(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.
Forecast Discussion
ZCZC SPCSWOD48 ALL
ACUS48 KWNS 200731
SPC AC 200731
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0231 AM CDT Fri Sep 20 2024
Valid 231200Z - 281200Z
...DISCUSSION...
Th latest suite of forecast guidance continues to show large spread
during the Day 4-8/Mon-Fri period. While the evolution of a central
U.S. upper trough is uncertain, it seems likely general troughing
across the eastern half of the U.S. will develop. Some severe
potential could develop around Days 4-5/Mon-Tue from the Midwest to
the Mid-Atlantic as a surface cold front advances east into a
seasonally moist airmass amid moderately enhanced mid/upper flow.
Severe potential should decrease late in the forecast period as the
surface trough moves offshore the Atlantic and Gulf coasts and
surface high pressure builds across the Midwest.
..Leitman.. 09/20/2024
CLICK TO GET WUUS48 PTSD48 PRODUCT