464
AWUS01 KWNH 011617
FFGMPD
WIZ000-ILZ000-MOZ000-IAZ000-012215-

Mesoscale Precipitation Discussion 1421
NWS Weather Prediction Center College Park MD
1215 PM EDT Thu Oct 01 2026

Areas affected...Far Southeast IA...Far Northeast
MO...West-Central to Northern IL

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

Valid 011615Z - 012215Z

SUMMARY...Localized swaths of heavy showers and thunderstorms may
tend to increase in coverage a bit more over the next few hours.
Areas of flash flooding with some concerns for urban impacts will
be possible going through the afternoon hours.

DISCUSSION...The latest radar imagery shows bands of heavy
rainfall with embedded stronger convection becoming a little more
concentrated across far southeast IA, far northeast MO and
west-central to northern IL. This is focused along and just to the
east of a quasi-stationary front draped southwest to northeast
across the Midwest.

A combination of very deep moisture with tropical origins, modest
instability, and frontal convergence is expected to sustain the
concerns for heavy rainfall across the region over the next
several hours. Some uptick in boundary layer instability and the
arrival of weak mid-level vort energy from northern MO will tend
to foster some additional uptick in the coverage of heavy rainfall
and the rainfall rates with time.

MUCAPE values are as high as 500 J/kg, but the PWs are upwards of
1.75 to 2.0 inches, and there is also the presence of a southwest
low-level jet of 30 to 40+ kts. This moisture transport and
overall axis of deeper layer ascent with the warm advection regime
will support some rainfall rates occasionally reaching 1 to 1.5
inches/hour. This will be aided by some very efficient warm rain
processes given the deeper tropical character of the vertical
column.

Some localized swaths of stronger convection and higher rainfall
rates may materialize over the next few hours, and this may yield
some pockets of additional 2 to 4 inch rainfall totals going
through at least mid-afternoon.

The FFG values across the region are relatively low, and therefore
these additional rains may result in some areas of flash flooding.
The more flood-prone urban areas will be at greatest risk for
impacts.

Orrison

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

ATTN...WFO...DVN...ILX...LOT...LSX...MKX...

ATTN...RFC...MSR...NWC...

LAT...LON   42598827 42478748 42028731 41588779 41028846
            40348972 39819103 39959172 40429196 41009166
            41629080 42268939