068
AWUS01 KWNH 301925
FFGMPD
MOZ000-IAZ000-NEZ000-310030-

Mesoscale Precipitation Discussion 0348
NWS Weather Prediction Center College Park MD
324 PM EDT Thu May 30 2024

Areas affected...Eaastern Nebraska...Southwest Iowa...Far
Northwest Missouri...

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

Valid 301925Z - 310030Z

SUMMARY...Slow moving showers with potential for mergers with
1-1.5"/hr across lower FFG values and possibility for isolated
incident or two of localized flash flooding.

DISCUSSION...Regional RADAR notes a shearing MCV across eastern
NEB slowly drifting east.  The southeast quadrant of the
circulation is providing an isentropic ascent plane fairly
orthogonal to 925-850mb south-southeasterly flow.  This flow is
slightly increased as an old MCV from NE KS is lifting northeast
and pinching on southeast NEB.  Air is not incredibly unstable,
but sufficient with 1000 J/kg of MLCAPE in this confluent flow.
Deep layer moisture is modest and up to 1.5" and should support
cells capable of 1-1.5"/hr rates.  The key is the slow cell
motions and ability for next pulse of the updraft to back-shear in
a favorable orientation for repeating or maintaining duration to
support localized 1.5-2.5" totals.  Aloft, updrafts should have
solid evacuation, as weak diffluence at the top of the synoptic
ridge (currently over SW IA) to keep updrafts solid for a few
hours as instability exhausts.

To complicate the situation, a few cells along the warm advective
arch of the approaching shortwave from KS may produce some cells
that may merge/collide and locally increase rates over 1.5"/hr for
short periods.  Given rates of 1.5"/hr and totals up to 2.5" for
2-3hrs...this aligns with lower FFG values in the area suggesting
widely scattered exceedance is possible resulting in localized
flash flooding incident or two over the next few hours.

Gallina

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

ATTN...WFO...DMX...EAX...OAX...

ATTN...RFC...MBRFC...NCRFC...NWC...

LAT...LON   42199597 42159521 41799476 40919462 40259477
            40039517 40029664 40119702 40949726 41959660