Storm Prediction Center Mesoscale Discussion 462

   Mesoscale Discussion 0462
   NWS Storm Prediction Center Norman OK
   0737 PM CDT Thu Apr 17 2025

   Areas affected...far eastern Nebraska and southwest Iowa

   Concerning...Tornado Watch 141...

   Valid 180037Z - 180130Z

   The severe weather threat for Tornado Watch 141 continues.

   SUMMARY...The tornado threat will be maximized over the next hour
   across far eastern Nebraska and southwest Iowa

   DISCUSSION...Two strong, mature supercells with a history of 2 to
   2.75 inch hail, wind gusts up to 82 mph and a few tornadoes,
   continue east this evening. The tornado threat has increased
   substantially over the past hour as the low-level jet has
   strengthened from 35 to 45 knots (per TWX VWP). This low-level jet
   will strengthen further this evening which will lead to continually
   increasing low-level shear. However, the boundary layer will start
   to cool rapidly as the sun sets which should eventually limit the
   tornado threat. Therefore, the combination of sufficient surface
   based instability and increasing low-level shear should lead to a
   favorable (~1 hour) window for a continued tornado threat, before
   the threat transitions to primarily large hail and severe wind gusts
   later this evening. 

   An additional watch/watch extension may be needed later this
   evening.

   ..Bentley/Guyer.. 04/18/2025

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

   ATTN...WFO...DMX...OAX...

   LAT...LON   40819641 41249598 41499575 41609523 41289470 40849481
               40679558 40689627 40819641 

   MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN