Apr 27, 2008 1100 UTC Day 3 Severe Thunderstorm Outlook
Updated: Sun Apr 27 06:36:38 UTC 2008
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Categorical Graphic
20080427 1100 UTC Day 3 Outlook Graphic
Probabilistic Graphic
20080427 1100 UTC Day Probabilitic Graphic
Probability Legend Image
   SPC AC 270635
   
   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0135 AM CDT SUN APR 27 2008
   
   VALID 291200Z - 301200Z
   
   ...NO SVR TSTM AREAS FORECAST...
   
   ...SYNOPSIS...
   SPEED MAX AND LOW-AMPLITUDE SHORTWAVE PERTURBATION - NOW EVIDENT IN
   MOISTURE CHANNEL IMAGERY INVOF MB-SASK BORDER -- IS EXPECTED TO
   AMPLIFY CONSIDERABLY AND DIG SEWD THEN EWD THROUGH DAY-2 ACROSS OH
   VALLEY AND CENTRAL APPALACHIANS.  TROUGH SHOULD BECOME NEGATIVELY
   TILTED BY 29/12Z...EJECTING NEWD OVER MID-ATLANTIC AND ERN NEW
   ENGLAND DURING ENSUING 18 HOURS...AROUND SERN RIM OF ERN CANADIAN
   UPPER CYCLONE.  SFC COLD FRONT -- NOW CROSSING OK AND W TX -- IS
   FCST TO EXPAND AND SWEEP SEWD ACROSS MOST OF ERN CONUS BY BEGINNING
   OF PERIOD...EXITING  S FL BETWEEN 29/12Z-29/18Z BASED ON CONSENSUS
   OF SREF AND OPERATIONAL/DETERMINISTIC GUIDANCE PACKAGES.  FROPA
   SHOULD LEAVE CONUS E OF ROCKIES TOO STABLE AND/OR DRY FOR SVR RISK.
   
   FARTHER W...LARGE MID-UPPER LEVEL CYCLONE CURRENTLY OVER GULF OF AK
   IS FCST TO SHIFT SEWD TO PACIFIC NW AND CENTRAL/SRN BC.  SEVERAL
   SHORTWAVES WITH EMBEDDED/SMALLER-SCALE VORTICES SHOULD ORBIT COMMON
   CENTER IN FUJIWHARA INTERACTION.  AS THIS OCCURS...HEIGHT FALLS AND
   LOW LEVEL WAA ARE FCST OVER NRN ROCKIES AND NRN HIGH PLAINS DURING
   LATTER PART OF PERIOD.  VERY WEAK MOISTURE AND STEEP LAPSE RATES MAY
   SUPPORT SOME THUNDER OVER THIS AREA...AND COLD-CORE TSTMS ALSO MAY
   OCCUR CLOSER TO COMPLEX UPPER LOW CENTER.  HOWEVER...FCST LOW LEVEL
   THETAE APPEARS TOO WEAK TO SUPPORT SVR THREAT.
   
   ..EDWARDS.. 04/27/2008
   
   CLICK TO GET WUUS03 PTSDY3 PRODUCT

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