(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 15%, 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 unlikely (i.e., less than 15%) for the forecast day.
ZCZC SPCSWOD48 ALL
ACUS48 KWNS 240759
SPC AC 240759
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0259 AM CDT Thu May 24 2018
Valid 271200Z - 011200Z
Medium-range model guidance is in general agreement that large-scale
ridging will hold over the Plains into early next week with broad
troughing expected over the West. While isolated-scattered
convection may develop along the lee trough during the day4-6 time
frame, there is considerable uncertainty regarding the eastward
progression of the western US trough. Additionally, significant low
pressure system is expected to migrate across the northern Gulf
Basin into the Gulf states which will limit northward moisture
return across the Plains. This could negate an otherwise potentially
more buoyant air mass along the lee trough. Isolated severe may
ultimately develop across portions of the High Plains but too much
uncertainty exists at this time to introduce 15% severe probs.
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