|Day 4-8 Severe Weather Outlook Issued on Sep 4, 2012|
|Updated: Tue Sep 4 08:59:03 UTC 2012|
|D4||Fri, Sep 07, 2012 - Sat, Sep 08, 2012
||D7||Mon, Sep 10, 2012 - Tue, Sep 11, 2012
|D5||Sat, Sep 08, 2012 - Sun, Sep 09, 2012
||D8||Tue, Sep 11, 2012 - Wed, Sep 12, 2012
|D6||Sun, Sep 09, 2012 - Mon, Sep 10, 2012
||(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 040857
SPC AC 040857
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0357 AM CDT TUE SEP 04 2012
VALID 071200Z - 121200Z
GFS AND ECMWF IN DECENT AGREEMENT ATTM THROUGH DAY 5 /SAT
9-8/...BRINGING A DIGGING/POSITIVELY TILTED UPPER SHORT-WAVE TROUGH
SEWD ACROSS UPPER MS VALLEY REGION AND PLAINS STATES DAY 4 /FRI
9-8/...AND THEN INTO THE MID-SOUTH REGION DAY 5 WHERE IT SLOWS AND
DEEPENS INTO A CLOSED LOW.
AFTER DAY 5...MODELS BEGIN DIFFERING AS THE ECMWF CONTINUES TO
DEEPEN THE LOW -- SHIFTING IT SLOWLY NEWD TOWARD THE MID-ATLANTIC
REGION THROUGH THE REMAINDER OF THE PERIOD. MEANWHILE THE GFS
DEPICTS A WEAKENING/OPENING FEATURE THAT EVENTUALLY SHIFTS OFFSHORE
INTO THE ATLANTIC.
SOME SEVERE POTENTIAL WILL LIKELY ACCOMPANY THE DIGGING TROUGH AND
ASSOCIATED/SEWD-MOVING COLD FRONT AS THEY MOVE ACROSS THE CENTRAL
U.S. DAY 4. WITH AMPLY UNSTABLE WARM SECTOR AND MODERATE WNWLYS AT
MID LEVELS...THE ENVIRONMENT SHOULD BE SUPPORTIVE FOR AT LEAST
ISOLATED STRONGER/SEVERE STORMS. HOWEVER...COVERAGE/INTENSITY
ANTICIPATED DOES NOT ATTM WARRANT INTRODUCTION OF A THREAT AREA.
A MORE LIMITED THREAT MAY CONTINUE INTO DAY 5...AS THE SURFACE FRONT
SHIFTS QUICKLY SEWD ACROSS THE MID SOUTH/SOUTHEAST. BEYOND THIS
TIME...COMBINATION OF MODEL UNCERTAINTY AND WHAT APPEARS OVERALL TO
BE A PATTERN UNFAVORABLE FOR WIDESPREAD SEVERE STORMS PRECLUDES
CONSIDERATION OF ANY AREAL HIGHLIGHTS THROUGH THE REMAINDER OF THE
CLICK TO GET WUUS48 PTSD48 PRODUCT