Mesoscale Precipitation Discussion 0363
NWS Weather Prediction Center College Park MD
501 PM EDT Wed Jun 04 2025

Areas affected...southern/east-central Missouri into
central/eastern Illinois

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

Valid 042101Z - 050201Z

Summary...A focused band of training convection has developed from
east of Springfield, MO to near St. Louis over the past couple
hours.  The scenario will allow for localized spots of 2-5 inch
rainfall totals to occur from east-central Missouri into central
Illinois - raising concerns for a locally significant flash flood
event especially near St. Louis Metro through 00Z.

Discussion...Recent radar/observations depict an increase of
convective intensity and coverage along a stalled synoptic front
extending from near Springfield, MO to St. Louis to Champaign, IL.
 The increase in convective coverage is attributed to persistent
convergence along the front and abundant sunshine/destabilization
out ahead of the front, which has allowed for 2500 J/kg SBCAPE to
develop amid 1.9 inch PW values near the storms. 

Of particular concern is the lack of indication that these storms
will begin to propagate off their current axis of rainfall for at
least the next couple hours or so.  This will enable persistent
training of convection to occur and support areas of 2-5 inch
rainfall totals over the next 2-4 hours across portions of
south-central to east-central Missouri.  These heavy rain rates
should pose a risk for locally significant urban flash flooding
near St. Louis through 00Z/7p CDT.

The bands of training convection are also expected to migrate
east-northeastward across portions of Illinois and western Indiana
through 02Z or so.  Flash flooding is a distinct possibility in
those areas as well given the propensity for storms to train in
the moist/buoyant pre-convective environment.

Cook

ATTN...WFO...ILX...IND...IWX...LOT...LSX...PAH...SGF...

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

LAT...LON   41118667 40318634 39158671 38318827 36829154
            37039259 37869264 39099072 40398935 41038776