Friday, January 13, 2012

Tornado days

Revisiting the tornado data set (1950-2010), I summed up the tornado's per day to take a look at the dependency of reports per day, daily path length, daily fatalities and daily injuries. The figure below shows these variables with respect to the daily maximum tornado magnitude. Given the magnitude of this years April, the April climatology is highlighted in Red.


 10 of the 43 E-F5 days (23%) occur in April contrast that with 71 of the 317 E-F4 days (22%). The April E-F5 fatalities have a median of 22 while injuries have a median of 290. This all occurs with a median of 26 tornadoes and a minimum of 11. The 3 April 1974 outbreak is the largest outlier in the E-F5 category with 148 tornadoes, 2553 miles path length, 368 fatalities, and and 6149 injuries.This years April had roughly 200 tornadoes with an estimated path length of 1950 miles. Final official numbers probably won't be available until March. I will update the graphics then.

 March has 7%, May has 35% and June has 20% of the E-F5 tornado days to make up the monthly distribution. The E-F4 tornado days are distributed as such: March has 10%, May has 23%, and June has 16%. These 4 months comprise the most deadly and numerous tornado days.

Always know your data: Note the outlier in the E-F0 category for Path Length. That is an error in the database associated with one tornado on 14 AUG 2006 in New Mexico. Apparently these types of errors appear now and again and are hard to officially remove.