Frigid By Friday With First Flakes Of Fall Snow
Taste Of Winter By End Of The Week
We've enjoyed 60s for highs the past two days in a row. Will Monday's high of 65° be the last of the 60s for this year? Not necessarily. The average last date for a high of 60° or warmer at O'Hare over the past 50 years is November 25th. We have hit 60° or warmer as late as December 30th (2002). Of course the further we get into the year the less likely we will be that warm again.
While 60s will become increasingly more rare this year, snow will become more likely. We are now overdue for our first flakes by a little over a week. I posted a few days ago some snow stats for Chicago. Here is a quick recap:
The average first date of a few flakes of snow here is October 31st although it has come as late as December 5th. The average first date of measurable snow (.1" or more) is November 18th but it has come as late as December 20th. The average first date of 1" of snow or more is December 7th but it has come as late as January 25th.
The HRRR model has highs today climbing into the middle 50s. That's just a bit above the average high of 52°.
Highs should stay in the 50s for Wednesday and Thursday but it gets frigid by Friday. The GFS Model has our highs falling into the lower 40s early Friday with temperatures tumbling into the upper 30s during the afternoon.
Gusty winds will kick in Thursday and continue through Friday. Winds could gust to 30 mph or more. The GFS Model has our wind chills Friday afternoon falling into just the middle to upper 20s.
Wintry this weekend with the cold sticking around through Saturday and Sunday. The GFS model temperature anomaly forecast for Saturday afternoon shows temperatures here between 6° to 10° below average. That means highs Saturday in the lower to middle 40s.
50s for highs today and tomorrow. Watch for winds gusting to near 20 mph today and then gusting to near 30 mph Wednesday.
Some sprinkles or light showers can't be ruled out today but the chance for rain ramps up Wednesday night into Thursday.
Temperatures Headed Downhill
While we won't climb into the 60s today we will be above average for the 4th day in a row. The National Blend Of Models has our highs falling back into the 50s today through Thursday. The dramatic drop comes for Friday with highs barely in the 40s and an early taste of winter this weekend with highs near just 40°. The unseasonable cold continues through Tuesday with highs in the 40s.
The longer range temperature outlooks move us from a relatively colder pattern to near normal. The 6-10 day outlook still has us favored for below average temperatures overall from November 14th through November 18th. The longer range 8-14 day forecast favors us for about average temperatures overall from November 16th through November 22nd. Average highs for this period are in the middle 40s to upper 40s.
The even longer term 30 day temperature anomaly forecast suggest our temperatures may level off back to about average over the period. Northern Illinois is outlooked to be near normal overall through the first week of December. This forecast covers the period from November 7th through December 7th. The Global Ensemble Forecast System (GEFS) is a weather forecast model made up of 21 separate forecasts, or ensemble members The model tries to give an idea of the amount of uncertainty in a forecast by running an ensemble of multiple forecasts which are each tweaked a bit with their initial conditions.
Waiting On First Fall Snowflakes
November's precipitation is now running .70" below average. On average by this point of fall we have about a third of an inch of snow. Our first flakes of this fall could come Friday.
The most recent US Drought Monitor analysis was released last Thursday. Here is a recap:
After three reports in a row with good news for Illinois the latest report is a bit more ambivalent. There is no areal increase in any of the drought categories but there is no decrease either. Things have not changed at all compared to the previous report. 9.29% of the state is in a moderate drought (level 1 out of 4) and 1.22% is in a severe drought (level 2 out of 4). The drought continues to be focused in northern Illinois entirely.
The report was more of a mixed bag for the Midwest region. While the areas in a severe to extreme drought decreased slightly, the area in a moderate drought increased slightly.
Some sprinkles or light rain could come today but most of the rain in this forecast will fall late Wednesday into Thursday. The GFS model's total precipitation forecast through Sunday afternoon spits out between a third of an inch to nearly a half inch.
The GFS model's total snowfall forecast through Sunday afternoon lays down a coating across northern Illinois and northern Indiana. This model suggests around a half inch to nearly an inch in total. Most of this would come late Friday into early Saturday but some flurries or light snow showers could continue on and off this weekend, especially late Saturday into Sunday.
The European model is suggesting similar snowfall. It spits out around a half inch to an inch for most of the area.
The GFS model's meteogram for O'Hare has the highest chance of rain coming on Thursday then some light rain and snow late Friday into Saturday.
The longer range precipitation forecasts are trending us towards a more active period of precipitation. The latest 6-10 day forecast has the Chicago area favored for near normal precipitation (which can take the form of rain or snow now) from November 14th through November 18th. The longer range 8-14 day forecast also has us outlooked for above average precipitation for the period from November 16th through November 22nd.
Here is my 7 day forecast:
Today: Mostly cloudy, spotty sprinkles or light showers possible, breezy High: 58
Wednesday: Partly to mostly cloudy, breezy Low: 41 High: 59
Thursday: Mostly cloudy, on & off rain, windy Low: 50 High: 57 (falling temps late)
Friday: Mostly cloudy, windy, light rain & snow showers Low: 38 High: 42
Saturday: Mostly cloudy (light rain/snow overnight) Low: 32 High: 41
Sunday: Mostly cloudy, light rain and snow possible Low: 30 High: 40
Monday: Partly to mostly cloudy Low: 29 High: 42