The Weather Channel 2014-2015 Winter Forecast

The Weather Channel has issued its winter forecast for 2014-2015, and it looks a bit different from last winter.

Compared to 2013-14, which was one of the coldest winters in recent memory in the Upper Midwest, this winter the chill looks to be more focused on the East Coast and Gulf Coast, according to the winter forecast prepared by WSI, which along with The Weather Channel is part of The Weather Company.

The forecast, which looks ahead to temperatures from Dec. 1, 2014 through Feb. 28, 2015, is based on an analysis of several large-scale factors in the land-ocean-atmosphere system.

One factor is, as you might expect, the presence or absence of El Nino -- an area of warmer-than-average water in the eastern Pacific Ocean near the equator.

While El Nino has not developed yet, WSI forecasters expect a weak to moderate El Nino to emerge over the winter months and potentially persist into the spring.

(MORE: El Nino: Facts Behind the Impacts)

The forecasters caution, however, that the resulting U.S. winter temperature pattern during an El Nino tends to hinge on what happens elsewhere in the atmosphere. One important question is how "blocky" the jet stream will be over North America. In other words, forecasters consider whether the jet stream will loop wildly north and south and tend to get stuck in patterns for long periods of time, or instead tend to blow from west to east and carry weather systems with their alternating warm and cold air masses quickly across the country.

Greenland block upper-air weather pattern, one of the patterns responsible for delivering prolonged Arctic outbreaks to the eastern U.S.

WSI forecasters point to an early buildup of snow cover across Eurasia -- and especially southern Siberia -- as a possible hint that the jet stream will behave erratically this winter.

The forecasters note that recent scientific research, pioneered by Dr. Judah Cohen of the Atmospheric and Earth Research division of Verisk Analytics, shows a strong connection between October snow cover in Siberia and breakdowns in the stratospheric polar vortex during the mid-winter months. The authors believe the early snow cover may cause a tighter temperature gradient over Asia, strengthening the jet stream. Eventually that momentum may work its way up into the stratosphere, which in turn would knock weather patterns off balance around the Northern Hemisphere several months later.

(VIDEO: WX Geeks Discuss the 'Polar Vortex')

WSI forecasters looked at several other technical indices and long-range computer models that also point to an above-average chance of blocking patterns in the northern latitudes -- the kind of patterns that can force bitterly cold air from the polar and Arctic regions southward into the U.S.

WSI says that, based on conditions over the Pacific Ocean, the West Coast is more likely to be protected from those intrusions by a northward bulge in the jet stream -- known as a high-pressure ridge -- and that those cold air intrusions are more likely to be pointing toward the East Coast and the Deep South instead.

Forecast Highlights

Here is an overview of the WSI forecasts for the next three months over the Lower 48. (Note: November is not included in the winter forecast above, and WSI has not released a separate breakout for February.)

November: Slightly cooler than average from New Mexico to Michigan to Georgia and points in between. Warmer than average elsewhere, but especially for the West Coast states plus Nevada, Idaho, and Montana.

December: Slightly cooler than average for Colorado, New Mexico, the Plains states from Nebraska to Texas, and the lower Mississippi River Valley. Warmer than average elsewhere, but especially in California and southern Nevada as well as the East Coast states from North Carolina to New England.

January: Cooler than average from Texas to Wisconsin and points eastward, but particularly cool from the southeast half of Texas east to the Florida Panhandle and inland as far north as the southern tip of Illinois. Warmer than average elsewhere, but especially over the Northwest, northern Rockies, and northern parts of California, Nevada, and Utah.

MORE ON WEATHER.COM: Extreme Cold Grips U.S., Jan. 6-8, 2014

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St. Louis

Snow and ice are seen covering up Mississippi River and downtown St. Louis Wednesday, Jan. 8, 2014. (AP Photo/Kiichiro Sato)