NOAA Winter Forecast

The NOAA winter forecast was released last week. They say,

For the second winter in a row, La Niña will influence weather patterns across the country, but as usual, it’s not the only climate factor at play. The ‘wild card’ is the lesser-known and less predictable Arctic Oscillation that could produce dramatic short-term swings in temperatures this winter.

Overall, northern Illinois is expected to have increased odds of being colder and snowier than normal – similar to last year. Here are the details. Below the forecast is a refresher on the winter of 2010-2011 that we all knew and loved.

Temperature:

For Illinois, the northern third of the state is expected to have an increased chance of below-normal temperatures. The southern two-thirds of the state has equal chances of above, below, or near-normal temperatures.

Precipitation:

Almost all the state, except for far western Illinois, is expected to have an increased chance of above-normal precipitation. Far western Illinois has equal chances of above, below, or near-normal temperatures. Although NOAA does not offer a winter snowfall forecast, increased precipitation in the winter months usually means increased snowfall.

Winter of 2010-2011

Here are the temperature map and snowfall map for the Midwest for the winter of December 2010 to February 2011. Both maps are expressed as departures from the 1971-2000 averages. The winter was both colder and snowier than average across the Midwest. Meanwhile, precipitation (rainfall and the water content of snow) was right at average for the winter.

Winter temperature departure
Temperature departures from average (1971-2000) for the Midwest in the winter of 2010-2011. Click to enlarge.
winter snowfall
Snowfall departures from average (1971-2000) for the Midwest in the winter of 2010-2011. Click to enlarge.