From summer to fall in the blink of an eye: Last weekend we were still talking about summer activities like boat rides and cooking out. This weekend is a much different story, with temperatures a far cry from the 80s we saw even as recently as just a few days ago. Fall has arrived and make quite the loud announcement with a pair of cold fronts that will keep our temperatures below the 60° mark through the next few days.
Officially our high temperature Friday was 55° in Rockford, but that was reached shortly after midnight. We were briefly back up to 54° late in the morning and 52° early in the afternoon. But otherwise, most of the afternoon featured temperatures down in the 40s with wind chills in the low 40s!
A few of the more robust showers from Friday afternoon may have contained some “graupel”. It forms when snow starts far up in the atmosphere and falls through supercooled water droplets. Graupel looks very similar to small hail but has a much softer texture.
Skies continue to clear toward midnight tonight as temperatures continue the downward spiral. We likely will see our first temperature below 40° since early May! Winds will remain strong at times, leading to even colder wind chills.
Tomorrow will feature some sunshine and as a result, a slightly warmer afternoon compared to Friday. It will still be a breezy afternoon with winds gusting close to 20 mph at times. Rain chances remain very low until Sunday morning.
The cooler weather (though closer to normal than the summer warmth from last week) will stick with us through the weekend partly due to an upper-level trough deepening over the Great Lakes region. This will keep us under a persistent Northerly flow aloft, helping to usher in the cooler air mass and keep it put through the weekend. This will also spin additional shortwaves around the parent trough, giving us pockets of very isolated showers Sunday through Tuesday.
Eventually this pattern starts to break down, leading to another system to work in from the West. This one could bring the potential for some heavy rain across portions of the Ohio Valley and Midwest, but the exact location is still very uncertain since this system is almost a week away.
Temperatures will continue to run cooler than normal both for the afternoon highs and overnight lows through all of the week ahead. Some patches of frost are possible Sunday, Monday, and Tuesday nights if skies remain clear and winds stay light during that time. During the daytimes, isolated pockets of showers (10-20% chances) are also possible Sunday through Tuesday. Toward the middle of the week, we will see increasing temperatures and rain chances Wednesday through Friday.