By Eileen Moustakis
NEW YORK (Reuters) - The Northeastern United States, the world's largest heating oil market, is set to post its warmest November in a decade, and the mildest for some cities like Boston in over 30 years, forecasters said this week.
The Northeast and East North Central regions, including Chicago, Cleveland and St. Louis, had their warmest November since 2001, Pennsylvania-based forecaster Planalytics said.
Boston was the warmest since 1975, while Indianapolis was the warmest in over 50 years.
Overall, forecasters expect this November to be the fifth-warmest since records began in 1950.
The mild weather was a result of "autumn being autumn" and not a sign of a weakening La Nina weather pattern - expected to continue through winter - or a harbinger of what's to come this winter, according to New York-based Weather 2000 meteorologist Michael Schlacter.
While November's mild weather aided U.S. retailers as shoppers took to the streets, it pressured demand for natural gas to fire furnaces and power plants.
Cash gas prices slid to their lowest levels in more than two years, while gas futures on the New York Mercantile Exchange slid to 11-month lows.
Heating oil prices, meanwhile, were weaker, but concerns about supply disruptions due to recent refinery closures limited the downside, market sources said.
The Southwest coast was the coolest since 2004, with Los Angeles the coolest since 2000, the forecaster said.
Weather 2000's Schlacter noted that while New York City had a "warm" November, it was not "off the charts" or historic in nature.
"Even just this past decade we've had some tremendous swings in weather in November temperatures. We're not that much warmer than 2009 or 2006. We are going to top those, but we're still in the same ballpark as the last five years," Schlacter said.
Overall this November will fall behind November 2001, and will likely be the fifth-warmest on recent record, Schlacter said. MDA EarthSat meteorologist Rick Groh agreed.
All the forecasters noted that cooler weather in the U.S. West would likely skew the overall national average.
"The tremendous cool in the West will likely dilute the impressiveness of the warmth for the nation as a whole," Schlacter said.
NOVEMBER VERSUS THE WINTER
Forecasters were quick to note that November weather patterns were not necessarily indicative of how the entire winter will turn out.
Forecaster WSI has called for the mildest winter in five years, lowering heating demand expectations.
U.S. government forecasters said a strengthening La Nina would grip the country for a second straight winter, causing colder and wetter weather in the most northern states and drier, warmer conditions throughout the drought-ravaged South.
The National Oceanic and Atmospheric Administration (NOAA) said it expects the La Nina weather phenomenon that results in cooler ocean temperatures in the Equatorial Pacific, to become the most dominant factor influencing weather across the country, but added that a change in pressure called the Arctic Oscillation could make it difficult for forecasters to predict more than a week or two in advance.
The volatile condition could produce dramatic short-term swings in temperatures. Arctic Oscillation can generate strong shifts in the climate patterns that could overwhelm or amplify La Nina's typical impacts, NOAA said.
Weather 2000 was calling for a below-normal period from December through March for the nation as a whole, with the Ohio Valley and Great Lakes area the focal points of the coolest weather.
"Last year was very impressive. It's probably not going to be as cold as last year, but could be similar to the 2008-2009 winter for the nation as a whole. The winters the last four years have been in that slightly cool direction and that's where we're leaning this year," Schlacter said.
"Chicago, which had a very, very warm November, just like New York, is already starting this new transition. It's a very slow progress and the Interstate-95 corridor on the East Coast is going to have to wait about six or seven days into December until we catch up with that," he said.
"Everything between the Rockies and the Appalachians are doing a 180 flip starting today or yesterday, compared to what was going on in November, which just shows how quickly things can change," Schlacter added.
MDA EarthSat said the December through February winter period would be normal to slightly above-normal for the Northeast and near to slightly-below normal for the Midwest, above-normal in Texas and below-normal on the West Coast and in the Rockies.
(Editing by Andrea Evans)