We kept the ABOVE NORMAL TEMP STREAK going in a month in which on four of the opening 20 days have come in below normal. The high temp of 46 Monday in Chicago marked the fourth consecutive day to post a high temp above 40. February is running nearly 6-deg above normal and nearly 7-deg warmer than a year ago.

Meteorological/climatological winter to date (the period which began Dec 1) ranks among the warmest 10% of winters on the books here in Chicago since 1871—even with two arctic blasts having occurred. That 82 day period as averaged 31.2-deg above normal and ranks 15th warmest of the 153 winters to date for which we have records.

WE HAVE QUITE A WEATHER WEEK AHEAD with a mammoth winter storm system coming together——one likely to produce a huge swath of heavy snow from the Rockies across the northern Midwest—including the Twin Cities  and central and northern Wisconsin—snow delivered with powerhouse winds which may bring conditions there to near blizzard levels. 

A significant ice storm appears to be coming together—with icing which may well reach into sections of northern Illinois just north and northwest of Chicago. It’s close enough for us to monitor closely. With strong ENE winds due to come off mid-30-deg lake waters, that could spare Chicago ice—but leave residents north and northwest of the city vulnerable to icing.

Heavy rains and high winds appears the storm’s impact in Chicago—commencing by lunchtime Wednesday and continuing Wednesday night with the potential for embedded t-storms.

Our in-house analysis of a suite of model precip forecasts suggests rainfalls of 1.20-1.60″ may be widespread. If so, this would be the metro area’s heaviest precip event since 1.58″ fell Dec 13-15.

In addition, this system is to hit with wind. Gusts topping 35 mph may lock in from the east/northwest Wednesday—then shift WSW and gust to 50 mph Thursday—reaching the threshold for damage if that prediction holds.  

Temps over the coming two weeks are to continue their above normal winter trend—but not by as much as last week when the full week temp average came in 8-deg above normal.  This week, for instance, is likely. to post a 3-deg surplus while next week may slip to just under a degree above normal.  Still, only four of the coming 15 days are predicted to post daily temp deficits (i.e. average colder than normal) while four of the coming 15 days may see temps within fractions of a degree of those days’ normals. 

The expanse of the coming week’s winter storm is impressive as indicated by the fact National Weather Service weather watches, warnings and advisories for is span all or parts of 16 states—among them some of our country’s largest states in terms of area. Snow accumulations over this storms cold northern flank could top a foot in many locations if forecast trends hold.  Such accumulations would reach from the northern Rockies across the northern Plains into sections of Minnesota and Wisconsin—though ice could be southern Wisconsin’s main concern with this storm. 

Full forecast details at the WGN Weather Center

TONIGHT: Partly cloudy and colder with winds shifting westerly and strengthening late. Low 23.

TUESDAY: Partly sunny and cold. Gusty morning winds ease in the afternoon and evening. High 39.

TUESDAY NIGHT: Clouding over, becoming breezy as east/northwest winds increase. Low 32.

WEDNESDAY: Windy with rain developing and possible embedded t-storms. Freezing rain north of I-88 could produce significant icing. The threat is being monitored.  East/northeast wind gusts increase to 35 mph. High 37—but low 30s colder northern counties along the Wisconsin line away from Lake Michigan.

WEDNESDAY NIGHT: Rain and t-storms and quite windy with a significant threat of freezing rain and icing in northern counties. Locally heavy rainfall. Low 33.

THURSDAY: Rain tapers to sporadic drizzle and sprinkles with some mixed sun emerging.  Turning quite windy with a high wind threat.  Freezing rain could linger a portion of the morning northern counties. High 45.

FRIDAY: Turning cloudy after some mixed sun, breezy and noticeably colder. High 25.

SATURDAY & SUNDAY: Partly sunny, seasonably chilly. High Saturday 38. Sunday’s high 39.

MONDAY: Rain likely and windy. High 43.