Why spotters die
The risk record, the one tornado that ever killed storm chasers, and why experience did not save the most experienced people in the field.
The ranking, and why it surprises people
Ask a new spotter what is most likely to hurt them and they will say the tornado. The evidence says otherwise, and the ordering is the single most useful thing in this module.
Flooding and hail have killed spotters in vehicles, which is really the first row again. Module 6 lesson 4 covers why flood deaths are overwhelmingly vehicle deaths.
El Reno, 31 May 2013
The one event that has to be taught, because it is the only tornado that has ever killed storm chasers and because the people it killed were not careless.
The last two rows are not a contradiction. The Enhanced Fujita scaleThe scale that estimates wind speed backwards from damage, using 28 damage indicators each with its own degrees of damage. It rates damage; it does not measure wind. rates damage, and NWS Norman stated that surveyors could not find damage supporting a higher rating. Official ratings do not use radar winds. Module 5 lesson 6 explains why.
The tornado was Hidden inside the precipitation around it. A rain-wrapped tornado breaks none of the identification rules; it just denies you the observation those rules rely on., its forward speed accelerated from around 35 to over 50 miles an hour, and it turned sharply left. Sub-vortices inside it moved far faster than the parent circulation, which is the mechanism the research afterwards identified as what caught the vehicles.
Three of those four were the TWISTEX research team: Tim Samaras, his son Paul Samaras, and Carl Young. A local resident, Richard Henderson, was killed in a separate vehicle. Tim Samaras was among the most experienced and most safety-conscious people working in the field, and had spent a career arguing for caution.
Roads kill in ordinary weather too
The other case worth knowing is the one with no storm in it. On 28 March 2017 near Spur, Texas, three chasers were killed when one vehicle ran a stop sign and struck another. Texas DPS confirmed inclement weather was not a direct cause, and one driver was not wearing a seatbelt.
A stop sign. That is the whole lesson of the next lesson, arriving early: the dangerous part of a spotting trip is usually the driving, and the driving is dangerous in the completely ordinary ways driving is always dangerous, made worse by distraction, fatigue and wet roads.
The distance question
Every risk in this module scales with how close you are and how much you are moving. So it is worth saying plainly what a report actually needs, because the answer is less than people assume.
You are planning to spot a severe weather event this afternoon. Statistically, what is most likely to injure or kill you?
One tornado in the entire record has killed storm chasers. Ask what the other cases have in common.The vehicle, by a wide margin, and it is not close. The NWS Service Assessment found all eight direct fatalities at El Reno were in vehicles, and the other well-known chaser fatality event involved a stop sign and no severe weather at all. Lightning is second. The tornado is third and the gap is large.