Storm Prediction Center Mesoscale Discussion 1333

   Mesoscale Discussion 1333
   NWS Storm Prediction Center Norman OK
   0155 PM CDT Tue Jun 17 2025

   Areas affected...Southeast Wyoming into the Front Range

   Concerning...Severe Thunderstorm Watch 428...

   Valid 171855Z - 172100Z

   The severe weather threat for Severe Thunderstorm Watch 428
   continues.

   SUMMARY...Large to very-large hail remains possible with supercells.
   Severe wind gusts are also possible, particularly with any upscale
   growth that can move off the terrain. A tornado or two may still
   occur with the most organized supercells.

   DISCUSSION...The back edge of mid-level ascent with a shortwave
   trough is now roughly along the Colorado western slope. Continued
   moist upslope flow and lift from the trough will promote persistent
   convective initiation along the higher terrain through the
   afternoon. Steep mid-level lapse rates and moderate effective shear
   (stronger with southward extent) should keep storm mode
   supercellular. With slightly weaker shear and greater storm coverage
   west of Cheyenne and Fort Collins, these areas would be preferred
   for eventual upscale growth. Low-level stratus has eroded east of
   these storms as well which will only further support moving off the
   terrain over the next few hours. Severe winds and large hail would
   be possible. Farther south, near Pueblo, the low-level stratus has
   remained. Storms will likely remain near the terrain as a result.

   Aside from hail and severe winds, a tornado or two will also be
   possible. Low-level hodographs are not overly large per regional VAD
   data, but low-level easterly winds, supercell modes, and numerous
   storm-scale boundaries to interact with will allow for some risk.
   One tornado has already been observed northwest of Cheyenne.

   ..Wendt.. 06/17/2025

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

   ATTN...WFO...GLD...PUB...BOU...CYS...

   LAT...LON   40840587 41920589 42290491 42180392 40130335 39350296
               38900286 38530299 38210417 38260531 38670575 40840587 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN