Storm Prediction Center Mesoscale Discussion 887

   Mesoscale Discussion 0887
   NWS Storm Prediction Center Norman OK
   0608 PM CDT Mon May 19 2025

   Areas affected...Eastern Nebraska...Southwest Iowa

   Concerning...Tornado Watch 293...

   Valid 192308Z - 200115Z

   The severe weather threat for Tornado Watch 293 continues.

   SUMMARY...A severe threat will continue over the next few hours
   across parts of eastern Nebraska and southwest Iowa. Tornadoes,
   large hail and wind damage will be possible.

   DISCUSSION...The latest hi-resolution radar imagery shows line of
   severe storms located to the west of Omaha, with an intense
   supercell at the northern end. Another intense supercell is located
   in far southeast Nebraska. The storms are located along and just to
   the east of an axis moderate instability, where MLCAPE is in the
   2000 to 3000 J/kg range. At the surface, dewpoints are in the lower
   to mid 60s F, and surface winds are backed to the east-southeast
   along a pronouced warm front. This is evident on the Omaha WSR-88D
   VWP, which has 0-3 km storm-relative helicity around 260 m2/s2. This
   will be favorable for a tornado threat over the next couple of
   hours. In addition, the RAP has 700-500 mb lapse rates of between
   7.5 and 8 C/km, which will also be favorable for large hail. The
   more intense cores could produce hail greater than 2 inches in
   diameter. Wind damage will also be possible with supercells and
   short bowing line segments. As the storms move east-northeastward
   toward the southwest Iowa later this evening, the cells should
   become elevated. This could mean the large hail will eventually
   become the primary threat.

   ..Broyles/Gleason.. 05/19/2025

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

   ATTN...WFO...DMX...EAX...OAX...TOP...

   LAT...LON   41919537 41599489 41139478 40519495 39979577 40059655
               40359695 40849718 41189716 41669693 41979634 41919537 

   MOST PROBABLE PEAK TORNADO INTENSITY...120-150 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN