045
AWUS01 KWNH 311442
FFGMPD
KYZ000-ILZ000-MOZ000-311900-

Mesoscale Precipitation Discussion 0904
NWS Weather Prediction Center College Park MD
1041 AM EDT Fri Jul 31 2026

Areas affected...East-Central/Southeast MO...Southern IL

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

Valid 311441Z - 311900Z

SUMMARY...An isolated threat for mainly urban flash flooding will
exist over the next few hours from locally repeating showers and
thunderstorms with heavy rainfall rates.

DISCUSSION...Radar imagery shows bands of heavy showers and
thunderstorms advancing across east-central MO and into western
and southwest IL. The convection is associated with a well-defined
warm air and moisture advection regime around the southeast flank
of a deeper layer trough over the Upper Midwest.

This coupled with relatively divergent flow aloft and some uptick
in boundary layer moisture convergence has been promoting some
localized expansion and uptick in intensity of this convection
over the last hour. Much of the convection is highly elevated and
focused along a rather strong instability gradient, but with some
cloud-top cooling noted, the activity should tend to persist over
the next few hours as it advances off to the east.

Some expansion of convection is possible across southern MO and
adjacent areas of southern IL as a warm front begins to encroach
on the area, and this will also lead to an increase in PWs which
are quite high across central and southern MO right now with
values of 2.25+ inches. Rainfall rates of 1 to 2 inches/hour are
expected with the stronger and more focused cells.

Some localized repeating of convective cells is noted in radar
imagery over the last hour, especially south of St. Louis, and
this may result in some localized 2 to 3+ inch totals as the
general convective mass advances more into areas of southern IL
over the next few hours.

An isolated and mainly urban flash flood threat will exist with
this activity over the next few hours.

Orrison

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

ATTN...WFO...ILX...LSX...PAH...SGF...

ATTN...RFC...KRF...MSR...ORN...TIR...NWC...

LAT...LON   39368898 38788818 38038808 37328851 36998956
            37109116 37559171 38259143 38789045 39248989