Tonight's Plane That Didn't Crash

One of the reasons weather science is not respected for its amazing accomplishments is because many are invisible. We may have had a big success earlier this evening. 

A thunderstorm developed near St. Louis' Lambert International Airport (KSTL for weather and aviation purposes) about 5:30 and drifted slowly south. It produced a series of downbursts -- which are highly dangerous to aircraft when landing and departing. 

Here's the success story: Nothing happened!

In 1973, a downburst caused the crash of an Ozark Airlines flight as it was on final approach to Lambert. There were 38 people killed. There was no system for warning pilots of these dangers. 

Two weeks ago, we commemorated the 40th anniversary of the awful crash of Delta Flight 191 at Dallas-Ft. Worth on August 2, 1985. The crash killed 137 with 20+ more injuries. Some of those injuries were horrific. The NTSB determined that the crew flew into the thunderstorm, knowing it was a thunderstorm (both FAA and Delta rules at the time forbad flying into thunderstorms). What they didn't know was the storm caused a powerful downburst. The L-1011 crashed well short of the runway. 

After the catastrophe in Dallas, the Federal Aviation Agency finally got in gear and installed Terminal Doppler Weather Radars at 44 high-risk airports, including St. Louis. That radar came in handy this evening. The white arrows are the wind direction near the ground. The gray indicates very light winds.

At 552pm, the downburst is affecting the north half of the airport (airport is circled).  

Five minutes later, with the southward movement of the storm, the line of wind shear extends across the airport (brown in the right panel). Wind speeds have increased considerably. 

At this point, absent a warning to pilots, there would have been a real chance of a wind shear crash. The wind was gusting to 58 mph. I believe that traffic was stopped as there were none of the pilot weather reports we would usually see in a situation like this. 

At 6:04, the strongest of the several downbursts pumped out by the thunderstorm was over the airport's runway complex. The FAA Doppler radar's wind data (below) shows the shear line over runway complex (look closely and you can see the runways). The radar is measuring a 65 mph gust over the northwest part of the airport. 

The winds began a weakening trend and here's what the radar wind data looked like at 6:22pm. There is no strong wind shear anywhere near the airport. 

At the same time, we received an in-flight pilot weather report (PIREP) from a landing Airbus A319 that reported "no wind shear" (below).

I suspect the tower requested the report. Traffic probably resumed in normal fashion in short order. No accident occurred!

The special Doppler radar, the special wind sensors surrounding the airport and the computer system to alert pilots and air traffic controllers evidently worked as designed. In Mexico, where they don't have all of the protective systems, a downburst downed an AeroMexico plane on takeoff in 2018. Fortunately, there were no fatalities. 

When a baseball player hits a home run in the 9th inning or a surgeon successfully completes an operation, everyone involved knows it. When Patrick Mahomes throws a touchdown pass to win the Super Bowl in overtime, the whole world knows. 

Not true with meteorologists' accomplishments. 

In this case, the pilots and air traffic control will not talk about it because of this silly fear of frightening the passengers (which is why you hear pilots describe "thunderstorms" as "a few light rain showers").

So, the systems that Ted Fujita, John McCarthy, Patrick Clyne and so many others devoted so much time and effort to paid off. But, very few outside of aviation know about it -- which is why I bring it up today. Thousands of lives around the world have been saved thanks to their work.