SPC AC 230749
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0249 AM CDT TUE SEP 23 2003
   
   VALID 241200Z - 251200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 45 NW
   ERI 20 NNE ZZV 25 NNW BWG 15 SSE CGI 25 NE VIH 25 SSW UIN 30 W CGX
   15 W GRR 60 NNE MTC.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 NNW SAN TRM 20 ENE
   BLH 10 NNW PHX 15 ESE SAD 75 ESE DUG.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 SE HUM 40 NW PNS
   15 SSW TOI 55 SSE MCN 15 ENE SSI.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 55 WNW MRF 15 N INK
   40 ENE BGS 15 ESE BWD 10 NNW AUS 20 WSW SAT 65 W COT.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 E MSS 30 SE BFD 20
   N HTS 20 SSE BWG 20 NE ARG 25 SSW SZL 45 SSE P35 40 W RFD 40 WSW OSH
   50 NE EAU 35 SE BJI 10 N RRT.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF LWR MI AND THE OH
   VLY....
   
   ...SYNOPSIS...
   PROGRESSIVE PATTERN WILL CONTINUE ACROSS MUCH OF THE NATION THIS
   PERIOD AS STRONG DISTURBANCES MOVE ALONG FAST POLAR JET EXTENDING
   FROM SW CANADA ACROSS THE NRN PLNS/UPR MS VLY TO THE NERN U.S. 
   CLOSED LOW NOW REDEVELOPING IN THE LEE OF THE CANADIAN ROCKIES
   EXPECTED TO REACH WRN ONTARIO/NRN MN BY THE START OF THE PERIOD...
   BEFORE CONTINUING E TO NEAR JAMES BAY BY 12Z THURSDAY. TRAILING
   SHORTWAVE TROUGH EXTENDING SW FROM THE LOW SHOULD SWEEP ACROSS THE
   UPR MS VLY/UPR GRT LKS DURING THE PERIOD.
   
   FARTHER S...EARLIER GFS/ECMWF GUIDANCE APPEARS TO HAVE BEEN ACCURATE
   IN FORECASTING DEVELOPMENT OF A SRN STREAM JET OVER S TX
   ...PARTIALLY IN RESPONSE TO OUTFLOW FROM T.S. MARTY.  THE JET SHOULD
   PERSIST THROUGH THE DAY 2 PERIOD.
   
   ...LWR MI INTO IL/IND/OH/ERN MO...
   COLD FRONT ASSOCIATED WITH POTENT UPPER SYSTEM CROSSING SRN CANADA
   SHOULD OVERTAKE 925-850 MB MOISTURE PLUME STREAMING NEWD FROM THE
   SRN PLNS EARLY IN THE PERIOD...MOST LIKELY IN THE VICINITY OF ERN
   MO/IL. WITH MID LEVEL WLY FLOW ON FRINGE OF DEEPENING UPPER TROUGH
   INCREASING TO BETWEEN 40 AND 50 KT ACROSS REGION...DEEP LARGELY
   UNIDIRECTIONAL SHEAR WILL BE MORE THAN ADEQUATE FOR SUSTAINED
   STORMS/SUPERCELLS.  WHILE SOME CLOUDINESS WILL ACCOMPANY DEVELOPING
   ZONE OF WARM ADVECTION/LARGE SCALE ASCENT AHEAD OF COLD
   FRONT...COMBINATION OF MODERATE SURFACE HEATING AND INCREASING
   MOISTURE INFLUX SHOULD ALLOW AFTERNOON MLCAPE TO RISE TO AOA 1000
   J/KG OVER FAR ERN MO/IL AND IND....WITH SOMEWHAT LESSER VALUES
   EXTENDING NE INTO SRN LWR MI/OH.  OVERALL SETUP SHOULD SUPPORT
   DEVELOPMENT OF SEVERAL SMALL BANDS/CLUSTERS OF STRONG STORMS/
   POSSIBLE SPLITTING SUPERCELLS...WITH A THREAT FOR BOTH HAIL AND HIGH
   WIND.  THIS ACTIVITY SHOULD MERGE INTO A SOLID LINE...WITH A
   DIMINISHING SEVERE THREAT POSSIBLY CONTINUING E INTO OH/WRN PA AND
   NY WEDNESDAY NIGHT.
   
   ...NRN LWR MI/UPR MI...
   A LIMITED DEGREE OF ELEVATED INSTABILITY MAY DEVELOP OVER THE NRN
   HALF OF MI WEDNESDAY AFTERNOON ALONG/AHEAD OF SAME COLD FRONT
   AFFECTING THE SRN PART OF THE STATE.  GIVEN STRENGTH OF
   UNIDIRECTIONAL WIND FIELD /PREFRONTAL 500 MB SPEEDS APPROACHING 60
   KT/...POTENTIAL WILL EXIST FOR EMBEDDED LEWPS/SMALL SCALE BOWS IN
   LINE OF FORCED CONVECTION EXPECTED TO DEVELOP ALONG FRONT.  STABLE
   LOWER LEVEL AIR SHOULD LIMIT DOWNWARD PENETRATION OF ANY ASSOCIATED
   GUSTS.
   
   ...S TX...
   RICH BOUNDARY LAYER MOISTURE WILL REMAIN IN PLACE ACROSS S TX WWD
   INTO THE MOUNTAINS OF N CNTRL MEXICO BETWEEN NOW AND WEDNESDAY. 
   COUPLED WITH SURFACE HEATING...WEAK LOW LEVEL UPSLOPE FLOW AND
   MODERATE WLY FLOW ALOFT ASSOCIATED WITH SRN STREAM/SUB TROPICAL
   JET...SETUP MAY PROVE FAVORABLE FOR EWD MOVEMENT OF THUNDERSTORMS
   LIKELY TO FORM OVER THE NRN MEXICAN MOUNTAINS OR THE MOUNTAINS OF
   THE TX BIG BEND REGION.  RIDGING/RELATIVELY WARM MID LEVEL
   TEMPERATURES SHOULD MINIMIZE DEGREE OF ANY ASSOCIATED SEVERE THREAT.
   
   ..CORFIDI.. 09/23/2003
   
   ...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.
   
   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED FOR 1730Z