ZCZC SPCSWODY1 ALL ACUS01 KWNS 091638 SPC AC 091636 STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS. VALID 091630Z - 101200Z THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF ERN IA...NERN MO...AND WRN IL TO THE RIGHT OF A LINE FROM 30 SE FOD 30 ESE MCW 55 NE ALO 35 NNE MLI 10 W MMO BMI 20 SSW SPI 40 NNW COU 25 S P35 25 N LWD 30 SE FOD. THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 SSE OAJ 40 ESE CLT 25 WNW AVL 45 NNE CSV 25 SW OWB 25 N CGI 45 NE UNO 25 SW JLN 35 S ICT 30 SE RSL 30 E SUX 10 N FRM 30 SSE MSP 35 SSW EAU 15 SSW VOK 30 NNW BEH 10 S JXN 20 NE TOL 30 ESE TOL 10 E MFD 30 ENE LBE 30 WSW ABE 10 E NEL. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 S DMN 10 SSW TCS 55 ENE 4CR 35 SE DHT 15 S GCK 25 ENE GRI 55 NW OFK 55 N OLF ...CONT... 20 WNW RRT 20 NNW BJI 50 SW IWD 25 ESE MBL 45 NNE MTC ...CONT... 20 N JHW 10 SE ISP. ...IA/NRN MO EWD TO IL/IND... UPPER LEVEL FLOW PATTERN WILL CONTINUE TO AMPLIFY TODAY AS A RIDGE BUILDS NWD ACROSS THE WRN STATES INTO WRN CANADA...AND THE DOWNSTREAM TROUGH OVER THE NRN-CENTRAL PLAINS THIS MORNING TRACKS SEWD THIS PERIOD DEEPENING THE TROUGH OVER THE GREAT LAKES REGION. SURFACE LOW OVER THE MID MO RIVER VALLEY THIS MORNING WILL TRACK EWD INTO SRN MN/NRN IA BY 00Z...WITH A COLD FRONT TRAILING SWWD THROUGH CENTRAL IA TO CENTRAL KS. MEANWHILE...A WARM FRONT IS EXPECTED TO LIFT NWD INTO NERN IA/NRN IL TO NRN IND BY 00Z AS THE UPPER TROUGH MOVES ACROSS THE UPPER-MID MS VALLEY. OUTFLOW BOUNDARIES...FROM EARLIER CONVECTION ACROSS THE OH VALLEY AND CURRENT COMPLEX OVER IL...EXTEND FROM SRN IND WNWWD TO NRN MO. THESE BOUNDARIES WILL PROVIDE ADDITIONAL FOCI FOR CONVECTIVE DEVELOPMENT TODAY AS THE WARM SECTOR DESTABILIZES WITH MLCAPE OF 3000-4000 J/KG EXPECTED ACROSS THE MODERATE RISK. AS LARGE SCALE ASCENT INCREASES ACROSS SRN MN SWD THROUGH IA TO NRN MO WITH THE APPROACH OF THE UPPER TROUGH...CONVECTION IS EXPECTED TO DEVELOP IN THE VICINITY OF THE SURFACE LOW AND SWWD ALONG THE COLD FRONT. POCKETS OF SURFACE HEATING IN THE WAKE OF THE STORMS NOW OVER IL SHOULD PROVIDE FAVORABLE THERMODYNAMICS FOR SEVERE STORMS AS A 50 KT WLY MID-LEVEL JET MAX TRACKS ACROSS NRN IA THIS AFTERNOON. DEEP LAYER SHEAR WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS WITH DAMAGING WINDS...A FEW TORNADOES AND HAIL THIS AFTERNOON WITH INITIAL STORMS ACROSS IA. CLUSTERS OF STORMS SHOULD EVOLVE INTO AN MCS BY THIS EVENING WITH ACTIVITY MOVING ESEWD INTO FAR SRN WI/CENTRAL-NRN IL AND EVENTUALLY REACHING SRN MI/IND OVERNIGHT...WITH DAMAGING WINDS BEING THE PRIMARY THREAT OVERNIGHT. ONGOING STORMS ACROSS CENTRAL-NRN IL WILL MOVE ESEWD ALONG THE WARM FRONT INTO CENTRAL IND THIS AFTERNOON WITH DAMAGING WINDS AND HAIL BEING THE PRIMARY THREAT. AN ISOLATED THREAT FOR TORNADOES WILL ALSO EXIST MAINLY ALONG THE WARM FRONT WHERE LOW-LEVEL SHEAR WILL BE ENHANCED. ...MID ATLANTIC STATES... SHORT WAVE TROUGH...CURRENTLY LOCATED FROM SERN OH TO ERN KY...WITH 40-45 KT OF WLY MID-LEVEL FLOW WILL PROVIDE SUFFICIENT LARGE SCALE ASCENT AND DEEP LAYER SHEAR FOR ORGANIZED STORMS ACROSS THE MID- ATLANTIC AND DELMARVA REGION TODAY. AIR MASS OVER THIS REGION WILL CONTINUE TO DESTABILIZE...GIVEN SUFFICIENT SURFACE HEATING AND SURFACE DEWPOINTS IN THE 70S RESULTING IN AFTERNOON MLCAPE VALUES OF 2000-3000 J/KG. DEEP WLY FLOW WILL FAVOR DAMAGING WINDS AS THE PRIMARY THREAT...WITH THE GREATEST POTENTIAL ACROSS WV/NRN VA INTO THE DELMARVA REGION WHERE MID-LEVEL FLOW WILL BE THE STRONGEST. ...CENTRAL FL... STRONG SURFACE HEATING COMBINED WITH FAVORABLE THERMODYNAMIC PROFILES OVER THIS AREA PER 12Z UPPER AIR ANALYSIS /-8.5 C AT TBW WITH LAPSE RATES OF 6.5 C/KM/ WILL RESULT IN A VERY UNSTABLE AIR MASS ACROSS FL BY THIS AFTERNOON. WV IMAGERY SHOWS A PLUME OF MOISTURE WITHIN ELY FLOW ACROSS CENTRAL FL. ALTHOUGH DEEP LAYER SHEAR IS EXPECTED TO REMAIN VERY WEAK ACROSS THIS REGION TODAY... EMBEDDED WEAK SHORT WAVE TROUGHS WITHIN THE MOIST PLUME ALOFT MAY ENHANCE UVVS FOR THUNDERSTORM DEVELOPMENT. GIVEN THE DEGREE OF INSTABILITY EXPECTED...ISOLATED DAMAGING WET MICROBURSTS AND MARGINALLY SEVERE HAIL WOULD BE THE PRIMARY THREATS. ..PETERS.. 07/09/03 NNNN |