Flooding

[Robert]

Last weekend in West Virginia it rained 3 to 4 inches in areas with topographical features that automatically channeled the runoff into floodwaters.

Eight people have died from devastating flash flooding in West Virginia as the rain threat continues with the possibility of more rain on saturated land. A state of emergency is in effect in West Virginia.

https://abcnews.go.com/US/west-virgin...

[Robert]

In 2017 Trump rescinded flood protection rules.

'Everybody is baffled' by Trump rescinding flood-protection rules...
“As far as the rules go, that FEMA and HUD were working on, they’re kind of in limbo now. Chances are they’re not going to move forward because the executive order was revoked,” Scata said.

https://www.yahoo.com/news/everybody-...

In 2025 Trump has now canceled the funds for flood prevention efforts for areas that are repeatedly hit by flooding conditions.

Many of these areas have been doing work using their own funds in anticipation of finishing the projects with federal funds.

There is no scientific reason for the cancellations which are happening because Trump believes the funding is wasteful and climate change is a hoax. 60 percent of the cuts have happened in areas that voted for Trump. He believes the states should be responsible for providing disaster relief.

Many of the locations are experiencing flooding conditions 90 days out of the year.

https://marylandmatters.org/2025/05/2...

[Clare]

https://www.rte.ie/news/us/2025/0705/...

"The US National Weather Service declared a flash flood emergency for parts of Kerr County in south-central Texas Hill Country, about 105km northwest of San Antonio, following thunderstorms that dumped as much as a foot of rain.

Dalton Rice, city manager for Kerrville, the county seat, told reporters the extreme flooding struck before dawn with little or no warning, precluding authorities from issuing advance evacuation orders as the Guadalupe swiftly rose above major flood stage.

"This happened very quickly, over a very short period of time that could not be predicted, even with radar," Mr Rice said.

"This happened within less than a two-hour span."

State emergency management officials had warned as early as Thursday that west and central Texas faced heavy rains and flash flood threats "over the next couple days," citing National Weather Service forecasts ahead of the holiday weekend.
...
"Lieutenant Governor Patrick said the Guadalupe River had risen eight metre in 45 minutes as heavy showers soaked the region.

As of last night, emergency personnel had rescued or evacuated 237 people, including 167 by helicopter."

[Robert]

Almost impossible to predict. That's the problem with the weather now. Less than 2 hours to figure out what was going to happen. Part of that 2 hours was the beginning of the storm that started as they normally do. Part of the two hours was the flooding already starting.

That leaves a hour at most, in the dark, swirling, rapidly rising water in unexpected places. Compounding the problem is that when we are in one of those very loud, pounding rainstorms, we don't go outside to see what is happening.

The National Weather Service issues emergency flash flood warnings anywhere from a few hours to 6 hours for situations that rapidly develop. One hour was not enough time to do anything except to try to flee the scene any way possible as rapidly as possible.

[Clare]

The Texas story is extremely distressing, and obviously, the damage was exacerbated by the holiday when people were out enjoying the countryside. However, we're told that even houses were washed away, just the concrete platforms remaining.
The link contains casualty updates.

https://www.rte.ie/news/us/2025/0706/...

"Local officials said the extreme flooding struck before dawn on Friday with little or no warning, precluding authorities from issuing advance evacuation orders as the Guadalupe River swiftly rose above major flood stage in less than two hours.

Ms Noem said a "moderate" flood watch issued the previous day by the National Weather Service did not accurately predict the extreme rainfall and said the Trump administration was working to upgrade the system.

The administration has cut thousands of jobs from the National Weather Service's parent agency, the National Oceanic and Atmospheric Administration, leaving many weather offices understaffed, said former NOAA director Rick Spinrad.

He said he did not know if those staff cuts factored into the lack of advance warning for the extreme Texas flooding, but said they would inevitably degrade the agency's ability to deliver accurate and timely forecasts."

[Robert]

The government is not working to upgrade the system because they have already done that.

"The National Weather Service (NWS) has completed the upgrade of its entire weather radar network, including all 122 NEXRAD (Next Generation Radar) systems, and 37 additional NEXRAD systems owned by the FAA and Department of Defense, according to Meteorological Technology International. This signifies that 100% of the NWS's core radar network has been updated. The upgrade project, which took nearly a decade, involved replacing obsolete components and implementing new technology to improve the network's performance and reliability. "

The radar information can be very complicated and can require extensive knowledge and powerful computer programs to correctly interpret the data. New procedures are being introduced such as rainfall estimation, which can take more time to compute than the development of the storm allows.

The weather can turn deadly with very little warning. Sometimes, until it crosses a certain threshold it is impossible to know what is going to happen. The first sign of this is when catastrophic weather data seen in real time exceeds the expected projections.

