433
AWUS01 KWNH 280406
FFGMPD
INZ000-ILZ000-MOZ000-281005-

Mesoscale Precipitation Discussion 0191
NWS Weather Prediction Center College Park MD
1205 AM EDT Sun Apr 28 2024

Areas affected...Northeast MO...Central IL...Northwest IN

Concerning...Heavy rainfall...Flash flooding likely

Valid 280405Z - 281005Z

SUMMARY...Areas of flash flooding will be likely over the next
several hours from occasional training of showers and
thunderstorms across portions of northeast MO, central IL and
northwest IN.

DISCUSSION...Radar imagery shows an expansive area of showers and
thunderstorms increasing in coverage across northwest MO through
much of central IL and into northwest IN. The activity is forming
with a strong warm air advection regime with rather strong
moisture transport and a moderately buoyant airmass.

MLCAPE of 1000 to 1500+ J/kg are pooled across areas of northeast
MO through central/northern IL which combined with evidence of a
weak surface trough is helping to focus a more west/east oriented
axis of convection across central IL. Some frontogenetic forcing
is noted in the 925/850 mb layer near and just north of this
surface feature.

A more organized QLCS is evolving gradually into northeast MO and
western IL, but the activity off to the east over central IL is
expected to maintain its character over the next few hours while
also tending to advance downstream into parts of northwest IN. The
interaction of a low-level jet of 30 to 40 kts with the
aforementioned surface trough is likely to be a key driver of this
convection. This activity is more aligned with the deeper layer
west-southwest flow over the region, and thus there will be
concerns for areas of cell-training as these showers and
thunderstorms continue to evolve.

Rainfall rates are expected to at least approach 2 inches/hour
with the stronger cells, and given the cell-training concerns,
some rainfall totals going through the remainder of the night may
reach into the 3 to 4 inch range with locally heavier totals which
is consistent with the 00Z HREF guidance. Some areas of flash
flooding will be likely as a result.

Orrison

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

ATTN...WFO...DVN...ILX...IND...IWX...LOT...LSX...

ATTN...RFC...NCRFC...OHRFC...NWC...

LAT...LON   41608617 40928584 40278651 39258885 38759074
            38969141 39549207 40119164 40719055 41258917
            41578769