Jarring 25-30 degree high temperature drop hits Wednesday followed by several cool days after backdoor cold front’s passage early Wednesday—But, warming is back for Memorial Day weekend; Bone dry weather persists—no rain over coming week

VIEW OF THE SMOKE ON MONDAY

Fires are burning—sending smoke across a wide area of the country

Heaviest smoke north of Chicago across Wisconsin, Minnesota and Michigan

Chicagoans enjoyed the 2nd warmest weekend of 2023 with a Saturday high of 73 and an 81-degree high Sunday

• Monday’s 84 degrees high likely marks the 9th time this year temps have reached or exceeded 80 degrees—and a 9th is likely Tuesday—with Tuesday likely to exceed Monday’s reading by 3 degrees. Lake breezes will continue cooling lakeshore areas.
• A jarring change to cooler weather with a 23-degree 24-hour high temp pullback likely at O’Hare is to hit Wednesday with a backdoor cold front’s passage. The front is to race southward the length of Lake Michigan ushering 25 to 30 mph north/northeasterly wind gusts into the area Wednesday. Strong winds likely to build 5 foot or greater waves and to produce rip currents along the shoreline.
• The front will pass with only a scattering of clouds but with smoke off Canadian wildfires likely to pick up in coming days. Firefighters in western Canada are hopeful rains in the British Columbia and Alberta will help in the effort to fight the fires there which have charred more than 2-million acres—2000% the amount of terrain burned in Canada by this time a year ago.
• From a July level 87-degree inland high Tuesday, temps Wednesday are likely to peak no higher than the low to mid 60s and likely hold to the 50s on the Lake Michigan shoreline. The predicted 64-degree high Wednesday and the 63-degree high expected Thursday equals normal late April-level temps.
• But jarring as the Wednesday/Thursday temp drop will be and as cool as morning temps will be Wednesday, Thursday and Friday mornings, a healthy temp rebound is likely to take place going into—and OVER—the coming Memorial Day weekend with temps predicted to surge back to 81 at O’Hare Saturday; 85 Sunday and 88 Memorial Day. Lake breezes will cool lakeshore areas each of those days but are expected to be fairly light and therefore to reach only a limited distance inland.
• It’s VERY DRY and going to stay that way. No rain is predicted in the coming week, and it may be mid next week before any occurs in the Chicago area extending the VERY DRY WEATHER REGIME which has dominated the past two months. Since April 1st, Chicago has recorded only a bit more than one-third of its normal rainfall—just 2.44” versus the normal 6.86” tally during that period of time. May by itself, now 3 weeks old, has recorded all of 0.42”—just 15% of its typical 3.11.”

WEDNESDAY’S BACK DOOR COLD FRONT RACES SOUTHWARD THE LENGTH OF LAKE MICHIGAN WITH STRONG “NNE” WINDS BEHIND IT

SUMMER-LIKE TUESDAY WARMTH TO GIVE WAY TO JARRING MID-WEEK TEMP DOWNTURN—A 23-DEGREE DAYTIME TUESDAY TO WEDNESDAY HIGH TEMP DROP FROM JULY-LEVEL MID 80s TUESDAY TO LATE-APRIL LEVEL LOW AND MID 60s

• Cool with brisk winds off Lake Michigan Wednesday and Thursday, but a temp surge is coming over the Memorial Day holiday weekend. Weather to stay bone dry into mid-next week.
• Chicagoans have come of the 2nd warmest weekend of 2023 and enjoyed a warm open to the new week—warmth which is to repeat Tuesday. Though lake breezes have cooled lakeshore areas Monday and will again Tuesday, temps elsewhere have surged into the 80s. Monday’s 84-degree likely high at O’Hare marks the 9th time this year the temp has broken above 80 degrees. And, Tuesday is likely to see temps 3 degrees higher on average.

• But, big changes loom as a back-door cold front racing southward with vigorous “NNE” winds to follow its passage into the Chicago area—is to crash area temps Wednesday.
• The cold front is to drop through the Chicago area Wednesday, propelled south by a strengthening Canadian high pressure system over Ontario province. Fronts such as this gather a head of steam as they drag cool air the full length of Lake Michigan into Chicago and arrive with strong winds. NNE winds Wednesday are likely to gust 25 to 30 mph and develop some impressive waves—5 feet and taller—on Lake Michigan. Rip currents will develop on the Lake Michigan shoreline, though temps plunging into the upper 40s then rising no higher than the low to mid 60s Wednesday, are likely to discourage swimmers from venturing into the still chilly low to mid 50-degree Lake Michigan waters.
• Upper winds are to guide smoke off Canadian wildfires into Chicago’s air space, most dense later Tuesday night into Wednesday. So, despite a precipitation-free and only partial cover of clouds in our skies as the cold frontal passes Wednesday morning, it’s likely we’ll notice increased, orange-hued haziness as the smoke layer aloft rides into the Chicago area Wednesday. It will be interesting to see if this smoke mixes down to the surface at that time.

THE COOL AIR’S WEDNESDAY/THURSDAY VISIT IS TO BE WANING BY FRIDAY AND A VIGOROUS MEMORIAL DAY WEEKEND WARM-UP SEEMS A GOOD BET, THOUGH LAKE BREEZES WILL MAINTAIN SOME HOLIDAY WEEKEND SHORELINE COOLING

Modeling has temps rebounding over the coming Memorial Day weekend. And given the recent bias of under forecasting warming, it’s likely temps may make it higher than forecast model temps averages would suggest—surging back to the low 80s Saturday, the mid 80s Sunday and potentially the upper 80s Monday (Memorial Day).

THE AREA IS RUNNING BONE DRY, AND THERE APPEARS LITTLE IF ANY PROSPECT FOR ANY RAIN HERE OVER THE COMING WEEK (i.e. INTO NEXT WEEK)

• And, given an atmospheric blocking pattern which traps a rain-defeating high pressure ridge of the Chicago area until mid next week, it appears the prospects for any rain may remain nil until Wednesday next week at earliest.
• While great news for holiday outdoor plans, the dry weather is quite noteworthy. The Chicago area has logged just over one third (35%) of its normal rain in April and May—with 2.44” on the books at O’Hare versus the normal to date of 6.86.” That’s an eye-catching 4.42” rainfall deficit. And, if May rainfall is examined, the 0.42” which has been recorded at O’Hare is 15% normal and a stunning 2.69” off the normal tally to date of 3.11.”
• It is going to be interesting to follow precip trends here. Longer range summer predictions out of the Weather Service’s Climate Prediction Center suggest a modest tendency toward ABOVE NORMAL precip during the June, July and August meteorological summer season. But, making up widespread precip deficits in the warm season can be problematic given the varied nature of warm season precip of rain to date.

A SERIES OF PREDICTED SURFACE WEATHER MAPS

Showing the building Canadian high pressure which is to power the southbound movement of a vigorous cold front to sweep across Chicago Wednesday morning, ushering strong “NNE” winds into the Greater Chicago area Wednesday. This series begins with the 7am CDT Tuesday forecast map.