After a few gloomy and rainy days in the Stateline, Friday was a pleasant fall day, even if it was a little breezy. Temperatures rose into the low 60s, just a touch above average for this time of year. The trend of clear skies we saw during the daytime continues into the night, as temperatures fall to the low 40s.
All will remain dry through at least 2/3AM, but isolated rain showers will develop across far Southeastern Wisconsin into far Northeastern Illinois toward the daybreak hours. Those who see the associated cloud cover may end up with temperatures a bit milder by the early morning than the official forecast low.
Highs tomorrow will top out near the 60° mark once again, this time under a bit more cloud cover than what we saw Friday. A front will pass early in the day, leading to strong Northwesterly winds behind it. Winds could gust upwards of 35 mph at times during the afternoon and evening. We may also see the redevelopment of some isolated showers toward the evening, mainly focused to the Northeast of Rockford once again.
The stronger wind Saturday is a result of the strong jet stream (winds aloft in the atmosphere). This helps to increase the pressure difference between the surface low pressure to the East and high pressure to the West. These strong winds help to usher in a much cooler air mass for Sunday, leading to patchy frost Sunday morning and highs only in the mid-50s Sunday afternoon.
The unsettled pattern in the weather continues into the week ahead as well. Moisture will continue to be transported into the Stateline area throughout the days following, giving us at least scattered chances for rain most days in the week ahead. Widespread rain may start as soon as Monday evening into Tuesday, with at least daily chances lasting through Friday.
Cooler air enters the region Sunday following a blustery Saturday. Highs reach near the 60-degree mark Saturday, followed by only the mid-50s on Sunday despite the sunshine. Patchy frost is possible at least Sunday morning, but nights become much milder for the week ahead as rain chances move through almost daily.