13B.5 Diagnosing Tornado Probability—Is Estimated Wind Speed Data More Useful than EF-Scale Rating Data?

Thursday, 25 October 2018: 3:00 PM
Pinnacle AB (Stoweflake Mountain Resort )
Bryan T. Smith, NOAA/NWS/NCEP/SPC, Norman, OK; and R. L. Thompson, D. Spegeher, A. R. Dean, and C. D. Karstens

The Storm Prediction Center (SPC) has developed a Lagrangian-oriented, research-purposed tornado database (2009–2016) to examine characteristics that change during a tornado lifecycle. Damage Indicators (DIs) and the associated wind-speed estimates from tornado damage surveys were linked to the nearest radar-observed circulation, including the manually calculated 0.5 degree rotational velocity. Data containing maximum wind speed from DIs for each radar scan, radar-estimated rotational velocity, and environmental conditions were collected for analysis.

The maximum DI wind speed (e.g., 144 mph) per 0.5 degree radar scan was binned to wind speed ranges (e.g., 140–154 mph) rather than its EF-scale rating (i.e., EF3). Minimum wind speed probabilities (e.g., 140+ mph) for tornadoes were derived similarly to minimum EF-scale probabilities (e.g., EF3+) in recent work by Smith et al. (2015). This presentation will compare tornadic wind speed probabilities that provide greater resolution than the current EF-scale ratings.

In addition, near-storm environmental information from the SPC mesoanalysis archive was examined for EF3–5 tornadoes with path lengths ≥40 km (25 mi). The presentation will articulate a vision to prompt new collaborative applied research for tornadoes, and the potential to exploit storm-scale numerical modeling simulations will be briefly discussed.

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