568
AWUS01 KWNH 030837
FFGMPD
WIZ000-MNZ000-IAZ000-031335-

Mesoscale Precipitation Discussion 0384
NWS Weather Prediction Center College Park MD
436 AM EDT Mon Jun 03 2024

Areas affected...Portions of Far Northern IA...Central/Southern
MN...Northwest WI

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

Valid 030835Z - 031335Z

SUMMARY...Clusters of heavy showers and thunderstorms will
continue to impact areas of northern IA through central/southern
MN and into northwest WI going into the early morning hours. Given
the locally moist antecedent conditions, the rainfall may foster a
couple instances of flash flooding.

DISCUSSION...The latest GOES-E IR satellite imagery in conjunction
with dual-pol radar shows multiple clusters of organized
convection continuing to advance downstream over the Upper
Midwest, with the strongest activity currently focused over
south-central MN where the convective tops are as cold as -70C.
Cold-topped convection is also noted a little farther south over
far northern IA which is seen gradually lifting into southern MN.

All of the activity continues to be fostered by a strong warm air
advection regime in association with a shortwave trough crossing
the region along with a wave of low pressure. Surface observations
show a low center over eastern SD getting ready to move into
southwest MN, and there is a strong and convergent low-level jet
of 40 to 50 kts out ahead of this which is overrunning a warm
front draped from southwest MN east-southeast down into northern
IL. A nose of MLCAPE values of 1500+ J/kg is nosed up across
southwest MN and this coupled with divergent flow aloft and the
low-level convergence in vicinity of the warm front should
maintain multiple clusters of strong convection with heavy
rainfall going into the early morning hours.

Rainfall rates especially with the south-central MN activity will
be capable of reaching 2"/hour, and there may be some brief
cell-training and cell-merger concerns over the next couple of
hours when also accounting for the convection lifting northeast
out of northern IA and into southern MN. Meanwhile, farther off to
the northeast, strong isentropic ascent and elevated instability
is also expected to drive areas of heavy rainfall across northwest
WI which will also be a target eventually for some of the more
concentrated/organized cells advancing east out of east-central MN.

Some additional rainfall totals through early this morning may
reach 2 to 4 inches, and with locally moist antecedent conditions
in place, there may be a couple instances of flash flooding. The
overall most sensitive areas are across south-central MN which
already have somewhat elevated streamflows from recent rainfall.

Orrison

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

ATTN...WFO...ARX...DLH...DMX...FSD...MPX...

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

LAT...LON   46469150 46389072 45429048 44139170 43229312
            42869481 43209558 43839555 44619449 45539328
            46259234