UPDATE: 10.8 Inches Was Largest Snowfall Total in 5 Years; Dangerous Cold Ahead
11:45AM MONDAY, FEB. 1, UPDATE
The weekend winter storm is over, for now, but many of us are still digging our way out, and there are some more events on the way — including more snow and potentially wicked-cold temperatures.
Fast Facts From Jan. 30-31 Event
Here are some fast facts, courtesy of the National Weather Service Chicago:
- Widespread snowfall of 6 inches to 12 inches were observed from the afternoon of Jan. 30 through the early evening of Jan. 31 (a 24- to 30-hour event). This was produced by a potent weather system, that in particular had a significant amount of moisture for heavy snow and also slowed as it moved over the area, resulting in persistent snow including lake enhanced snow on Jan. 31. This system will bring significant snowfall to the Northeast today (Monday, Feb. 1, 2021) and tonight.
- Impacts were widespread hazardous to even dangerous road conditions on the night of Jan. 30 into the early morning of Jan. 31. This had resulted in numerous auto accidents or slide-offs, relayed through partners and the public to us in the NWS.
- The official event snowfall for Chicago was 10.8 inches observed at Chicago O’Hare International Airport. Facts about this:
- Largest snowfall event total in five years, since Nov. 20-21, 2015 (11.2 inches)
- Second 6+ inch snow event in a week. The last time that occurred was early January of 2014
- The 16.8 inches from Jan. 25-31 was the snowiest week in six years — since Feb. 1-7, 2015 (19.9 inches)
- The official event snowfall for Rockford was 6.8 inches observed at Chicago Rockford International Airport.
- Other event snowfall amounts include 12.9 inches at the NWS Chicago in Romeoville and 11.3 inches observed 3 miles southwest of Chicago Midway International Airport.
- Heavy snowfall rates were key in this event, with rates of 1+” per hour for several hours during mid-evening January 30th into the early overnight. This was highlighted by Chicago O’Hare being 1/4 to 1/2SM visibility in moderate to heavy snow for five straight hours, which is rare to have such a duration!
4-Day Outlook
After the weekend winter storm, we’ll have quiet and seasonable early February weather through Wednesday, according to the NWS Chicago.
Our next threat for wintry weather in at least parts of the area comes with precipitation ahead of and behind a sharp cold front Thursday into Thursday evening. The wintry mix potential, in addition to rain and snow, includes a risk for freezing rain and some ice accumulations through about mid day.
Temperatures will plummet behind the front Thursday evening and night and with precipitation into the evening, this means that any liquid on paved surfaces could freeze and lead to slick travel, possibly into Friday morning.
Coldest Weather of Season Is Coming
Despite the snowy turn to this winter, temperatures have been mostly mild. That’s appearing likely to change in a big way this weekend into early next week, as guidance is pointing toward the first true blast of arctic air arriving sometime over the weekend.
It’s too early to say exactly how cold it will be, but an early look suggests widespread sub-zero low temperatures and single digit high temperatures are a distinct possibility, with lowest wind chill values well below zero, possibly to a dangerous extent for anyone not adequately prepared for the elements.
Prior to the likely arrival of this bitterly cold air mass, snow and travel impacts are possible for portions of the region.
Stay tuned to the latest forecast updates. Now is a good time to brush up on your cold weather safety!
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Snowfall Totals
The totals below were received after 3 pm Sunday, January 31. Observations are collected from a variety of sources with varying equipment and exposures. We thank all volunteer weather observers for their dedication. Not all data listed are considered official. Location Amount Time/Date Provider ----------------------------------------------------------------------- NWS Chicago-Romeoville 12.9 in 1200 AM 02/01 Official NWS Obs Thornton 12.7 in 1100 PM 01/31 Trained Spotter Peotone 12.7 in 0655 PM 01/31 Trained Spotter 1 NNW Downers Grove 12.4 in 0600 PM 01/31 Cocorahs Morton Grove 12.1 in 0730 PM 01/31 Broadcast Media Deerfield 12.0 in 0500 PM 01/31 Public Flossmoor 11.5 in 0709 PM 01/31 Trained Spotter Mokena 11.4 in 1200 AM 02/01 Trained Spotter 1 NNW Lindenhurst 11.4 in 0930 PM 01/31 Cocorahs 1 NNW Roselle 11.4 in 0600 PM 01/31 Cocorahs 3 SW Midway Airport 11.3 in 1200 AM 02/01 CO-OP Observer Morgan Park - Chicago 11.0 in 1000 PM 01/31 Public 2 N Homer Glen 11.0 in 0520 PM 01/31 Public Ohare Airport 10.8 in 1200 AM 02/01 Official NWS Obs 1 SW Medinah 10.8 in 0800 PM 01/31 Cocorahs Joliet 10.7 in 0500 PM 01/31 Trained Spotter Libertyville 10.5 in 0900 PM 01/31 Trained Spotter Oak Lawn 10.5 in 0515 PM 01/31 Public 1 WNW Woodridge 10.5 in 0415 PM 01/31 NWS Employee 1 ESE Schaumburg 10.3 in 0630 PM 01/31 Cocorahs Antioch 9.8 in 0930 PM 01/31 Public Kentland 9.5 in 0830 PM 01/31 Public Lemont 9.5 in 0340 PM 01/31 Emergency Mngr Kouts 9.0 in 0650 PM 01/31 Public 1 N Medinah 9.0 in 0500 PM 01/31 Cocorahs 1 ENE Chicago Loop 8.6 in 0800 PM 01/31 Broadcast Media 1 ENE St. Charles 8.4 in 0519 PM 01/31 Trained Spotter Lake Summerset 7.8 in 0740 PM 01/31 Public Pecatonica 7.0 in 0530 PM 01/31 Public New Milford 7.0 in 0526 PM 01/31 Public Rockford Airport 6.8 in 1200 AM 02/01 Official NWS Obs South Beloit 6.5 in 0526 PM 01/31 Public 2 SW Rockford 6.0 in 0526 PM 01/31 Public Chatsworth 4.0 in 0500 PM 01/31 CO-OP Observer Gilman 2.0 in 0830 PM 01/31 Public Gibson City 1.5 in 0830 PM 01/31 Public
SOURCE: National Weather Service Chicago
