Joe, remember that there's a distinction between a prediction that more of X should be seen with more warming and a formal attribution of an observed increase in X to the warming.  To be fair, Edwards seemed to be referring to the latter.

Um, NASA is probably seeing a correlation with warming temperatures and the ability to evaporate more water into the air, which can have some unpredictable results (droughts in this region, severe storms in that).

But Joseph, tornadoes are caused by cold air colliding with warm air ... no cold air no tornadoes. The cold air came from the arctic on the jet stream as the subtropical jet pumped up warm, moist air from the equatorial Pacific, over Mexico and Texas. Before the storm it was 70-80 degrees F and the cold air was at least 30 degrees cooler. Add a meso-cumulus storm that can pump air up 50,000 feet into the air you might predict some tornadoes.  That prediction was made 24 hours ahead of when the storm hit.

The point is, if the entire US was cold, or warming uniformly with an early spring, the severe thunderstorms which packed four EF-4 tornadoes and many smaller twisters would not have happened. You have a point that many NWS records were set before the cold front, some dating back to the early 1950's.  Yes, it was that warm on that calendar date in 1949, too.

It doesn't help that NASA, NOAA, NWS, and the academics are all racing to publish papers on such issues, creating a great deal of confusion.  -sam

Onward through the fog