Storm of June 24: Instantaneous 27°F Drop

[RhythmDoctor]

This is not earth shattering news, but might be interesting to some.

In the Philly area wehad an unusually strong storm come through last Thursday. I don't ever recall seeing storm clouds that were that black - it was like nighttime at 3:30 pm. In my town about a third of the houses lost power for over 24 hours. I went down to the boat to check on it, and the radio reported that Philly airport (directly adjacent to the marina) had 75 mph winds and hail.

I was curious to see how the barometer varied during the storm so I checked the NOAA site. Much more interesting was the temperature change, which I finally decided to capture today before it scrolled off their plot. Note the abrupt change from 98°F to 71°F:

I clicked around some of the other regions and nobody outside the Philly area had a temperature change that came close to this one.

[CharlieCobra]

I've seen that happen with cold front blowing through. It's really something when you're on the water...

[Allanbc]

I was kayaking on a Central Texas river when a strong cold front blew through. It passed really quickly and dropped the temperature quite a bit. After the front passed, it got really still and fog formed on the river. The top of the fog was right about the top of my head and very thick. We continued on through the fog and every now and then you had to rise up in the kayak and look over the fog. It was pretty strange. Fortunately, the wind started again before long and blew the fog away.

[RhythmDoctor]

Yes, I remember "blue northers" from the year that we lived in Plano. Especially scary was in winter when the roads would be wet and temps would hover around 33°F, and the front would come through and drop things suddenly below freezing. Black ice everywhere!

One interesting thing about this storm is it was not a cold front. You can see that after the sudden drop, the temp rose back to the mid-80s and then resumed its normal descent as the sun set.

Note also from this pic that the temp at 9 am was already 84°F - too hot to be sailing!

[sww914]

Montana is good for that. Their record is an 84 degree change in 12 hours. It went from 63 at noon to 21 below at midnight. It's really interesting.