SPC MD 461

MD 0461 CONCERNING SEVERE THUNDERSTORM WATCH 140… FOR SOUTHEAST MINNESOTA INTO NORTHWEST IOWA

Mesoscale Discussion 0461
NWS Storm Prediction Center Norman OK
0556 PM CDT Thu Apr 17 2025

Areas affected...Southeast Minnesota into Northwest Iowa

Concerning...Severe Thunderstorm Watch 140...

Valid 172256Z - 180100Z

The severe weather threat for Severe Thunderstorm Watch 140
continues.

SUMMARY...Storms in southeast Minnesota will pose a short-term
threat for small to marginally severe hail and perhaps isolated wind
damage. Additional development, though not certain, is possible in
Northwest Iowa. Large hail and damaging winds would be the main
threat in that area.

DISCUSSION...A line of storms south of the Twin Cities will continue
eastward. This line has shown a weakening trend over the last hour
as it has encountered cooler/drier air. Isolated wind damage and
small to marginally sever hail could occur with this activity, but a
continued downward trend in intensity is expected.

A small zone of greater surface heating ahead of the cold front is
situated in northwest Iowa. As an upstream shortwave perturbation
moves towards the area this evening, modestly increasing frontal
convergence and mid-level ascent could promote an additional storm
or two within this zone. Should storms form here, steep mid-level
lapse rates and  40 kts of effective shear will support large hail
and damaging wind potential.

..Wendt.. 04/17/2025

...Please see www.spc.noaa.gov for graphic product...

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

LAT...LON   42299536 42279594 42319622 42489614 42889588 43759492
            44189462 44449410 44539336 44269239 43779237 42819424
            42399481 42299536 

MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN

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