The Texas Flooding Tragedy: Could It Have Been Avoided?

On Friday morning, heavy rains led to catastrophic flooding along the Guadalupe River in central Texas.  

Tragically, it appears that at least fifty people lost their lives.  

But what is particularly disturbing is that the National Weather Service (NWS) provided excellent warnings and forecasts before the event that clearly predicted a substantial threat.  

And yet, no attempt at evacuation was made.

Furthermore, weather model forecasts indicated the potential for a major precipitation event over this historically flood-prone region during the prior days.

The Event

The flooding occurred around 4 AM on July 4. 

A heavy precipitation event was forecast for the region during the previous days.  For example, the NOAA/NWS HRRR forecast from 8 PM July 3 (the evening before) predicted a band of heavy rain over central Texas.

THE DAY BEFORE, the NWS Forecast Office in San Antonia put out a flood watch for central Texas Hill Country, which included the site of the tragedy.  

During the subsequent hours, the National Weather Service communicated increasingly strong warnings, including flash flood warnings.    A children's camp on a floodplain should have been evacuated.

Here is the warning by the local NWS office several hours before the flood. 

Also consider the warning by the National Weather Service Weather Prediction Center (WPC) before the event:

As the event got closer, with National Weather Service radar showing the event unfolding,  the San Antonia office made the threat explicit, noting a very dangerous flash event.

Any media or other organization suggesting that the National Weather Service was not on top of this event is not only not telling the truth, but doing a deep disservice to the highly professional and skillful folks in that organization.

Some folks are making such suggestions for patently political reasons.  Extraordinarily unethical and wrong.

Areas along the Guadalupe River have flooded catastrophically many times in the past, and not evacuating low-lying areas with such warnings verges on criminal neglect.  The local county (Kerr) does not even have a flood warning system in place. 

The Texas flooding is another example of large numbers of deaths, even when weather forecasts are excellent, with all too many other examples, including the Maui wildfires, the LA wildfires, and flooding from Hurricane Helene. 

But if you really want to experience media and advocacy group loss of moral compass, consider those claiming this event is the result of global warming.

For example, this connection was suggested by the New York Times:

There is NO EVIDENCE that the central Texas floods are the result of climate change.

For example, the Environmental Protection Agency has noted that flooding is DECLINING over time in that region (see below)

I examined this issue myself.  Below is a plot of the extreme daily precipitation in July for nearby San Antonio from the 1940s to today.  

There is NO upward trend, which suggests that climate change is not a factor in this event. 

If climate change was significant, there WOULD be an upward trend.

In summary, society needs to learn how to effectively use the greatly improved prediction and observational capabilities that now exist.

Most weather-related deaths can be prevented if society makes use of this valuable information.

Those using disasters to support their political and social change agendas are not only hurting those they wish to help, but acting in a morally and ethically indefensible way.

July 4 Weather and Fire Threat

 July Fourth is the most wildfire-prone day of the year, with a massive number of human ignition sources spread across the region.  So please be careful.

Today, Washington will be relatively dry, but eastern Oregon will have some natural fireworks from several thunderstorms.

The current (Friday at 8 AM) radar image shows the rain from the thunderstorms over Oregon (below).

With the lightning strike map at 8 AM indicating a number of strikes at that time (red crosses)

The UW WRF model predicts that the main shower area will move to northern Oregon and Idaho by mid-afternoon.

Why showers over Oregon?  Because of an upper-level trough/low pressure moving through southern Oregon and northern California.

The biggest wildfire threat today is from fireworks igniting dry grass and light vegetation. 

 Below is the map (from USDA Fuelcast) of dry fuel amounts over the region. Plenty of fuel over eastern Washington and Oregon.

And, in fact, there are some grass fires burning now, such as the Apple Acres fire near Wenatchee and the Cold Springs fire south of the Tri-Cities. 

The biggest threat will be where there are both strong winds and dry fuels.   

Below are the forecast surface winds around 8 PM tonight.  As expected, the strongest winds are on the eastern slopes of the Cascades, descending into eastern Washington and Oregon.  

This is where folks will have to be very, very careful

Another threat is from lightning-initiated fires over eastern Oregon, something that happened last year.

In short, be careful today and enjoy the 4th.

Mountain Wave Fest East of the Cascade Crest

 Those living in eastern Washington had quite a treat this afternoon and early evening as an impressive show of mountain wave clouds extended over large portions of the region.

Some of the new wildfire cams really displayed the ethereal beauty of the wave clouds (see below).

Below is a nice visible image this afternoon, with lots of mountain wave clouds downstream of the Cascades.

The wave clouds (also called lenticular clouds) are the result of the greatly increased westerly (from the west) winds that developed last night.  Air from the Pacific was pushed up over the Cascade crest and then oscillated up and down downstream of the terrain (see schematic below).

When the air ascended, clouds formed.

The increased flow over and down the Cascades had another major impact: a major increase in wind energy from eastern Washington (green line below).  Ironically, wind energy is very poor around here when we really need it...during the middle of heat waves. 

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Warming and Then Much Cooler for July 4

Time for the July 4th forecast, and we are close enough that skill should be good.  

The bottom line:  current warming (caused by high pressure aloft) will be followed by a cool-down as an upper-level trough approaches.

This morning, the Northwest was clear except for the typical June low clouds along the coast:

During the next 48 hours, a transient upper-level ridge will be positioned over southwest Canada, allowing temperatures to rise into the 80s in western Washington and mid to upper 90s over eastern Washington (see upper level map, 500 hPa, around 18,000 ft today).

The high temperatures as of 4 PM today (Monday) are shown below.  50s and 60s on the coast, 80s over the Puget Sound lowland, and 90s in the Willamette Valley. Toasty east of the Cascades.

Tomorrow will be similar.   But then the situation will change significantly as a complex collection of low-pressure troughs approaches the region (see the upper level map at 11 PM Thursday) as the ridge of high pressure moves eastward.

Consider the forecast temperatures for Seattle (below).   Lower 80s on Tuesday, followed by a decline into the mid to lower 70s.

In the Tri-Cities, temperatures near 100F will decline into the "cool" upper 80s.

The normal high for Seattle right now is about 74F and for the Tri-Cities about 88F.   So a return to near normal conditions by the end of the week...nearly perfect weather.

What about precipitation?

The predicted ten-day total is shown below.  Precipitation over northern BC, Idaho, and Montanta.  Eastern Oregon gets a few showers.  But nothing really over Washington.

Strangly enough, this has a silver lining:  no forecasts of thunderstorms over WA state, which means fewer fire starts.

Which is a reminder to be careful with fireworks...or avoid them completely.

Will Fewer Balloon Weather Observations Mean Reduced Forecast Skill?

 Due to retirements and hiring suspensions, the number of launches of balloon-launched weather balloons (called radiosondes) has been reduced by about 10% in the U.S.  

Specifically, of the 92 U.S. radiosonde locations, about ten have reduced launches either totally or partially.

Several media sources have suggested this reduction could seriously degrade U.S. weather prediction (see samples below).   

But is this true?   As discussed below, there are several reasons to expect that the impacts will be very small, not the least because balloon-launched weather observations now play a much, much smaller role in the modern observing network.

Why upper air data matters

The atmosphere is fully three-dimensional, and predicting the weather requires understanding the 3D distribution of temperature, wind, and humidity.

Such three-dimensional data is the starting point of the key technology of weather forecasting: numerical weather prediction (NWP), in which meteorologists simulate the evolution of the atmosphere by solving the equations describing atmospheric physics on the largest computers available.

Such forecasts start with a three-dimensional description of the atmosphere, called the initialization.

During the early years of NWP (1950-1970), radiosondes were the only source of weather information above the surface.  Absolutely critical.

The number of radiosondes has declined modestly over the years, with the current global network shown below.  

Lots over the U.S., Europe, and Southeast Asia.  You will notice a major issue with the radiosonde distribution:  there are few over the oceans and the polar regions, which encompass about 70% of the planet!

The current U.S. radiosonde network is displayed below, with red circles indicating radiosonde sites that are either suspended or only launched once per day.  Keep in mind that at most sites, these observations are only made twice per day.

Is there any objective evidence that forecasts have declined with fewer U.S. radiosonde observations?

As far as I can tell, the answer is no.  

