(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 060956
SPC AC 060956
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0356 AM CST Thu Feb 06 2025
Valid 091200Z - 141200Z
...DISCUSSION...
The zonal flow aloft which has persisted over the U.S. recently --
and into the start of the medium-range period -- is progged to
gradually amplify, with flow becoming more cyclonic with time across
the U.S. through the period. The initial effect of this gradual
upper flow field evolution will be to gradually suppress the
persistent west-to-east surface front over the U.S. southward.
Through day 5 (Monday), this front should extend from Texas eastward
through the Gulf Coast States to Georgia/South Carolina. Severe
weather is not expected, as this front drifts southward and settles
across this area.
Through the second half of the period (late day 6 onward),
disturbances moving across the southern U.S. within increasingly
cyclonic flow aloft will influence potential for surface wave
development along the front. Any appreciable cyclogenesis could
result in northward transport of higher theta-e Gulf air, and thus
some destabilization ahead of the low. With strong flow aloft atop
the surface front, this would suggest an environment that would
support severe-weather potential.
With that said, while a general/overall increase in severe-weather
probabilities over the Gulf Coast region is becoming evident during
the second half of the period, uncertainty remains high. Timing and
degree of any such risk will depend upon subtle features aloft, and
their effects on surface mass response. And given predictability
issues with respect to timing an intensity of such subtle features,
it appears premature at this time to introduce 15% risk areas in the
day 7 to 8 time frame.
..Goss.. 02/06/2025
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