WSR-88D-based storm-scale circulation tendencies preceding tornadogenesis: A preliminary study
Start
October 31, 2018 - 3:00 pm
End
October 31, 2018 - 4:00 pm
Address
120 David L Boren Blvd, Norman, OK 73072 View mapCategories
Weather and Climate SystemsWeather & Climate Seminar
Wednesday, October 31st at 3:00 PM in NWC 5930
Authors:
Bryan Baerg, NWS Topeka, KS
Ariel Cohen, NWS Topeka, KS
Title:
WSR-88D-based storm-scale circulation tendencies preceding tornadogenesis: A preliminary study
Abstract:
This study analyzes rotational velocity signatures from WSR-88D data preceding tornadogenesis for 134 tornadoes across Kansas. Manual analyses of storm-scale circulations were performed as far back in time as circulations were apparent for the tornadoes. Subsequent statistical analyses aggregating all tornadic storms will be presented. The results are quite telling, especially when comparing time series of tornado-preceding average rotational velocities, to the tornado-probability output from a recently developed probabilistic model. This model simultaneously considers attributes of the storm-scale circulation with environmental conditions and will also be addressed in this presentation. This blended approach to tornado-threat assessment suggests a signal for tornado prediction based on WSR-88D data, particularly in the 15 minutes prior to tornadogenesis. A notable increase in probabilities at or above around 10 percent consistently precedes tornadogenesis, and differences between tornado probabilities preceding weak and significant tornadoes will also be considered separately. The behaviors of parameters accompanying small samples of tornadoes outside of Kansas and non-tornadic convection will also be presented, as an initial attempt to broaden the scope of this analysis.