After a hot spring and a scorching summer, this winter is likely to continue a U.S. warming trend that could make 2012 the hottest year since modern record-keeping began, U.S. weather experts said Oct. 18. Drought that ravaged much of the United States this year may spread in the coming months, said Mike Halpert at the National Oceanic and Atmospheric Administration’s Climate Prediction Center.
"The large majority of that drought we expect to persist," Halpert said. "We even see drought expanding westward… into Montana, Idaho and part of Oregon and Washington."
Drier-than-usual winter weather is expected in much of the Pacific Northwest, with higher-than-normal precipitation predicted for the Gulf Coast, according to NOAA forecasts.
For much of the country, a three-month (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."
An El Niño pattern — a recurring patch of warmer-than-usual water in the equatorial Pacific that can have a potent effect on U.S. weather — gave hints of developing in September but then subsided, the first time this has happened in approximately 60 years of record-keeping on this phenomenon, Halpert said.
"This is one of the most challenging outlooks we’ve produced in recent years because El Niño decided not to show up as expected," he said.
A record-warm winter would be in line with NOAA’s latest report on global temperatures, which found September 2012 tied for the hottest September in world records going back to 1880.