Tuesday, September 16, 2014

Study: Tornado season starts earlier

A group of scientists from Montana State University issued a report Tuesday that says the tornado season is starting a week earlier than in the past across a part of the Midwest known as Tornado Alley.

The report looked at tornado statistics from 1954 to 2009 and focused primarily on Oklahoma, northeast Texas and Nebraska. Scientists said they found that the peak of tornado season in recent years has been around May 19, compared to May 26 in the early and mid 1950s.

"If we take Nebraska out (of the data), it is nearly a two-week shift earlier," said John Long, a Montana State researcher who was lead author of the study.

The scientists found a link between early tornadoes in Oklahoma and the presence of stronger El Nino conditions. You'll remember that El Nino is a condition of warmer-than-usual surface water temperatures in the eastern Pacific.

El Nino conditions tend to put a lid on hurricane development in the Atlantic and Caribbean, but they also tend to produce a lot of rain and storm activity in the winter and early spring months across a corridor stretching from California and Arizona to Texas, Oklahoma, Louisiana, Arkansas, Tennessee, Mississippi, Alabama, Georgia, and the Carolinas.

So it makes sense that El Nino years would produce early tornado outbreaks.

The Montana State researchers didn't spend a lot of time in the study looking for causes of the early tornadoes, but they said it is in line with what you'd expect from a warmer climate.

Hurricane activity: As we expected, hurricane activity in the Atlantic remains rather quiet this season. The strongest storm so far, Category-3 Hurricane Edouard, is moving across the central Atlantic Ocean this week.

It is expected to curve east of Bermuda and head back toward Europe, possibly threatening the Azores with strong winds this weekend as it turns into a post-tropical storm.

Meanwhile, Odile has weakened from a strong hurricane to a tropical storm as it pushes northward through the Gulf of California, between Baja California and the Mexican mainland. That storm is forecast to make landfall in northwest Mexico and then move northward -- in a much weakened state -- into Arizona.

Look for plenty of news coverage in coming days about flash flooding in Arizona and New Mexico. Parts of those states could get very heavy rain later this week.


Anonymous said...

Don't we get a tornado, or "quarter-size" hail, or severe wind, or flash flood warning every single day of this sorry summer?

Anonymous said...

Was there supposed to be a legitimate argument to remove the Nebraska data or was that completely arbitrary?