Storm Prediction Center Mesoscale Discussion 2312

   Mesoscale Discussion 2312
   NWS Storm Prediction Center Norman OK
   0705 PM CDT Sat Sep 19 2026

   Areas affected...Central Plains

   Concerning...Severe Thunderstorm Watch 670...

   Valid 200005Z - 200130Z

   The severe weather threat for Severe Thunderstorm Watch 670
   continues.

   SUMMARY...Scattered strong-to-severe thunderstorms will be possible
   this evening. Locally damaging winds and hail will be the main
   threats. The need for a downstream watch will continue to be
   assessed.

   DISCUSSION...Thunderstorms are ongoing this evening along a surface
   boundary/wind shift that stretches from the south Texas Panhandle
   northeast into southeast Iowa. Along and ahead of this boundary,
   temperatures warmed and remain in the mid-90Fs to lower-100Fs, with
   surface dewpoint temperatures in the mid-to-upper-60Fs along the
   boundary. The result is a very unstable environment with MUCAPE
   values in excess of 2000 J/kg and DCAPE in excess of 1000 J/kg.
   However, the stronger vertical shear is lagging the instability axis
   and remains along and behind the surface boundary. Thunderstorms
   ingesting this airmass have been capable of producing measure severe
   wind speeds (65 mph) across Dickinson County, KS. These storms will
   continue northeast and threaten the northwest Kansas City metro area
   over the next couple of hours. 

   The latest high resolution guidance suggests that ongoing
   thunderstorms will continue to move east, northeast and increase in
   number this evening. The increase in number of storms with their
   congealing outflow boundaries, coupled with nocturnal cooling,
   should eventually weaken overall instability and limit the long-term
   wind threat, especially with the strongest vertical shear remaining
   west of the area. 

   A local extension of Severe Thunderstorm Watch #670 just occurred,
   and the need for a downstream watch will continue to be assessed.

   ..Marsh.. 09/20/2026

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

   ATTN...WFO...SGF...DMX...EAX...TSA...OAX...TOP...ICT...OUN...
   DDC...AMA...

   LAT...LON   35840006 37709957 39799715 40399587 40979388 39929331
               38509395 37319471 36079667 35599868 35840006 

   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN