(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 010824
SPC AC 010824
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0324 AM CDT MON SEP 01 2014
VALID 041200Z - 091200Z
EDMWF/GFS AGREE IN TAKING A STRONG SHORT-WAVE TROUGH ACROSS THE NRN
PLAINS INTO THE UPPER MS VALLEY DAY4...THOUGH PRIMARY FORCING FOR
THIS FEATURE IS EXPECTED TO REMAIN NORTH OF THE INTERNATIONAL
BORDER. WITH STRONGEST UVV EXPECTED TO OVERSPREAD SRN MANITOBA/NWRN
ONTARIO...FRONTAL CONVERGENCE AND DIABATIC HEATING SHOULD BE THE
PRIMARY FORCING FOR DEEP CONVECTION ACROSS THE UPPER MS VALLEY/UPPER
GREAT LAKES. WHILE SCT THUNDERSTORMS...POTENTIALLY SEVERE...SHOULD
DEVELOP ALONG THE PROGRESSIVE WIND SHIFT COVERAGE/INTENSITY OF
STORMS MAY NOT REACH 30 PERCENT CRITERIA. BEYOND THE DAY4
PERIOD...STRONG SHEAR REQUIRED FOR ORGANIZED SEVERE STORMS SHOULD
REMAIN DISPLACED FROM MOST BUOYANT ENVIRONMENT OVER SRN HALF OF THE
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