SPC AC 120720
   
   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0220 AM CDT TUE APR 12 2005
   
   VALID 141200Z - 151200Z
   
   ...NO SVR TSTM AREAS FORECAST...
   
   MODELS SUGGEST SUFFICIENT WEAKENING OF UPPER BLOCK...LATE THIS WEEK 
   INTO THE WEEKEND...FOR A TRANSITION TOWARD A SOMEWHAT MORE ZONAL
   FLOW REGIME.  HOWEVER...INCREASING STABILIZING INFLUENCE OF ONGOING
   PATTERN TODAY THROUGH THURSDAY WILL BE SLOWER TO MODIFY.
   
   BY THURSDAY...CONFLUENT UPPER FLOW ACROSS EASTERN NORTH AMERICA IS
   PROGGED TO SUPPORT A MASSIVE SURFACE RIDGE EXTENDING FROM HUDSON BAY
   INTO THE WESTERN GULF OF MEXICO.  THIS WILL PRECLUDE RETURN FLOW OF
   MOISTURE OFF THE GULF OF MEXICO INTO VICINITY OF COLD FRONT
   ADVANCING EAST OF THE NORTHERN ROCKIES...AND SURFACE TROUGH
   DEVELOPING IN THE LEE OF THE CENTRAL/SOUTHERN ROCKIES. LAPSE RATES
   WILL BECOME VERY STEEP NEAR THESE BOUNDARIES...AND INFLUX OF MID-
   LEVEL MOISTURE OFF THE SUBTROPICAL PACIFIC MAY SUPPORT SCATTERED
   STORMS ACROSS THE SOUTHERN ROCKIES...PERHAPS A FEW HIGH-BASED STORMS
   EAST OF NORTHEAST COLORADO THERMAL LOW.  HOWEVER...LACK OF CAPE IS
   EXPECTED TO INHIBIT SEVERE THREAT.
   
   ACROSS THE FLORIDA PENINSULA...WESTERLY THEN NORTHWESTERLY SURFACE
   FLOW WILL CONTINUE TO DRY BOUNDARY LAYER.  THIS MAY BE COMPENSATED
   FOR SOMEWHAT BY COLD MID-LEVEL TROUGH SHIFTING ACROSS REGION. 
   HOWEVER...STRONGER LOW-LEVEL CONVERGENCE AND POTENTIAL FOR ISOLATED
   THUNDERSTORMS WILL LIKELY BE CONFINED TO AREAS NEAR/JUST EAST OF THE
   ATLANTIC COAST.
   
   ..KERR.. 04/12/2005
   
   ...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