Late June 2025 Heat Wave

[Geoboy645]

The forecast has really zeroed in on a potentially quite significant heat wave for most of the subforum starting tomorrow and going through at least the weekend. At least 3-4 days of mid 90s over mid 70s dew points is going to cause heat index values to rise over 100 degrees over the weekend, especially in the Chicago and Detroit UHI's. While at this juncture it doesn't look like record highs are in jeopardy, the heat index and warm nights could cause some issues in the metro areas. This will probably be the most significant heatwave since the 2 day heatwave back in August 23. Figured that this is significant enough to warrant a thread of it's own.

Edit: As I was typing this out, ARX just put out an Extreme Heat Watch. With heat indexes up to 105 mentioned over the weekend.

[TheClimateChanger]

Good post. Although I do disagree with this part: "While at this juncture it doesn't look like record highs are in jeopardy..."

Below, is the current point-click forecast centered on DTW Airport. Record highs for Saturday through Tuesday are: 96, 98, 95, and 97. Record high minima are: 75, 73, 74, and 74. So this forecast would imply a new record high on Monday, June 23, and record high minima on Sunday, Monday, and Tuesday (tie). So I don't agree with that conclusion. Clearly, records are in jeopardy or else the NWS forecast is out to lunch. And this is just one location. I'm sure other locations will be at or near record high temperatures as well.

[Torchageddon]

DTX looks to be at 100F, just about on Mon, I'll be 92F. Top tier lows during the weekend/Mon - so far showing 22C-24C. I'm looking forward to it!

[OrdIowPitMsp]

2-3 days of 90s and dews in the 70s here then moderation and hopefully a ring of fire pattern. Of course it’s centered right on the weekend so the beaches will be absolutely packed.

[Harry Perry]

Generally speaking from heat-waves in the past with dews that high, the temps seem to under-perform a bit around here. Be interesting to see if that will happen this time around, especially after this deluge. 

[Baum]

4 hours ago, TheClimateChanger said:

Good post. Although I do disagree with this part: "While at this juncture it doesn't look like record highs are in jeopardy..."

Below, is the current point-click forecast centered on DTW Airport. Record highs for Saturday through Tuesday are: 96, 98, 95, and 97. Record high minima are: 75, 73, 74, and 74. So this forecast would imply a new record high on Monday, June 23, and record high minima on Sunday, Monday, and Tuesday (tie). So I don't agree with that conclusion. Clearly, records are in jeopardy or else the NWS forecast is out to lunch. And this is just one location. I'm sure other locations will be at or near record high temperatures as well.

unexpected convection and blow off cirrus will keep it in check....almost always does. It'll feel like summer,and the lighting bugs will prosper. Good stuff.

[roardog]

20 minutes ago, Harry Perry said:

Generally speaking from heat-waves in the past with dews that high, the temps seem to under-perform a bit around here. Be interesting to see if that will happen this time around, especially after this deluge. 

Yeah. If dewpoints really are in the mid 70s, I wouldn’t be surprised if we see a lot of low 90s for highs. Nights on the other hand are going to be awful. 

[A-L-E-K]

Time to start heating the lake up for late summer swimming 

[Baum]

11 hours ago, Baum said:

unexpected convection and blow off cirrus will keep it in check....almost always does. It'll feel like summer,and the lighting bugs will prosper. Good stuff.

on cue:A MIDDLE LEVEL SHORTWAVE WILL MOVE FROM THE DAKOTAS   
TOWARD LAKE SUPERIOR AND POTENTIALLY SEND A MCS WEST TO EAST   
JUST NORTH OF THE FORECAST AREA OVER WISCONSIN. WHILE BOTH   
SATURDAY AND SUNDAY ARE EXPECTED TO BE DRY, THERE IS STILL   
UNCERTAINTY ON THIS STORMS TRACK AND ITS INFLUENCE IN NORTHERN   
ILLINOIS. FOR NOW, IT WAS DECIDED NOT TO ISSUE ANY EXCESSIVE   
HEAT PRODUCTS FOR THE WEEKEND. -LOT

