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 1639
< Previous MD         Next MD >
MD 1639 graphic

   MESOSCALE DISCUSSION 1639
   NWS STORM PREDICTION CENTER NORMAN OK
   0312 PM CDT SAT AUG 30 2014

   AREAS AFFECTED...PORTIONS OF THE WRN DAKOTAS...NRN WY...SERN MT

   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

   VALID 302012Z - 302245Z

   PROBABILITY OF WATCH ISSUANCE...40 PERCENT

   SUMMARY...THE AREA IS BEING MONITORED FOR AN INCREASING RISK OF
   SEVERE THUNDERSTORMS INTO THE LATE AFTERNOON/EVENING HOURS. THE
   ISSUANCE OF A WW IS POSSIBLE.

   DISCUSSION...MOISTURE-CHANNEL IMAGERY IMPLIES DCVA OVERSPREADING A
   DIURNALLY HEATED BOUNDARY LAYER ACROSS PORTIONS OF NRN WY...WHERE
   STEEPENING LOW-LEVEL LAPSE RATES ARE SUPPORTING SCATTERED STORMS
   ACROSS WRN PORTIONS OF THE STATE. THIS ACTIVITY WILL LIKELY DEVELOP
   EWD/ENEWD DURING THE NEXT COUPLE OF HOURS WHILE REMAINING
   HIGH-BASED...WITH THE POTENTIAL FOR SPORADIC SVR WIND GUSTS. AS
   THESE STORMS SPREAD DOWNSTREAM TOWARD THE HIGH PLAINS E OF THE BIG
   HORNS AND ACROSS SERN MT...THEY WILL ENCOUNTER HIGHER BOUNDARY-LAYER
   THETA-E ASSOCIATED WITH SFC DEWPOINTS IN THE MIDDLE/UPPER 50S AND
   1000-2000 J/KG OF MLCAPE IN MANY AREAS. THIS MAY LEAD TO A GRADUAL
   INTENSIFICATION OF ONGOING STORMS AS THEY SPREAD EWD -- ESPECIALLY
   INTO THE WRN DAKOTAS -- WITH THE POTENTIAL FOR ADDITIONAL CONVECTIVE
   INTENSIFICATION FARTHER E INCLUDING THE BLACK HILLS.

   RIW/BLX VWPS SAMPLE 35-45 KT OF MID-LEVEL WSWLYS...THAT WILL SUPPORT
   SUFFICIENT DEEP-LAYER SHEAR FOR SUSTAINED MULTICELL
   CLUSTERS...INCLUDING BOWING SEGMENTS...AND PERHAPS A FEW SUPERCELLS.
   LARGE HAIL AND SVR WIND GUSTS WILL BE THE MAIN CONCERNS WITH THIS
   ACTIVITY...WITH THE GREATEST SVR POTENTIAL OCCURRING WITH STORMS
   EMERGING OVER THE HIGH PLAINS WHERE A TORNADO CANNOT BE RULED OUT.
   THE LACK OF RICHER BOUNDARY-LAYER MOISTURE CASTS SOME DOUBT ON THE
   DEGREE/COVERAGE OF THE SVR RISK...THOUGH CONVECTIVE TRENDS WILL
   CONTINUE TO BE MONITORED.

   ..COHEN/HART.. 08/30/2014


   ATTN...WFO...ABR...BIS...UNR...CYS...BYZ...GGW...RIW...

   LAT...LON   44210845 45090776 46210545 47460378 47400243 45860173
               44180202 43450396 43340662 43580801 44210845 

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: August 30, 2014
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities