|Day 4-8 Severe Weather Outlook Issued on Sep 3, 2012|
|Updated: Mon Sep 3 08:54:03 UTC 2012|
|D4||Thu, Sep 06, 2012 - Fri, Sep 07, 2012
||D7||Sun, Sep 09, 2012 - Mon, Sep 10, 2012
|D5||Fri, Sep 07, 2012 - Sat, Sep 08, 2012
||D8||Mon, Sep 10, 2012 - Tue, Sep 11, 2012
|D6||Sat, Sep 08, 2012 - Sun, Sep 09, 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 030853
SPC AC 030853
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0353 AM CDT MON SEP 03 2012
VALID 061200Z - 111200Z
SUBSTANTIAL DIVERGENCE IN MEDIUM-RANGE MODEL SOLUTIONS BEGINS DAY 5
/FRI. 9-1/...AS THE PERSISTENT CANADIAN VORTEX SHIFTS EWD TOWARD ERN
CANADA AND A SHORTER-WAVELENGTH FEATURE DIGS SEWD IN NWLY CYCLONIC
FLOW ON THE WRN FRINGE OF THE LARGER-SCALE LOW.
THE GFS -- LIKE 24 HOURS AGO -- REMAINS SLOWER...WEAKER...AND
FARTHER W WITH THIS FEATURE...RESULTING IN FAIRLY SUBSTANTIAL
DIFFERENCES IN SURFACE PATTERN EVOLUTION AS WELL.
PRIOR TO THE DIVERGENCE IN SOLUTIONS...SEVERE POTENTIAL IS APPARENT
DAY 4 /THU. 9-6/ ACROSS THE CENTRAL PLAINS REGION...AS THE DIGGING
SHORT-WAVE FEATURE HEADS SEWD ACROSS THE NRN INTERMOUNTAIN REGION --
DRIVING SURFACE PRESSURE FALLS OVER THE CENTRAL HIGH PLAINS.
RESULTING LOW-LEVEL SELYS BENEATH 30 TO 40 KT WLYS ATOP THE WARM
SECTOR WILL YIELD SHEAR SUPPORTIVE OF ORGANIZED STORMS...AND
ASSOCIATED WIND/HAIL THREATS. HOWEVER...THREAT DOES NOT APPEAR
QUITE SUBSTANTIAL ENOUGH ATTM TO CONFIDENTLY INTRODUCE A 30%
EQUIVALENT THREAT AREA.
BEYOND DAY 4...PREVIOUSLY MENTIONED SOLUTION DEVIATIONS PRECLUDE
CONSIDERATION OF THREAT AREAS THROUGH THE REMAINDER OF THE PERIOD.
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