ZCZC SPCSWODY1 ALL ACUS01 KWNS 151218 SPC AC 151218 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0718 AM CDT MON SEP 15 2003 VALID 151300Z - 161200Z GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 NW BML 20 SE LCI 15 ENE EWB ...CONT... 10 W AQQ MAI 30 WNW HSS HTS DAY DEC RFD 40 SSE IMT 115 NNW ANJ. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM MLC 35 ESE OKC 45 W END 45 ENE DDC SLN 25 WNW CNU 25 E MKO MLC. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 NW LRD 35 E COT 15 ESE PSX. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 65 NNW ISN LWT BTM 65 NW 27U 30 N 63S. ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER AIR PATTERN WILL REMAIN PROGRESSIVE ACROSS CONUS...PARTICULARLY IN NRN STREAM. DEEP TROUGH NOW EVIDENT ON MOISTURE CHANNEL IMAGERY BETWEEN UPPER MS VALLEY AND LM WITH EMBEDDED CYCLONE OVER NRN IL/SRN WI. EXPECT THIS TROUGH TO BECOME MORE NEGATIVELY TILTED AS IT MOVES ENEWD ACROSS GREAT LAKES THROUGH REMAINDER PERIOD. ASSOCIATED SFC COLD FRONT -- ANALYZED FROM SRN ONT ACROSS ERN KY AND SWRN LA -- IS EXPECTED TO MOVE TO VICINITY ERN NY BORDER AND MID ATLANTIC COAST BY 16/12Z...BECOMING DIFFUSE SWWD TOWARD CENTRAL GULF COAST REGION. MEANWHILE...LEE-SIDE SFC CYCLOGENESIS WILL INTENSIFY OVER HIGH PLAINS FROM SERN MT TO SWRN SD...AS MID-UPPER LEVEL TROUGH NOW APPROACHING PACIFIC NW COAST CAUSES HEIGHT FALLS ACROSS NRN ROCKIES REGION. WARM FRONTOGENESIS SHOULD TAKE PLACE OVER NEB/SD. THIS PROCESS MAY BLEND LATE IN PERIOD WITH DECELERATING BAROCLINIC ZONE NOW MOVING SEWD ACROSS SASK/MT AS COLD FRONT. ...ERN GREAT LAKES/MID-ATLANTIC... ISOLATED TO WIDELY SCATTERED TSTMS MAY DEVELOP LATE MORNING THROUGH AFTERNOON...ALONG/AHEAD OF SFC COLD FRONT. AIR MASS WILL BE CHARACTERIZED BY RICH LOW LEVEL MOISTURE...BUT VERY WEAK LAPSE RATES. LATTER WILL LIMIT MLCAPE TO AOB 700 J/KG IN MODIFIED RUC/ETA SOUNDINGS OVER MOST OF REGION. KINEMATICALLY...NEARLY UNIDIRECTIONAL DEEP LAYER FLOW IS EXPECTED...WITH WEAK LOW LEVEL SHEAR AND SMALL 0-1 AND 0-3 KM AGL HODOGRAPHS. THIS SHOULD LIMIT OVERALL SEVERE POTENTIAL...ALTHOUGH A FEW CELLS OR SHORT LINE SEGMENTS OF CONVECTION MAY PRODUCE STRONG GUSTS CAPABLE OF MINOR DAMAGE. INSTABILITY SHOULD BE GREATER CLOSER TO ATLANTIC COAST AND FARTHER S ACROSS CAROLINAS...AND TSTMS HAVE BEEN OBSERVED PAST SEVERAL HOURS DELMARVA REGION NWD THROUGH EXTREME ERN PA. HOWEVER...WEAK DEEP-LAYER WINDS WILL LIMIT POTENTIAL FOR WELL-ORGANIZED CONVECTION WITH EWD DISTANCE FROM BOTH FRONT AND MID-UPPER LEVEL TROUGH. ..EDWARDS/TAYLOR.. 09/15/2003 ...NOTICE... FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3. THE INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED. $$ |