ZCZC SPCSWOMCD ALL
ACUS11 KWNS 210131 
SPC MCD 210131 
NDZ000-SDZ000-210300-

Mesoscale Discussion 1387
NWS Storm Prediction Center Norman OK
0831 PM CDT Fri Jun 20 2025

Areas affected...portions of extreme northern South Dakota into
central North Dakota

Concerning...Tornado Watch 447...448...

Valid 210131Z - 210300Z

The severe weather threat for Tornado Watch 447, 448 continues.

SUMMARY...A mature MCS is evolving into a bow-echo, and a derecho is
expected.

DISCUSSION...An intense MCS, with a history of several severe gusts
(including a recently measured gust at 94 mph in Grant County, ND),
is in progress across western ND into far northern SD. This MCS is
rapidly propagating eastward, and is demonstrating signs of a
progressive cold pool and a rear-inflow jet. This MCS is morphing
into an even more organized, bow-echo structure. As the bow-echo
progresses eastward, it will encounter low 70s F surface dewpoints
and resultant 3500-4500 J/kg MLCAPE, as noted by the 01Z
mesoanalysis. As such, a derecho will likely ensue as the MCS moves
into this greater instability, with widespread severe winds expected
to accompany this MCS, including multiple 75-100 mph burst swaths.

..Squitieri.. 06/21/2025

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

ATTN...WFO...ABR...BIS...UNR...

LAT...LON   47320290 47760120 47700065 47340026 46749998 45809986
            45510083 45350175 45340229 45480273 45620285 47320290 

MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...95-115 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN

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