Day 4-8 Severe Weather Outlook Issued on Apr 23, 2013
Updated: Tue Apr 23 09:00:03 UTC 2013
Area (sq. mi.)
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Fri, Apr 26, 2013 - Sat, Apr 27, 2013
Mon, Apr 29, 2013 - Tue, Apr 30, 2013
Sat, Apr 27, 2013 - Sun, Apr 28, 2013
Tue, Apr 30, 2013 - Wed, May 01, 2013
Sun, Apr 28, 2013 - Mon, Apr 29, 2013
(All days are valid from 12 UTC - 12 UTC the following day)
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 230859
SPC AC 230859
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0359 AM CDT TUE APR 23 2013
VALID 261200Z - 011200Z
A SPLIT/ZONAL UPPER PATTERN WILL INITIALLY PREVAIL INTO LATE
WEEK...WITH SOME TROUGH AMPLIFICATION POSSIBLE OVER THE
NORTHWEST/NORTH-CENTRAL CONUS BY THE WEEKEND OR EARLY NEXT WEEK.
INITIAL FOCUS WILL BE ON A SOUTHERN STREAM SHORTWAVE TROUGH AS IT
MOVES EASTWARD OVER THE SOUTH-CENTRAL/SOUTHEAST CONUS ON DAYS 4-5
FRIDAY/SATURDAY. AS MOISTURE SPREADS NORTHWARD IN ADVANCE OF THIS
SYSTEM...SOME STRONG/SEVERE TSTMS WILL BE POSSIBLE ON DAY 4/FRIDAY.
THIS COULD INCLUDE AREAS SUCH AS OK/NORTH TX TO THE ARKLATEX. BY DAY
5/SATURDAY...A SIMILAR SEVERE THREAT COULD DEVELOP
EAST-SOUTHEASTWARD INTO PARTS OF THE LOWER MS VALLEY/TN VALLEY AND
PERHAPS SOUTHEAST STATES. IN EITHER CASE...A 30 PERCENT EQUIVALENT
SEVERE RISK IS NOT CURRENTLY EXPECTED.
THEREAFTER...WHILE A BIT MORE NUMERICAL GUIDANCE AGREEMENT EXISTS AS
COMPARED TO THE PRIOR FEW DAYS...OVERALL PREDICTABILITY STILL
CONSIDERABLY DECREASES THROUGH LATE WEEKEND/EARLY NEXT WEEK. EVEN
SO...AIDED BY LEE TROUGHING...CURRENT INDICATIONS ARE THAT MOISTURE
WILL GRADUALLY SPREAD NORTHWARD ACROSS THE PLAINS THROUGH DAYS 6-7
SUNDAY-MONDAY IN ADVANCE OF A POSSIBLE NORTHERN PLAINS COLD FRONT.
WHAT DOES SEEM LIKELY IS THAT THE STRONGEST WESTERLIES WILL BE
RELEGATED TO THE NORTHERN TIER OF THIS CONUS...WITH ANY PLAINS
SEVERE POTENTIAL LIKELY TO BE RELATIVELY ISOLATED AND/OR
DISPROPORTIONATELY REGULATED BY MESOSCALE PROCESSES THROUGH AT LEAST
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