Heaviest isolated downpour I've experienced

We had a brief 15-20 min storm come through about 90 minutes ago. It dropped a legit 7" of rain in less than a half hour. 

That can was empty, I should've put something in it for scale of the depth, it was above mid shin. 

Wow, hope no one got washed out.

That's a pretty good one.  The kind you need the ZAV for. 

That's really amazing! I've only ever seen it rain like that here in Florida.

The Orlando Airport recorded 5 inches in 35 minutes one afternoon back in the seventies. I remember it well, because we were driving on the beach in New Smyrna where the runoff was about a foot deep. It was like driving in the surf.

That kind of rain from a summer shower is not at all unusual here. It just impressed me because I happened to hear the number. The only reason it was on the news is because of the fact that a family drove their car under an underpass, where they all drowned.

Still, 7 inches in 15 to 20 minutes? Outside of a tropical system, I'm not sure I've ever seen anything like that!

I’ve driven through one of those except it was an hour, the water coming down the streets at me was high enough that it was inside my trailer, branches were coming at me and nailing the truck, and the wipers on high did nothing.  Flash flooding was bad, i was the last one to make it through the intersection up the street before it turned 5 feet deep and the river my parents live on rose 14 feet in that time.  Water is scary.

Probably not as heavy, but lasted a lot longer:  I was in Costa Rica (Caribbean side).  It was so heavy I literally could only see a foot or so in front of me.  It was like standing in a gigantic shower.

Clearly some sort of gigantic thunderhead went through.

In reply to aircooled :

Great photo!

We're going to see a lot more of this kind of severe weather 

We had a storm system come through a couple of years ago that dumped 24" of rain in under 12 hours. It flooded the entire state and washed out a bunch of roads and bridges. 

I can't even imaging was 7" in under a half hour would be like. 

Here's an interesting tidbit. Heaviest recorded rainfall was in Maryland in 1956. They got 1.23" of rain in 60 seconds. That comes out to over 73" per hour! You might as well stand under a garden hose. 

We had a storm come through one morning last spring that dumped so much rain it flooded the highway & the lobby of the Hard Rock Casino. The Casino is what separates the highway from the gulf at that point & is about 5’ above sea level. There’s an open 2-lane drive perpendicular to the highway that runs between the casino lobby & garage, and terminates at the water’s edge. 

That means there’s a 2-lane unobstructed path from the highway to the sea, and the rain was still deep enough to flood the casino lobby. 

Unless I’m just more aware of weather in my older age, I don’t recall the volume of sudden pop up type storms like we’ve had the past few years.  

drainoil said:

Unless I’m just more aware of weather in my older age, I don’t recall the volume of sudden pop up type storms like we’ve had the past few years.  

I agree, it does seem like more to the rest of the country. They have always been pretty normal here in Florida.

Particularly since even the weather has been politicized now, I'm kinda a "Show me the study," guy. I still believe in science.

In reply to drainoil :

I don't know about where you are, but we are in the south and on the coast. We get violent popup thunderstorms on any given summer afternoon. Like yesterday. Lasted about 15 minutes and was gone. It's supposed to happen every day this week. I've enjoyed them since I was a kid. 

Floating Doc said:

drainoil said:

Unless I’m just more aware of weather in my older age, I don’t recall the volume of sudden pop up type storms like we’ve had the past few years.  

I agree, it does seem like more to the rest of the country. They have always been pretty normal here in Florida.

Particularly since even the weather has been politicized now, I'm kinda a "Show me the study," guy. I still believe in science.

I'll have to search for the data, but somewhere I have a few charts saved showing that rainfall is increasing in the Chicago area, and that it has been a significant uptick since the 70's. There are a few droughts that still happen, but like a baseball season you can't look at one at bat/game, you have to look at the bigger picture. The interesting thing to me is that the increase was almost all attributed to the summer rainfall figures; fall, winter, and spring precipitation didn't move much on the average. 

I didn't save the information for a climate change debate, just a "my information" stuff because I live in Chicago, but now I'm curious to compare Chicago to NY to STL to San Diego etc., and see if the same trend holds true. 

I stayed in Franz Josef, New Zealand in 2011. They get about 120" of rain a year, and from my couple days there it seems like it comes in buckets. One of the days it was clear and nice, people were going about their business. Then what looked like about a foot of rain fell in a half hour. Then as soon as it cleared up, everyone went back about their business. It was nuts - a storm like that would have shut parts of our city down for at least a few hours or a day while the storm drains dealt with the flow. They're so used to it, everything's built up having planned for it. The water was just gone. It helps, I'm sure, that they're in a mountainous area so they can just dump it down the side of the mountain. But I was impressed.

What if the rain fell in one drop?

XKCD What If?

In reply to dculberson :

I was going by memory with the 120" of rain annually thing. Turns out it's more like 160" of rain. Just an enormous amount. Seattle, by comparison, has about 37 inches of rain annually.

In reply to 11110000 :

I really hate vox, but they did make this awesome infographic after Harvey making it look like one raindrop

We had some pretty crazy storms here in Georgia on Saturday night - first time I've seen golf ball sized hail in person. Of course, heavy thunderstorms are about par for the course in Georgia, and I've often heard reports of golf ball sized hail here, but this is the first time I've had it fall on my house. Luckily, no injuries, although I haven't checked to be sure all the shingles are still on the house.

We had one last weekend.  I was actually working on the computer in the living room when it started just DUMPING rain.  The road flooded, the downspouts where pouring out water and I was afraid the basement was going to flood.  The super weird thing was that the sky never got dark in the least.  It lasted 15 to 20 minutes then quit almost instantly.  All of the sudden, my wife starts laughing, says "you have to see this" and shows me the historical weather radar on her weather app.  She had zoomed into our location and played the radar history for the last half hour.  A "pop up" thunderstorm appeared over our house, went from yellow to orange to purple, then disappeared all within about 20 minutes and all without ever moving.  The whole storm never got bigger than about a mile in diameter, hence the lack of an overall dark sky.  Never seen anything like it.