Catastrophic flooding in central Texas

Hi. It’s me again. Let’s talk about cloud seeding.
We’re all hurting over here in Texas after these floods. Children are still among the missing. The death toll is now over 100. We’re in various stages of grief and still trying to make sense of what just happened as we grapple with the reality that this flood has permanently altered the trajectory of so many family histories.
So why am I bringing up cloud seeding? Because I’ve seen the same viral videos and posts you have seen claiming that cloud seeding is responsible for the floods in the Texas Hill Country, and it’s inserting confusion and questions into a grieving community that really needs to be focused on other things at this time. Scientific voices in the meteorology community are needed right now to help put these claims to rest, so I will again lend my voice to help answer some of your questions and hopefully clear up some confusion.
What is cloud seeding?
Cloud seeding is a type of weather modification that involves injecting a few grams of a chemical (usually silver iodide) into an existing cloud to “seed” the formation of larger water droplets or ice crystals that will then cause the cloud to precipitate slightly more than it would have if left alone. We’ve been doing it in America since the 1940s, and the physics behind it is pretty simple.
How does it work?
Clouds are composed of tiny water droplets or ice crystals called hydrometeors (and that my friends, is where the word “METEORology” comes from!) that need even smaller microscopic particles called “cloud condensation nuclei” to form. These are things like specks of dust, salt, and smoke. When they are present in a moist airmass, that moisture can condense around those particles to create water droplets. Most clouds don’t rain or snow because the water droplets or ice crystals remain too small for gravity to pull them down to the earth. The silver iodide particles injected into clouds are significantly larger “cloud condensation nuclei” that happen to be really good at creating larger droplets or ice crystals that can fall to the ground.
What is the purpose of cloud seeding operations?
Generally these are designed to help enhance rainfall or snowpack in arid regions of the country that do not have dependable rainfall and are subject to droughts.
Is cloud seeding regulated?
Yes, there are both federal regulations and state regulations. It is not done in secret. You can read about federal regulations here library.noaa.gov/.../weather-modification-project... and you can read about Texas regulations here www.tdlr.texas.gov/weather/
Were cloud seeding operations conducted on the storms that produced the Texas floods?
No. In fact, Texas regulations prohibit cloud seeding on storms that could produce severe weather, tornadoes, or flash floods. One of the companies singled out on social media for cloud seeding conducted its last operation on Wednesday, July 2nd.
Could the cloud seeding conducted two days before the floods have created or impacted the storms on July 4th?
No. Only an existing cloud can be seeded, and once that cloud has been seeded, it rains itself out. Furthermore, the cloud seeding took place southeast of San Antonio, roughly 150 miles away from Kerr County.
Does cloud seeding create stronger “super storms” or lead to less rainfall elsewhere?
The science and observations say no. According to the Texas Department of Licensing and Regulation website, “There is no evidence that the seeding contributes to less rainfall anywhere else. What is more, there is no evidence that seeding causes clouds to grow substantially taller and produce unwanted effects (such as damaging winds, hail, and flash floods). To the contrary, the available evidence from over eight years of research in West Texas suggests cloud seeding, when done timely and accurately, contributes to more gentle, widespread, and longer-lasting rains.”
The TDLR FAQ section on cloud seeding is an excellent resource, and I highly recommend you read it if you would like explore this topic more: www.tdlr.texas.gov/weather/weatherfaq.htm
I also once again recommend watching this exceptional video primer from my weather friend ABC News Chief Meteorologist Ginger Zee: www.goodmorningamerica.com/video/116008822
Even though cloud seeding was not responsible for the Hill Country floods, I know there are moral and ethical concerns when it comes to modifying the weather (or any natural Earth system), however small those modifications may be, and the topic is worth more public discourse and scrutiny.
At the end of the day, this flood was caused by the remnants of two tropical weather systems that cannot be created nor controlled by mankind, despite claims to the contrary. I mean, look at this rainfall map. That's a year's worth of rain in some communities that fell in 5 days over a geographic area bigger than many states in our country. Does it make sense to you that dropping a few grams of silver iodide into a cloud 150 miles away from the hardest hit communities two days before the flood even occurred could have caused this?
It’s been said before that extraordinary claims you encounter can be true, but you should demand extraordinary evidence to back them up.
If you made it this far, congratulations. I hope it helped. Now let's focus on what really matters: Helping the grieving families and communities in their time of need.
Here are some ways you can help: abc13.com/17000575/h