003
ACUS11 KWNS 212059
SWOMCD
SPC MCD 212058
MTZ000-212230-

Mesoscale Discussion 1361
NWS Storm Prediction Center Norman OK
0358 PM CDT Fri Jun 21 2024

Areas affected...Central Montana

Concerning...Severe Thunderstorm Watch 442...

Valid 212058Z - 212230Z

The severe weather threat for Severe Thunderstorm Watch 442
continues.

SUMMARY...The severe thunderstorm threat continues for WW 442. The
threat for damaging winds and hail is greatest in Central MT where
two isolated supercells have developed and begun tracking
east-southeast. Local WW extension may be needed further N into
Phillips County due to a southeastward moving supercell in Blaine
County.

DISCUSSION...Thunderstorm coverage has increased this afternoon over
the northern Rockies in W MT, with clusters of cells beginning to
move off of the higher terrain into the better buoyancy and shear.
These cells are capable of producing 1+ inch hail and damaging
winds.

In Central MT, two isolated supercells have developed and begun
moving east-southeast. These storms are in an environment of
1000-1500 J/kg MLCAPE and 45-50 kts of deep layer shear, supporting
a continued damaging wind and large hail threat.

Further east in Blaine County, near the Canadian border, a storm has
developed that may track outside of the watch area, warranting local
WW extension.

..Halbert/Weinman.. 06/21/2024

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

ATTN...WFO...BYZ...GGW...TFX...

LAT...LON   47721223 47991270 48401317 48731307 48871264 48831217
            48871114 48881046 48890977 48880900 48880860 48810822
            48660797 48510776 48320765 47980753 47570733 47310725
            47000719 46680716 46410744 46250788 46210863 46210888
            46180898 46180954 46241042 46361076 46631113 46901149
            47151176 47451185 47721223