SPC AC 200836
   
   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0336 AM CDT WED APR 20 2005
   
   VALID 221200Z - 231200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM TX INTO THE LOWER MS
   VALLEY...OH AND TN VALLEYS AND PARTS OF THE SERN STATES...
   
   ...SYNOPSIS...
   
   VORTICITY MAXIMUM NOW ROUNDING BASE OF WRN U.S UPPER LOW IS FORECAST
   TO PHASE WITH NRN STREAM TROUGH FRIDAY AS IT ADVANCES SEWD INTO THE
   MS VALLEY. THE UPPER TROUGH WILL CONTINUE TO AMPLIFY TOWARD THE OH
   AND TN VALLEYS DURING THE DAY WITH ATTENDANT SURFACE LOW FORECAST TO
   DEEPEN OVER THE OH VALLEY THURSDAY THEN LIFT NEWD INTO THE NERN
   STATES FRIDAY NIGHT. THIS PROCESS WILL DRIVE A COLD FRONT SEWD INTO
   TX...THE MS AND OH VALLEYS AS WELL AS THE SERN STATES. A WARM FRONT
   SHOULD LIFT NWD INTO THE OH VALLEY AND MID ATLANTIC AS THE SURFACE
   LOW DEEPENS OVER THE NERN STATES FRIDAY EVENING. CONSIDERABLE
   UNCERTAINTY EXISTS REGARDING THE DETAILS OF THE UPPER AIR PATTERN
   EVOLUTION.
   
   ...OH VALLEY...LOWER MS VALLEY...TX AND SERN STATES...
   
   A CLUSTER OF MOSTLY ELEVATED STORMS WILL LIKELY BE ONGOING IN THE
   WARM ADVECTION REGIME OVER PARTS OF THE OH VALLEY EARLY FRIDAY.
   OTHER STORMS MAY ALSO BE IN PROGRESS ALONG PRE-FRONTAL REMNANT
   OUTFLOW BOUNDARIES OVER PARTS OF THE TN AND LOWER MS VALLEYS. THOUGH
   A LIMITED SEVERE THREAT MAY EXIST WITH THE EARLY ACTIVITY...THE
   PRIMARY THREAT IS EXPECTED DURING THE AFTERNOON AND EVENING.
   MODERATE INSTABILITY IS EXPECTED IN WAKE OF MORNING ACTIVITY E OF
   COLD FRONT WITH MLCAPE FROM 2000 J/KG FROM TX TO THE LOWER MS VALLEY
   TO AROUND 1000 J/KG FARTHER NEWD INTO THE OH VALLEY. ADDITIONAL
   STORMS ARE EXPECTED TO DEVELOP ALONG AND E OF THE FRONT FROM THE OH
   VALLEY SWWD THROUGH TX. INSTABILITY WILL BE MORE LIMITED FARTHER NE
   INTO THE OH VALLEY. HOWEVER...STRONGER FORCING FOR ASCENT WILL EXIST
   IN THIS REGION DOWNSTREAM FROM EWD ADVANCING VORT MAX. PRIMARY
   THREATS WILL BE FOR DAMAGING WIND OVER THE OH AND TN VALLEYS AND
   LARGE HAIL FARTHER SWWD OVER THE LOWER MS VALLEY INTO TX.
   
   ..DIAL.. 04/20/2005
   
   ...NOTICE...
   THE STATION RELATIVE POINTS IN THIS PRODUCT ARE NOW AVAILABLE
   SEPARATELY UNDER THE WMO HEADINGS WUUS01 PTSDY1...
   WUUS02 PTSDY2...WUUS03 PTSDY3.  THE INCLUSION OF POINTS
   IN THIS DISCUSSION WILL BE DISCONTINUED AFTER THE 2005
   CONVECTIVE SEASON.  A PUBLIC NOTIFICATION STATEMENT (PNS)
   WILL PROVIDE DETAILS ON THE TRANSITION.
   
   CLICK TO GET WUUS03 PTSDY3 PRODUCT

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 1100Z