Mesoscale Precipitation Discussion 1566
NWS Weather Prediction Center College Park MD
840 AM EST Wed Nov 11 2026

Areas affected...eastern Iowa into northern/central Illinois

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

Valid 111338Z - 111738Z

Summary...Isolated/spotty flash flood potential exists from the
Cedar Rapids area east-southeast into portions of Illinois over
the next 2-4 hours (through 17Z/11a central).

Discussion...A small cluster of convection has materialized in
east-central Iowa with local training noted near the Cedar Rapids
area.  The cells are being maintained by 1) convergent flow in the
850-700mb layer, 2) steep lapse rates (7.5 C/km) from cool air
aloft, and 3) a vigorous mid-level shortwave trough moving through
the region.  The orientation of the axis of convergence (and
resultant convection) is parallel to westerly steering flow aloft,
allowing for local training and spots of rain rates exceeding 1.5
inch/hr, which is also surpassing local FFG thresholds.  Flash
flood potential exists in the near term.

Over time, models/CAMs and observations hint at persistence of
this cluster eastward into northern IL through at least 17Z. 
Local/limited training of cells will pose a continued flash flood
threat as local FFG exceedance (and 1+ inch/hr rain rates) is
possible.  This threat should remain isolated though.  Cells
should reach the Peoria/Bloomington/Peru region of IL through
16-17Z.

Cook

ATTN...WFO...DMX...DVN...ILX...LOT...

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

LAT...LON   42429041 42048876 41318813 40578865 40729018
            41269214 42419207