SPC MD 770



MD 0770 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR WESTERN MONTANA

MD 0770 Image

Mesoscale Discussion 0770
NWS Storm Prediction Center Norman OK
0600 PM CDT Sat May 30 2020

Areas affected...western Montana

Concerning...Severe potential...Watch unlikely 

Valid 302300Z - 310030Z

Probability of Watch Issuance...5 percent

SUMMARY...A few strong to severe thunderstorms are possible across
western Montana into this evening. Marginally severe wind/hail are
the main threats, but a watch issuance is unlikely.

DISCUSSION...A vigorous upper low is moving northward over northern
California helping to displace an upper-level ridge over the
Intermountain West and lowering heights across the region. Broad
large-scale ascent is overspreading much of the Pacific Northwest
and into northern Rockies. However, with the strongest forcing for
ascent west of the northern Rockies, terrain-induced circulations
and temperatures rising to the upper 80s to low 90s F with dewpoints
in the 50s F have helped initiate convection over western Montana
and vicinity. Steep mid-level lapse rates (8+ C/km) per mesoanalysis
and forecast soundings and effective bulk shear of 30-40 knots
indicate the potential for stronger, organized updrafts capable of
large hail. Additionally, relatively high LCLs and steep low-level
lapse rates indicate the potential for downdrafts with DCAPE in
excess of 1200 J/kg per mesoanalysis and forecast soundings. 

Storms may persist beyond sunset. However, the storm environment
becomes less conducive over northern/central Montana, which is north
of the lifting surface front and within higher heights/warmer
mid-level temperatures. Overall, the severe threat is likely to
remain marginal and isolated.

..Nauslar/Thompson.. 05/30/2020

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

ATTN...WFO...BYZ...TFX...MSO...

LAT...LON   47721154 47421108 46611046 46031053 45821085 45941148
            46051217 46271422 46791444 47391428 47851381 48081335
            48121275 47991210 47721154 

Read more



Source link

Editor
  • Editor
  • Website is owned by STL.News, LLC, but hosted, designed and maintained by WebTech Group (WTG). WTG is a St. Louis based web designed firm offering digital marketing services and news sites. We created RSSWX.News to help the major search engines easily find news direct from the source, which is the National Weather Service.