El Nino Strengthens Heading Into Winter
2 PM EDT, October 8, 2009
By WeatherBug Sr. Meteorologist, James West
The weak but strengthening El Nino brewing in the Pacific will likely continue through this winter, impacting the U.S. weather. Above-normal temperatures across the northern Plains, powerful winter storms for the California Coast and a soggy Gulf Coast and Florida are just a few possible effects from El Nino.
In its latest forecast issued Thursday, government experts project that the current weak El Nino will likely reach moderate, possibly strong levels this winter.
El Nino, the abnormal warming of the Pacific Ocean off South America`s west coast, alters climate patterns around the world and causes shifts in North America`s jet stream, the high altitude winds that steer storms. El Nino`s intensity guides the severity of these shifting weather patterns.
A moderate to strong El Nino usually produces warmer than normal temperatures with significantly less snowfall in the northern Plains, upper Midwest and western Great Lakes. Strong El Ninos keep the brutal arctic air bottled up in Canada.
An active southern jet stream would bring more rain and mountain snow to the southern U.S. from California to the Gulf Coast, accompanied by cooler temperatures. This increase in precipitation can lead to dangerous flooding and mudslides in California and the Southwest. This is particularly dangerous in wildfire ravage areas of southern California and the Southwest, where heavy rain can cause devastating mudslides.
The Southeast would more than likely see frequent winter storms and colder than normal temperatures during a strong El Nino, while the displaced jet stream will steer storms away from the Ohio Valley, producing less rain and snow there.
El Nino could also be a leading factor in the relatively quiet 2009 Atlantic Hurricane Season compared to the hyperactive years seen over the last half decade. Past hurricane seasons with a weak to moderate El Nino have seen lower hurricane activity as increased wind shear in the Gulf of Mexico and Caribbean Sea slows tropical system development. Wind shear has been a common problem affecting tropical development this year.
WeatherBug will continue to be a reliable source to get up-to-date information on El Nino and how it can impact weather in your neighborhood.
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