Mesoscale Discussion 0474
   NWS Storm Prediction Center Norman OK
   1242 PM CDT Fri Apr 17 2026

   Areas affected...portions of the southern/central Great Plains into
   the mid-Missouri Valley

   Concerning...Severe potential...Watch likely 

   Valid 171742Z - 172015Z

   Probability of Watch Issuance...95 percent

   SUMMARY...Numerous severe thunderstorms are expected to form
   along/ahead of a cold front and dryline from northern Missouri
   southwestward into northwestern Oklahoma this afternoon. Storms will
   pose a threat for all hazards, including hail to 3-3.5+ inches in
   diameter, very strong wind gusts of 60-80+ mph, and a couple of
   tornadoes (perhaps strong). Watch issuance will be needed in the
   next 1-2 hours.

   DISCUSSION...Latest mesoanalysis depicts a strongly unstable air
   mass in place ahead of a triple point over northwestern Oklahoma and
   the associated cold front/dryline. Temperatures in the upper-70s F
   and dewpoints in the mid/upper-60s are contributing to strong
   instability of 2000-3000+ J/kg MLCAPE across the region per latest
   mesoanalysis. Low-level convergence is forecast to lead to
   convection initiation near the triple point and along the cold
   front/prefrontal confluence zone through the afternoon. Strong
   southwesterly flow (50+ kts at 4-5 km AGL per regional VWPs) is
   contributing to effective bulk shear of 40-50 kts (locally greater
   near the triple point), which will support supercells with initial
   storm formation. Steep mid-level lapse rates (as sampled by the 12z
   OUN/TOP/SGF soundings and recent ACARS profiles), elongated
   hodographs, and ample buoyancy within the hail growth zone will
   support the potential for hail of 3-3.5+ inches in diameter. Strong
   downdrafts (with wind gusts up to 60-80 mph) are also possible given
   the presence of some drier mid-level air.

   The tornado threat remains more uncertain as deep-layer flow is
   largely oriented parallel to the cold front, which may yield complex
   storm mode/interactions. Given the potential for supercellular mode
   and storm/outflow interactions, at least some potential for a couple
   of tornadoes (perhaps strong) appears to exist, however. This
   appears most likely with any supercell that is able to remain more
   discrete into the evening hours when a strengthening nocturnal
   low-level jet will yield increasingly curved low-level hodographs.
   Trends will continue to be monitored, and a tornado watch will be
   needed within the next 1-2 hours to cover these threats.

   With time, the development of a forward-propagating MCS is
   anticipated across much of this area, with an accompanying
   transition towards severe wind gusts (80+ mph wind gusts possible)
   and perhaps embedded tornadoes as the primary threats.

   ..Chalmers/Mosier.. 04/17/2026

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

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

   LAT...LON   36559959 37359896 38879741 40089628 40419548 40519443
               40279381 39679370 38659397 37659462 36669558 35639699
               35079813 34999904 35509967 36559959 

   MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
   MOST PROBABLE PEAK WIND GUST...75-90 MPH
   MOST PROBABLE PEAK HAIL SIZE...2.75-4.25 IN