Near Miss On Sunday Night Snow But Direct Hit For Cold
Snow Staying North
On average we get our first flurries or trace of snow around Halloween and our first measurable snow (.1" or more) by the middle of November. So seeing some snow this time of year is not unusual. The first snowfall of the season though always gets our attention. It now looks like that first snow won't be early next week. Models have been shifting a band of light snow back and forth precariously close to northern Illinois the past few days. The latest GFS model runs suggest a near miss for us (at least in terms of accumulation snow) late Sunday night and into Monday. There could be a period of very light snow but the sticking snow should stay north of here. The GFS snowfall accumulation forecast through Tuesday has up to nearly two inches of snow in southern Wisconsin.
Coldest Air Of Season So Far
While the snow might be a near miss the cold will be a direct hit. Highs today will be about 10° to 15° below average. Highs today will be in the middle 40s.
The The GFS model keeps highs in the 40s or even colder all the way through the end of next week. If that verifies, it will the coldest streak of weather we have seen since February. Next week would be the coldest week in nearly nine months. The model may be running just a bit too cold with highs only in the 30s on Monday and Tuesday but there is no doubt that the coldest air of the season so far is coming.
Chicago won't be the only place to experience this blast of chilly October weather. Highs will be 20° to 30° below average from the Rockies and Northern Plains all the way southward to Texas on Monday.
Milder Next Month
This cold pattern that kicked in Friday may weaken by the end of the month with a return of relatively milder weather for just beyond the beginning of next month. The 6-10 day temperature probability forecast has us outlooked for below average temperatures overall from October 29th through the November 2nd but the probabilities have dropped from previous forecasts. The blues on this forecast (bottom left graphic)aren't as deep. The longer range 8-14 day forecast has us near normal for October 31st through November 6th. It also shows a growing area of above average temperatures expanding eastward well into the middle of the country.
The even longer range experimental multi-ensemble model forecasts have us above average for the weeks ending November 13th and November 20th. It's looking more likely that next month will be relatively mild.
Shift To A Drier Pattern Could Be Coming
The wet pattern that has seen rain reported for ten of the last twelve days may finally be trending towards a drier pattern. We have seen more than two inches of rain at O'Hare during this period. The best chance of rain will be late Sunday into early Monday but that rainfall should be light. After that, there are only a few chances for additional light rain through next weekend.
There are signs of hope in the longer range precipitation probability forecasts that a drier pattern might last right into the middle of next month. The 6-10 day forecast has us outlooked for below precipitation from October 29th through the November 2nd. The longer range 8-14 day has us favored for below average precipitation from October 31st through November 6th.
Here is my 7 day forecast:
Today: Partly to mostly sunny High: 45
Sunday: Mostly cloudy, light rain late (light snow possible overnight) Low: 36 High: 49
Monday: Mostly cloudy, light rain mainly early Low: 35 High: 43
Tuesday: Becoming partly to mostly sunny Low: 30 High: 45
Wednesday: Partly to mostly sunny Low: 28 High: 50
Thursday: Partly to mostly sunny Low: 35 High: 49
Friday: Partly to mostly sunny Low: 37 High: 48