Colder weather continues.
A shift in the upper level steering winds toward colder conditions took place late last week and into last weekend. The colder weather will continue through the last week or so of October and temperatures are expected to average around 5 to 10 degrees below normal! For this period, the normal high temperature is in the middle 50s in Madison and Milwaukee. The normal low temperature is in the middle 30s in Madison, and in the upper 30s to around 40 in Milwaukee.
While low temperatures tonight will only drop to the lower 40s, high temperatures on Saturday will only recover to the mid to upper 40s. Temperatures will only be slightly warmer on Sunday.
The image below depicts a large bubble of warmer than normal air around 20,000 feet situated over western Canada and the northern Pacific for the period October 27th through October 31st. Downstream, a corresponding large area of colder than normal air will be locked over the Upper Midwest and Great Lakes region.
The 8 to 14 day outlook depicted below is for October 29th through November 4th. The large warm bubble of air upstream over the northern Pacific and western Canada has decreased slightly allowing a slight modification of the air streaming into the Upper Midwest. However the cold pool of air over the Great Lakes will have expanded to include much of the eastern U.S. A slight overall warming is expected the last days of the month into November for southern Wisconsin, however temperatures will likely remain below seasonal normal.
Below is the Climate Prediction Center's 6-10 Day Outlook for the United States for the last days of October. Clearly, confidence is high that southern Wisconsin, as well as the Midwest and much of the eastern part of the country, will be colder than normal through the period. Meanwhile, the western part of the country will enjoy warmer than normal conditions.
National Weather Service Milwaukee/Sullivan, WI