An upward trend in Ontario tornado frequency (about 1.6 tornadoes/decade with the statistically significant level at least at 95%) is identified using three independent approaches. The first method is the conventional linear regression method that had no disturbance to the original tornado time series. The second approach is to employ the Mann-Kendall test with consideration of removing a lag o...

The upward trend in reported tornadoes during the past few years has led many people to suspect that atomic explosions are responsible for the increase. Because there is no known physical reason for believing that atomic explosions should affect the tornado frequency, the records of tornadoes and atomic explosions are examined in considerable detail to find evidence which will support or contra...

This paper estimates regional tornado risk from records of past events using statistical models. First, a spatial model is fit to the tornado counts aggregated in counties with terms that control for changes in observational practices over time. Results provide a long-term view of risk that delineates the main tornado corridors in the United States where the expected annual rate exceeds two tor...

Two organizations within the National Oceanic and Atmospheric Administration’s (NOAA) National Weather Service (NWS) are responsible for disseminating critical information to their customers prior to and during severe weather. The Storm Prediction Center (SPC) focuses on conducting an overall assessment of the environmental conditions on the national scale, and issues the appropriate severe wea...

This paper addresses the historical documentation of tornadoes and the awareness of tornadic events in the area of the present Czech Republic throughout the last nine centuries. The oldest records of tornado occurrence in the region can be found in chronicles from the first half of the 12 century – the two most interesting of these are presented here in original Latin texts. Several other cases...

Radar-identified convective modes, peak low-level rotational velocities, and near-storm environmental data were assigned to a sampleof tornadoes reported in the contiguousUnitedStates during 2009–13.The tornado segment data were filtered by the maximum enhanced Fujita (EF)-scale tornado event per hour using a 40-km horizontal grid. Convectivemodewas assigned to each tornado event by examining f...

This paper documents tree-ring responses to a historic tornado and re-evaluates prehistoric tree-ring changes seen in archaeological wood of Wupatki Ruin used to date the 11 century eruption of Sunset Crater. The historic tornado occurred at Sunset Crater, northern Arizona, on 24 October 1992, and trees within areas damaged by the tornado survived the event and continue living today. The object...

On average more than 1000 tornado touchdowns hit the continental U.S. every year causing significant human and economic losses. In order to manage tornado risk, we need to assess tornado hazard, the subsequent damage, and the resulting loss. This paper presents a methodology for tornado hazard assessment, which is an important step in the management of risk. For this purpose, a simulation appro...

Tropical cyclone (TC) tornado prediction remains a substantial challenge, both on its own and compared to advances made in prognostically relevant understanding of midlatitude supercells in particular. An ingredients-based approach (e.g., Johns and Doswell 1992), used for supercell tornado environments in midlatitudes, likewise can be applied to TCs, focusing on moisture, instability, vertical ...