Big Heat Week into July 4th Weekend

[dailylurker]

17 minutes ago, Interstate said:

STW???

Seems odd. None of the models show any storms anywhere. I guess the RRFS has storm and nws is hugging it. 

[Eskimo Joe]

Looks like MRB had some kind of equipment failure.

[pazzo83]

At my PWS it was 101/78 about an hour ago for a heat index of 118F.  Now it's 102.6/75.2 for a heat index of 117.3

[Eskimo Joe]

Just now, pazzo83 said:

At my PWS it was 101/78 about an hour ago for a heat index of 118F.  Now it's 102.6/74.5 for a heat index of 116.3

My Cooperative Observation site (RSTM2) is making a run to 99° for the second day in a row.

[stormy]

16 minutes ago, pazzo83 said:

98/70 at SHD is pretty brutal for them.

The NWS had predicted a high of 95.0 for me today.    Right now I am 98.9!

[snowfan]

6 minutes ago, stormy said:

The NWS had predicted a high of 95.0 for me today.    Right now I am 98.9!

Those darn shitty forecasters

[NorthArlington101]

I had to eat my words pretty hard off the jump… I really thought we hadn’t hit 100 since 2012.

Anyway, was out in the sun from 7-11am. Usually not a big deal, but that totally took me out. Just woke up from like a 3 hour recovery nap. Seriously draining.

[Hank Scorpio]

Maxed out at 100.2° which is good for the all time high on my station. I've only had it installed for two years, so not all that surprising. Officially hot though! 

[Kay]

There's a squirrel imby chilling on the ground, in the shade, sort of like a dog does in the heat. Bit of an odd sight. Must not care about being eaten by a fox atm, the ground coolness is all.  This must be getting a bit tough for some of the fur bearing wildlife. Reminds me to keep birdbaths full.

97/82

[pazzo83]

15 minutes ago, NorthArlington101 said:

I had to eat my words pretty hard off the jump… I really thought we hadn’t hit 100 since 2012.

Anyway, was out in the sun from 7-11am. Usually not a big deal, but that totally took me out. Just woke up from like a 3 hour recovery nap. Seriously draining.

we went to the pool for a bit (Katie Ledecky's childhood pool actually) - water temp had to have been 90+.  Wasn't really refreshing lol.

[Kay]

58 minutes ago, Interstate said:

STW???

Well damn.

Storms good. Power outage bad. VERY bad.

[yoda]

Uh what?  

VAZ053-054-505-506-526-527-050400-
Fairfax-Western Loudoun-Eastern Loudoun-Northwest Prince William-
Central and Southeast Prince William/Manassas/Manassas Park-
Arlington/Falls Church/Alexandria-
440 PM EDT Fri Jul 3 2026

...AIR QUALITY ALERT IS IN EFFECT FOR SATURDAY JULY 4 2026...

The Virginia Department of Environmental Quality has issued a
Code PURPLE Air Quality Alert Saturday for Northern Virginia.



For more information on ground-level ozone and fine particles
visit the web site Virginia DEQ air quality web site at
www.deq.virginia.gov

 

DCZ001-050400-
District of Columbia-
440 PM EDT Fri Jul 3 2026

...AIR QUALITY ALERT IS IN EFFECT FOR SATURDAY JULY 4 2026...

The Metropolitan Washington Council of Governments and District
Department of Environment has issued a Code PURPLE Air Quality
Alert Saturday for the District of Columbia.



For more information on ground-level ozone
and fine particles visit the web site
https://www.mwcog.org/environment/air/forecast/

 

[yoda]

MDZ013-504-506-050400-
Central and Southeast Montgomery-Central and Southeast Howard-
Prince Georges-
440 PM EDT Fri Jul 3 2026

...AIR QUALITY ALERT IS IN EFFECT FOR SATURDAY JULY 4 2026...

The Maryland Department of the Environment has issued a Code
RED Air Quality Alert Saturday for the Maryland suburban DC region.

A Code Red Air Quality Alert means that air pollution
concentrations within the region are unhealthy for the general
population. The effects of air pollution can be minimized by
avoiding strenuous activity or exercise outdoors.

For more information on ground-level ozone
and fine particles visit the web site
mde.maryland.gov/programs/air/AirQualityMonitoring/Pages/index.aspx

 

[nw baltimore wx]

Just now, yoda said:

Uh what?  

VAZ053-054-505-506-526-527-050400-
Fairfax-Western Loudoun-Eastern Loudoun-Northwest Prince William-
Central and Southeast Prince William/Manassas/Manassas Park-
Arlington/Falls Church/Alexandria-
440 PM EDT Fri Jul 3 2026

...AIR QUALITY ALERT IS IN EFFECT FOR SATURDAY JULY 4 2026...

The Virginia Department of Environmental Quality has issued a
Code PURPLE Air Quality Alert Saturday for Northern Virginia.



