ZCZC SPCSWODY1 ALL ACUS01 KWNS 091315 SPC AC 091312 STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS. VALID 091300Z - 101200Z THERE IS A MDT RISK OF SVR TSTMS ACROSS SERN AND ECNTRL IA...FAR NERN MO...WCNTRL AND NWRN IL TO THE RIGHT OF A LINE FROM 40 SE IRK 25 SE P35 15 S LWD 25 NNW LWD 20 WSW DSM 20 NNE DSM 30 SSW ALO 30 NE CID 35 SE DBQ 45 WNW MMO 30 N BMI 20 SW BMI SPI 35 WSW SPI 25 SSE UIN 40 SE IRK. THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 45 NE UNO 15 WNW UMN PNC 35 ESE P28 20 N P28 40 S RSL 15 N RSL 55 WNW CNK 40 WNW BIE 15 WSW OMA 55 E SUX 35 SSE FRM 30 NNE MCW 35 SW LSE 20 ESE LNR 35 SSE SBN MIE 45 ESE IND 25 SSE BMG 30 ESE MVN 45 NE UNO. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 40 ESE DUG 65 NW TCS 30 SSE GNT 15 N SAF 30 NNW CAO 45 N EHA 40 NW GCK 50 WSW HLC 35 SE LBF 45 SSW ANW 35 NE VTN 30 NW Y22 60 N OLF ...CONT... 20 WNW RRT 35 NNW BJI 25 S HIB 25 E IWD 35 ESE ESC 20 SSW OSC ...CONT... 15 NW BUF 20 N BGM 20 SSW GON. ...SYNOPSIS... UPPER-TROUGH OVER THE DAKOTAS WILL SHIFT SEWD TODAY AND SHOULD BE ACROSS THE GREAT LAKES REGION BY LATE IN THE PERIOD. COLD FRONT WILL ORGANIZE AND MOVE SEWD ACROSS THE CNTRL PLAINS AS A SYNOPTIC LOW PRESSURE CENTER AND ASSOCIATED WARM FRONT LIFTS NEWD ACROSS THE UPPER MIDWEST. ...IA/SRN MN/SW WI/IL/MO/ERN NEB/ERN KS... ONGOING MCS ACROSS IA WILL COMPLICATE THINGS TODAY AS A LARGE COLD POOL HAS BEEN LEFT BEHIND OVER ERN NEB/WRN IA. A WARM FRONTAL BOUNDARY EXISTS ACROSS ERN IA/NRN IL WITH AN OUTFLOW BOUNDARY EXTENDING ACROSS SRN IA INTO CNTRL IL. S OF THIS BOUNDARY...ABUNDANT LOW-LEVEL MOISTURE EXISTS WITH SFC DEWPOINTS IN THE LOWER 70S F. AS THE SFC LOW DEVELOPING ACROSS SRN-SERN NEB MOVES NEWD TODAY...THIS BOUNDARY SHOULD LIFT SLOWLY NWD BEING POSITIONED ACROSS SCNTRL IA EXTENDING EWD INTO NCNTRL IL. ALONG AND S OF THIS BOUNDARY...SFC HEATING WILL LIKELY RESULT IN MODERATE INSTABILITY WITH 2000 TO 3000 MLCAPE BY MID-AFTERNOON. HOW FAR NWD THIS BOUNDARY CAN GET REMAINS IN QUESTION BUT THE INSTABILITY COMBINED WITH THE UPPER-TROUGH APPROACHING FROM THE NRN PLAINS EVIDENT ON WV IMAGERY SHOULD PROVIDE SUFFICIENT LIFT FOR THUNDERSTORM DEVELOPMENT ALONG THE BOUNDARY THIS AFTERNOON ACROSS SCNTRL IA. A BAND OF STRONGER MID-LEVEL FLOW ROUNDING THE BASE OF THE TROUGH WILL INCREASE DEEP LAYER SHEAR DURING THE AFTERNOON ACROSS IA/NRN MO. FORECAST SOUNDINGS SHOW 0-6 SM SHEAR OF 4O TO 50 KT SUGGESTING SUPERCELLS AND/OR BOW ECHOES WILL BE LIKELY AS A BROKEN LINE OF CONVECTION DEVELOPS AND SPREADS EWD ACROSS ECNTRL-SERN IA/NERN MO AND INTO WCNTR-NW IL THIS EVENING. SUPERCELLS SHOULD BE CAPABLE OF PRODUCING A FEW TORNADOES ALONG THE WARM FRONT SE OF THE SFC LOW ACROSS ERN IA WHERE THE LOW-LEVEL JET WILL BE STRONGEST. AN ISOLATED TORNADO WILL ALSO BE POSSIBLE FARTHER SW ALONG A COLD FRONT MOVING ACROSS ERN KS/NRN MO LATE THIS AFTERNOON/EVENING. BOW ECHOES IN THE LINE WILL HAVE A WIND DAMAGE POTENTIAL WITH GUSTS OVER 70 MPH POSSIBLE WITH A FEW STORMS. EMBEDDED SUPERCELLS WITHIN THE LINE WILL ALSO HAVE A WIND DAMAGE/LARGE HAIL THREAT. ...MD/VA/DE/SERN PA/NJ... SFC DEWPOINTS IN THE UPPER 60S TO LOWER 70S F EXIST CURRENTLY ACROSS VA/ERN MD/NJ. STRONG SFC HEATING ALONG THE MOISTURE AXIS WILL LIKELY RESULT IN MODERATE INSTABILITY WITH MLCAPE OF 2000 TO 3000 J/KG ALONG THE MID-ATLANTIC COASTAL AREAS BY AFTERNOON. A STATIONARY FRONTAL BOUNDARY EXTENDS E TO W FROM OH TO MD. THIS WILL BE A FOCUS FOR CONVECTION THIS AFTERNOON. ALTHOUGH...MID-LEVEL WIND FIELDS WILL DECREASE SOME DURING THE DAY...FORECAST SOUNDINGS SHOW 35 KT AT 500 MB BY 21Z. THIS COUPLED WITH THE VERY UNSTABLE AIR MAY BE ENOUGH FOR AN ISOLATED SEVERE STORM MAINLY ACROSS NRN VA/MD OR SERN PA BY MID AFTERNOON. AN ISOLATED DAMAGING WET MICROBURST WOULD BE THE MAIN THREAT CONSIDERING THE MODERATE SHEAR AND ABUNDANT LOW- LEVEL MOISTURE. ..BROYLES/TAYLOR.. 07/09/03 NNNN |