827
ACUS01 KWNS 291959
SWODY1
SPC AC 291958

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0258 PM CDT Fri Aug 29 2025

Valid 292000Z - 301200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF
WESTERN/CENTRAL NEBRASKA...SOUTHEAST COLORADO AND ADJACENT AREAS...

...SUMMARY...
Thunderstorms capable of large hail and isolated severe wind gusts
will be possible mainly late this afternoon into evening across
parts of the southern and central High Plains.

...20Z Update...
Given observational and CAM guidance trends, an area of greater
supercell potential appears evident in parts of southeast Colorado
and nearby vicinity. Discrete storms would be most likely within the
surface trough. A cluster or two of storms could also potentially
move off the higher terrain later this afternoon. Large hail and
isolated severe winds would be the primary threats, though a brief
tornado could occur in the surface trough.

Observational trends also suggest limited potential for severe
storms in the Sabine Valley region. Severe probabilities have been
removed.

..Wendt.. 08/29/2025

.PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Aug 29 2025/

...Central/Southern High Plains...
Recent surface analysis show a reservoir of low-level moisture
across the central/southern High Plains, varying from the mid 60s
across eastern NM into the lower 60s across northeast CO and the NE
Panhandle. General expectation is for modest upslope flow to
contribute to another day of afternoon/evening thunderstorms across
much of central/eastern CO and eastern NM. Thunderstorms also look
probable farther north in the vicinity of a weak surface low, which
is expected to develop along a sharpening lee trough over the NE
Panhandle. Current surface low over western SD will likely fill
throughout the day, although there could still be enough low-level
convergence near the remnant troughing to support a few
thunderstorms as well. In general, there looks to be more overall
storm coverage than the last few days.

Some modest enhancement of the mid-level flow is possible as the
low-amplitude shortwave trough currently over southern UT continues
northeastward through the periphery of the ridge into the central
Rockies. The strongest flow will extend from northern CO/southeast
WY into central NE, where elongated hodographs result in a wind
profile that supports supercells capable of large hail. Lapse rates
are generally poor, but ample low-level moisture should still result
in enough buoyancy for mature updrafts. Highest storm coverage
across this region is anticipated over western NE, where 15% hail
probabilities were introduced.

A secondary area of greater storm coverage is expected farther south
from southeast CO through northeast NM as storms move eastward off
the Colorado mountains/Raton Mesa vicinity. Mid-level westerly flow
will be a bit weaker here than farther north but should still be
sufficient for around 35-40 kt of effective bulk shear. Lapse rates
are poor and overall storm strength will likely be limited by
tempered buoyancy. Even so, multicells and a supercell or two are
still possible initially, with eventual clustering as storms move
across eastern Colorado/northeast New Mexico toward western Kansas
and the Oklahoma/Texas Panhandles. Isolated hail is possible with
the initially more cellular storms, with a trend towards damaging
gusts as storms become more linear.

...Sabine River Valley...
A relatively widespread corridor of showers/thunderstorms is
ongoing this morning from east Texas into central/southeast
Louisiana, to the north of a front that will continue to settle
southward today. A related cloud canopy extends across the warm
sector, but moderate destabilization should still occur into the
afternoon south of the front and on the south/southwest flank of the
residual early day storms. Some stronger storms could persist and/or
develop this afternoon, with isolated instances of damaging winds a
possibility as low-level lapse rates steepen.

$$