La Niña Causing Warm Weather in Southern California
January 17, 2011 - Unusual warm weather in Southern California this weekend caused many Californians to come out in shorts and t-shirts to enjoy the sunny days. Temperatures ranged from 75 all the way to 85 degrees during the day this Saturday, Sunday, and Monday which is a Martin Luther King Jr. Holiday for most. Of course it is a brisk 40 degrees at night, but the daytime temperatures are amazing considering that most of the country in the middle of winter snow storms and buried under several feet of snow.
The warm weather here in Southern California and the flooding in Australia is caused by a weather pattern over the Pacific Ocean called La Niña. From the National Oceanic and Atmospheric Administration we get the explanation:
"Q: What is a La Niña? La Niña refers to a period of time when ocean temperatures across the central and eastern tropical Pacific Ocean are cooler than normal. The cooling of the ocean waters leads to changes in the patterns of tropical rainfall from Indonesia to South American (a distance of more than one-half the circumference of the earth), which significantly affects the strength and location of the atmospheric jet stream over the eastern North Pacific and North America. These changes in the jet stream alter the weather patterns."
In other words our normal winter weather patters are changed, such that there is great flooding in Australia and warm sunny weather in Southern California. For North America the changes in the jet stream may also contribute to causing really heavy snowstorms where snow normally falls and snow to fall in parts of the United States where snow normally doesn't fall at all during winter. Enjoy the change to the jet stream while it lasts and take advantage of the weather in your neighborhood.