The recent cold snap lowered the month-to-date and season-to-date average temperatures quite a bit. However, average temperatures have been above normal so far this January, as well as for meteorological winter (December 2012, January and February 2013).
So far this month, Milwaukee's average temperature is 23.2 degrees, which is 1.0 degree above normal. Madison's average temperature is 20.4 degrees, which is 1.9 degrees above normal. Milwaukee's average temperature so far this winter, through January 24th, is 29.2 degrees (14th warmest on record). Madison's is 25.7 degrees (tied for 18th warmest on record).
However, the question is, will below normal temperatures continue for the rest of the month? How about the rest of the meteorological winter?
Near or above normal temperatures are forecasted this Sunday through Wednesday, but temperatures are expected to return to below normal values for the latter half of the week.
Looking farther out, beyond our forecast domain, the Climate Prediction Center's 6 to 10 Day, 8 to 14 Day, and February Temperature Outlooks indicate increased chances of below normal temperatures for our area. The outlooks are shown in order below. Click on each image for a larger version:
6 to 10 Day Temperature Outlook
8 to 14 Day Temperature Outlook
February Temperature Outlook
The increased chance for below normal temperatures, indicated by the long term forecasts is likely due in part to the elevated chance for a negative phase Arctic Oscillation pattern. When the Arctic Oscillation is in the negative phase the atmospheric pressure over the polar region is relatively high and the pressure over the middle latitudes, at about 45 degrees north, is relatively low. This pattern allows cold air from the polar region to plunge into the Midwest. The image below, from the University of Washington, depicts the pattern and its effects.
NWS Milwaukee/Sullivan, WI