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 1519
< Previous MD         Next MD >
MD 1519 graphic

   MESOSCALE DISCUSSION 1519
   NWS STORM PREDICTION CENTER NORMAN OK
   0208 PM CDT FRI JUL 24 2015

   AREAS AFFECTED...PARTS OF NRN INTO CNTRL MISSOURI...ADJACENT W CNTRL
   ILLINOIS

   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

   VALID 241908Z - 242015Z

   PROBABILITY OF WATCH ISSUANCE...40 PERCENT

   SUMMARY...THE MAINTENANCE OF VIGOROUS CONVECTIVE DEVELOPMENT NOW
   SPREADING SOUTH OF THE MISSOURI-IOWA BORDER AREA REMAINS UNCLEAR. 
   THE NEED FOR A WATCH STILL SEEMS UNLIKELY AT THIS POINT...BUT IF
   ACTIVITY BEGINS TO SHOW SIGNS OF SUSTAINED RE-INTENSIFICATION...A
   SEVERE WEATHER WATCH MAY BECOME NECESSARY.

   DISCUSSION...ONGOING THUNDERSTORM ACTIVITY APPEARS LONG DECOUPLED
   FROM ITS SUPPORTING MID-LEVEL SHORT WAVE IMPULSE...WHICH APPEARS TO
   BE PROGRESSING EASTWARD THROUGH THE UPPER MIDWEST.  BUT AN AREA OF
   ENHANCED LOW-LEVEL WARM ADVECTION MAINTAINED CONVECTIVE DEVELOPMENT
   LONG ENOUGH TO GENERATE A SIGNIFICANT SURFACE COLD POOL.  BOTH THE
   LOW-LEVEL WARM ADVECTION AND THE COLD POOL APPEAR TO BE
   WEAKENING...BUT AT LEAST A WEAK NORTHERLY COMPONENT TO THE DEEP
   LAYER MEAN FLOW FIELD HAS CONTRIBUTED TO A SOUTH SOUTHEASTWARD
   PROGRESSION OF THE COLD POOL.  FORWARD PROPAGATION HAS BEEN AROUND
   30 KT.  

   AT THIS PACE...IT SHOULD ADVANCE SOUTH OF KIRKSVILLE INTO PORTIONS
   OF CENTRAL MISSOURI BETWEEN COLUMBIA AND ST. LOUIS DURING THE 20-23Z
   TIME FRAME.  THIS IS GENERALLY ALONG THE EASTERN EDGE OF A DEEPER
   MOIST BOUNDARY LAYER CHARACTERIZED BY MID/UPPER 70S SURFACE DEW
   POINTS...WITH MODERATE TO STRONG CAPE EVOLVING WITH CONTINUED
   SURFACE HEATING.  WHILE THE LATEST RAPID REFRESH/OBJECTIVE ANALYSES
   SUGGEST INHIBITION FOR BOUNDARY LAYER PARCELS ACROSS THIS REGION IS
   BECOMING INCREASINGLY NEGLIGIBLE... ON THE LARGE-SCALE INCREASINGLY
   WARM ELEVATED MIXED LAYER AIR ALSO CONTINUES TO ADVECT EAST OF THE
   CENTRAL PLAINS.

   AT THIS POINT...THE MAINTENANCE OF VIGOROUS CONVECTIVE DEVELOPMENT
   ALONG THE SOUTHWARD ADVANCING OUTFLOW REMAINS UNCLEAR.  LONGER TERM
   RADAR TRENDS HAVE INDICATED A PROLONGED SLOW WEAKENING TREND TO
   CONVECTION IN GENERAL...THOUGH WITH OCCASIONAL SHORT-LIVED
   INTENSIFICATION OF EMBEDDED CELLS.  SOME RECENT MORE SUBSTANTIVE
   INTENSIFICATION HAS BEEN EVIDENT WITHIN RADAR DATA...AND A MORE
   SIGNIFICANT INTENSIFICATION ALONG THE SOUTHWARD ADVANCING COLD POOL
   SEEMS AT LEAST POSSIBLE THIS AFTERNOON.  HOWEVER...A NUMBER OF THE
   CONVECTIVE ALLOWING MODELS...INCLUDING THE LATEST HIGH RESOLUTION
   RAPID REFRESH... SUGGEST OTHERWISE.  IF FORCING ALONG THE COLD POOL
   IS ABLE TO OVERCOME CONVECTIVE INHIBITION...DEEP LAYER SHEAR BENEATH
   25-30 NORTHWESTERLY 500 MB FLOW PROBABLY IS SUFFICIENT TO SUPPORT
   THE EVOLUTION OF AN ORGANIZED MESOSCALE CONVECTIVE SYSTEM.

   ..KERR/DIAL.. 07/24/2015


   ATTN...WFO...LSX...DVN...SGF...EAX...

   LAT...LON   40149287 40349231 40129141 39519105 38489062 38049181
               38379269 39269306 39889314 40149287 

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: July 24, 2015
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities