4Warn Weather Alert: Wildfire smoke leading to ‘unhealthy’ air quality in Metro Detroit

4Warn Weather – The dangerous heat that gripped Metro Detroit Wednesday will ease, but having slightly lower temperatures does not mean that Southeast Michigan is in the clear.

The 4Warn Weather Alert remains in effect Thursday, as a thick plume of wildfire smoke from Canada settles into the region, bringing some of the poorest air quality this season.

While the Heat Advisory was allowed to expire Wednesday evening, the Air Quality Alert continues through Thursday, and for many communities, the smoke will pose the greatest health concern.

Unlike some air quality events driven by ozone or lighter smoke high in the atmosphere, this smoke is expected to settle close to the ground.

The result is unhealthy air pollution for the general population, with some neighborhoods potentially reaching very unhealthy and hazardous levels for a time, especially late Wednesday night through Thursday morning.

A few storms beating the odds Wednesday night

Although most of Southeast Michigan will stay dry Wednesday night, a few isolated thunderstorms developed Wednesday evening along the advancing cold front. Just enough instability developed for a handful of storms to briefly become severe.

The National Weather Service issued Severe Thunderstorm Warnings for portions of Oakland, Genesee and Shiawassee counties, with radar indicating the potential for wind gusts up to 60 mph and hail up to quarter-size.

Quarter-sized hail was reported in Holly at 7:19 p.m.

The Storm Prediction Center noted the overall severe weather threat remained isolated.

Overnight, attention turns back to the arrival of dense Canadian wildfire smoke, which is expected to become the dominant weather story through Thursday.

Smoke thickens late Wednesday night

The cold front opened the door for dense Canadian wildfire smoke to pour into Southeast Michigan on Wednesday.

The thickest smoke is expected overnight into Thursday morning, when cooler temperatures and a stable atmosphere trap the smoke close to the surface.

Visibility may be reduced at times; skies will appear hazy, and many people may notice the smell of smoke even indoors.

Those with asthma, COPD, heart disease, children, older adults, and pregnant women should avoid prolonged outdoor activity.

However, even healthy adults may experience irritated eyes and throats, coughing, headaches, or shortness of breath during periods of heavier smoke.

If possible:

• Limit strenuous outdoor activity.

• Keep windows closed.

• Run your air conditioning on recirculate if available.

• Change air filters.

• Consider wearing a properly fitted N95 mask if you must spend extended time outdoors in smoky conditions.

Still hot Thursday

Even though the oppressive humidity backs off behind the front, Thursday will not feel cool.

Afternoon highs climb back into the lower 90s, with “feels like” temperatures generally remaining in the lower 90s as well.

That is noticeably more tolerable than Wednesday’s triple-digit heat indices, but it is still hot enough to require frequent hydration and breaks if you are spending time outside.

The combination of heat and smoky air may make outdoor conditions especially taxing, even if temperatures are not as high.

Rain chances return

Thursday stays dry before moisture begins returning on Friday.

Scattered showers and thunderstorms become possible Friday afternoon and continue at times into Saturday as the next weather system approaches the Great Lakes.

Not everyone will see rain, but several opportunities for showers and thunderstorms develop through the weekend.

By Sunday and early next week, temperatures settle closer to normal with highs generally in the lower to mid-80s, along with periodic chances for additional showers and thunderstorms into Tuesday.

While the cooler weather will be welcome, air quality should also gradually improve as the weather pattern becomes more active and winds help disperse lingering smoke.

The wildfire smoke will lead to more vibrant and redder sunsets and sunrises. Share your weather and nature photos with Local 4 at MIPics.