Flash floods--how do the hills and valleys turn rain into a wall of water?

[marble falls]

?si=3vvxs3_lGxwYfPR1

[TnDem]

1. Flash floods

I saw it happen in East Tennessee once in the foothills of the Smoky Mountains/Cherokee national Forest...

The water moved so fast, your eyes couldn't follow it...I have never seen anything like it in my life.

[Warpy]

24. My first experience here in the desert

was when I first moved to the city and was driving next to a cement lined arroyo, saw a whole garden shed gping down.

I'd seen floods before back east, had walked old fllks out of their flooded houses (snakes and all), but I'd never seen anything like what we get here in the Rockies.

[ms liberty]

2. It's what happened in the Asheville area with Helene last year.

All the rain falling on the mountains and rushing downhill.

[yardwork]

3. On a smaller scale, I watched a city street flood in seconds.

I'll never forget it. Standing in a sandwich shop I watched a torrential downpour overwhelm the storm drains in less than a minute. Cars that had stopped at a red light before it started raining were flooded - water up to the windows - before the light changed.

I wouldn't have believed it if I hadn't seen it with my own eyes. Multiply this effect by miles...

[ITAL]

10. I sorta had that experience

Back when I was in college 25+ years ago, I was driving home from my job in the rain and I came to a 4 way stop. The street I was on sort of had a dip down to the intersection and the road that crossed it had a slight downhill. There was some water coming from my left as I started to cross, but even as I was going through the water came up a foot or two and I my car nearly stalled just in those 3-4 seconds. Thankfully I got up out of if it. The water never really got higher than that as I looked behind, but I was kinda shaken. I was just glad I hadn't been on the other road!

[marble falls]

20. That's when one needs to be very careful unclogging sewers and parking lot drains! When the water is at your ankles, ...

... get out!! We had to rescue a co-worker who got knocked down over the drain in our lot and it took three of us to pull up off the grate.

[yardwork]

23. That must have been terrifying.

Water is an incredible force.

[marble falls]

25. That was frightening. I know we hurt him getting him off his back, his face was under water most of the time ...

... cured me of clearing drains that late in the game.

[Brenda]

4. Climate Chaos Rain Bombs

They are happening in some of the most unexpected places.

I believe I read somewhere this morning that part of Texas received 28 inches of rain in 45 minutes.

Just insane how this catastrophic environmental ongoing disaster is happening on exponential levels.

[ananda]

8. This is what the Trump admin cannot deal with.

This disasters will accumulate faster and faster,
and they will literally be inundated with disasters.

Imagine that.

[Brenda]

11. Yep.

And yet...they are doing everything possible to make things WORSE. Cutting the experienced NWS meteorologists in that part of TX in April. Cutting all discussion of climate change on government sites. Cutting NOAA, etc. etc.

End timers may be more in control than we know.

[TnDem]

21. Flash flooding

has been happening for hundreds and hundreds of years.

[Brenda]

22. Oh, you.

Pay attention: flash flooding is not equal to rain bomb.

Are you denying these once in a century events and records for floods, heat, storms are happening on a weekly if not daily basis now?

Climate denier?

[TnDem]

26. Flash flooding most of the time...

Is just that...Flash flooding from a lot of rain in a short time in an area, (like the Texas hill country), that doesn't drain efficiently, nor fast enough.

Like I said, many years ago, i witnessed something like this near the Smoky Mountains....A TON of rain had fallen near the top of the mountain, and none at the bottom where we were. We were in a cabin way above the stream bed, but we heard a distant roar. In less than one minute, the entire tiny stream that had just had 10 inches of water in it, now had 15 FEET of raging water, boulders, tree trunks and everything else it could carry.

It was simply that, a FLASH flood that dumped three-four inches of rain on a near vertical surface several miles away from us.

[Brenda]

27. You are not telling the truth.

It was not simply a flash flood event. Yeah, we all know flash flooding has happened forever. These types of rain bombs, which refers to huge numbers like 28" rainfall in one area in 45 minutes, are happening in increasing numbers and severity all over the world. In America it happened last year in KY and this year in TN, FL and now TX.

To dismiss this as oh, it's just flash flooding is to deny the reality of how bad the climate instability is which is the same thing as putting your head in the sand and or purposefully misguiding people into thinking this is "somewhat" normal.

Hmmmm.

https://www.gza.com/insights/sheltering-storm-rain-bombs-and-developing-mitigation-approaches#:~:text=A%20rain%20bomb%20is%20usually,serious%20potential%20for%20doing%20damage.

There are many terms for this type of intense rainfall generated flooding, from urban flooding to cloudbursts to local intense precipitation. However, the most attention-grabbing phrase we’ve heard (albeit one that is not meteorologically recognized) is “rain bomb.”

A rain bomb is usually associated with the weather phenomenon known more properly as a “wet microburst.” This is a wet column of sinking air, or downdraft, associated with thunderstorms that have serious potential for doing damage. Other intense rainfall events have resulted from larger storms like hurricanes, or simply a series of storms along a stalled weather front that gets “stuck” over a certain area.

[TnDem]

28. So I am lying about what I saw then?

I literally saw it happen...I also lived in Central Florida for several years and went through multiple tropical systems..Tennessee has a high propensity for tornadic activity. I saw one of those in person and witnessed the devastation from several others. As a child growing up in Maryland. I went through Hurricane Agnes that inundated Maryland and PA fifty years ago.

I am not saying that climate change doesn't have anything to do with it. I AM saying that a lot of rain being dropped in a short period of time over any area that doesn't drain fast enough causes these issues like Texas Hill country have.

[Tetrachloride]

5. Flooding has occurred in the Old Testament

and science and TikTok and some baseball games.

in fact, water high and low.

Trump has not yet agreed to throw paper towels.

these are the facts.

[ms liberty]

9. DU'zy

"In fact, water high and low"

[yardwork]

12. In fact sometimes it's dry.

Snowball in Congress.

[snot]

6. Fwiw, ill-planned development can also contribute,

as large areas of the surface are paved over with roads, parking lots, warehouses, etc. – rain just runs off instead of being absorbed into the ground.

[cbabe]

7. My town knocked down an entire neighborhood of single family homes with gardens and put up blocks of six floor condos

The streets flood every rain.

[marble falls]

19. Here in Texas they take messing with "the natural flow" of water seriously, that development would have require to ...

... amend their plans before they even break ground.

[DFW]

13. Some thirty years ago, we visited Zion National Park

There was one very narrow gorge with very high walls and a path along one of them. We were warned never to walk far down that path. We asked why? The rangers said that the lightest of rainfall could cause a flash flood so sudden and so deep/high that anyone caught inside those walls was in danger of getting swept up in the violent flow and drowned before they knew there was any danger, and nothing could be done to save them. We heeded their warning.

[marble falls]

17. Not a good place to get caught!

[electricmonk]

14. As a geology nerd that is one of my favorite YouTube channels

In a comment on one of his videos someone called him the Bob Ross of geology. He's based in Asheville and went to Virginia Tech so he's made a lot of videos about my backyard in southwest Virginia including a mountain I practically grew up on, Sinking Creek Mountain in Craig County, Va.

[chowder66]

16. I just watched the video and it was fascinating. I also sent it to my nephew who is a geologist.

I love the Bob Ross reference!

[raccoon]

15. Dayum, that sounds like the area where I live. Upstate SC.

[marble falls]

18. Gotta pay attention to them cricks!