Storm Prediction Center Mesoscale Discussion 1907

   Mesoscale Discussion 1907
   NWS Storm Prediction Center Norman OK
   0539 PM CDT Mon Aug 10 2026

   Areas affected...Western South Dakota into north-central Nebraska

   Concerning...Severe potential...Watch likely 

   Valid 102239Z - 110045Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Thunderstorms developing across western South Dakota may
   intensify into a robust MCS in the coming hours. If/when this
   occurs, the potential for severe winds will substantially increase
   downstream into southern South Dakota and north-central Nebraska.
   Watch issuance is probable if convection intensifies as expected.

   DISCUSSION...Large-scale ascent continues to spread east across the
   central and northern High Plains based on recent GOES imagery with
   several clusters of high-based thunderstorms emerging from eastern
   MT into eastern WY and CO. More recently, a cluster of high-based
   thunderstorms has developed across far western SD in proximity to
   the western fringe of a moist plume that extends from the central
   Plains into western SD around a weak surface low analyzed south of
   the Black Hills. Over time, this convection should intensify as it
   continues to spread east into the moist air mass where MLCAPE
   rapidly increases into the 3000-4500 J/kg range. 

   Additionally, the combination of southeasterly low-level winds to
   the north of the low with 30-40 knot mid-level flow aloft is
   supporting around 40-50 knots of effective bulk shear across the
   warm sector. This will likely promote organization of deepening
   convection over the next few hours - most likely into an MCS as cold
   pools continue to amalgamate and deepen. If an MCS emerges, the
   downstream environment will likely support severe gusts as high as
   65-80 mph, and potentially a few embedded circulations given strong
   westerly low-level shear.

   Most high-res solutions over the past several hours have depicted
   some form of an MCS emerging out of the Dakotas this evening, though
   considerable spread is noted on precisely when and where such an MCS
   will emerge. Based on these observed trends, this cluster may
   develop into the anticipated MCS. Trends will continue to be
   monitored, and watch issuance will likely be required if the cluster
   continues to intensify.

   ..Moore/Mosier.. 08/10/2026

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

   ATTN...WFO...FSD...ABR...LBF...UNR...CYS...

   LAT...LON   42350100 43390398 43660419 44160422 44430415 44640385
               44700351 44349913 43859875 43259880 42839910 42539963
               42360032 42350100 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN