Courtesy: Ft. Worth Star-Telegram Used with permission Today is the 40th anniversary of the crash at Delta 191 at DFW International Airport. The terrible crash killed 136. Twenty-five were injured; some of the injuries were horrific. The story begins with Dr. Ted Fujita examining the crashes of Ozark Flight 809 in St. Louis (1973) and Eastern Flight 66 at JFK in New York (1975). Ted published a paper in the journal Monthly Weather Review  (February, 1977) hypothesizing the existence of a "downburst" -- a previously undiscovered feature of thunderstorms -- that could cause extreme wind shear which in turn would cause planes to crash.  In the summer of 1978, Ted ran Project NIMROD and found a downburst via radar and measured its characteristics. A couple of weeks later, I was storm chasing with my friend meteorologist Steve Amburn and I was able to take a series of seven photos that -- for the first time -- showed what a downburst looked like and its life-cycle. One of the phot...

While very short, storm chaser Spike recorded a terrific time-lapse of a downburst's "curl" yesterday. You can view it here .  Here is one of a sequence of photos of a downburst I took in July, 1987 -- the first of its type ever taken.  A pronounced curl = a strong downburst = strong wind shear. If you are piloting an aircraft and you see one of these curls when readying to land to take off, please:  Curl Near the Ground? Go Around!! Addition: I was reminded this morning that today is the 36th anniversary of the downburst crash of Delta 191. Here is a posting I did on the 25th anniversary of that terrible event. The good news is that thanks to Dr. Ted Fujita, Dr. John McCarthy and others aviation weather was revolutionized and the downburst was conquered in the United States.  Addition #2: A spectacular downburst video is here . Look at the curl at lower left. Violent winds and wind shear occurred.