Mesoscale Discussion 0150
   NWS Storm Prediction Center Norman OK
   0132 PM CST Wed Mar 10 2021

   Areas affected...portions of central and northern IA...southeast MN
   and west-central WI

   Concerning...Severe potential...Watch possible 

   Valid 101932Z - 102130Z

   Probability of Watch Issuance...60 percent

   SUMMARY...Severe potential is increasing across parts of central IA
   and southeast MN this afternoon. Thunderstorms are expected to
   develop in the next 1-3 hours. A watch may be needed by 3pm.

   DISCUSSION...Strong surface heating ahead of a surface low and cold
   front has resulted in temperatures climbing into the mid 60s to low
   70s F across much of IA this afternoon. Strong southerly low level
   flow has allowed low-to-mid 50s F surface dewpoints to spread
   northward across IA into southeast MN and west-central WI, aiding in
   weak destabilization. The strongest instability as of 19z resides
   over the western half of IA, where skies have cleared and
   temperatures are warmer. Cumulus across this area have deepened over
   the past hour, and some stronger reflectivity is now evident across
   far northwest IA/southwest MN. This activity is elevated on the cool
   side of a warm front stretching from northwest IA into west-central
   WI. While this activity could result in some small hail given steep
   midlevel lapse rates (7-8 C/km), any severe threat this far
   west/north should remain limited. 

   As the surface low continues to develop east/northeast this
   afternoon, additional heating is expected in broken cloudiness
   across central IA into southeast MN, resulting in weakening
   inhibition. This will coincide with stronger upper forcing ejecting
   across the region with the upper shortwave trough and additional
   surface-based thunderstorms are expected to develop in the next 1-3
   hours. Favorably curved low-level hodographs are apparent in
   forecast soundings as well as in VWP data from KARX. While
   instability will remain weak through this evening, strong effective
   shear coupled with backed low level flow should support a couple of
   storms with supercell structures capable of all severe hazards. With
   time, any discrete cells that develop are expected to become more
   linear during the evening as the cold front surges eastward and
   deep-layer flow becomes more parallel to the surface boundary. This
   could result in increasing potential for a few strong-to-severe wind
   gusts into the nighttime hours.

   ..Leitman/Kerr.. 03/10/2021

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

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

   LAT...LON   41659232 41389288 41249402 41309448 41499486 41889519
               42259527 42829525 43489475 44439399 44949309 45169228
               45079188 44909141 44639119 44159114 42209182 41659232