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 1411
< Previous MD         Next MD >
MD 1411 graphic

   MESOSCALE DISCUSSION 1411
   NWS STORM PREDICTION CENTER NORMAN OK
   0330 PM CDT FRI JUL 18 2014

   AREAS AFFECTED...ERN NORTH DAKOTA AND ADJACENT PORTIONS OF NRN SOUTH
   DAKOTA/NWRN MINNESOTA

   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

   VALID 182030Z - 182230Z

   PROBABILITY OF WATCH ISSUANCE...20 PERCENT

   SUMMARY...AT THIS POINT...IT STILL SEEMS UNLIKELY THAT A WATCH WILL
   BE NEEDED DUE TO LIMITED STORM COVERAGE.  BUT THE SEVERE WEATHER
   POTENTIAL IS NOT NEGLIGIBLE LATE THIS AFTERNOON...WITH ISOLATED TO
   WIDELY SCATTERED STORM DEVELOPMENT POSSIBLE DURING THE 21-23Z TIME
   FRAME.

   DISCUSSION...BENEATH MODIFIED ELEVATED MIXED LAYER AIR...SURFACE DEW
   POINTS HAVE RISEN INTO THE MID 60S F IN A NARROW PRE-FRONTAL
   CORRIDOR NORTH OF MOBRIDGE SD INTO AREAS NORTHWEST OF DEVILS LAKE
   ND.  COINCIDING WITH WARMING TEMPERATURES THROUGH THE 80S F WITH
   CONTINUING INSOLATION...IT APPEARS THAT MID-LEVEL LAPSE RATES ARE
   STEEP ENOUGH TO SUPPORT MIXED LAYER CAPE AS HIGH AS 2000+ J/KG.  AND
   THE LATEST OBJECTIVE SURFACE ANALYSES SUGGESTS SUBSTANTIAL WEAKENING
   OF INHIBITION DURING THE PAST COUPLE OF HOURS.

   DESPITE THESE TRENDS...CONSIDERABLE UNCERTAINTY REMAINS CONCERNING
   THE EXTENT OF THE CONVECTIVE POTENTIAL LATE THIS AFTERNOON. 
   APPRECIABLE MID/UPPER FORCING FOR UPWARD VERTICAL
   MOTION...ASSOCIATED WITH A SIGNIFICANT SHORT WAVE TROUGH PROGRESSING
   ACROSS SASKATCHEWAN INTO MANITOBA...APPEARS LIKELY TO REMAIN MOSTLY
   NORTH OF THE INTERNATIONAL BORDER.  AND THE STRENGTH OF
   FORCING/CONVERGENCE ALONG THE ASSOCIATED EASTWARD/SOUTHEASTWARD
   ADVANCING SURFACE FRONT...EXTENDING TO THE SOUTH OF THE
   BORDER...REMAINS UNCLEAR. 

   WHILE THE 21-23Z TIMING OF CONVECTIVE INITIATION SUGGESTED BY THE
   RAPID REFRESH APPEARS REASONABLE...IT CURRENTLY SEEMS MOST PROBABLE
   THAT THE MORE SUBSTANTIVE STORM DEVELOPMENT MAY OCCUR ACROSS
   SOUTHERN MANITOBA.  HOWEVER...IT DOES APPEAR THAT THIS ACTIVITY
   COULD EXTEND AS FAR SOUTH AS AREAS NEAR/JUST SOUTH OF THE
   INTERNATIONAL BORDER...ON THE SOUTHERN FRINGE OF 30-40 KT CYCLONIC
   500 MB FLOW...WHERE VERTICAL SHEAR WILL BE SUFFICIENT FOR ORGANIZED
   CONVECTION...INCLUDING SUPERCELLS.  AND MORE WIDELY SCATTERED OR
   ISOLATED STORM DEVELOPMENT MAY NOT BE COMPLETELY OUT OF THE QUESTION
   FARTHER TO THE SOUTH...ACROSS THE REMAINDER OF NORTH DAKOTA...AS
   INHIBITION WEAKENS MORE GRADUALLY ALONG THE PRE-FRONTAL INSTABILITY
   AXIS.

   ..KERR/CARBIN.. 07/18/2014


   ATTN...WFO...FGF...ABR...BIS...

   LAT...LON   49099635 47869704 46109867 45570022 46010082 47060034
               47589982 49169931 49099635 

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 18, 2014
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities