Heat and humidity lingers

Mother Nature is turning up the heat this week. It is a good time to be positioned closed to cool water. Slow down. We will experience dangerous heat index levels through Thursday, particularly over southern Minnesota and adjacent areas.

One of the computer models is showing a chance that the thermometer could reach 100 degrees in the shade in the Twin Cities this afternoon. A heat advisory has been posted for all but far northeast Minnesota for today. Hot and humid conditions will push the Heat Index Value close to 105 for several hours. The record high for the Twin Cities for today is 96 degrees, set in 1911.

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Source: NWS

The heat index does not take into consideration exposure to direct sunshine. Temperatures in the direct sunshine can be as much as 15 degrees hotter.

Mid afternoon temperature forecast from the NAM:

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Source: Twisterdata.com

The UV index will be high. If you must be in the sunshine be sure to apply appropriate skin protection.

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Heat safety Information from the National Weather Service

Severe thunderstorms are possible in northern Minnesota today. Stay alert for developing storms and the risk for gusty winds and hail from the lake country north.

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We do not see a break in the hot temperatures until a weak cool front settles south of the Great Lakes on Friday. Temperatures may be close to normal on the weekend. Highs will likely still be in the 80s.

Take it easy today. Complete necessary outdoor chores early in the day if possible.

Soon we may be longing for a scene like this!

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Photo by Craig Edwards

  • Chris

    Little help with the heat index thing. I’m looking at the Weather Channel and an Aviation weather site.

    The Weather Channel is reporting at home right now (Hanover) 88 deg and 73 dew point and a feels like temperature of 95. But if I look above heat index should be about 101 or 102?

    The Aviation weather is 83/73 with a 90 feels like temperature. Close enough. But for today’s high they forecast 96/72 and a 105 feels like. But from above isn’t that 126 or slightly more?

    Any thoughts on why the difference between several reporting outlets and the NOAA chart? Are heat index and feels like supposed to be the same thing? I know heat index does not take into account wind and solar which in thoery would be in a true feels like temperature model. But I have not heard of a complete feels like model. We have heat index lacking wind (chill) and wind chill lacking humidity and neither take into account sun/clouds/night.

  • http://bobtusecommentary.blogspot.com/ Bob MacNeal

    Last summer I wrote an essay lamenting the slow arrival of Canadian Air.

    This summer I’m beginning to wonder if Canadian Air isn’t a ruse contrived to keep the Minnesotans from yanking stakes, folding tents, and pointing their covered wagon’s GPS to the Canadian Rockies.

    Minnesotans are fresh-air nomads at heart. Perhaps we’re too stubborn to admit the kinks in the jet stream that makes us a forward-thinking Gulf state just might be permanent.

  • Mark

    It’s a fresh, breezy 68 degrees on Superior Street in downtown Duluth early this afternoon. It’s hard not to gloat.

  • Craig

    I’m pretty old school when the heat index was initially known as the livestock safety index. It was used as an indicator of problems transporting livestock. Some folks called it the hog advisory.

    The feels like temperature should be the same as the Heat Index. The NWS does not use the feels like indicator.

    If you are looking at the hourly weather on the NWS website you will see the heat index in the remarks section. It may be confusing because of the talk of dew points being in the low 70s. While the heat index chart posted is combining Relative Humidity and temperature. RH in the Twin Cities at noon was around 43 percent.

    Smoke is visible on satellite imargery and could hold the temperatures down as we move through the heat of the day.

  • Disco

    I will never long for that scene no matter how hot it gets.

  • Katie

    In response to Chris:

    The reason you are not getting the same readings from the heat index chart and the weather reports is that you are hearing temperature + dew point from weather reports and the chart uses the relative humidity percentage to calculate heat index.

    Instead of looking at the dew point (a degree measurement), revisit the sites you are getting your weather reports from and see if they provide the relative humidity (%). Then you will see a “feels like” temperature that matches this chart included in this article.

  • Craig

    new record high at MSP, EAU and STC for heat today. can we reach 100 at MSP?