400 

AWUS01 KWNH 160311
FFGMPD
ILZ000-MOZ000-160800-

Mesoscale Precipitation Discussion 0112
NWS Weather Prediction Center College Park MD
1110 PM EDT Wed Apr 15 2026

Areas affected...Central Illinois...East-Central/Southeast
Missouri...

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

Valid 160310Z - 160800Z

SUMMARY...Mature MCV continues to provide solid WAA ascent coupled
with nose of enhanced deep layer moisture likely to support
efficient rainfall production with rates of 1.5-1.75" and streaks
of 2-3" totals resulting in possible incident(s) of localized
flash flooding.

DISCUSSION...Regional RADAR suite depicts a maturing MCV just
southwest of metro St. Louis lifting northeastward at this time.
GOES-E WV and RADAR show a broadening mid-level baroclinic
leaf/shield indicative of continued favorable evacuation aloft to
maintain the MCS for the next few hours.  VWP and RAP analysis
denote the broad divergence is supporting strengthening low level
flow with solid confluence at the nose of the deeper layer
moisture axis.  CIRA LPW shows corridor of 850-500mb moisture is
aligned ideally with the southwesterly flow but sfc to 850mb
moisture is very broad and increasing to support TPW value in
excess of 1.5".  The 30-35kts of 850-700mb confluent flow in this
moisture regime will support 1.5-1.75" rainfall production even
with reducing/narrowing unstable axis (generally 500-750 J/kg of
MUCAPEs).  The MCV is also providing a corralling of downstream
flow into a well defined deformation axis that is generally
parallel to the deeper layer steering.  This orientation will be
the supportive requirement for increased duration to support
localized steaks of 2-3" totals.

Unlike further north, the ground conditions are much drier due to
the prolonged drought.  Yet, FFG values of 1.5-2"/hr and 2-3"/3hr
are in the realm of exceedance and while not all locations will be
exceeded there should be a few areas that may lead to localized
flash flooding conditions through the early overnight period.  As
such, flash flooding is considered possible across central IL back
through east-central MO; with slightly higher potential in the
urban areas near Metro St. Louis, due to hydrophobic grounds and
drainage.

Gallina

...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   40338843 39928763 39148773 38638840 37699014
            37499135 37969181 38549157 38819130 39579024
            40138941