286
ACUS01 KWNS 011934
SWODY1
SPC AC 011933

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0233 PM CDT Mon Sep 01 2025

Valid 012000Z - 021200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SOUTHERN KANSAS
TO NORTHWEST OKLAHOMA...

...SUMMARY...
Isolated severe thunderstorms may occur across parts of southern
Kansas and western/northern Oklahoma this afternoon and evening,
with isolated large hail and damaging winds the main threats.

...20z Update...
The previous forecast remains on track with only minor adjustments
made to reflect recent convective trends. Initial thunderstorm
development along a weak surface front is noted from northeast to
southwest KS as of 19 UTC. Based on regional VWPs, mid-level flow
remains relatively strongest across southern to southwest KS on the
west/southwest side of the upper wave, which should promote a
slightly higher potential for severe gusts and/or hail this
afternoon/evening. The Marginal risk area was slightly adjusted to
better capture this potential. See MCD #2025 for additional
short-term details.

Elsewhere, only minor adjustments to the thunder line were needed.
An occasional lightning flash or two will be possible during the
09-12 UTC period across central CA, but recent guidance continues to
suggest that lightning coverage/probability will likely remain below
10%.

..Moore.. 09/01/2025

.PREV DISCUSSION... /ISSUED 1122 AM CDT Mon Sep 01 2025/

...Southern/Central Plains...
A mid-level shortwave trough centered over eastern NE late this
morning will move southeastward toward the southern Plains and
Ozarks by tonight. This will occur in association with a belt of
modestly enhanced north-northwesterly mid-level winds (around 30-40
kt at 500 mb). While the related surface response will remain muted,
a weak surface front/wind shift will progress southward from KS into
OK, with a relatively moist air mass preceding the advancing
boundary. Ongoing low clouds/stratus should continue to gradually
erode this afternoon, yielding ample insolation and a corridor of
moderate instability and steepening low-level lapse rates,
particularly across southern KS into northwest OK. Widely scattered
thunderstorm development is probable by mid/late afternoon near the
front/wind shift as the boundary layer warms. The enhanced
north-northwesterly flow aloft will contribute to 30-40 kt of
effective bulk shear, which should support multicell clusters and
perhaps marginal supercells. Isolated severe hail/damaging winds
will be possible through early evening as storms develop southward
from parts of southern KS into western/northern OK.

$$