Federal meteorologists are forecasting a milder and drier winter for much of the western United States, but say they are stumped about what will happen in the East.
Officials forecast a drier-than-normal winter for a region from the Pacific Northwest to Nevada, as well as Minnesota, Iowa, Wisconsin and northern Missouri. Much of the southeast should be wetter than normal.
The climate prediction center's Mike Halpert says this forecast has meteorologists somewhat stumped, especially the East, because an El Niño weather oscillation didn't form as predicted. It began brewing months ago and suddenly stopped.
Meteorologists hadn't seen that happen before.
For much of the country, a December-February winter forecast is hard to pin down. The vast majority of states have what the experts said was an equal chance of below-normal, normal or above-normal precipitation.
The densely populated East Coast, along with the southern tier of states from Texas to Florida and the upper Midwest also have an equal chance of colder, normal or warmer weather this winter, according to the forecasters.
Still, there is enough data to predict a warm winter overall, said Deke Arndt, chief of climate monitoring at NOAA's National Climatic Data Center. The first nine months of 2012 were the warmest of any year on record in the contiguous United States, and this has been the third-hottest summer since record-keeping began.
"The main issues facing the U.S. going into this [winter] outlook period stem from persistent heat and drought," Arndt said at a telephone briefing. "It is likely that 2012 will be the warmest of the 118-year record for the contiguous United States."