SPC AC 260736

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0236 AM CDT Wed Jun 26 2019

   Valid 281200Z - 291200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
   NORTH-CENTRAL MONTANA INTO WESTERN NORTH DAKOTA...

   ...SUMMARY...
   Widely scattered severe storms are expected across parts of
   north-central Montana into western North Dakota on Friday. Large
   hail and damaging wind gusts will be possible with these storms.

   ...Montana into North Dakota...

   The overall pattern will not change much on Friday from the Northern
   Rockies eastward into the Plains. The Pacific Northwest upper low
   will lift northeastward into Alberta while a large-scale trough is
   maintained across the Pacific Northwest in its wake. Strong
   deep-layer southwesterly flow will continue to overspread MT into
   the Canadian Prairie Provinces. Ongoing convection is expected at
   the beginning of the period, likely across northwest ND. This
   activity may be strong to severe initially, but will weaken as
   capping associated with the Plains/Upper Midwest ridge increases
   with eastward extent. Later during the afternoon and evening, storms
   are expected to develop once again across parts of north-central MT
   as the upper low ejects northeastward. A very moist and unstable
   boundary layer beneath steep midlevel lapse rates in the midst of
   strong shear will once again support large hail and damaging winds.
   A cold front will shift east across MT overnight and a line of
   strong to severe storms may once again move into western ND. 

   ...Great Lakes Vicinity...

   Several weak shortwave impulses, along with potential outflows
   and/or MCVs related to the prior day's convection will track across
   the Great Lakes vicinity on Friday. Deep layer northwesterly flow
   will be somewhat modest, which may limit organized severe threat
   somewhat. However, a moist and unstable boundary layer will be in
   place with strong heating resulting in MLCAPE values 1500-3000 J/kg.
   Depending on the timing of shortwave impulses migrating through
   broad cyclonic mid/upper level flow and MCVs floating eastward
   across the region, strong to severe storms will be possible, but
   uncertainty is still too great to include higher than Marginal
   severe probs.

   ..Leitman.. 06/26/2019

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   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z