Active tornado seasons in the U.S. are almost always due to the presence of unusually cool air persisting over the nation’s heartland.
Coeur d'Alene, ID (PRWEB) March 19, 2013
Harris-Mann Climatology forecasters are predicting a near to slightly above normal season for tornadic activity this spring season. Most of the twisters are expected to form east of the Rockies, especially in 'Tornado Alley' from Kansas southward into Texas.
"Since early this year, we've been in a 'La Nada', or in-between the cooler La Nina and warmer El Nino sea-surface temperature pattern in the south-central Pacific Ocean," says Meteorologist Randy Mann.
Some long-term computer models indicate that ocean temperatures are expected to cool into a new La Nina later this year. Harris-Mann Climatology warns that a new La Nina could lead to a rash of twisters sometime in May or June if ocean temperatures suddenly become colder.
According to Climatologist Cliff Harris, "active tornado seasons in the U.S. are almost always due to the presence of unusually cool air persisting over the nation’s heartland. For example, the super outbreaks of tornadoes in 1974 and 2011 occurred during extremely chilly “La Nina” sea-surface temperature events. Arctic cold fronts push much farther to the south during the spring months during a La Nina which, of course, leads to many more violent collisions of air masses, hence more tornadoes."
The U.S. receives approximately 1,200 tornadoes each year, about four times more than Europe. Most of the twisters strike from March to August. On January 30, 2013, several strong tornadoes were reported in Georgia, Mississippi and Alabama.
Harris also believes that 'global warming' has little to do with the number of tornadoes or their formation.
"Tornadoes are almost unheard of in the tropics despite frequent violent thunderstorm activity producing torrential downpours. Instead, tornadoes require strong WIND SHEAR weather patterns, the kind which develop when widely-opposing cold and warm air masses ‘collide,’ fighting furiously for the same air space. Heat and cold must both be present for tornadoes to occur, not just unusually warm air supposedly linked to global warming, Manmade or otherwise," says Harris.
Harris-Mann Climatology currently offers a daily weather, commodity and stock advising service. Many of the trade recommendations are computer-generated and have been back tested for improved accuracy. Annual and monthly subscriptions are available.
Also, Harris-Mann Climatology provides free detailed monthly temperature, precipitation and snowfall forecasts for most U.S. and Canadian cities, including graphics, plus outlooks for the following 12 months for most major world cities. This information is available at http://www.LongRangeWeather.com.