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 1738
< Previous MD         Next MD >
MD 1738 graphic

   MESOSCALE DISCUSSION 1738
   NWS STORM PREDICTION CENTER NORMAN OK
   0125 PM CDT SAT SEP 20 2014

   AREAS AFFECTED...NRN/CENTRAL IL...SRN LAKE MI...NRN INDIANA

   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

   VALID 201825Z - 202000Z

   PROBABILITY OF WATCH ISSUANCE...40 PERCENT

   SUMMARY...STORMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSIFY
   THIS AFTERNOON ACROSS NRN/CENTRAL IL INTO NRN INDIANA.  AREA WILL BE
   MONITORED FOR POSSIBLE SEVERE THUNDERSTORM WATCH BY 20Z.

   DISCUSSION...A FEW STORMS ARE DEVELOPING FROM ERN IA INTO NRN IL
   WITHIN A PRE-FRONTAL AIR MASS EARLY THIS AFTERNOON.  THIS REGION IS
   AHEAD OF A WELL-DEFINED EWD MOVING SHORT WAVE TROUGH/ZONE OF
   MID-UPPER LEVEL DRYING EVIDENT IN WV IMAGERY MOVING ACROSS IA. 
   VISIBLE IMAGERY SHOWS THE SRN EDGE OF A REGION OF THICKER CLOUD
   COVER EXTENDING FROM ERN IA ACROSS FAR NRN IL AND SRN LAKE MI...WITH
   THIN CLOUDS TO THE SOUTH.  STRONGER DIABATIC HEATING IS OCCURRING TO
   THE SOUTH OF THE CLOUD EDGE WITH RESULTANT MESOSCALE DIFFERENTIAL
   HEATING CIRCULATIONS OCCURRING ALONG THIS AXIS.  THIS IS EXPECTED TO
   PROMOTE ADDITIONAL CONVECTIVE DEVELOPMENT THIS AFTERNOON WITHIN THE
   DISCUSSION AREA.

   MOISTURE CONTINUES TO SPREAD NEWD FROM THE MIDDLE MS VALLEY WITH
   SURFACE DEW POINTS IN THE MID/UPPER 60S ACROSS MUCH OF IL INTO  NWRN
   INDIANA...CONTRIBUTING TO AIR MASS DESTABILIZATION WITH SBCAPE OF
   1000-2000 J/KG.  LARGELY UNIDIRECTIONAL WESTERLY WINDS OF 35-45 KT
   ABOVE 1-2 KM AGL INDICATED ON LATEST DVN AND LOT VAD PROFILES AND
   ASSOCIATED VERTICAL SHEAR OF 35-40 KT IN THE LOWEST 4-6 KM WILL
   ENHANCE STORM ORGANIZATION...WITH SHORT LINE SEGMENTS AND ISOLATED
   SUPERCELLS POSSIBLE.  AS ACTIVITY STRENGTHENS THIS AFTERNOON...MORE
   INTENSE CELLS WILL HAVE POTENTIAL TO PRODUCE DAMAGING WIND GUSTS AND
   HAIL...WHILE AN ISOLATED TORNADO CANNOT BE RULED OUT.  AREA IS BEING
   MONITORED FOR THE POSSIBLE ISSUANCE OF A SEVERE THUNDERSTORM WATCH
   BY 20Z.

   ..WEISS/CARBIN.. 09/20/2014


   ATTN...WFO...IWX...IND...LOT...ILX...DVN...

   LAT...LON   41829016 42398950 42478764 42108632 41748571 40778592
               40508708 40178887 39959036 40439116 41419064 41829016 

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: September 20, 2014
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities