775
ACUS01 KWNS 290458
SWODY1
SPC AC 290457

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1157 PM CDT Thu Aug 28 2025

Valid 291200Z - 301200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN AND CENTRAL HIGH PLAINS...AND IN PARTS OF THE SABINE
RIVER VALLEY...

...SUMMARY...
Thunderstorms with potential for hail and isolated severe gusts will
be possible today across parts of the southern and central High
Plains. A few marginally severe gusts could also occur over parts of
the Sabine River Valley.

...Southern and Central High Plains...
At mid-levels, flow will be northwesterly over much of the central
U.S. today, as a ridge remains in place over the central High
Plains. At the surface, a low is forecast to move eastward through
southwestern South Dakota as a lee trough deepens across western
Nebraska and eastern Colorado. As surface temperatures warm and
low-level convergence increases, scattered thunderstorms are
expected to develop near the surface trough. Along and to the east
of the trough, surface dewpoints in the lower to mid 60s F will
contribute to an axis of moderate instability by afternoon. In
addition, RAP forecast soundings along this corridor show moderate
deep-layer shear, owing mostly to speed shear in the mid-levels.
This instability/shear environment could be enough for a marginal
severe threat late this afternoon and early this evening, with the
primary threats being for hail and isolated severe gusts.

...Sabine River Valley...
A mid-level trough will move across the eastern U.S. today, as
cyclonically curved northwesterly flow remains over much of the
Southeast. At the surface, a slow-moving front will be positioned
from east Texas eastward into the central Gulf Coast states.
Thunderstorms are expected to be ongoing near the front in the
morning. This convection should move southeastward across the lower
Mississippi Valley during the day. To the southwest of this
convection, the airmass will remain undisturbed from southeast Texas
into southwest Louisiana. This will allow for stronger surface
heating, which should result in a pocket of moderate instability by
afternoon. Isolated thunderstorms that develop within this pocket of
instability could produce marginally severe wind gusts, mainly when
low-level lapse rates become steep in the mid to late afternoon.

..Broyles/Thornton.. 08/29/2025

$$