A Fuzzy Logic Nowcasting Approach Using COTREC and Model Wind Field Vectors

A new approach is proposed that uses fuzzy logic to combine TREC (Tracking Radar Echoes by Correlation) vectors with model windfield vectors calculated from the Rapid Refresh (RAP) numerical weather prediction (NWP) algorithm. These vectors are then subjected to smoothing and forced continuity through the COTREC (continuity of TREC) technique. Past COTREC vectors are incorporated to further smooth the vectors. These vectors are then used in the advection of precipitation echoes.

This proposed approach was evaluated with two individual 48 hour hurricane cases that caused major economical and ecological damages for the southeastern portion of the United States during 2017.

The proposed approach was compared with results from COTREC and the High Resolution Rapid Refresh (HRRR) prediction algorithm at forecast times of an hour. The proposed technique produced a slight improvement over COTREC and further reinforced the fact that extrapolation techniques are still superior to NWP techniques for shorter lead times.