Mesoscale Discussion 0167
   NWS Storm Prediction Center Norman OK
   0505 AM CST Sat Mar 09 2019

   Areas affected...Portions of eastern SD...northwestern IA...and
   southwestern MN

   Concerning...Freezing rain 

   Valid 091105Z - 091600Z

   SUMMARY...Freezing rain rates up to 0.05 inch per hour may occur
   through 16Z (10 am CST).

   DISCUSSION...Showery precipitation ongoing across eastern NE/SD and
   western IA at 11Z is likely related to low-level warm and moist air
   advection occurring with a 30-40 kt south-southeasterly low-level
   jet. Surface temperatures remain at or below freezing across much of
   eastern SD, northwestern IA, and southwestern MN this morning per
   recent surface observations. A +2 to +4C warm nose centered around
   850 mb associated with the low-level jet is melting hydrometeors
   aloft, with refreezing occurring at the surface. One observation
   site in eastern SD (KMHE) recently reported 0.06 inch of ice
   accretion in one hour. Freezing rain rates around 0.05 inch per hour
   should remain possible across this region for at least the next few
   hours. A better chance for ice accretion should develop where
   surface temperatures can remain at or below 30F, namely parts of far
   eastern SD into southwestern MN. The freezing rain should slowly
   change to rain from south to north across northwestern IA and
   vicinity later this morning as surface temperatures climb above
   freezing. A transition from freezing rain to snow may also occur
   across parts of eastern SD around 14-16Z as the low-levels cool,
   with the northeastward progression of an upper trough across the
   Plains.

   ..Gleason.. 03/09/2019

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

   ATTN...WFO...MPX...DMX...FSD...ABR...

   LAT...LON   42929609 43029724 43309800 43779833 44399825 44869723
               44979585 44659484 44119407 43469414 43169450 42949533
               42929609