Sunrise over Chicago on October 22, 2010. Air temperature about 36°F.
NOAA released their winter forecast and it is calling for “a winter of extremes” with an ongoing La Nina that usually has a big influence on the nation’s weather this winter. Chicago’s winters under La Nina influence are not as certain as the south, southeast and northwest regions of the United States, but temperatures are generally a little warmer, and skies bring a little more snow than normal. Blasts of arctic air are a characteristic of La Nina winters in Chicago. But NOAA says the Central U.S. has equal chances of above-near-or below normal temperatures and precipitation.
Here’s how how NOAA rounds up La Nina winters for regions of the rest of the mainland …
Pacific Northwest: colder and wetter than average. La Niña often brings lower than average temperatures and increased mountain snow to the Pacific Northwest and western Montana during the winter months, which is good for the replenishment of water resources and winter recreation but can also lead to greater flooding and avalanche concerns.
Southwest: warmer and drier than average. This will likely exacerbate drought conditions in these areas. All southern states are at risk of having above normal wildfire conditions starting this winter and lasting into the spring.
Northern Plains: colder and wetter than average. Likely to see increased storminess and flooding.
Southern Plains, Gulf Coast States & Southeast: warmer and drier than average. This will likely exacerbate drought conditions in these areas. All southern states are at risk of having above normal wildfire conditions starting this winter and lasting into the spring.
Florida: drier than average, with an equal chance for above-, near-, or below-normal temperatures. Above normal wildfire conditions.
Ohio and Tennessee Valleys: warmer and wetter than average. Likely to see increased storminess and flooding.
Northeast and Mid-Atlantic: equal chances for above-, near-, or below-normal temperatures and precipitation. Winter weather for these regions is often driven not by La Niña but by weather patterns over the northern Atlantic Ocean and Arctic. These are often more short-term, and are generally predictable only a week or so in advance. If enough cold air and moisture are in place, areas north of the Ohio Valley and into the Northeast could see above-average snow.
Last year’s El Nino pattern brought higher than average snowfall and lower than average temperatures — making winter 2009-2010 officially the 6th snowiest of the past 139 winters with 52.4″ of snow.
Last night we reached a low of 34°F officially at O’Hare International Airport. We haven’t been that cold since April 28th when the temperature dipped to 33°F. April 9, 2010 was the only day in April 2010 to hit below freezing at 30°F.
According to NOAA, La Niña is associated with cooler than normal water temperatures in the Equatorial Pacific Ocean, unlike El Niño which is associated with warmer than normal water temperatures. Both of these climate phenomena, which typically occur every 2-5 years, influence weather patterns throughout the world and often lead to extreme weather events.
Check Arlingtoncardinal.com/weather for forecasts, radar, maps, satellite views and organized links to the best weather resources on the net.