ZCZC SPCSWOD48 ALL
ACUS48 KWNS 070909
SPC AC 070909
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0309 AM CST Fri Mar 07 2025
Valid 101200Z - 151200Z
...DISCUSSION...
A progressive upper pattern is forecast during the Day 4-8 period.
An upper shortwave trough over the Southeast will move offshore the
Atlantic coast on Day 4/Mon. In its wake, low-amplitude upper
ridging is forecast from the southern Plains into the Southeast
through Day 5/Tue. Severe thunderstorm potential will be low during
this time as surface high pressure near the Gulf coast maintain a
dry continental airmass.
By Day 6/Wed, an upper trough over the southern Rockies and northern
Mexico will shift east across the southern Plains to the Sabine
Valley vicinity. Enhanced southwesterly deep-layer flow will develop
ahead of the trough across TX into the Lower MS Valley. Surface
cyclogenesis is currently forecast to remain modest, but southerly
low-level flow will transport Gulf moisture northward across the
south-central states. Higher-quality moisture is expected to remain
offshore or very near the TX/LA coast, with low 60s F dewpoints
possible across parts of east TX and LA ahead of an eastward
advancing cold front. Thunderstorm potential will accompany this
system, but moisture return will likely remain sub-optimal for a
greater severe risk.
By the end of the period, around Day 8/Fri, medium range guidance
develops a larger-scale, deepening trough ejecting into the Plains
and Upper Midwest vicinity. While some severe potential may increase
around the Friday time frame, large spread among guidance with
regards to timing and placement of the upper trough and key surface
features lends to low predictability. Trends will be monitored over
the coming days and outlook areas may become necessary if confidence
increases.
..Leitman.. 03/07/2025