People typically ignore flood warnings because they usually cover a wide area over which actually only a relatively small area is impacted. There were flash flood warnings for the Texas storm but they can't narrow down the area until they are actually seeing it happening.

We get flash flood warnings with some rain storms and no one does anything different from what we were doing. Evacuating an area alongside a river or a place where run off accumulates every time a flash flood warning is given isn't something people are going to do. It isn't practical and people aren't going to do it.

If the the severe weather continues to intensify and if the chances of experiencing severe weather becomes so commonplace that if you get a warning it goes from possibly expecting severe weather to chances are very good you will be getting severe weather, people will start paying attention.

Severe weather was forecast for my area and a very wide path of isolated destruction and power outages was experienced over an area of hundreds of square miles. 200 miles apart two cars were involved with falling trees, one twenty miles away, the car ran into a fallen tree on a parkway, the other, two people died after a tree fell on their car. Thousands were without power from falling tree branches that hit power lines on streets or where they connected to individual houses. Lots of houses were struck by falling trees from the high winds.

This damage was wide spread but happened almost randomly and hit some areas and skipped over other areas. I was within 5 miles of the destructive weather but over 5 hours, all I heard was a few gusts of wind, some very light rain, and a few claps of thunder.

For people who experienced damage from the storm, they needed to take shelter, and for people like me, who got nothing, and frequently get nothing, it was 5 hours of nothing happening. This was just another weather front passing through as they do just about every week. For everyone to quit doing what they are doing and sit it out in a secure place for few hours while it rains just isn't going to happen as long the severe damage occurs sporadically here and there.

If you can hear the severe damage being done or see the water rising that is a different story, but seeing it is the warning as it is happening. If you don't hear anything you assume nothing is happening.

One thing that can be done is to run simulations of different rainfall amounts for very small areas over different time periods, say from 1 hour to 24 hours. This would allow people to know what it takes for the area they are in to flood. This would require a lot of expensive computer time which isn't likely to be free.

There would be a report for each hour that would run through rainfall projections of 1 inch to 10 inches per hour, which approximates what we are seeing today. The number of reports would be 10 with 24 zeroes after it. It could be cut down to 1 to 5 inches over 6 hours to reduce computing time, which would make it 15,625 reports. Which is why it isn't done.

That would also need somewhat accurate estimates of the runoff capabilities of the ground. A hard packed or rocky area would flood faster than an area with good soil ad lots of plants. The runoff parameters would become moot after several inches of water had accumulated.

Sloping areas would flood slower than flat areas except as you approached the bottom of the slope the amount of runoff water would be adding up from everything coming down the slope. As the amount of rainfall per hour number increased the slope of the land would stop impeding the water from getting deep enough to flood.

The land also erodes away which deepens the flood channel and contains the water eventually. If the severe rainfall was falling over a wide enough area, the whole area would flood uniformly whether there was a river there or not.

https://www.weather.gov/news/241908-w...

[Clare]

Thanks, Robert, I'm so glad you were safe this time.

[Robert]

The rain in Texas was augmented by the remnants of Tropical Storm Barry which occurred June 28th, in Mexico, 600 miles away, and drifted over West Texas 6 days later.

It is very difficult to predict what the rain will do every time it rains, because sometimes it isn't clear until only hours, or less, before it rains.

One thing is emerging and that is that up to a week after a hurricane or tropical storm has happened, the atmosphere can be in a much more unstable state than normal. This atmospheric instability can be hundreds, up to a thousand miles away, where it changes a normal local weather disturbance into a major disaster. The locally severe weather that results can form in only hours but the original disturbance, tropical storm or hurricane, happened up to a week earlier.

A new warning rule could be formulated that if the remnants of a named disturbance are heading in a particular direction that there would be 2 weather predictions. One for what looks like what is going to happen, and a second warning that is based on the assumption that the remnants will amplify the original prediction making it much worse than it could be.

That way an enhanced warning could be made while the original prediction is still in place. Weather warnings err on the side of caution because if they included the maximum effects every time people would stop paying attention the weather forecasts. The enhanced warning would only be issued for areas in the path of named storm remnants that are expecting some kind of weather event. The enhanced warnings would expire after the remnants had gone by.

Using named storms as precursors for enhanced warnings insures that a minimum amount of water vapor is present in the atmosphere. Unnamed events could be included but a limit has to used or too many enhanced warnings would be broadcast.

[Clare]

I've read a request that sirens be provided in areas known to be prone to flash flooding. I don't think it would be all that expensive, and it would give even ten minutes of warning. There just isn't a way to put a price on so many lives.

[Robert]

The prospect of installing sirens came up several years ago. In 2016 Kerr County asked for money to upgrade their equipment. It asked for $1 million to build a flood warning system that would have upgraded 20 water gauge systems, added new water level sensors and posts, and created software and a website to distribute that information to the public in real-time.

