ZCZC SPCSWODY1 ALL ACUS01 KWNS 121629 SPC AC 121629 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1129 AM CDT FRI SEP 12 2003 VALID 121630Z - 131200Z GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 40 E ANJ 25 NNW MBS 25 NNE IND 40 SSW EVV 25 WNW TUP 15 NW MEI 30 SSW MOB ...CONT... 25 ESE MFE 30 SE SAT 55 E JCT 20 NNE BWD 50 SSW TUL 30 SW CID 35 SW EAU 40 ENE ELO ...CONT... INL 35 NW VTN 40 E RWL 25 ENE BPI 35 SSE MQM 55 ESE S80 35 E GEG 90 WNW FCA. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 N PIE 40 N MLB. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 10 E ILM 20 SE DAN 45 S MRB 30 W ABE 10 SW JFK. ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER LOW WILL CONTINUE MOVING SLOWLY EWD OVER THE CANADIAN PRAIRIES AND THE NRN PLAINS OF THE U.S. TODAY...WHILE SRN PLAINS UPPER LOW WEAKENS AND BEGINS EJECTING NEWD TOWARDS THE OZARK REGION. LEADING SURFACE COLD FRONT NOW MOVING ACROSS THE MS RIVER VALLEY AND INTO AR/CENTRAL TX WILL SLOW THROUGH THE PERIOD...AS STRONGER COLD FRONT ADVANCES SEWD OUT OF THE NRN PLAINS. ...NRN MS RIVER VALLEY INTO THE WRN/NRN GREAT LAKES... APPEARS LEADING EDGE OF CONVECTION AND PRIMARY SURFACE WIND SHIFT IS ALREADY MOVING EAST OF THE MS RIVER OVER WRN WI/NRN IL LATE THIS MORNING. GIVEN THE LIMITED HEATING EXPECTED AHEAD OF THIS ACTIVITY AND THE SERN BOUNDARY LAYER FEED OFF LAKE MI...INSTABILITY IS NO LONGER EXPECTED TO SUPPORT STRONG STORMS DESPITE THE MODEST LOW AND DEEP LAYER SHEAR ACROSS THIS REGION. ...NRN PLAINS... APPEARS VORT MAX IS NOW EXITING NERN ND/NWRN MN...WITH WEAK SUBSIDENCE IN ITS WAKE. THIS SHOULD ALLOW SOME HEATING TO COMMENCE AHEAD OF APPROACHING COLD FRONT AND NEXT UPPER LEVEL SYSTEM MOVING SEWD INTO THE NRN HIGH PLAINS. ISOLATED CONVECTION SHOULD DEVELOP DUE TO STEEPENING LAPSE RATES AND WEAK INSTABILITY. HOWEVER... ACTIVITY IS EXPECTED TO REMAIN SUB-SEVERE EVEN THOUGH SOME HAIL MAY OCCUR WITH A STRONG CELL OR TWO. ...LOWER MS RIVER VALLEY INTO THE OZARK REGION... DEEP MOIST CONVECTION WILL LIKELY WEAKEN OVER THE LOWER MS RIVER VALLEY AS UPPER SYSTEM BEGINS LIFTING SLOWLY NEWD. HOWEVER...DEEP MOISTURE AND SUFFICIENT LOW LEVEL CONVERGENCE WILL LIKELY MAINTAIN A BAND OF NON-SEVERE THUNDERSTORMS ACROSS ERN TX/LA INTO PORTIONS OF AR THROUGH THE DAY. ..EVANS/JEWELL.. 09/12/2003 ...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. $$ |