Storm Prediction Center Mesoscale Discussion 1366

   Mesoscale Discussion 1366
   NWS Storm Prediction Center Norman OK
   0540 PM CDT Fri Jun 21 2024

   Areas affected...Parts of far eastern WY...northeast CO...and the NE
   Panhandle

   Concerning...Severe Thunderstorm Watch 443...

   Valid 212240Z - 220015Z

   The severe weather threat for Severe Thunderstorm Watch 443
   continues.

   SUMMARY...The greatest threat for large hail, severe/damaging winds,
   and perhaps a tornado should spread eastward this evening over the
   Nebraska Panhandle and northeast Colorado.

   DISCUSSION...Weak low-level upslope flow is aiding widely spaced
   supercells across far eastern WY into northeast CO and the western
   NE Panhandle early this evening. Surface dewpoints and low-level
   moisture increase with eastward extent across these areas based on
   latest observations, with greater instability also being estimated
   by recent mesoanalysis. Strong deep-layer shear should continue to
   support a supercell mode in the short term, with large to isolated
   very large hail around 1.5-2.5 inches in diameter possible.
   Severe/damaging downdraft winds around 60-70 mph may also occur,
   especially where low-level lapse rates have become steepened with
   daytime heating. The southern supercell in northeast CO is the
   strongest storm across this region at the moment. It should have
   access to an unimpeded low-level moisture feed, and will likely
   maintain its intensity in the short term. A brief tornado may also
   occur this evening, particularly if supercells can be maintained
   farther east into the NE Panhandle where greater low-level
   moisture/lower LCLs are present. Based on latest observational
   trends, Severe Thunderstorm Watch 443 has been locally extended in
   area to include more of the western NE Panhandle and northeast CO.

   ..Gleason.. 06/21/2024

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

   ATTN...WFO...LBF...BOU...CYS...

   LAT...LON   40760432 41790439 42560416 42930351 42900230 41720146
               40770131 40430165 40460339 40760432