Weather: Hot and humid Saturday with highs near 90 degrees

Heat advisory issued

Saturday, Aug. 28, 2021
Saturday, Aug. 28, 2021

DETROITA heat advisory has been issued for Genesee, Lapeer, Lenawee, Livingston, Macomb, Monroe, Oakland, St. Clair, Washtenaw and Wayne counties from 2 p.m. to 8 p.m. Saturday, Aug. 28.

It’s been quite a summer.  As if the numerous high-end flooding events weren’t enough, the stifling heat and humidity has made life rough especially for those who work outside and those without air conditioning. 

As far as the heat and humidity are concerned, I have both good and bad news: The bad news is that this weekend will be the hottest of this current stretch of dangerous heat.  The good news is that relief is on the way.

Yesterday’s thunderstorms with torrential downpours were expected.  However, the coverage ended up being much more widespread than I expected.

Instead of just a few pop-up storms, the storms that fired congealed into a large mass of torrential rain.  One weather observer in Garden City reported an astounding 3.73 inches of rain in only four hours. That type of rain event is statistically expected to occur only once every 50 to 100 years.

Fortunately, it appears that any thunderstorm chance this afternoon will remain widely scattered. Most of us likely won’t see one.  Perhaps the best chance to see one could end up being on the east side near the big lakes where the lake breeze could trigger a few.

Temperatures will skyrocket into the mid 80s (30 degrees Celsius) by noon, and to near 90 degrees (32 degrees Celsius) for an afternoon high.  However, the humidity will make it feel much hotter:  the heat index will be 91 degrees (33 degrees Celsius) at noon, 98 degrees (37 degrees Celsius) at 4 p.m., and 92 degrees (33 degrees Celsius) in the early evening.  And urban areas could see the heat index even reach 100 degrees (38 degrees Celsius) this afternoon.  The National Weather Service has issued a Heat Advisory, as well as an Air Quality Alert also known as an Ozone Action Day.  The combination of sunshine, heat, humidity and light wind means that we’ll have increased low-level ozone to deal with.  Ozone is beneficial ten miles up, where it filters some of the sun’s ultraviolet rays.  But here at the surface, it’s bad stuff to breath and causes problems for those with respiratory issues or who are in poor health.  And some of you have e-mailed me over the years telling me how your health struggles on Ozone Action Days.

Fortunately, there are simple things you can do that make a significant difference in the amount of low-level ozone that forms today:

  • Hold off until evening to fuel your vehicle.  Those gas fumes create a lot of ozone on a day like this.
  • Likewise, hold off on using any gasoline powered lawn equipment until evening, as their exhaust also creates a lot of ozone.
  • Avoid unnecessary errands or put them off until evening.  The less we drive our gasoline vehicles, the less exhaust we put into the air.
  • Finally, cut back on our electricity use.  Turn off lights when leaving a room for a while.  Dial the thermostat up a degree or two.  Unplug chargers that aren’t being used (they use electricity even when just sitting there plugged in and not charging anything).  Hold off on using major electricity appliances (dishwasher, washer, drier) until evening.  The less electricity we use during the day, the less energy our coal-burning power plants have to produce.

Saturday night will be warm and muggy with lows only in the low to mid 70s (22 to 23 degrees Celsius).

Partly cloudy, hot and humid once again on Sunday, with scattered afternoon and evening thunderstorms popping up.  Some of those could be strong-to-severe, so be weather aware Sunday and keep an eye on our app’s real-time radar to stay ahead of the weather.  Highs Sunday near 90 degrees (32 degrees Celsius), with the afternoon heat index reaching at least the mid 90s (35 degrees Celsius).

A cold front finally crosses the area Monday morning.  We’ll wake up to another steamy morning, but drier air will filter in during the afternoon, and we’ll have comfortable temperatures and lower humidity for the rest of next week. It will be a splendid week of weather coming our way!

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About the Author:

Local 4 meteorologist Paul Gross was born in Detroit and has spent his entire life and career right here in southeast Michigan. Paul has researched, written and produced eight half-hour documentaries for WDIV, as well as many science, historical and environmental stories.