799
AWUS01 KWNH 140512
FFGMPD
WIZ000-MNZ000-140910-

Mesoscale Precipitation Discussion 0617
NWS Weather Prediction Center College Park MD
111 AM EDT Sun Jul 14 2024

Areas affected...central/eastern Minnesota, western Wisconsin

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

Valid 140510Z - 140910Z

Summary...Training convection extending from near Saint Cloud to
near Saint Paul will pose a risk of flash flooding for the next
few hours - particularly in the Minneapolis/Saint Paul Metro areas.

Discussion...A quickly moving segment/cluster of storms was
migrating southeastward across central Minnesota and has reached
areas near Saint Cloud.  Additionally, robust cellular development
has developed from that cluster southeastward through Saint Paul
and near Eau Claire, WI over the past half hour or so.  The newer
development was occurring along and just north of a subtle
confluence axis/old outflow, with buoyancy values on the warm side
of this axis exceeding 4000 J/kg MLCAPE.  Additionally, the axis
was oriented parallel to west-northwesterly flow aloft, allowing
for training and increasing rain rates into the 1-2 inch/hr range
(estimated per MRMS).  These rates were heaviest across areas of
relatively high FFG thresholds (2+ inch/hr), but were moving
toward Minneapolis/Saint Paul where FFGs drop considerably to less
than 1 inch/hr.

As these storms continue their southeastward trek, they will
likely cause at least isolated/urbanized flash flood potential
in/near Minneapolis through 07Z.  They are also likely to result
in areas of 2-3 inch rainfall totals from Minneapolis
southeastward into western Wisconsin, where FFG thresholds were
generally in the 1.5 inch/hr range.  Flash flood potential is
expected to increase as these storms mature.

Over time, some upscale growth of cells into lines/bowing segments
will likely result in a few areas of training/cell mergers that
could still keep rain rates above 1 inch/hr in spots.  The degree
of upscale growth/propagation may mitigate the extent of flash
flood potential due to faster cell movement, although it is a bit
uncertain how quickly the upscale growth will evolve.

Cook

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

ATTN...WFO...ARX...DLH...GRB...MPX...

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

LAT...LON   46009449 45729215 44468991 43859021 43479087
            43699214 44379327 45079465