Slower start to severe weather across most of the U.S.

It may not seem like it to Stateline residents -- especially after the bout of severe weather we experienced on April 5th with hail and high winds. But tornadic activity and severe thunderstorms are down for the nation in 2010 compared to the last two years. By this time in 2008, we'd seen nearly 450 U.S. tornadoes. This year, we've only seen about 70 of them. Lighting strikes are down, too. An estimated 500 thousand have hit the U.S. to date this year, compared to about 2 million at this time in 2008 and about one million in 2009.

So what is going on?

The main reason that the usual severe weather hot spots haven't seen their share of action so far is a cool Gulf of Mexico. The Gulf of Mexico is the primary source of moisture for thunderstorms. This year, most of the Gulf is running 1 to 2 degrees Celsius below average... That's about 2 to 4 degrees Farenheit. Cooler water is less volitile... It doesn't evaporate as readily. Therefore, the air above the Gulf is drier than it usually is in April, and moisture transport northward into tornado alley is less boisterous than it usually is.

But there are exceptions to every rule! We saw that here on April 5th (severe weather here usually doesn't really begin until May), and we'll be ready in case it happens again.  --TS