Mesoscale Discussion 1774
   NWS Storm Prediction Center Norman OK
   0853 PM CST Sat Nov 07 2020

   Areas affected...portions of western Montana

   Concerning...Heavy snow 

   Valid 080253Z - 080900Z

   SUMMARY...An increase in coverage/intensity of snowfall is expected
   across portions of western Montana -- particularly in
   upslope-favored areas on northeastern-facing slopes of the higher
   terrain.  Rates of 1-2 inches per hour will evolve over the next
   several hours.

   DISCUSSION...Latest surface analysis shows a low over the eastern
   Idaho/far southwestern Montana vicinity, with a warm front extending
   eastward across southern Montana.  While temperatures remain in the
   40s at lower elevations just north of the warm front, colder air --
   on northerly to northeasterly surface winds -- continues to filter
   southward into northern Montana, with elevations near 3000 feet now
   near freezing per recent observations.

   Radar data reveals bands of moderate snow ongoing in the Great Falls
   vicinity, and snow is expected to increase in coverage and intensity
   over the next several hours as large scale ascent increases in
   advance of the northeastward-moving short-wave trough pivoting
   toward the region.  Given persistent upslope-enhanced ascent, as the
   surface low slides eastward along the warm front with time
   maintaining northerly isallobaric low-level flow, a prolonged period
   of heavy snowfall is expected.

   ..Goss.. 11/08/2020

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

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

   LAT...LON   49051191 48941096 48011019 46940977 46251007 45981115
               46541249 49061395 49051191