New Outlook for December – Wetter, Colder in Illinois

The NWS released their latest outlook for December. They have Illinois with equal chances (EC) of above, below, and near-normal temperatures for the entire month. However, the day to day forecasts out to 14 days show Illinois having colder than normal temperatures on most of the days. The NWS product for weeks 3 and 4 suggest that warmer-than-normal weather will return in the second half of December. In general, I have higher confidence in the forecasts out to 14 days.
The December outlook also shows Illinois with an increased chance of being wetter than normal. This is true in the shorter range forecasts out to 14 days as well. Considering it’s December, a forecast of colder and wetter than normal conditions sure sounds like a recipe for snow. As you may recall, last December was notable for having almost no snow.
Click to enlarge.

Will It Ever Snow Again in Illinois?

With the streak of warm weather this fall, thoughts of snow are far away – but not for much longer. The first significant winter storm for the Midwest is on the horizon on Thursday and Friday. It will likely hit Nebraska, the Dakotas, and Minnesota, but miss Illinois (blue shading on the map below).
capture
So when can we expect to see that first measurable snowfall (0.1 inches or more) in Illinois?
Here is a map that we constructed a few years ago using data from 1971-2000. No surprise – the earliest dates are in the Chicago area and cluster around November 20. For the rest of the northern half of the state, the average date is towards the end of November. In central Illinois, I have always considered Thanksgiving to be the start of the snowfall season. The average dates get dramatically later as you go southward, getting closer to Christmas by the time you get to Carbondale and southward.
picture1
Continue reading “Will It Ever Snow Again in Illinois?”

February Snowfall in Illinois

Much of the southern third of Illinois received between 1 and 12 inches in this last winter storm. The highest amount reported was 12.5 inches at Smithland with several other stations reporting in the 7 to 8 inch range, including Jerseyville with 7.8 inches, Newton with 7.8 inches, and Brookport Dam with 8.8 inches.

map1The northern third of Illinois received a considerable amount of snow from the January 31 – February 2, 2015 storm.

As a result, total February snowfall has ranged from 15 to 20 inches in northeast Illinois and widespread amounts of 5 to 15 inches across the state (first map below). As a result for the month to date, most of the state is 1 to 8 inches above average except for the northeast which is 8 to 12 inches above average (second map below).

map2map3