Colder pattern set to return this week

 

After an unseasonably warm January, the pattern has changed quite a bit as we look to end the month on a much colder note. Temperatures Sunday afternoon warmed to only the upper teens and low 20s, reaching 21 degrees in Rockford. While it wasn't quite as snowy as Saturday, the impacts from the snow were still felt Sunday afternoon. A few flurries remain possibly during the night as temperatures are expected to fall into the single digits. Wind chills, however, will fall below zero - and already have (and have been) over far northwest Illinois. This has been in an area that experienced a little less cloud cover Sunday afternoon.

Cloud cover looks to stick around during the day Monday, although we may see a little clearing take place during the afternoon and evening. This will occur as high pressure brings drier air into the region. Temperatures Monday won't warm much, in fact, it's possible that our highs may be reached early in the day, with numbers slowly falling back into the evening.

A colder pattern settles in thanks to a couple cold, Canadian, high-pressure systems moving through the Plains and Midwest this week. The first is set to move in Monday night/Tuesday morning, centering right over west-central Illinois. With the fresh snow cover, temperatures are likely to fall quick Monday evening. However, some models are suggesting that an increase in cloud cover will occur during that time. If this occurs, our temperatures may not fall as fast, or as low, as expected keeping wind chills a little warmer than anticipated. Right now, it looks like wind chills could fall as low as -20 degrees in some locations Tuesday morning.

Winds will turn back to the south as the first high-pressure system departs Tuesday night. It won't do much to warm our temperatures, however, as highs are still expected to remain in the 20s. The next high will move to our north, shifting winds to the northeast Thursday night and Friday. Those northeast winds will increase once again - especially Friday - pushing temperatures back down into the teens Friday afternoon and overnight lows back down below zero. We may see a little bit of a pattern change the first weekend of February with temperatures warm back into the low 30s. Longer-range outlooks place northern Illinois at a slightly higher probability for above average temperatures within the first week and a half of the month.