The state of Texas turned down the request in 2017 and again in 2018, 2020 and 2023. In 2020 the alert system that is broadcast on phones was updated so that you didn't need to sign up to get the warnings.

Nearby Comal County, built a siren system to alert residents to floods. Approximate costs for the county for installing a siren system was $20,000–$50,000 for each individual siren, includes hardware + installation. This includes water depth gages in the river for each siren. 10–20 sirens would be needed with a total cost of $500,000 to $1 million total. The annual maintenance cost is $1,000–$2,000 per siren. Comal County got federal and state grants along with local funds to pay for the system.

The current population of Comal County is around 200,000 residents. It is strongly connected to San Antonio which feeds a population growth rate of 24 percent.

Kerr County has a population of around 55,000 with a growth rate of less than 1 percent. The residents of Kerr county wanted to upgrade the river flood gages but decided not to build a siren system and instead use a phone alert system and a website to distribute the warnings. For whatever reason, the plan was not approved by the state. To build an updated water gage and alarm system Kerr County would have had to raise city tax rates.

https://www.yahoo.com/news/texas-coun...

https://wordcc.com/area/flood-sirens/

[Clare]

https://www.rte.ie/news/us/2025/0709/...

"Footage shows the moment a house is swept away following flash flooding in New Mexico.

The floods were triggered by heavy monsoon rains in the southern US state, trapping dozens of people in homes and vehicles in and around the mountain resort village of Ruidoso.

The US National Weather Service said a section of the Rio Ruidoso river had reached a crest of 6.16 metres provisionally, and would be a record high if confirmed."

[Clare]

Robert wrote: "The prospect of installing sirens came up several years ago. In 2016 Kerr County asked for money to upgrade their equipment. It asked for $1 million to build a flood warning system that would have ..."

Thanks very much for the info. Maybe if AI is brought into the loop this kind of project will get cheaper.
I think the problem with a purely phone alert is that we do not all have our phones on all night, or they may be out of battery, or not near the person. The awareness of flood danger would have to be there in the first place, and if you think the river will flood tonight, why would you camp beside it?
I can foresee that people will not go to stay where there are no sirens, for the future, and such areas will lose the income that might have built the sirens. A grant from state level might be a better answer. Tourism money is spent within the state, on petrol, tolls, foods, attractions.

[Robert]

Texas Did Little to Brace for Floods despite Knowing Risks

Texas has identified more than $50 billion in flood control needs, but lawmakers have devoted just $1.4 billion to address them

Before lawmakers were willing to commit money to flood projects, they wanted to make sure that plans were written to address each river basin in the state.

Otherwise, there’s the risk that a project in one city would simply steer floodwaters to other communities, said state Sen. Charles Perry, who chairs the Senate Committee on Water, Agriculture and Rural Affairs.

Perry said he’s working on a bill that would allow some of the state water funds to flow toward emergency response equipment. Lawmakers considered a bill this spring that would’ve paid for warning sirens and other communications equipment, but they rejected it because of its cost.

https://www.scientificamerican.com/ar...

[Robert]

Cloudburst are becoming increasingly dangerous as the amount of water that comes down quickly has been increasing. For every 1 degree C the air warms up, it can hold up to 7 percent more moisture. The sudden deluge happens so quickly that current warning systems are having trouble getting people warned in time.

For India and Pakistan, the frequency of cloudbursts in these two South Asian nations has been steadily rising. The warming of the Indian Ocean and the mountain ranges force the cloudbursts over certain geographical areas.

"As many as 300 people died in one northwestern Pakistani district, Buner, after a cloudburst. The strength and volume of rain triggered flash flooding, landslides and mudflows. Boulders from steep slopes came crashing down with the water to flatten homes and reduce villages to rubble.

The northern Indian state of Uttarakhand had a cloudburst earlier this month. Local TV showed floodwaters surging down a mountain and crashing into Dharali, a Himalayan village."

https://apnews.com/article/cloudburst...

https://apnews.com/article/india-flas...

[Clare]

From what you are describing, it's not just that rivers rise during a cloudburst, but an instant river forms where there was none. Homes can be built to avoid known rises in river levels, but if a whole side of the mountain liquefies, nobody can get out of the way in time.

[Robert]

Sometimes there is very little warning. If you are not packed up and ready to go, and most people are not, it can be very difficult to get out of harms way. People can't treat every storm like it is going to be a huge disaster, there are way too many of them. Disaster fatigue would probably set in.

Depending on the distance you have to travel, sometimes the escape routes get cut off before you can leave the area.

Perhaps each house or a neighborhood needs a rain gauge that works similar to a smoke detector. Once a certain amount of rain in a certain amount of time has been detected, it alerts you to the situation. Sort of like a pre-alarm that tells you that there might be situation developing. Then you could pay more attention to official sources.