The National Convective Weather Forecast (NCWF) product, designed and implemented by the National Center for Atmospheric Research (NCAR), provides current convective hazards and 1 hour extrapolation forecasts of thunderstorm hazard locations. The hazard field and forecasts update every 5 minutes. The NCWF development is sponsored by the Federal Aviation Administration's (FAA) Aviation Weather Research (AWR) program as part of the Convective Weather Product Development Team. The Convective Weather Product Development Team consist of MIT Lincoln Laboratories, National Severe Storms Laboratory (NSSL), National Weather Service's Aviation Weather Center (AWC), and NCAR.  The NCWF target users are airline dispatch, general aviation and FAA Traffic Management Units (TMU).  Usability studies are conducted periodically by the FAA William J. Hughes Technical Center's Communication, Navigation, and Surveillance Engineering and Test Division, ACT-320. The NCWF product is available on the WWW via the Aviation Digital Data Service (ADDS) and on FAA-CDMnet.

The diagnostic analysis combines WSR-88D national radar and echo top mosaics (provided by NOAA with mosaics created and distributed by UNISYS) and cloud-to-ground lightning (provided by Global Atmospherics Inc). The Convective Hazard Detection field is depicted based on a 6 level intensity scale.  The 6 levels fundamentally correspond to VIP level (see images above and to the right).   

Forecasts are determined by applying a stratiform-convective partitioner (Steiner 1985) and an elliptical filter (Wolfson et al. 1998) to the hazard detection field. These filters eliminate stratiform return and small-scale perishable features that are not a hazard to aviation or are not likely to persist for 1 hour, respectively. Extrapolations are performed based on the Thunderstorm Identification Tracking and Nowcasting (TITAN, Dixon and Wiener 1993) algorithm. 

Click on the above image to plot forecast polygons (blue shapes). 

The NCWF forecast product does well with long lived mature systems. However, the initiation, growth, and dissipation of these systems, as well as shorter lived isolated storms, are not well forecast. Work on automated methods to forecast the growth and dissipation of storms is on going.

This training module is broken into 7 categories. For information on:

  • setting up your browser - click on "Setup".

  • how to use the web page - click on "Navigation".

  • steps taken to create hazard field - click on "Hazard field".

  • how forecasts are produced - click on "Forecast".

  • how to interpret performance image - click on "Performance".

  • what to do when things don't work - click on "Help".

  • frequently asked questions - click on "FAQ".

Also, a quick reference to the product can be viewed by clicking on "Reference". 

To view the "Aeronautical Information Manual" click on "AIM".

Click on the "Intro" link (left menu) to return to this introduction page.

Click on the "NCWF" logo (top left) to return to NCWF Javascript page.