABQ 35 W ELP ...CONT... CZZ RAL 30 ENE OXR 25 N OXR 25 S BFL 45 N BFL 10 N FAT 35 NNE SAC 15 NNW SVE 30 SE LOL 45 WSW OWY 20 NNW BOI 45 NNE BNO 40 ESE PDT 45 SSE GTF 80 SSW GGW 60 NNW OLF ...CONT... 70 ENE ELO 50 SSW IWD 35 SE MSP 25 N DBQ 30 N CGX 25 S MTC 15 E BUF 10 NW UCA 25 NW PBG. ...SYNOPSIS... MAIN MID-LEVEL FLOW PATTERN WILL FEATURE A RIDGE CENTERED OVER THE CENTRAL ROCKIES AND A DEEPENING TROUGH IN THE ERN CONUS THROUGH THE PERIOD. SEVERAL DISTURBANCES ARE FORECAST TO ROUND THE NERN FRINGE OF THE RIDGE AND DROP SEWD IN FAST NWLY FLOW BETWEEN THESE TWO MAIN UPPER FEATURES. AT THE SURFACE...A BAROCLINIC ZONE STRETCHING FROM NEW ENGLAND WSWWD ACROSS PA / NY AND THEN WWD INTO THE CENTRAL PLAINS IS FORECAST TO MOVE SLOWLY SEWD / SWD THROUGH THE PERIOD...WHILE A SECOND FRONT IS EXPECTED TO MOVE SEWD ACROSS ERN MT INTO THE NRN PLAINS THROUGH THE PERIOD. ...MIDDLE MS AND LOWER OH VALLEYS... WIDESPREAD THUNDERSTORMS ARE ONGOING ATTM ALONG THE MS RIVER FROM SERN IA SSEWD INTO SRN IL...AHEAD OF UPPER SHORT-WAVE TROUGH MOVING SEWD ACROSS THIS REGION. STORMS SHOULD CONTINUE THROUGH THE DAY... WITH REDEVELOPMENT EXPECTED ACROSS ERN / CENTRAL MO ALONG CONVECTIVE OUTFLOW WHERE MODERATELY-UNSTABLE AIRMASS WILL DESTABILIZE FURTHER WITH DAYTIME HEATING. MID-LEVEL NWLY FLOW AROUND 50 KT WILL PERSIST ACROSS THIS REGION... SUFFICIENT FOR CONTINUED BOWS WITH EMBEDDED ROTATION AND ASSOCIATED THREAT FOR VERY STRONG / DAMAGING WINDS AND LARGE HAIL AS STORMS MOVE SEWD / SSEWD ACROSS THE REGION TOWARD WRN KY / WRN TN / NRN AR. ...NRN PLAINS... THUNDERSTORMS ARE ONGOING ACROSS NWRN ND...AND SHOULD INCREASE SWWD LATER TODAY AS AIRMASS DESTABILIZES AHEAD OF COLD FRONT MOVING SEWD INTO THIS REGION. STORMS SHOULD ALSO DEVELOP FURTHER SOUTH INTO ERN WY WITH PERSISTENT ELY LOW-LEVEL UPSLOPE FLOW. THIS REGION IS FORECAST TO REMAIN ON THE SRN FRINGE OF STRONGER MID-LEVEL FLOW...BUT DEEP-LAYER SHEAR SHOULD BE MARGINALLY- SUFFICIENT FOR MULTICELL / ISOLATED SUPERCELL STORMS. LARGE HAIL AND DAMAGING WINDS CAN BE EXPECTED. THIS EVENING / OVERNIGHT... LOW-LEVEL JET IS FORECAST TO INCREASE ACROSS WRN NEB...WHICH MAY ALLOW STORMS TO SPREAD EWD INTO WRN NEB ALONG WITH ASSOCIATED SEVERE THREAT. ...UPPER OH VALLEY / DELMARVA REGION... THUNDERSTORMS ARE ONGOING ATTM ACROSS ERN NY INTO NRN PA AHEAD OF COLD FRONT. STORMS SHOULD CONTINUE THROUGH THE DAY -- AND PERHAPS DEVELOP SWD INTO THE DELMARVA REGION ALONG LEE TROUGH FORECAST TO DEVELOP. CONVECTIVE DEVELOPMENT WILL BE AIDED BY VORTICITY MAXIMA ROTATING CYCLONICALLY ACROSS THIS REGION / AROUND STRONG UPPER LOW OVER QUEBEC. ALTHOUGH INSTABILITY IS FORECAST TO REMAIN LIMITED...MODERATELY-STRONG / NEARLY UNIDIRECTIONAL FLOW THROUGH A DEEP LAYER SUGGESTS THE POTENTIAL FOR STORM ORGANIZATION AND ISOLATED SEVERE STORMS. OVERALL THREAT SHOULD BE LIMITED BY MARGINAL INSTABILITY...AND BY THE FACT THAT THE FRONT / CONVECTIVE INITIATION ZONE IS ROUGHLY PARALLEL TO THE MEAN WIND. ..GOSS.. 07/18/03 NNNN |