Becoming Wet & Windy Then Wintry By The Weekend
Slow Start To Snow Season
Just 3.4% of the country was reporting snow cover on Tuesday with an average depth of .2". We are still waiting for our first flakes to fall. So far they are running about 10 days behind schedule.
Some snow stats from yesterday's post:
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.
What a difference a year can make when comparing the country's snow cover from one to the next.
At this point last year we had more than five times the amount of snow cover compared to this year. Last year just over 18% of the country was reporting snow on the ground. The average depth last year of .7" was more than three times as much as we are seeing now.
Snow is in our forecast but we have some rain to get through first before the flakes fly. The HRRR model has highs today climbing into the middle to upper 50s. That's at least a bit above the average high of 51°.
Our temperatures will fall only slightly into the middle 50s this evening and then hold steady through early Thursday. The GFS Model has us falling into the the middle to upper 40s later in the day tomorrow. This is the beginning of a shift towards a colder pattern.
Even colder air catches up to us on Friday as highs fall into the lower 40s. The GFS Model suggests it could be the coldest high temperatures in over seven months here.
We stay wintry through the weekend. The GFS model temperature anomaly forecast for Saturday afternoon shows temperatures here between 3° to 6° below average. That means highs Saturday in the lower to middle 40s.
The hourly forecast through Thursday has more details in terms of our wind and temperature trends.
Winds pick up out of the southeast today with gusts over 20 mph but get especially strong tomorrow. Winds will gust over 30 mph on Thursday with a few spots possibly seeing gusts near 40 mph.
Some spotty sprinkles or light showers are possible this afternoon and evening but the best chance of rain is early Thursday. A soggy start to tomorrow may slow down your morning commute.
Colder Pattern About To Kick In
Today will be the fifth day in a row with above average temperatures. Enjoy it because a colder pattern begins tomorrow. The National Blend Of Models has our highs falling from the upper 50s today to the middle 50s Thursday. Our highs tomorrow will occur early in the morning as temperatures should fall during the afternoon. Much colder air arrives for Friday and sticks around through the start of next week with highs only in the lower 40s.
The longer range temperature outlooks has us near normal overall from next Monday to the Tuesday before Thanksgiving. The 6-10 day outlook still has us favored for about average temperatures overall from November 15th through November 19th. The longer range 8-14 day forecast favors us for about average temperatures overall from November 17th through November 23rd. Average highs for this period are in the middle 40s to upper 40s with average lows in the lower 30s.
The even longer term 30 day temperature anomaly forecast has most of the area near normal overall but south of the city is outlooked to be a bit above average. Our south suburbs are forecast to be about 1° to 3° below average. This forecast covers the period from November 8th through December 8th. 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.
Dry Start To November So Far
November's precipitation is now running .78" below average. Yesterday was the 10th straight dry day. On average by this point of fall we have about a four tenths of an inch of snow. Some scattered snow showers are expected on Friday with more light snow or flurries possible at times this weekend.
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 showers possible this afternoon and evening but the soaking rain holds off until after midnight and lingers through Thursday morning's commute. The GFS model's total precipitation forecast through Sunday afternoon spits out between a third of an inch to just over a half inch. Most of this will be in the form of rain early tomorrow but our first snow of this fall is coming.
The GFS model's total snowfall forecast through Monday morning lays down a total of nearly an inch across the area. I think this is a bit overdone. The ground is still warm so more likely we might get a coating of some slushy snow on some grassy surfaces with Friday's snow showers. More light snow or flurries can't be ruled out especially Saturday night into Sunday.
The European model is suggesting less snowfall. It spits out around a third of an inch to about three quarters of an inch for most of the area. The heavier amounts in north central Indiana would come in the form of lake-effect snow late this weekend.
The GFS model's meteogram for O'Hare has the highest chance of rain coming still on Thursday then some light rain and snow showers Friday. It also spits out some additional light snow on Sunday.
The longer range precipitation forecasts trend us from near normal to above normal. 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 15th through November 19th. The longer range 8-14 day forecast also has us outlooked for above average precipitation for the period from November 17th through November 23rd.
Here is my 7 day forecast:
Today: Becoming mostly cloudy, breezy, pm spotty sprinkles/light showers High: 59
Thursday: Mostly cloudy, on & off rain, windy Low: 54 High: 57 (falling temps late)
Friday: Mostly cloudy, windy, rain & snow showers Low: 38 High: 42
Saturday: Mostly cloudy, a few flurries possible Low: 32 High: 41
Sunday: Mostly cloudy, light rain and snow possible Low: 30 High: 40
Monday: Partly to mostly sunny Low: 29 High: 42
Tuesday: Partly to mostly sunny Low: 32 High: 48