Revised Winter Forecast from NOAA

NOAA has revised their winter outlook for the U.S, according to a recent post on their ClimateWatch Magazine. An earlier outlook had northern Illinois with chances of well below normal temperatures. The new outlook (below) has pulled the colder outlook out of Illinois as well as expanded the area in the southern half of Illinois with an increased chance of  above normal temperatures. So overall, a milder winter is expected in terms of temperatures.
The precipitation outlook for this winter remains unchanged for Illinois. Most of the state, except for far western Illinois, has an increased chance of above normal precipitation. Unfortunately, NOAA does not do a snowfall forecast. Research indicates that the Great Lakes region has better chances for above normal snowfall during past La Niña events. However, the weaker than expected La Niña event this winter and the slow start to the snowfall season suggest that the pattern of increased snowfall during La Niña winters may not pan out this year.
The winter outlook covers the period of December-February, the heart of the winter weather season in most of the U.S.

Sixth wettest and ninth warmest November on record for Illinois

November was an interesting month in Illinois. The four outstanding features were:

  1. the sixth wettest November on record with a statewide average precipitation amount of 5.23 inches, 1.9 inches above average; several sites in southern Illinois had over 9 inches of rain, including Cairo with 9.92 inches (the most of any site in the state);
  2. the end of drought for western and central Illinois as a result of the above average rainfall in November;
  3. the ninth warmest November on record with a statewide average temperature of 45.3 degrees, 3.6 degrees above average;
  4. the snowiest spot in the state was in far southern Illinois, 2.5 inches of snow fell by the morning of November 30 at Grand Chain Dam on the Ohio River. A few sites in northern Illinois reported an inch or less of snow. As was noted in an earlier post, the “normal” snowfall for November ranges from 1 to 2 inches in northern Illinois to no snowfall in southern Illinois – the near opposite of this year. It is just another example of Illinois weather “not playing by the rules.”

Statewide records of temperature and precipitation go back to 1895. Here are the precipitation and snowfall maps for November.

November precipitation
November precipitation (inches) for Illinois. Click to enlarge.

November precipitation departure
November precipitation departure from average for Illinois. Click to enlarge.

November snowfall
November snowfall (inches) for Illinois. Click to enlarge.