31ºF

Dangerous heat wave begins Friday in Metro Detroit

High temps, humidity, increasing drought all a concern

Paul Gross takes a look at the upcoming Metro Detroit weather forecast for June 28, 2018. (WDIV)
Paul Gross takes a look at the upcoming Metro Detroit weather forecast for June 28, 2018. (WDIV)

DETROIT – We’ve been telling you about it all week long, and now the time draws near: a very dangerous heat wave begins on Friday, and certain aspects of it look even worse than they did yesterday.

Expect mostly clear skies overnight, with lows near 70 degrees (21 degrees Celsius). Calm air means that there won’t be any breeze blowing in the windows to help out those without air conditioning.

Mostly sunny, hot and humid on Friday, with highs in the low 90s (33 degrees Celsius), and a south wind at 8 to 13 mph. The humidity will make it feel like mid to upper 90s (36 degrees Celsius).

Ozone Action day

The combination of sunshine, high heat and humidity will induce much higher than normal air pollutants, so Friday has been declared an Ozone Action day. Most people don’t realize that a few small, simple steps actually make a huge difference in reducing those pollutants:

  • If you can, hold off on fueling your vehicle until the evening hours. Gasoline fumes contribute mightily to the formation of air pollutants on sunny, hot, humid days, so delaying that trip to the gas station until evening really helps a lot.
  • Delay mowing your lawn or using other gasoline powered lawn equipment until evening, as you’d be shocked at how much air pollution these things produce. Again, we want to try and reduce those pollutants during the day, when the weather conditions make them even worse.
  • Drive less, especially during the daytime hours. Same reasoning as above.
  • Try to cut back on your electricity use during the day. That means turning off lights and TVs when they aren't being used, hold off on running your major appliances until evening, dialing up your thermostat if you have air conditioning, etc. Anything that cuts back on the amount of electricity being used in our area reduces the amount of electricity being produced by our coal-burning power plants, which reduces air pollutants.
  • We likely will have multiple Ozone Action Days over the next week, as the stagnant air in this heat and humidity are cumulative. The above tips really do help -- let’s all do our part!

    Weekend forecast

    Warm and oppressively muggy Friday night, with lows in the mid 70s (24 degrees Celsius).

    Mostly sunny and even hotter and more humid on Saturday, with highs in the mid to upper 90s (36 degrees Celsius). The humidity will make it feel like 107 degrees (42 degrees Celsius). By the way, Saturday’s record high is 96 degrees 36 degrees Celsius), set in 1931.

    Warm and oppressively muggy Saturday night, with lows in the mid 70s (25 degrees Celsius).

    Mostly sunny to partly cloudy on Sunday, and continued hot and humid. There’s a smaller chance now for a late-day thunderstorm, but still be aware if you have outdoor plans -- keep a close eye on our app’s radar.  Highs in the low to mid 90s (34 degrees Celsius). The humidity will make it feel like 104 degrees (40 degrees Celsius).

    Scattered thunderstorms are possible Sunday night. Warm and oppressively muggy, with lows in the mid 70s (24 degrees Celsius).

    Fourth of July week

    Right now, it looks hot and still humid for the entire holiday week. Keep in mind when it’s this hot and humid, the atmosphere is very, very unstable, so even the smallest upper level disturbance can trigger pop-up thunderstorms.

    In fact, even a strong lake breeze can generate some thunderstorms. While there is very little suggestion by the computer models for any widespread thunderstorm activity during the week, remember that those models also typically don’t handle very well weak upper level disturbances several days in advance.

    So, at this point, expect a mainly dry week with just a possible thunderstorm here and there. Highs should generally be near 90 degrees (32 degrees Celsius) early in the week, then rising into the low to mid 90s (33 to 34 degrees Celsius). Obviously, the humidity will make it feel hotter.

    The long-range computer models indicate a possible dip in the jet stream starting next weekend that would finally bring some relief from the high heat.

    Heat safety

    Time is running low to prepare for this heat.  Those without air conditioning, especially the elderly, those in poor health, and very young children, are particularly susceptible.

    Try to make plans with family and friends that do have air conditioning to perhaps visit with them to take some of the heat stress off your body. Remember that this is much more than about the daytime highs: overnight lows being so warm don’t allow your body to cool down much, so you remain stressed through the night, which further taxes your system.

    If you don’t have access to air conditioning, do whatever you can to cool your core body temperature, and also stay well hydrated with water (remember that alcohol and caffeine dehydrate you). Cold showers and baths work wonders to cool you off -- please consider that, and also please check on your relatives, elderly neighbors, and neighbors with children.

    Remember that you can also head to the air conditioned mall and do a little shopping to escape the heat. 

    Finally, you’ve undoubtedly seen the news stories this summer about children dying when left in hot cars. You need to understand that a car in the sun will heat up 20 degrees (about 10 degrees Celsius) just in the first 10 minutes, and then another 10 degrees (about five degrees Celsius) in the following twenty minutes.  So, let’s keep the math simple and consider the following…

    In a car left outside with an initial interior temperature of 70 degrees, (21 degrees Celsius) if you had the air conditioning on when you parked, the following applies:

    • In 10 minutes, it’s 90 degrees (32 degrees Celsius) in your car.
    • In 30 minutes, it’s 100 degrees (38 degrees Celsius) in your car.

    That’s why you can’t leave your young children or pets in the car, even just for ten minutes, in this heat.

    Pet safety during heat waves

    This heat is dangerous for our pets, too. They need access to cool, fresh water to stay hydrated (perhaps add ice cubes to their water dish), and remember if you take your dog for a walk that the pavement will be VERY hot during the day, and can burn the bottoms of their feet.

    Also remember that, in the same way that we humans shouldn’t overexert ourselves in this heat, the same goes for your pet.

    They can suffer heat stroke in as little as ten minutes in this weather. If you suspect that your pet has heat stroke, here are some important tips from the Michigan Animal Adoption Network / Animal Care Network:

    • Move your pet out of the heat and away from sun right away.
    • Go to your local veterinarian immediately.
    • Begin cooling your pet down by placing a cool washcloth or towel on the body,  especially foot pads and around the head.
    • Do not use ice or very cool water; only slowly offer cool water and do not force.

    Potential drought conditions developing

    Some of us have been pretty dry this month, and the U.S. Drought Monitor this week designated parts of the Thumb (specifically, parts of Sanilac, Tuscola and Huron Counties) as being abnormally dry -- last night’s rain certainly helped. Given that we don’t have much rain in the forecast with the expected very hot temperatures, we’ll only get drier. Let’s hope we get some thunderstorms with nice downpours at some point over the next week.

    90-degree days

    In case you’re wondering, we’ve already had six 90-degree days this season. Our long term average is twelve and, by the end of next week, we could potentially already be above average for the season…and it’ll only be the first week in July. Our record for most 90-degree days in a season was 1988, when we had an incredible thirty-nine of them.


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