Skip Navigation Links weather.gov 
NOAA logo-Select to go to the NOAA homepage NOAA's National Weather Service   Select to go to the NWS homepage
Storm Prediction Center
navigation bar left  
  navigation bar end cap


 
USA.gov is the U.S. Government's official Web portal to all Federal, state and local government Web resources and services.

Mesoscale Discussion 15
< Previous MD         Next MD >
MD 15 graphic

   Mesoscale Discussion 0015
   NWS Storm Prediction Center Norman OK
   0200 PM CST Fri Jan 11 2019

   Areas affected...East-central Missouri...far west-central Illinois

   Concerning...Heavy snow 

   Valid 112000Z - 120200Z

   SUMMARY...Heavy snow is expected over the next several hours, with
   up to 1 in/hr rates likely in some spots, especially along the I-70
   corridor, including the St. Louis metropolitan area.

   DISCUSSION...As a mid-level trough continues to progress across the
   Central Plains during the afternoon, the northward advection of a
   deep, moist airmass will continue across the region along with
   increasing large-scale ascent. Recent Mesoanalysis has indicated
   700-500 mb frontogenesis is underway across the area, where an
   800-1000 m deep, near-saturated to saturated dendritic layer is
   present, fostering the potential for efficient snowfall production.
   Latest KEAX and KLSX dual-polarimetric data suggest a transition to
   all snow north of a west-east oriented line approximately through
   Cass County to Jefferson County in Missouri.

   While several locations are above freezing at the surface, 10+F T/Td
   spreads and a sub-saturated sfc-850 mb layer suggest that
   evaporative cooling with the onset of the initial precipitation will
   cool and saturate the lower-level troposphere to foster occasionally
   heavy snow, with up to 1 in/hr rates possible in some areas. Latest
   high resolution ensemble guidance continues to suggest that the
   greatest threat for heavy snow will remain confined in a narrow
   corridor across portions of central/eastern Missouri through the
   evening hours.

   ..Squitieri.. 01/11/2019

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

   ATTN...WFO...LSX...EAX...

   LAT...LON   38608991 38299021 38249085 38789260 39229373 39589353
               39549207 39499078 39148997 38868989 38608991 

Top/All Mesoscale Discussions/Forecast Products/Home
Weather Topics:
Watches, Mesoscale Discussions, Outlooks, Fire Weather, All Products, Contact Us

NOAA / National Weather Service
National Centers for Environmental Prediction
Storm Prediction Center
120 David L. Boren Blvd.
Norman, OK 73072 U.S.A.
spc.feedback@noaa.gov
Page last modified: January 12, 2019
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities