Nov. 21 (Bloomberg) -- Winter’s bite probably won’t be as harsh in the U.S. Northeast and mid-Atlantic states as last year, according to Matt Rogers, president of Commodity Weather Group LLC.
Rogers’s revised winter outlook calls for the period from November through March to be warmer than last year while still cooler than the 10-year average. He forecast in October that the coming U.S. winter may be the coldest in more than 10 years.
“The best threat for colder winter weather is more to the North and West,” Rogers said in his forecast today. “We could still see a colder January-February yet, but confidence is lowering.”
Traders use long-range temperature predictions to gauge energy use and market fluctuations. Hot or cold weather can increase demand for heating and cooling, and power plants use about 30 percent of the nation’s gas supplies, according to Energy Department data.
Rogers updated his outlook in part because there’s no sign of pressure changes that would help trap cold air along the eastern U.S. In addition, November has been warmer than expected and December may follow suit.
Rogers now forecasts that the Northeast, mid-Atlantic and Ohio Valley regions will have more seasonal temperatures in December rather than being 2 to 3 degrees Fahrenheit below normal, as predicted in October.
The natural gas-weighted heating degree days for November through March will probably be 3,869.6, Rogers said today. In October, he predicted that would be 4,024.
The gas-weighted degree days for the period in the U.S. last year was 3,928.2 and the 10-year average was 3,724.4, according to Rogers, who’s based in Bethesda, Maryland.
Heating degree days, calculated by subtracting the daily average temperature from a base of 65 degrees, are designed to show energy demand. Higher values mean cooler weather and more energy being used to heat homes and business.
Gas-weighted degree days give more value to areas where there are higher populations using natural gas to stay warm.
Rogers said the gas-weighted degree days value for December will probably be 885, cooler than the 10-year average of 855.7 and warmer than last year’s 939.2.
There is still a chance December will be colder than forecast, Rogers said. He will release his final December outlook maps next week.
Pressure differences over the North Pole known as the Arctic Oscillation can have a major impact on how cold the U.S. Northeast and mid-Atlantic states get.
When the oscillation is in what’s known as a negative phase, it can create frigid conditions along the East Coast by allowing cold air to drop down from the pole and creating blocking patterns that help it linger. When the oscillation is in a positive phase, that isn’t as likely.
“The quieter start to the heating season in terms of high-latitude blocking and through the stratosphere is a stark contrast to the last two winters,” Rogers said. “The current stratospheric cooling argues for a more positive Arctic Oscillation and at least a big delay in a colder winter outcome.”
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