Sliding From 70s Today To Snow By Sunday Night
So Long 70s :(
Thursday felt more like May than October. O'Hare's high reached 78°. It was the 8th time this month we've seen a high in the 70s or warmer. Today's high occurred just after midnight last night as temperatures hovered in the lower 70s. A strong cold front comes through early today to send those temperatures tumbling.
The HRRR model has us in the 40s by this afternoon with gusty north, northwest winds to make it feel even colder.
Those gusty winds will whip up big waves along the south and east shores of Lake Michigan. A lakeshore flood advisory is in effect from 3 pm today until 10 am tomorrow morning in northern Indiana. Waves will grow to between 8 to 11 feet with occasional waves possibly as high as 14 feet.
The Big Drop
We will experience a dramatic drop in temperatures today of nearly 40°. O'Hare started off just after midnight in the lower 70s and will fall to near freezing by just before midnight tonight. The chill that arrives today sticks around through next week. We are looking at 40s for highs at least four days in a row starting on Saturday. The last time we did that was the middle of April. This will be the coldest streak we have seen in just over seven months.
October averages .2" of snow at O'Hare. The GFS model suggests some of could see close to that amount of snow late Sunday into early Monday. The GFS snowfall accumulation forecast through Tuesday lays down between .1" to .2" for most areas with more significant snow downstate.
Showers and thunderstorms today then drying out this evening and staying dry Saturday. Light rain develops late Sunday and could change to or mix with light snow Sunday night into the early morning hours Monday.
It is a tricky forecast and not all models agree so it will have to be watched closely. The snowfall accumulation forecast has been changing almost every day. There is a slight chance for some very light additional snow late Monday into early Tuesday too.
Speaking Of Snow
This could be a bad sign for those of us who prefer a kinder, gentler winter. The area of the country with snow cover yesterday (lower left graphic) is more than double what we saw at the same time last year (lower right graphic). 13.8% of the country had snow cover with an average depth of .5" on October 22. On the same day last year nearly 6% of the country had snow cover with an average depth of .3".
This cold pattern that comes crashing in today may ease a bit by the start of November but the long range outlook has us colder than average overall for the next two weeks.
The 6-10 day temperature probability forecast has us outlooked for below average temperatures overall from October 27th through the 31st and the longer range 8-14 day extends that cold pattern, albeit with lower probabilities, from October 20th through November 5th.
Milder Next Month?
There is hope for a turnaround and milder weather for next month. The experimental multi-ensemble model forecasts have us above average for the weeks ending on November 6th and November 13th.
Shift To Dry Pattern Possible
It's been a wet pattern as of late. 10 of the last 12 days have reported rain. 2.92" has fallen so far this month which is .70" above average. There are signs in the longer range forecasts that point towards a drier pattern by the start of November. The 6-10 day forecast has us outlooked for above average precipitation from October 27th through the 31st. The longer range 8-14 day has us favored for below average precipitation from October 30th through November 5th.
Here is my 7 day forecast:
Today: Showers & scattered thunderstorms, breezy Temperatures falling from 60s into 40s
Saturday: Partly to mostly sunny Low: 34 High: 47
Sunday: Mostly cloudy, light rain late (light snow possible overnight) Low: 35 High: 49
Monday: Mostly cloudy, light rain mainly early Low: 34 High: 42
Tuesday: Becoming partly to mostly sunny Low: 30 High: 49
Wednesday: Partly to mostly sunny Low: 29 High: 49
Thursday: Partly to mostly sunny Low: 35 High: 48