Awww darn, I was wrong. I thought the Potomac would keep the airport cooler.

How often does it happen that National is warmer than Dulles or BWI Marshall?

A thunderstorm blew up here, over Calverton, brief very heavy downpour, the wind really kicked up and we're still getting some thunder and lightning.

Q: How often does it happen that National is warmer than Dulles or BWI Marshall?

A: Quite often. As an example, if you look at May 2008, and compare the daily highs for Dulles (KIAD) and National (KDCA), you'll see the following:

KIAD KIAD = KDCA: 5 days same temp
KIAD > KDCA: 3 days warmer at Dulles

Why? Because National is inside the DC Urban Heat Island.

Q: How often does it happen that National is warmer than Dulles or BWI Marshall?

A: Quite often. As an example, if you look at May 2008, and compare the daily highs for Dulles (KIAD) and National (KDCA), you'll see the following:

* 23 cooler days at Dulles
* 5 days same temp
* 3 days warmer at Dulles

Why? Because National is inside the DC Urban Heat Island.

Thanks Craig...I always thought that DCA would be cooler than landlocked Dulles because of the water.

Pretty good storm here in Lake Ridge. Raining pretty hard. Thunder every 10 seconds or so. NO SEVERE WARNINGS. This is the kind of storm I like. :)

aaaaaaaand here comes round two, it's absolutely pouring down, the wind is gusting, not as much lightning and thunder this time.

Thunderstorm developed over eastern Loudoun at about 7:45 and moved across the river into NW Montgomery and suddenly expanded. Only got about .25 inches but there was frequent cloud to ground lightning which caused momentary power interruptions.

Just when I thought it was safe to do something else, comes a severe thunderstorm heading just to the north of me. It is raining hard and there is some thunder. I think I am going to unplug for a while.

lol, I had to go and say something.

Svr Tstorm warning until 1015. Severe storm located near Lake Ridge. Right over me. I thought I heard a little hail earlier but it was raining too hard to see anything. The lightning is spectacular, lemme tell you.

Well, after a week of SPECTACULAR (and terrifying) tornadic storms while I was home in Indiana, I'm still impressed by this one here. Constant lightning, satisfying thunder and decent rain.

Second time in a week, I hear!

Laura in NWDC...you have NO idea... ;)

So it's all your fault, weatherdude??

The storm is diminishing in intensity. Still lightning and thunder, with the volume of rain tapering off.

Yes, Laura, you have no idea. Compared to Wednesday, tonight's storms are a brief drizzle.

I take back what I said about the lightning and thunder, it's almost constant right now although the rain has diminished a lot.

Wow. Tons of cloud to ground lightning here... quite the fireworks show. And not even a severe thunderstorm warning issued.....

DCA was a blistering 90F at 9pm, so this should cool things down.

Yeah, it sounds like I didn't have to go all the way home to see a good storm this week. Figures!

I like this kind though...beautiful with no power outages. Good summer storm.

I'm appreciating how long this one is taking to pass through.

Cooled almost 10 degrees in one hour at DCA. Love the storms.

It might not be as bad as Wednesday but it's like shell shock. After awhile every storm makes you jumpy

I heard today at bar study that some locations have been trying to go forward without power. THAT must be interesting.

We have a severe thunderstorm rolling through right now with hail, heavy rain, and frequent cloud to ground lightning.

The fireworks at Celebrate Fairfax still went on. There was a double light show- lightning to the south and the fireworks.

A thunderstorm grazed by me to the west here over the past hour...it was far enough way that I went and stood outside with several neighbors to watch the lightening show.

Stupid thunderstorms. Thought we might see the first lightning bugs of the year tonight after a nice warm day. grr.

great lightning. one was right over my house and so loud!! now around 75 degrees. still have power.

West Springfield (Accotink Lk/Mixing Bowl) --> Storm total this evening 0.27" in a short period. Fun to watch...and about the temperature of my shower.

I don't know whether that's lightning or a giant strobe light that I'm seeing outside. The frequency of the bolts is astounding.

Arlington - Four Mile Run

No rain, no thunder, but quite a cloud-to-cloud lightning show for the last half hour. At it's peak it was like strobe lights going off several times a second.

Yep, the storms are miles and miles away and we're still hearing thunder every few seconds. I guess these storms are nature's way of resetting itself after nearly incinerating.

Monster lightning out here in Calvert County. Many trees down across the roads (again) but few without power thus far (well, a few thousand, but better then tornado day).

Storms are intense but short lived. Watching on radar they pop up and disappear within an hour or so.