422
ACUS11 KWNS 222055
SWOMCD
SPC MCD 222054
NDZ000-SDZ000-MTZ000-222300-

Mesoscale Discussion 1376
NWS Storm Prediction Center Norman OK
0354 PM CDT Sat Jun 22 2024

Areas affected...portions of eastern Montana into far western North
Dakota and extreme northwestern South Dakota

Concerning...Severe potential...Watch unlikely

Valid 222054Z - 222300Z

Probability of Watch Issuance...5 percent

SUMMARY...A couple instances of severe hail/wind gusts are possible
this afternoon with the stronger storms. The severe threat should
remain isolated and a WW issuance is not expected.

DISCUSSION...The passage of a 500 mb vort max along the U.S./Canada
border is supporting convective initiation across portions of
eastern Montana. Latest visible satellite imagery, MRMS mosaic radar
and NLDN lightning data, all indicate some increase in thunderstorm
coverage and intensity, with some indications of hail occurring in
Musselshell County, MT. The stronger flow aloft with the passing 500
mb vort max is contributing to straight, elongated hodographs and
accompanying 40-50 kts of effective bulk shear. Coinciding this axis
of shear are 8.5+ C/km 0-3km lapse rates, which may support a couple
of stronger thunderstorms this afternoon. Multicells and transient
supercells would be the most likely storm modes with the
longest-lived storms, accompanied by an isolated severe wind/hail
threat. Given the expected sparse nature of the severe wind/hail, a
WW issuance is not anticipated.

..Squitieri/Hart.. 06/22/2024

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

ATTN...WFO...BIS...UNR...BYZ...GGW...

LAT...LON   46620881 47050761 47570467 47290258 46570237 45930299
            45610451 45400591 45410708 45780817 46620881