Skip Navigation Links weather.gov 
NOAA logo-Select to go to the NOAA homepage NOAA's National Weather Service   Select to go to the NWS homepage
Storm Prediction Center
navigation bar left  
  navigation bar end cap


 
USA.gov is the U.S. Government's official Web portal to all Federal, state and local government Web resources and services.

Day 4-8 Severe Weather Outlook Issued on Apr 22, 2011
Updated: Fri Apr 22 08:56:03 UTC 2011
Day 4-8 Severe Weather Outlook Graphics Issued on Apr 22, 2011
D4Mon, Apr 25, 2011 - Tue, Apr 26, 2011 D7Thu, Apr 28, 2011 - Fri, Apr 29, 2011
D5Tue, Apr 26, 2011 - Wed, Apr 27, 2011 D8Fri, Apr 29, 2011 - Sat, Apr 30, 2011
D6Wed, Apr 27, 2011 - Thu, Apr 28, 2011 (All days are valid from 12 UTC - 12 UTC)
Note: A severe weather area depicted in the Day 4-8 period indicates a 30% or higher probability for severe thunderstorms within 25 miles of any point.
PREDICTABILITY TOO LOW is used to indicate severe storms may be possible based on some model scenarios. However, the location or occurrence of severe storms are in doubt due to: 1) large differences in the deterministic model solutions, 2) large spread in the ensemble guidance, and/or 3) minimal run-to-run continuity.
POTENTIAL TOO LOW means the threat for a regional area of organized severe storms appears highly unlikely during the entire period (e.g. less than a 30% probability for a regional severe storm area across the CONUS through the entire Day 4-8 period).

 Forecast Discussion

   ZCZC SPCSWOD48 ALL
   ACUS48 KWNS 220855
   SPC AC 220855
   
   DAY 4-8 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0355 AM CDT FRI APR 22 2011
   
   VALID 251200Z - 301200Z
   
   ...DISCUSSION...
   MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT THROUGH DAY 7 /THU.
   4-28/...WITH RESPECT TO A LARGE TROUGH NOW MOVING INTO/DEVELOPING
   ACROSS THE WRN CONUS.  THE TROUGH IS FORECAST TO EJECT/EVOLVE SLOWLY
   EWD ACROSS THE CENTRAL AND ERN U.S. THROUGH DAY 7...AND AS IT
   DOES...AN ASSOCIATED SURFACE COLD FRONT WILL ALSO SHIFT SLOWLY EWD
   ACROSS THIS REGION.
   
   WITH PERSISTENT SLY LOW-LEVEL FLOW AHEAD OF THIS SYSTEM ADVECTING
   GULF MOISTURE NWD...AMPLE INSTABILITY SHOULD BE AVAILABLE -- BEING
   ENHANCED EACH AFTERNOON IN CONJUNCTION WITH THE DIURNAL HEATING
   CYCLE.  WITH STRONG MID-LEVEL FLOW ACCOMPANYING THE ADVANCING
   SYSTEM...SHEAR WILL ALSO BE FAVORABLE FOR
   ORGANIZED/POTENTIALLY-SEVERE CONVECTION.  AS A RESULT...A
   MULTIPLE-DAY PERIOD OF SEVERE WEATHER IS EXPECTED...WITH THE MAIN
   THREAT AREA SHIFTING SLOWLY EWD WITH TIME.  
   
   WILL HIGHLIGHT A THREAT AREA FROM E TX NWD ACROSS THE ARKLATEX TO
   ERN OK/WRN AR/SWRN MO FOR DAY 4 /MON. 4-25/...WHERE RELATIVELY
   SUBSTANTIAL SEVERE WEATHER POTENTIAL IS EVIDENT INCLUDING SUPERCELLS
   AND SOME THREAT FOR TORNADOES.
   
   A SIMILAR THREAT APPEARS POSSIBLE DAY 5...AS THE INITIAL SHORT-WAVE
   TROUGH EJECTS NNEWD AND A SECOND SHORT-WAVE FEATURE DIGS SEWD
   TOWARD/INTO THE BASE OF THE LARGER-SCALE TROUGH.
   
   ATTM...SPECIFICS OF THE SEVERE WEATHER THREAT GET MORE DIFFICULT TO
   DISCERN DAY 6 /WED. 4-27/ AND BEYOND...AS THE FRONT SHIFTS E OF THE
   MS VALLEY.
   
   ..GOSS.. 04/22/2011

   CLICK TO GET WUUS48 PTSD48 PRODUCT

Weather Topics:
Watches, Mesoscale Discussions, Outlooks, Fire Weather, All Products, Contact Us

NOAA / National Weather Service
National Centers for Environmental Prediction
Storm Prediction Center
120 David L. Boren Blvd.
Norman, OK 73072 U.S.A.
spc.feedback@noaa.gov
Page last modified:
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities