The western half of the continental U.S. and central and northern Alaska could be in for a warmer-than-average winter, while most of Florida might be colder-than-normal December through February, according to NOAA's annual Winter Outlook.
Forecasters with NOAA's Climate Prediction Center say a wavering El Niño, expected to have developed by now, makes this year's winter outlook less certain than previous years.
"This is one of the most challenging outlooks we've produced in recent years because El Niño decided not to show up as expected," said Mike Halpert, deputy director of NOAA's Climate Prediction Center. "In fact, it stalled out last month, leaving neutral conditions in place in the tropical Pacific."
When El Niño is present, warmer ocean water in the equatorial Pacific shifts the patterns of tropical rainfall that in turn influence the strength and position of the jetstream and storms over the Pacific Ocean and United States. This climate pattern gives seasonal forecasters confidence in how the U.S. winter will unfold. An El Niño watch remains in effect because there's still a window for it to emerge.
Other climate factors can influence winter weather across the country. Some of these factors, such as the North Atlantic Oscillation, a prominent climate pattern, are difficult to predict more than one to two weeks in advance. The NAO adds uncertainty to the winter outlook in the Northeast and Mid-Atlantic portions of the country.
Areas ravaged by extreme drought over the past year are unlikely to see much relief from drought conditions this winter.
In the 2012 U.S. Winter Outlook (December through February) odds favor:
-Warmer-than-average temperatures in much of Texas, northward through the Central and Northern Plains and westward across the Southwest, the Northern Rockies, and eastern Washington, Oregon and California, as well as the northern two-thirds of Alaska.
-Cooler-than-average temperatures in Hawaii and in most of Florida, excluding the panhandle.
-Dryer-than-average conditions in Hawaii, the Pacific Northwest and Northern California, including Idaho, western Montana, and portions of Wyoming, Utah and most of Nevada.
-Dryer-than-average conditions in the upper Midwest, including Minnesota, Wisconsin, Iowa and northern Missouri and eastern parts of North and South Dakota, Nebraska, Kansas, and western Illinois.
-Wetter-than-average conditions across the Gulf Coast states from the northern half of Florida to eastern Texas.
The rest of the country falls into the "equal chance" category, meaning these areas have an equal chance for above-, near-, or below-normal temperatures and/or precipitation.
This seasonal outlook does not project where and when snowstorms may hit or provide total seasonal snowfall accumulations. Snow forecasts are dependent upon the strength and track of winter storms, which are generally not predictable more than a week in advance.
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A new storm will spread a swath of snow and sleet spanning more than 1,500 miles from northern Texas to Massachusetts, during Wednesday into Thursday.
A volcano erupted in southern Chile early Tuesday morning, prompting the evacuation of nearby communities.
As another winter storm ramps up, snow and ice has begun to pummel the Midwest before the storm eventually moves into the Northeast.
Fresh cold air will slash temperatures and bring another dose of wintry weather to the Southeast later this week with widespread travel problems.
Innovations to the heating/cooling industries have inspired cost-effective and efficient methods to regulate temperatures.
Plains Blizzard (1985)
Snow Amounts..... Huron, SD 22" Faulkton, SD 17" Pierre, SD 11" Many highways were closed in parts of South Dakota and Minnesota. At Huron, SD, 18.3" of snow on March 3rd was a new 24-hour record. Snow drifted to heights of 15-20 feet in Park Point, MN, covering houses and telephone poles.
A dust storm reduced visibility to near zero along sections of I-10 in Cochise County. Twenty-five vehicles were in accidents and two people were killed.
Ontario, Canada (1996)
Snow squalls resulted in the closure of most highways in Southeastern Ontario near Lake Huron. Also, there was a 38-car pileup just north of Toronto.