Mesoscale Precipitation Discussion 0168
NWS Weather Prediction Center College Park MD
515 AM EDT Thu Apr 25 2024

Areas affected...Northeast OK...Southeast KS...Southwest
MO...Northwest AR

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

Valid 250915Z - 251515Z

SUMMARY...Heavy showers and thunderstorms with some concerns for
cell-training are expected to develop this morning. Some instances
of flash flooding will be possible.

DISCUSSION...Areas of showers and thunderstorms are expanding in
coverage across portions of northeast OK and eastern KS as a
gradually strengthening warm air advection pattern ensues across
the central and southern Plains.

A gradually moistening and strengthening low-level jet is
overrunning a returning warm front draped generally northwest to
southeast across the region, and this is yielding an increase in
isentropic ascent which coupled with the arrival of a well-defined
elevated instability axis is favoring the development and
expansion of the convective activity. Another factor driving the
increasing convective threat is a corridor of divergent flow aloft
associated with the southeastward advance of an upper-level jet
max over the lower OH Valley and corresponding RRQ jet dynamics.

MUCAPE values are on the order of 1000 to 1500 J/Kg, but with a
notable destabilization trend seen aloft over northern OK and
southern KS where 3-hour MUCAPE differentials of +500 to +1000
J/kg are currently seen. This elevated instability pool continues
to advance off to the northeast as the low-level jet strengthens
and transports increasingly moist air up from the southern Plains.

This combined with the aforementioned forcing should favor an
expansion of convection going through the early to mid-morning
hours across northeast OK, eastern KS, and eventually into areas
of southwest MO and northwest AR. Increasing PWs, reaching upwards
of 1.5+ inches by 12Z, will work in tandem with the instability
pool and moderately strong effective bulk shear to help drive
rainfall rates that may reach 1.5 to 2 inches/hour with the
stronger cells.

The 00Z HREF guidance supports some of the convection becoming
increasingly aligned in a northwest to southeast fashion, and this
will favor cell-training concerns. Thus, a threat for locally
enhanced rainfall totals will exist. Some storm totals of 3 to 4
inches, with isolated heavier amounts, will be possible through
mid-morning. In fact, a couple of HREF members suggest spotty 5+
inch totals.

While the antecedent conditions have been quite dry, the high
rainfall rates and training concerns suggest that some instances
of flash flooding will be possible.

Orrison

ATTN...WFO...EAX...ICT...LZK...SGF...TOP...TSA...

ATTN...RFC...ABRFC...LMRFC...MBRFC...NWC...

LAT...LON   38359536 38249419 37719302 36919226 35799196
            35009238 34819338 35009448 35649552 36709660
            37599674 38139631