|Day 4-8 Severe Weather Outlook Issued on Apr 22, 2011|
|Updated: Fri Apr 22 08:56:03 UTC 2011|
|D4||Mon, Apr 25, 2011 - Tue, Apr 26, 2011
||D7||Thu, Apr 28, 2011 - Fri, Apr 29, 2011
|D5||Tue, Apr 26, 2011 - Wed, Apr 27, 2011
||D8||Fri, Apr 29, 2011 - Sat, Apr 30, 2011
|D6||Wed, 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).
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
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
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