ZCZC SPCSWOMCD ALL
ACUS11 KWNS 100234 
SPC MCD 100234 
MTZ000-100400-

Mesoscale Discussion 0904
NWS Storm Prediction Center Norman OK
0934 PM CDT Wed Jun 09 2021

Areas affected...North-central MT

Concerning...Severe Thunderstorm Watch 250...

Valid 100234Z - 100400Z

The severe weather threat for Severe Thunderstorm Watch 250
continues.

SUMMARY...The threat for isolated large hail and damaging wind may
continue into the late evening. Some threat may spread downstream of
WW 250 in the short term.

DISCUSSION...At 0230Z, a long-lived supercell is ongoing across
Phillips County MT, where it earlier produced 3-inch diameter hail.
Trends in visible satellite and objective mesoanalysis suggest that
MLCINH is increasing downstream, so the longevity of this cell is
uncertain. However, given the well-organized nature of the storm and
still-favorable MUCAPE and effective shear, some threat may spread
downstream of WW 250 into Valley County, MT in the short term. 

Further west, convection has occasionally pulsed up to near severe
limits, though individual cells have struggled to remain organized.
While MLCINH may be too prohibitive for surface-based storms in that
area, persistent large-scale ascent and favorable instability may
allow for occasionally organized clusters or perhaps an elevated
supercell, with a continued threat for hail and perhaps an isolated
strong wind gust.

..Dean.. 06/10/2021

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

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

LAT...LON   48971054 49030909 48940823 48660707 47580723 46920832
            46781048 47091090 48751065 48971054 

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