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 458
< Previous MD         Next MD >
MD 458 graphic

   MESOSCALE DISCUSSION 0458
   NWS STORM PREDICTION CENTER NORMAN OK
   0338 PM CDT MON APR 28 2014

   AREAS AFFECTED...PORTIONS IA...IL...EXTREME ERN MO.

   CONCERNING...TORNADO WATCH 109...

   VALID 282038Z - 282245Z

   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 109 CONTINUES.

   SUMMARY...ARC OF STG-SVR TSTMS WILL CONTINUE TO POSE RISK OF LARGE
   HAIL AND DAMAGING GUSTS...WITH A FEW TORNADOES STILL POSSIBLE. 
   ADDITIONAL SVR MAY OCCUR E OF WW ACROSS PORTIONS CENTRAL/NRN
   IL...INVOF WARM FRONT DESCRIBED BELOW...AND ANOTHER WW MAY BE
   REQUIRED AS INSTABILITY/CONVECTIVE TRENDS WARRANT.

   DISCUSSION...SFC MESOANALYSIS SHOWS DEEP/OCCLUDED LOW OVER NERN
   NEB...WITH OCCLUDED FRONT ARCHING ACROSS EXTREME NERN NEB AND
   W-CENTRAL IA CLOSE TO ONGOING BAND OF CONVECTION.  TRIPLE POINT WAS
   ESTIMATED NEAR DSM WITH WARM FRONT WELL-DEFINED EWD ACROSS KEOKUK
   COUNTY IA TO PEORIA/VERMILION COUNTIES IL.  COLD FRONT WAS DRAWN
   FROM DSM AREA SEWD BETWEEN IRK-EOK THEN SEWD ACROSS ERN MO TO NEAR
   JBR.  SVR THREAT SHOULD END BEHIND EXISTING BAND OF CONVECTION
   LOCATED JUST E OF COLD FRONT...GIVEN NEGATIVE THETAE ADVECTION
   BEHIND THAT BOUNDARY.  WARM FRONT SHOULD CONTINUE TO MOVE NWD ACROSS
   PORTIONS NRN IL...S OF WHICH FAVORABLE DESTABILIZATION IS EXPECTED
   UNTIL
   1. SUN ANGLE GETS LOW CLOSE TO SUNSET... 
   2. ANVIL MATERIAL FROM COLD-FRONTAL TSTM ARC SPREADS OVER AREA
   AND/OR
   3. NWRN FRINGE OF RELATIVELY LOW-THETAE AIR FROM SRN IL ADVECTS INTO
   AREA...LIMITING ERN EXTENT.  

   VERTICAL SHEAR PROFILES WILL CONTINUE TO FAVOR ORGANIZED MULTICELL
   AND OCNL SUPERCELL STRUCTURES IN CONVECTIVE ARC...WITH A FEW
   QLCS/BOW CIRCULATIONS ALSO POSSIBLE.  

   REF SPC MESOSCALE DISCUSSION 457 FOR SVR POTENTIAL IN AREAS SE OF WW
   ACROSS SERN MO...SRN IL...WRN/CENTRAL KY AND NRN TN.

   ..EDWARDS.. 04/28/2014


   ATTN...WFO...LOT...ILX...LSX...DVN...DMX...

   LAT...LON   38399088 40169166 41259312 41489413 41859504 42059503
               42089436 41929287 41869083 41689000 41508940 40988821
               40248795 39168862 38458936 38039037 38399088 

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: April 28, 2014
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities