SPC MD 1263

MD 1263 CONCERNING SEVERE THUNDERSTORM WATCH 449... FOR MUCH OF MONTANA AND FAR NORTH-CENTRAL WYOMING

Mesoscale Discussion 1263
NWS Storm Prediction Center Norman OK
0703 PM CDT Wed Jun 26 2019

Areas affected...much of Montana and far north-central Wyoming

Concerning...Severe Thunderstorm Watch 449...

Valid 270003Z - 270100Z

The severe weather threat for Severe Thunderstorm Watch 449
continues.

SUMMARY...The severe threat continues across WW 449.

DISCUSSION...Within the past hour, satellite/lightning imagery has
indicated an overall increase in convective coverage across WW 449. 
The environment continues to support damaging wind gusts and large
hail given weak to moderate instability (700-2500 J/kg MUCAPE) and
strong deep shear (50 kts 0-6km shear).  The boundary layer across
this region is well mixed, with weak low-level wind fields (outside
of thunderstorm cores) and cloud bases rooted around 3km.  Thus, the
expectation is that storms will be outflow dominant and perhaps grow
upscale into linear segments - especially across southeastern
Montana - which should continue to foster a wind/hail threat through
the next few hours.  Additional convection just south of the WW
(across far northeastern Idaho and northern Wyoming) will also enter
the WW area and pose a wind/hail threat.

..Cook.. 06/27/2019

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

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

LAT...LON   47931317 48221254 48271130 48070940 47300648 46430510
            45650486 44850503 44480623 44570750 44820872 44871053
            44751141 45401209 46171282 46971335 47551343 47931317 

Read more

from SPC Forecast Products http://www.spc.noaa.gov/products/md/md1263.html