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.

SPC Mesoscale Discussion Changes

As part of SPCs efforts to more efficiently convey critical forecast information, standardized content structure within the Mesoscale Discussion (MD) product will increase, including new information on the probability of watch issuance for severe potential MDs. Starting May 1, 2012, MDs will include the following sections:

  • For Severe Potential MDs,
       AREAS AFFECTED...(PORTION OF STATES OR GEOGRAPHICAL AREAS) 
    
       CONCERNING...(TYPE OF MD) 
    
       VALID DDHHMMZ - DDHHMMZ 
    
       PROBABILITY OF WATCH ISSUANCE...[increments of 20% from 20-80%,
       including 5% and 95%]
    
       SUMMARY...A concise one or two sentence statement regarding the 
       forecast (timing, coverage, intensity, and mode) severe threat.
    
       DISCUSSION...The description of significant mesoscale features and 
       atmospheric processes which will likely result in the expected event.
    
       Definitions:
       PROBABILITY OF WATCH ISSUANCE in percent...5 and 20 for Unlikely,
       40 and 60 for Possible, 80 for Likely, 95 for Needed Soon. 
    
  • For all other MDs,
       AREAS AFFECTED...(PORTION OF STATES OR GEOGRAPHICAL AREAS)
    
       CONCERNING...(TYPE OF MD)
    
       VALID DDHHMMZ - DDHHMMZ
    
       SUMMARY...A concise one or two sentence statement regarding the
       forecast (timing, coverage, intensity, and mode) severe threat.
    
       DISCUSSION...The description of significant mesoscale features and
       atmospheric processes which will likely result in the expected event.
    
  • 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: March 22, 2012
    Disclaimer
    Information Quality
    Help
    Glossary
    Privacy Policy
    Freedom of Information Act (FOIA)
    About Us
    Career Opportunities