32nd Conference on Broadcast Meteorology/31st Conference on Radar Meteorology/Fifth Conference on Coastal Atmospheric and Oceanic Prediction and Processes

Friday, 8 August 2003: 12:15 PM
Predictability of storm characteristics based on RUC environmental fields
Cynthia K. Mueller, NCAR, Boulder, CO; and D. Megenhardt and N. Oien
Poster PDF (337.0 kB)
Correlations between storm characteristics (primarily life-time and size) as determined from national WSR-88D mosaics and synoptic forcing as determined by the RUC are shown. Storm characteristics are derived from the Thunderstorm Identification Tracking Analysis and Nowcasting (TITAN) software. In this study, TITAN provided the initial storm locations, maximum storm area, and storm duration. A fuzzy logic routine was used to determine regions of large-scale forcing. The algorithm combines RUC low-level equivalent potential temperature, vorticity, and convergence fields into a "frontal likelihood" predictor field. The frontal likelihood field has a range of 0 to 1 with 1 indicating large-scale forcing. The initial location of storms and their characteristics are compared to frontal likelihood field. As expected, analysis shows that large (>2000 km2) long-lived (>2 hrs) storms generally form in regions of large-scale forcing. Further sensitivity studies are shown and methods for utilizing the likelihood fields in a forecast algorithm are explored.

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