683
AWUS01 KWNH 260019
FFGMPD
ILZ000-MOZ000-IAZ000-260600-

Mesoscale Precipitation Discussion 0496
NWS Weather Prediction Center College Park MD
814 PM EDT Tue Jun 25 2024

Areas affected...Portions of the Mid-Mississippi Valley

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

Valid 260013Z - 260600Z

SUMMARY...Cell mergers, training, and backbuilding thunderstorm
cells may cause localized possible flash flooding.

DISCUSSION...Multiple areas of storms...one over central and
southern Iowa, and another over east central Missouri are causing
numerous interactions between the cellular storms as outflow
boundaries and cells interact with terrain over Missouri and with
each other. As a result, where the storms interact, there have
been localized areas where multiple storms have moved overhead,
resulting in long periods of time, occasionally as long as a
couple hours, of heavy rain. Thus, while resultant flash flooding
has been localized, the complexity and frequency of those cell
mergers along with the forecast of additional storm development
suggests the flash flooding threat in this area has increased.

CAMs guidance suggests that both areas of storms will begin to
push southeastward with time. This scenario would keep the storms
over east-central Missouri moving down the Mississippi River into
areas that have at or below average soil moisture for this time of
year...thus keeping the flooding threat relatively low. However,
the potential for the storms over Iowa to not only eventually move
over the areas being hit now in Missouri later on tonight, but
additional convection to form in between near the IA/MO/IL
tripoint region suggests that additional flash flooding will be
possible through the evening.

Wegman

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

ATTN...WFO...DMX...DVN...EAX...ILX...LSX...SGF...

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

LAT...LON   42299206 42128991 41628970 40758922 39699022
            38698999 38018988 37689018 37339024 37549145
            37989198 39269307 40369376 41199397 41859396
            41959385