High Risk Periods in Tornado Outbreaks in Central USA
Igor G. Zurbenko
Department of Epidemiology and Biostatistics, State University of New York at Albany, New York, USA
Mingzeng Sun *
Department of Epidemiology and Biostatistics, State University of New York at Albany, New York, USA
*Author to whom correspondence should be addressed.
Abstract
This study provides numerical comparisons of tornado outbreak risks in developed synoptic system along the season and along the time of a day. Time of day yields sharply changing risk along the geographic time (solar time) adjusted to the longitude of location, which makes it equal opportunities to sun energy supply in different locations. As a result of this paper, most dangerous short time interval for each location can be provided in approaching tornado watch situation. Diurnal probability profile of tornado outbreaks in Texas from 1955 through 2012 was investigated and sharply changing diurnal risks were provided based on actual data. Of all 7,997 tornadoes in Texas, about 54% (4352 tornadoes) developed during the high risk spring season. In the spring season 55% (2,392 tornadoes) occurred during the high risk time window (geographically adjusted time 3:31PM to 8:30PM). Those patterns remain absolutely the same for neighboring states. These data assure us to make extra warnings in many practical situations of approaching dangerous front that depends on a time of event.
Keywords: Kolmogorov-zurbenko fourier transform, tornadoes, geographic time, solar time, spectral analysis, diurnal risk, probabilistic intensity