ZCZC SPCSWOMCD ALL
ACUS11 KWNS 081853 
SPC MCD 081853 
MTZ000-WYZ000-IDZ000-082100-

Mesoscale Discussion 1412
NWS Storm Prediction Center Norman OK
0153 PM CDT Mon Jul 08 2019

Areas affected...southern Montana and northern Wyoming

Concerning...Severe potential...Severe Thunderstorm Watch likely 

Valid 081853Z - 082100Z

Probability of Watch Issuance...80 percent

SUMMARY...Convection continues to deepen across western portions of
the discussion area and will pose a gradually increasing hail/wind
risk  with eastward extent.

DISCUSSION...The combination of surface heating/destabilization and
lift associated with a couple of subtle mid-level impulses over
southwestern Montana and northeastern Idaho was resulting in
gradually increasing convection over the past hour or so near the
Big Horns/Absaroka Range and vicinity.  This initial convection was
in an environment marginally supportive of severe hail/wind risk
(1000-1500 J/kg MUCAPE and 30-40 kt deep shear).  However, the
downstream environment over north-central Wyoming and southeastern
Montana is more moist/unstable (2000-2500 J/kg MUCAPE), with steep
lapse rates aloft and mid-50s F dewpoints expected support a greater
hail/wind risk as storms migrate eastward.  Latest CAMs/model
guidance suggests that storms will tend to grow upscale with
eastward movement, with a mix of clusters and linear segments
expected to evolve through the afternoon.  This severe risk will
likely necessitate a Severe Thunderstorm Watch issuance in the next
couple hours or so.

..Cook/Grams.. 07/08/2019

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

ATTN...WFO...UNR...BYZ...GGW...RIW...TFX...PIH...

LAT...LON   45671091 46041020 46680849 47230647 47330513 46900428
            45710415 44610427 43970505 43630659 43250794 42760967
            42701043 43071109 43811143 44701127 45671091 

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