DENSE FOG SHROUDED THE AREA as Tuesday got underway—then thinned allowed sunshine through the haze as the day proceeded.
A wind off the lake meant temps remained in the mid to upper 30s at shoreline locations but rose into the low 50s warmer inland spots where fog thinning most expeditiously. A mid afternoon, the spread in Greater Chicago area temps was 36 at Waukegan Harbor to 50-deg in Naperville. Chicago’s saw readings which varied from 38 at its lakefront to 48 at O’Hare.
Light winds will permit low clouds and fog to reassemble with nighttime cooling again Tuesday night into Wednesday morning. Visibilities may drop to fractions of a mile in some locations.
BUT WARMER WEATHER’S AHEAD as southerly winds take hold. Only modest cooling is likely on the immediate lakeshore Wednesday as Chicago heads into 3 days of 50-deg inland warmth—with the potential of 60-deg reading in some warmer locations amid strong south winds Thursday. Wind gusts by Thursday afternoon could top 40 mph as the storm system which has drenched California sweep across the Rockies and into the Plains tightening the pressure gradient BIG TIME across the Greater Chicago area.
As noted yesterday only 26 of the past 153 years since 1871 have seen temps hit or exceed 60-deg in Chicago by Feb 10th—so a 60-deg high on Thursday would represent the warmest 17% of pre-Feb 10 temps of the past 153 years. Put a bit differently, only just shy of 2 in 10 days have managed a temp that warm. Such unseasonably mild air is a product of mild oceanic air associated with the El Nino pattern which has dominated this winter taking control once again. Current indications are Thursday may end up averaging an eye-catching 25-deg above normal and Friday 20-deg above normal.
This week as a whole is likely to finish close to 15-deg above normal.
A CHANGE IN THE PATTERN SUGGESTS COLDER DAYS AHEAD—though nothing close to the arctic chill of two weeks ago is currently indicated. And if there is any kind of late winter storm in our future, it’s not showing up on model projections at this point. That doesn’t necessarily mean there isn’t such a system out there—-IT’S JUST NOT CAUGHT THE ATTENTION OF OUR MODELS at this point.
Where yesterday had two of three major ensemble models we examine with the hint of some snow or a wintry mix in our future toward Sunday night into Monday—only one model, the Canadian ensemble model, offers a hint of snow now.
The changing pattern involves the development of a pool of abnormal warmth over Greenland in the next week and a half. This buckles the North American jet stream, which guides the movement of weather systems across the continent. Typically upper winds blowing into the Midwest shift INTO THE REGION FROM CANADA—thus dropping temps. That’s what appears to be in the offing next week and into the week which following. Thius should produce a near 10-deg drop in the average weekly temp here in Chicago next week—a noticeable change to colder air—but not the sort of arctic blast we saw two weeks ago. We’ll keep monitoring developments, of course, and keep you updated.
Full forecast details and more at the WGN Weather Center blog
Whereas this week is to see an average temp 15-deg above normal, NEXT WEEK’S AVERAGE TEMP is to come in only a bit more than 3-deg above normal. That translates to our late week 50s this week cooling to the 30s next work week. And signs of cooling will be evident as early as this weekend when Saturday’s predicted high will fall from Friday’s 56 down to 43-deg—and Sunday’s high temps may struggle through the upper 30s.
Drenching rains have produced 3 day totals in southern California approaching or creeping past one foot in the hardest hit locations. I’ve coveredf the impact of the El Nino induced rains there in greater detail on my Facebook page:
HERE’S MY LATEST TUESDAY CHICAGO METRO FORECAST (2/6/2024):
TONIGHT: Haze thickens to areas of fog and low clouds overnight. Mild for the season—but with freezing temps which could lead to icy patches on less traveled or untreated roads or outdoor surfaces and a coating of frost. Low 32.
WEDNESDAY: Extensive cloudiness lingers, though some clouds break may allow spells of mixed sun to develop as morning fog thins to haze and southerly winds pick up. High 51—but 40s immediate lakeshore.
WEDNESDAY NIGHT: More cloudy than not, steady southerly winds with much above normal February temps. Low 44.
THURSDAY: Clouds and a bit of mixed sun, turning windy and unseasonably mild. Scattered afternoon showers develop amid wind gusts to 40 mph. More widespread rain possible Thursday night. High 59.
FRIDAY: Partly cloudy, windy and mild. Gusts topping 30 mph likely from the west/southwest. High 56.
SATURDAY: Partly sunny, breezy and colder. High 43.
SUNDAY: Partly cloudy, chilly—though still above normal for the time of year. High 39.
MONDAY and TUESDAY: Partly cloudy and chilly. Highs both days 39.