540
AWUS01 KWNH 280501
FFGMPD
OKZ000-KSZ000-281000-

Mesoscale Precipitation Discussion 1017
NWS Weather Prediction Center College Park MD
100 AM EDT Thu Aug 28 2025

Areas affected...Western and Southern KS...Northern OK

Concerning...Heavy rainfall...Flash flooding possible

Valid 280500Z - 281000Z

SUMMARY...Gradually organizing clusters of heavy showers and
thunderstorms will eventually pose a threat for scattered areas of
flash flooding going through the remainder of the overnight hours.

DISCUSSION...The latest GOES-E IR satellite imagery shows cooling
convective cloud tops across western KS as modest shortwave energy
ejecting east-southeast across the region interacts with a
stationary frontal zone and gradually strengthening warm air
advection associated with an increasing south-southwest low-level
jet.

So far, area VWP show the low-level jet reaching only 20 to 30+
kts across northern OK and southern KS, and the instability
profiles are rather modest too with MUCAPE values along and
northeast of the front of 500 to 1000 J/kg. This has been
tempering the convective organization and coverage over the last
couple of hours, but as the low-level jet strengthens further
(especially after 0600Z), there should be a more substantial
increase in elevated convection across western and southern KS,
and perhaps across northern OK as well where the best instability
gradient is currently situated.

The latest hires CAMs show a fair amount of spread with the exact
placement of the heaviest rainfall threat overnight along with the
totals. Overall, the 00Z HREF suite appears to potentially be a
bit overdone (especially considering the very aggressive 00Z
NAM-Conest), and the consensus may be a bit too far off to the
northeast into the more stable airmass that is currently locked in
place across eastern KS.

Radar and satellite trends along with some of the recent WoFS
guidance suggests areas of western and southern KS will see the
main concentration of heavier shower and thunderstorm activity
over the next few hours. By later tonight, areas of northern OK
should begin to also see more focus for convection as the nose of
a gradually veering low-level jet impinges on this region.

Rainfall rates of 1 to 2 inches/hour are expected with the
stronger storms, and eventually sufficient organization is
expected to foster some cell-training concerns. This will
potentially support rainfall totals of 2 to 4 inches with isolated
5+ inch amounts possible. These rains will eventually pose a
threat for some scattered areas of flash flooding.

Orrison

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...AMA...DDC...GID...GLD...ICT...OUN...TSA...

ATTN...RFC...KRF...TUA...NWC...

LAT...LON   39410098 39179896 37919665 36589641 36089814
            36740033 37760163 38680190