(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 200905
SPC AC 200905
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0305 AM CST Wed Nov 20 2024
Valid 231200Z - 281200Z
...DISCUSSION...
An upper trough will move out of the northeastern states from Sat/D4
into Sun/D5, with the ridge flattening over the Plains. This will
result in a broad belt of near zonal flow across much of the CONUS,
with perhaps a slight propensity for cyclonic height curvature over
the Great Lakes into eastern Canada.
Low-level moisture return will occur gradually, especially from
Mon/D6 onward when 60s dewpoints may extend from eastern TX into the
lower MS Valley. However, not until around Tue Night/D7 do most
models show any appreciable instability, and even then it will
likely be weak. As such, severe storms are not forecast. However, a
few strong storms cannot be ruled out by around Wed/D8 due to
several days of persistent moistening, especially if a shortwave
trough can amplify within the strong flow regime.
..Jewell.. 11/20/2024
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