Mesoscale Discussion 1445
   NWS Storm Prediction Center Norman OK
   0118 PM CDT Thu Jun 27 2024

   Areas affected...Portions of central and eastern Montana

   Concerning...Severe potential...Watch likely 

   Valid 271818Z - 272045Z

   Probability of Watch Issuance...80 percent

   SUMMARY...The severe-storm threat will gradually increase from west
   to east across portions of central and eastern Montana this
   afternoon. Large hail and severe gusts are the main concerns. A
   watch will likely be needed for parts of the area later this
   afternoon.

   DISCUSSION...Latest water-vapor imagery indicates a band of
   large-scale ascent overspreading west/central MT -- ahead of a
   midlevel trough/low tracking eastward across the Northwest. At the
   leading edge of this ascent, isolated to widely scattered
   thunderstorms are tracking east-northeastward along the higher
   terrain in west/central MT. Over the next several hours, this
   activity will continue spreading eastward across central into
   eastern MT, generally in tandem with the large-scale ascent.
   Additional development is also possible in areas of differential
   heating farther east. Ample diurnal heating/destabilization beneath
   steep midlevel lapse rates (sampled by 12Z regional soundings) will
   erode remaining low-level inhibition and promote a gradual uptick in
   updraft intensity through the afternoon. 

   Around 50 kt of effective shear associated with the
   eastward-advancing trough will support storm organization, and a
   mostly straight hodograph should favor a mix of splitting supercell
   structures and organized clusters. Large hail (some potentially 2+
   inches) and severe outflow winds are possible with the strongest
   storms. The risk of severe gusts (some 75+ mph) should increase with
   eastward extent, especially with any upscale-growing clusters. While
   a brief tornado cannot be entirely ruled out in this area, the
   more-favorable tornado environment should generally develop over
   areas farther east (far eastern MT into the Dakotas), where richer
   boundary-layer moisture and curved hodographs are expected. 

   A watch is likely for portions of the area later this afternoon,
   though timing of issuance is a bit uncertain at this time.

   ..Weinman/Hart.. 06/27/2024

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

   ATTN...WFO...BYZ...GGW...TFX...

   LAT...LON   46320967 46920906 47200870 47580813 47800768 48110706
               48290651 48430569 48330512 47910473 46990450 46390455
               45770483 45470550 45220700 45160853 45240924 45430965
               45710987 46030989 46320967