Automatic Detection of Gust Fronts.
Abstract
Early displays of Doppler spectral moments demonstrated that many hazardous weather features produce characteristic signatures that human observers can readily interpret. Although recognition of these signatures by by trained human observers is not complicated, there are strong reasons to develop automated techniques that would help or in some cases even replace the human operator. We have developed a procedure that detects and tracks gust fronts automatically. It does not rely on a single method but requires simultaneous operation of two related algorithms. The convergence algorithm measures radial convergence and hence only gusts propagating along radials can be readily detected. The mesocyclone-shear algorithm measures azimuthal shear and is suitable for detecting gusts parallel with radials as well as low level vortices. Long shear lines that these algorithms detect are classified as gusts whereas symmetric shear features are rejected if their shear and momentum are insignificant; otherwise they are classified as low level vortices. To track gusts we use second order polynomials in the range-azimuth plane. It is shown that predicted gust locations from simple linear projections of the least square fitted curves agree very well with actual gust locations. Keywords: Storms; Gust fronts; Automatic tracking algorithm; NEXRAD(Next Generation Weather Radar).
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1985
- Accession Number
- ADA156723
Entities
People
- D. S. Zrnic'
- H. Uyeda
Organizations
- National Oceanic and Atmospheric Administration