(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 280857
SPC AC 280857
Day 4-8 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0357 AM CDT Mon Apr 28 2025
Valid 011200Z - 061200Z
CORRECTED FOR INCORRECT DAY REFERENCE
...DISCUSSION...
The extended period will begin with broad troughing across the
eastern US and a surface low tracking northeastward across the Great
Lakes. A cold front will stretch from the northeastern US southward
into the southern Plains, shifting eastward on D4/Thursday across
the Ohio Valley into the southeastern US. Beyond D4/Thursday,
heights will begin to rise across the Plains as an upper level high
strengthens, which will limit the severe threat through the end of
the extended.
...D4/Thursday - Tennessee and Ohio Valley...
On D4/Thursday, thunderstorm development is expected along the cold
front across portions of the Ohio Valley into the southern
Mississippi Valley. Model solutions differ on how much instability
will be available across Tennessee into the Ohio Valley, where the
strongest flow aloft will reside. There appears to be little overlap
between the better flow aloft and any meaningful instability, which
keeps probabilities too low to include areas in the extended.
However, some instances of wind and hail from stronger storms will
be possible across portions of Tennessee into Ohio.
...D5/Friday - Southwest Texas...
Thunderstorm development is possible along the dryline in
southwestern Texas on D5/Friday. During this period, heights aloft
will be rising, which will likely work to limit overall coverage of
thunderstorm activity. Nonetheless, a few isolated supercells may
develop with potential for large hail and severe wind. Overall,
limited coverage does not warrant inclusion of probabilities.
..Thornton/Bentley.. 04/28/2025
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