I have gone through all the objective verification scores and could not find any degradation in National Weather Service forecast skill.  For example, the 5-day precipitation scores over the U.S. in March 2025 are better than March 2024.

I could show you a dozen more like this.  

But we have to be careful here.  Perhaps 2025 was an easier year to forecast.  

To do this right, we need to do OSSEs...observing system simulation experiments... in which we run identical periods we different amounts of radiosonde data.

However, there are powerful arguments about why the radiosondes are no longer as important to weather prediction, and particularly whether the temporary loss of a few of them would make much of a difference.

Today, three-dimensional satellite observations are dominant--in fact, approximately 99% of the weather data used today in numerical weather prediction is from satellites.    For example, we can determine the winds by tracking features in the infrared part of the spectrum.

 Or we can use satellites to measure how humidity varies with height.

Other satellites measure temperature and humidity with height by noting how GPS signals are bent by the Earth's atmosphere.

I have hardly warmed up.  There are dozens of other examples of how satellites provide detailed, three-dimensional weather data over the entire planet...over most of which there are no radiosondes.

But there is more.   Many aircraft take continuous observations in flight and provide vertical profiles of the atmosphere (called soundings) are they take off and land at airports (see below).   Such soundings are very much like the radiosonde data, but are taken at more locations and at more times.

The bottom line of all this is that balloon-launched weather instruments (radiosondes) are now only a very, very small proportion of the atmospheric weather data used by meteorologists for weather prediction.   

As a result, a loss of a few observations over a portion of one country probably has very little impact.

Thus, the headlines of gloom and doom are probably wrong.    

Let me be clear....I think we should restore the U.S. radiosonde network and then complete careful experiments to determine how many of them are really needed for calibrating the satellite data and other uses.  From what I have learned, restoration of the missing radiosondes will occur over the next few months, with the National Weather Service now hiring again.

Below-Normal Wildfire Year so Far

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Even with a relatively dry spring,  cumulative wildfire acreage in Washington State is currently below normal.  

You read that right, below normal.

Interestingly, the dry condition may have even contributed to the modest wildfire totals so far this year.

To start, consider the Washington State Department of Natural Resources (DNR) acres burned statistics for Washington State (below).  This year is very low...the second lowest since 2015.

Currently, there are only two significant wildfires burning in Washington right now, and both are relatively small:  the Pomas and Barstow Road fires (see map below).

While the wildfire season has been restrained so far, spring precipitation has been below normal, and temperatures have been above normal (see plots below).  

Western Washington has been particularly dry, with the Columbia basin modestly below normal.

So, how could the wildfire area be less with warmer and drier conditions?

Because wildfire generation is more complicated than communicated in the media, such as the Seattle Times.

To get a wildfire, you need ignition, sufficient fuels, dry fuels, and supportive meteorological conditions, with wind being the most important.

Precipitation during late winter and spring is important for producing bountiful light fuels, such as grasses and range-type vegetation.

Rainfall deficit has resulted in normal to lower than normal amounts of annual vegetation over much of the region, something shown by the USDA Fuelcast site (see graphic below).

Last weekend, I explored the situation in the hills north of Teanaway, WA on the eastern side of the Cascades.  Grass productivity was less than I have seen in recent years, and much of it was still green in forested areas (see pictures below).

So we start with a light to normal fuel load over much of the region.

What about ignitions?  

 Many utility companies are stating they will be more aggressive with strategic power shut-offs, which should help.   But what about lightning-initiated fires, which are often in remote areas and difficult to extinguish?

The extended precipitation forecast this summer is for drier than normal conditions (see below).  Since thunderstorms are the big precipitation producers for much of the summer (particularly east of the Cascade crest), this implies fewer thunderstorms.

Which means fewer lightning starts and fewer ignitions.  This implies less wildfire activity.

August and September are generally our big wildfire months.   The European Center's prediction of precipitation anomaly (difference from normal) is near normal for August (except north of the border) and perhaps wetter than normal over western Washington in September (see below).   Not very threatening.

All in all, I don't think there is much reason to expect an above-normal wildfire season over Washington, even with the teeth gnashing in a certain local paper.

David Horsey, Seattle Times