SPC MD 1387

MD 1387 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHWESTERN AND SOUTH-CENTRAL MONTANA

Mesoscale Discussion 1387
NWS Storm Prediction Center Norman OK
0636 PM CDT Mon Aug 03 2020

Areas affected...Southwestern and south-central Montana

Concerning...Severe potential...Watch unlikely 

Valid 032336Z - 040130Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated damaging wind gusts possible into the early
evening. Large hail is possible, but should be less of a threat
relative to wind gusts. This marginal threat is not expected to
require a WW.

DISCUSSION...In the wake of early convection, temperatures have
risen into the low 90s F across parts of southwestern and
south-central Montana. With the continued influence of an upstream
shortwave within central/southern Idaho, the ongoing cluster of
storms is expected to be maintained into the early evening. With
low-level lapse rates having been able to steepen with several hours
of heating, a few damaging wind gusts will be possible. Potential
exists for isolated large hail as well given 35-50 kts of effective
shear and steep mid-level lapse rates. However, the hail threat will
be limited by multicellular storm mode as well as MLCAPE only
500-1000 J/kg. Farther north, convection has also redeveloped, but
the airmass has not been able to recover due to lingering cloud
cover during the day. The severe threat should be much more limited
in north-central Montana. No WW is expected for this activity.

..Wendt/Hart.. 08/03/2020

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

ATTN...WFO...BYZ...RIW...TFX...PIH...MSO...

LAT...LON   44321170 44101279 44831313 45211286 45771186 46271112
            46521039 46570915 45960789 45100801 44890912 44321170 

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from SPC Forecast Products http://www.spc.noaa.gov/products/md/md1387.html