Winter temperature and precipitation outlooks for the U.S. likely will depend largely on one main factor: whether the long talked about El Nino in the Equatorial Pacific Ocean ever fully develops.
Right now, there are indications of a weak El Nino as sea surface temperatures continue to run slightly warmer than normal across much of the Equatorial Pacific. The warming trend during the early to mid-summer has waned, however, which casts some doubt on the full development of an El Nino phase. The chances for an El Nino phase to develop during fall and winter have decreased slightly again to 60 to 65 percent.
As for November temperatures, some climate models suggest milder temperatures across much of the Plains, Midwest and Northeast with cooler than normal temperatures across parts of the southern Rockies and Texas. These models are more El Nino-biased, though. Instead, the November forecast includes slightly cooler than normal temperatures throughout the Great Lakes and Midwest. This is based on the possibility that the North Atlantic Oscillation (NAO) might become negative during the next month, which usually allows for more shots of colder air to dive southward from Canada. These regions likely will see a surplus of heating degree-days by between 30 and 60.
On this flip side, slightly warmer than normal temperatures are projected across the Pacific Northwest, northern Rockies and Great Basin. Much of the southern United States will see temperatures average closer to normal.