[A-L-E-K]

smart

[roardog]

8 minutes ago, Baum said:

on cue:A MIDDLE LEVEL SHORTWAVE WILL MOVE FROM THE DAKOTAS   
TOWARD LAKE SUPERIOR AND POTENTIALLY SEND A MCS WEST TO EAST   
JUST NORTH OF THE FORECAST AREA OVER WISCONSIN. WHILE BOTH   
SATURDAY AND SUNDAY ARE EXPECTED TO BE DRY, THERE IS STILL   
UNCERTAINTY ON THIS STORMS TRACK AND ITS INFLUENCE IN NORTHERN   
ILLINOIS. FOR NOW, IT WAS DECIDED NOT TO ISSUE ANY EXCESSIVE   
HEAT PRODUCTS FOR THE WEEKEND. -LOT

How many times have we seen a MCS two hundred miles to the north send a lake enhanced outflow down the lake causing a NE wind and big drop in temps? It happens over here with Lake Huron too. You guys should be in the clear from that by Sunday though. 

[Baum]

17 minutes ago, roardog said:

How many times have we seen a MCS two hundred miles to the north send a lake enhanced outflow down the lake causing a NE wind and big drop in temps? It happens over here with Lake Huron too. You guys should be in the clear from that by Sunday though. 

Left home several years back and it was near a 100 at home to see a concert at Ravinia on the lake 30 miles asway. Ended up buying sweatshirts in mid July for the wife and I. Brutal.

[luckyweather]

2 hours ago, A-L-E-K said:

Time to start heating the lake up for late summer swimming 

That blessed stretch where Oak St beach might as well be Waikiki.

[michsnowfreak]

15 hours ago, roardog said:

Yeah. If dewpoints really are in the mid 70s, I wouldn’t be surprised if we see a lot of low 90s for highs. Nights on the other hand are going to be awful. 

Dewpoints in the mid-70s would be choking. Obviously big heat is coming, but models have constantly overdone heat for us the past several years. I dont think we see highs in the mid to upper 90s with lows in the mid to upper 70s. I feel it goes one of two ways. Either we DO see highs in the mid to upper 90s but cool off to at least the low 70s at night, OR we stay in the mid to upper 70s at night but only warm to the low 90s due to the humidity. I can see maybe one day of, say, 96/76, but not 3.

[Frog Town]

5 hours ago, michsnowfreak said:

Dewpoints in the mid-70s would be choking. Obviously big heat is coming, but models have constantly overdone heat for us the past several years. I dont think we see highs in the mid to upper 90s with lows in the mid to upper 70s. I feel it goes one of two ways. Either we DO see highs in the mid to upper 90s but cool off to at least the low 70s at night, OR we stay in the mid to upper 70s at night but only warm to the low 90s due to the humidity. I can see maybe one day of, say, 96/76, but not 3.

I know you're a stats guy but this is consistent with what's happened the past few years with this set-up.  End's cooler vs. warmer.  

[roardog]

Another thing is when the dewpoints get that high, there’s usually a lot of cumulus development even with a capped atmosphere which also helps limit the highs. Some of the hottest actual temps I can remember come with dewpoints at or below 60. I think that also helps to limit the cumulus development leading to higher temps. It’s just really hard to get extreme highs with dewpoints well into the 70s. Just look at Florida all summer.

[A-L-E-K]

Headlines up

[Jackstraw]

95/75 nearly every day for 5 months is SE US living at it's finest lol. Then break out the giant tiger mosquitos that can drain a pint per bite. The old saying in South Calalacky if you ain't on the coast your toast lol.

Usually the first time it gets like that around here I go into a few days of therapy from having flashbacks causing heat trauma related PTSD 

 

[cyclone77]

Been in the 60s/70s out here in Washington with very low humidity.  The heat/humidity combo should be a great welcome back feature this weekend lol.