Mesoscale Precipitation Discussion 0312
NWS Weather Prediction Center College Park MD
804 AM EDT Sun May 25 2025

Areas affected...South-Central Kansas through the Ozarks

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

Valid 251203Z - 251700Z

Summary...Showers and thunderstorms will continue to train to the
southeast for several more hours this morning. Rainfall rates
within this convection will reach 1-2"/hr, at times higher,
leading to pockets of rainfall that may exceed 3". This rain
falling atop saturated soils may produce additional flash flooding.

Discussion...The regional radar mosaic early this morning shows an
impressive axis of showers and thunderstorms organized from
central Kansas through northeast Arkansas. These storms are
developing along the convergent nose of the LLJ which is measured
via regional VWPs to be 30-40 kts, with weak impulses embedded
within the mid-level flow contributing additional ascent. The
primary storm mode within this area has been multiple clusters,
organized through 40-50 kts of bulk shear as analyzed by the SPC
RAP, helping to reinforce radar-estimated rain rates to above
2"/hr as measured by local WSR-88Ds. On the western edge of this
complex, an MCV is developing as noted within reflectivity, and it
is this feature which will eventually sweep through from west to
east, combining with the veering of the LLJ to bring a slow
wane/end to the morning activity.

During the next few hours, the high-res CAMs are in good agreement
that, in general, activity will become more progressive to the
east and begin to weaken. This will be due in part to the veering
of the LLJ which will less efficiently transport the elevated
thermodynamics south of the warm front into the region, while the
MCV also sweeps through, with weak NVA in its wake suppressing
additional ascent. Until this occurs, PWs of around 1.7 inches and
MUCAPE around 2000 J/kg will support continued rain rates of
1-2"/hr, with locally higher rates possible as reflected by HREF
and REFS hourly-rain rate probabilities and the 15-min HRRR
rainfall accumulations. This will lead to additional rainfall of
1-3", with locally higher amounts possible where HREF exceedance
probabilities rise to above 20% for 3"/6hrs.

Although there is some spread both temporally and spatially among
the guidance as to where the heaviest rain will occur the next few
hours, the HREF EAS probabilities suggest the area from far SE KS
through far NW AR has the greatest potential for heavy rain during
the next few hours. This is also where 48-hr rainfall has been
most prolific, 3-6", leading to FFG that is compromised to
1.5-2"/3hrs due to exceptionally moistened soils. While flash
flooding is possible anywhere within this area through late
morning, these primed soils will be most susceptible to additional
flash flooding.

Later this afternoon, potentially after a break, additional
convection is expected. While there is still uncertainty as to
exactly where this will develop, it is likely that additional MPDs
will be needed to address this threat.


Weiss

ATTN...WFO...DDC...EAX...ICT...LZK...MEG...OUN...PAH...SGF...
TOP...TSA...

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

LAT...LON   38639803 38479646 37959454 37499252 37179143
            36729089 36649090 36329078 35869082 35469139
            35259248 35409425 35769556 36439678 36909773
            37209833 37519870 38159880