The Enhanced Fujita Scale is used to assign tornadoes a rating based on estimated wind speeds and damage.
The EF Scale became operational on Feb. 1, 2007. It was revised from the original Fujita Scale, developed in 1971 by Tetsuya Fujita, to better reflect wind speed with damage observed in tornado surveys.
Deadly Severe Weather Facts & Safety Tips:
Snow and spotty ice will swing across parts of the central and northern Plains to the Upper Midwest as November ends and December begins.
After the brief shot of chilly air this past weekend, the month of December will start out mild across the Northeast.
December will begin with a roar across the Northwest as rounds of rain, mountain snow and even ice are in store this week.
The reprieve from heavy rain across southern India will not last with the threat for flooding downpours set to return for the final day of November.
Studies show that heart attacks increase in December and January each year.
Buffalo, NY (2001)
The month was the mildest, most snow-free Novembers in history. There was not a flake of snow the entire month, which was the first time since records were kept.
Severe early cold with record November lows: Location Temperature Buffalo, NY 2 degrees New York City 7 degrees Boston -2 degrees Philadelphia 8 degrees (earliest ever below 10 degrees for city)
Washington, DC (1967)
A total of 6.9 inches of snow - greatest amount ever recorded in DC on one calendar day in November.