For more information on ground-level ozone and fine particles
visit the web site Virginia DEQ air quality web site at
www.deq.virginia.gov

 

DCZ001-050400-
District of Columbia-
440 PM EDT Fri Jul 3 2026

...AIR QUALITY ALERT IS IN EFFECT FOR SATURDAY JULY 4 2026...

The Metropolitan Washington Council of Governments and District
Department of Environment has issued a Code PURPLE Air Quality
Alert Saturday for the District of Columbia.



For more information on ground-level ozone
and fine particles visit the web site
https://www.mwcog.org/environment/air/forecast/

 

Just wait until after 850,000 fireworks go off.

[Eskimo Joe]

1 minute ago, yoda said:

Uh what?  

VAZ053-054-505-506-526-527-050400-
Fairfax-Western Loudoun-Eastern Loudoun-Northwest Prince William-
Central and Southeast Prince William/Manassas/Manassas Park-
Arlington/Falls Church/Alexandria-
440 PM EDT Fri Jul 3 2026

...AIR QUALITY ALERT IS IN EFFECT FOR SATURDAY JULY 4 2026...

The Virginia Department of Environmental Quality has issued a
Code PURPLE Air Quality Alert Saturday for Northern Virginia.



For more information on ground-level ozone and fine particles
visit the web site Virginia DEQ air quality web site at
www.deq.virginia.gov

 

DCZ001-050400-
District of Columbia-
440 PM EDT Fri Jul 3 2026

...AIR QUALITY ALERT IS IN EFFECT FOR SATURDAY JULY 4 2026...

The Metropolitan Washington Council of Governments and District
Department of Environment has issued a Code PURPLE Air Quality
Alert Saturday for the District of Columbia.



For more information on ground-level ozone
and fine particles visit the web site
https://www.mwcog.org/environment/air/forecast/

 

Fireworks. PM 2.5 gonna be lit tomorrow evening.

[yoda]

1 minute ago, Eskimo Joe said:

Fireworks. PM 2.5 gonna be lit tomorrow evening.

But they dont go off until way late

[nj2va]

High of 87. Currently 84/77

[Eskimo Joe]

26 minutes ago, yoda said:

But they dont go off until way late

Our AQ folks are concerned about the increased number of fireworks in DC combining with increasing pooling of low level moisture from convection. Combine that with the nocturnal boundary layer and it's a recipe for Code Purple inside the beltway.

[yoda]

Just now, Eskimo Joe said:

Our AQ folks are concerned about the increased number of fireworks in DC combining with increasing pooling of low level moisture from convection. Combine that with the nocturnal boundary layer and it's a recipe for Code Purple inside the beltway.

Okay, thank you for the explanation.  It just seemed weird to have it as an all day thing - but I guess you can't just say AQ will be code purple after 6pm, but before it will be orange 

[Eskimo Joe]

2 minutes ago, yoda said:

Okay, thank you for the explanation.  It just seemed weird to have it as an all day thing - but I guess you can't just say AQ will be code purple after 6pm, but before it will be orange 

We've also observed some pm 2.5 increases this evening from a variety of sources. It's almost like there's a little layer of this stuff sloshing around within the metros.

[nj2va]

1 hour ago, NorthArlington101 said:

I had to eat my words pretty hard off the jump… I really thought we hadn’t hit 100 since 2012.

Anyway, was out in the sun from 7-11am. Usually not a big deal, but that totally took me out. Just woke up from like a 3 hour recovery nap. Seriously draining.

Naps are my favorite hobby 

[Miss Pixee]

2 hours ago, pazzo83 said:

102/74/115 at DCA is just brutal.

The reputation is legendary. 

[snowfan]

I-97 in aa county buckled across the entire width of the road near Benfield Blvd. NB lanes closed.

[yoda]

4 minutes ago, snowfan said:

I-97 in aa county buckled across the entire width of the road near Benfield Blvd. NB lanes closed.

https://wtop.com/traffic/2026/07/portion-of-i-97-in-anne-arundel-co-buckles-under-extreme-heat/

But also

https://foxbaltimore.com/news/local/crash-investigation-shuts-down-northbound-i97-friday

 

[Terpeast]

Mby highs:

7/1 - 100
7/2 - 101
7/3 - 102 (101.5 rounded up)

[Eskimo Joe]

99.4° for a high in Reisterstown

[snowfan]

This is the station a stones throw from mby. MOG.

 

[Eskimo Joe]

20 minutes ago, snowfan said:

This is the station a stones throw from mby. MOG.

Looking at MD mesonet, AWOS/ASOS, and the reliably sited CWOP sites had made it clear the Chesapeake Bay added a few degrees to the humidity. It's always amusing to see some of the national mets look at our heat index and dewpoints in Maryland and go "no way".

[kgottwald]

IAD back down to 97. Guess we won't get triple digits today. 

And I don't see a single cloud out the window of Caboose Mosaic.