National Convective Weather Forecast Product (NCWF)

National Convective Weather Forecast Product (NCWF)

The National Convective Weather Forecast (NCWF) product was developed by NCAR/RAL and eventually operationalized by the NWS Aviation Weather Center (AWC).  It was the first extrapolation-based convective weather forecast system to be implemented on the national scale providing an indication of where current convective hazards (derived from radar and lightning data) to aircraft exist and where they are expected to be in 1 hour.  Both the convective hazard detection field (NCWD) and the extrapolated polygons (NCWF) update every 5 minutes.  The NCWF product is currently available from the AWC.  NCWF was developed by the Convective Weather Product Development Team through sponsorship by the Federal Aviation Administration's (FAA) Aviation Weather Research Program (AWRP).

NCWF detection field (fill) with storm motion vectors and 1 hour extrapolation forecast locations (blue polygons).
NCWF detection field (fill) with storm motion vectors and 1 hour extrapolation forecast locations (blue polygons).

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Following on the success of NCWF, NCAR developed a prototype for the probabilistic short-term prediction of convective hazards that included heuristics (i.e., rules) for convective storm growth and decay and accounted for uncertainties in storm motion and evolution by transforming the extrapolated convective hazard detections into probabilities using a spatially-dilating filter that increases in size with forecast lead time.  This prototype included both an improved method for detecting convective hazards and heuristics that account for storm growth and decay to produce probabilistic forecasts depicting the likelihood of the convective hazards extending 2 hours into the future.  The prototype ran as a D3 supplemental product at the AWC for several years and was one of the first probabilistic nowcasts available at the time.

Related Products and Tools:
NCWF Hazard Detection Description
NCWF running at the Aviation Weather Center

This product has a project page. See more details here.