Mesoscale Discussion 1092
   NWS Storm Prediction Center Norman OK
   0100 PM CDT Fri Jun 25 2021

   Areas affected...Western to central Iowa

   Concerning...Severe potential...Watch unlikely 

   Valid 251800Z - 252000Z

   Probability of Watch Issuance...5 percent

   SUMMARY...Thunderstorms will increase in coverage along an effective
   warm front through mid-afternoon. A few storms may be strong to
   severe and pose a brief hail and damaging wind threat. A watch is
   not expected.

   DISCUSSION...Recent GOES imagery shows convective towers attempting
   to deepen along an effective warm frontal boundary across IA. While
   most towers have shown only transient intensification, more robust
   convective initiation appears underway across western IA. As
   destabilization continues through the early afternoon hours
   sustained convection will become more likely along the front. A
   pocket of richer boundary-layer moisture with dewpoints in the 70s
   is supporting MLCAPE values near 1000-1500 J/kg with minimal
   inhibition. Despite favorable instability, deep-layer flow is
   somewhat weak with only 15-25 knots of effective bulk shear over the
   region (per recent mesoanalysis estimates). Mean flow over the
   region is also oriented largely along the boundary, suggesting that
   clusters with numerous storm interactions are likely. As such, the
   potential for robust and long-lived severe thunderstorms appears low
   and precludes the need for a watch. That said, brief hail threats
   may evolve with any stronger updraft pulses, and damaging down burst
   winds are possible.

   ..Moore/Guyer.. 06/25/2021

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

   ATTN...WFO...DVN...ARX...DMX...FSD...OAX...

   LAT...LON   42519624 42879560 42949423 42809273 42409113 41889018
               41489036 41509146 41609252 41699355 41859478 41889572
               41999618 42519624