NOAA Forecasts US Likely to Have Above-Average Winter Temperatures; La Niña Arrives, Southern Drought Concerns

9 October 2007

NOAA US winter 2007-2008 temperature forecast. Click to enlarge.

Forecasters at the National Oceanic and Atmospheric Administration (NOAA) are projecting above-average temperatures over most of the US and a continuation of drier-than-average conditions across already drought-stricken parts of the Southwest and Southeast in its winter outlook, announced at the 2007-2008 Winter Fuels Outlook Conference in Washington, DC.

This winter is predicted to be warmer than the 30-year norm. For the country as a whole, NOAA’s heating degree day forecast for December through February projects a 2.8% warmer winter than the 30-year normal, but a 1.3 percent cooler winter than last year.

La Niña is here, with a weak-to-moderate event likely to persist through the winter. The big concern this winter may be the persistence of drought across large parts of the already parched South. And while December through February is likely to be another milder-than-average winter for much of the country, people should still expect some bouts of winter weather.

—Michael Halpert, head of forecast operations and acting deputy director of NOAA’s Climate Prediction Center

NOAA US winter 2007-2008 precipitation forecast. Click to enlarge.

For the 2007-2008 US winter, from December through February, NOAA seasonal forecasters predict:

• In the Northeast and the Mid-Atlantic, temperatures are expected to be above average in response to the long-term warming trend. Snowfall for the region will depend on other climate factors, which are difficult to anticipate more than one-to-two weeks in advance.

• The drought-plagued Southeast is likely to remain drier-than-average due to La Niña, while temperatures are expected to be above average.

• In the Great Lakes and Tennessee Valley, temperatures and precipitation should be above average.

• The south-central Plains should see drier-than-average conditions and warmer-than-average temperatures. Above-average temperatures are also expected in the central Plains. The northern Plains has equal chances of above-, near-, or below-average temperature and precipitation.

• In the Northwest, there are equal chances for above-, near-, or below-average temperatures. Precipitation should be above average in much of the region due to La Niña.

• Drought conditions are expected to persist in the Southwest due to La Niña, and temperatures are likely to be above average.

• Northern Alaska is expect to be milder–than-average, while the rest of Alaska has equal chances of above-, near-, or below-average temperatures and precipitation. In Hawaii, temperatures and precipitation are expected to be above average.

The US winter outlook is produced by a team of scientists at the Climate Prediction Center in association with NOAA-funded partners. Scientists base this forecast on long-term climate trends and a variety of forecast tools from statistical techniques to extremely complex dynamical ocean-atmosphere coupled models and composites. The outlook will be updated on 18 Oct. and again on 15 Nov.