Last week's tornadoes were were powered by

[pscot]

a jet stream moving at 115 mph. Jeff Masters provides an analysis:

The speed with which some of the storms moved was truly exceptional, thanks to jet stream winds of up to 115 mph that pushed the thunderstorms forward at amazing speeds. A number of the tornadoes ripped through Kentucky with forward speeds of 70 mph, and two tornado warnings in Central Kentucky were issued for parent thunderstorms that moved at 85 mph. If damage surveys reveal that these thunderstorms did indeed spawn tornadoes, they will set the record for fastest-moving tornadoes in recorded history. The record for the fastest moving tornado is 73 mph, set in 1925 for the great Tri-State Tornado, the deadliest U.S. tornado of all-time. Here's the text from one of the tornado warnings yesterday, featuring a storm moving at 85 mph:

http://www.wunderground.com/blog/JeffMasters/article.html

[ewagner]

1. Wow!!!

It's hard to even imagine a thunderstorm moving at 85 mph!

[phantom power]

2. terrible outbreak - 117 tornados