The car is the hazard
The behaviours that produce spotter crashes, the two-person rule that prevents most of them, and why fatigue is a weather hazard.
What actually goes wrong
The NWS mobile spotter guidance, written from an essay by Chuck Doswell, is blunt that the highway is threat number one, and the list of behaviours is unglamorous. Every one of them is something an ordinary competent driver does when their attention is on the sky.
- Driving with less than full attention. Watching the storm, watching radar, talking on a net. The road gets whatever is left.
- Speed, usually to keep up with a storm or get ahead of it. The storm is not going to wait, and it is not worth it.
- Rain and hail covered roads. Hail on tarmac behaves like ball bearings, and standing water hydroplanes at speeds well below the limit.
- Sudden stops, because something appeared in the sky, taken by somebody who forgot there was a vehicle behind them.
Stopping
Almost every good observation happens stationary, so how you stop matters more than how you drive.
- Never stop in the roadway. Not in a lane, not partly in one, not on a bend, not over a The highest level a river reaches in an event, and the time it reaches it. On large catchments the crest routinely arrives a day or more after the rain has stopped, and well downstream of where it fell.. Hazard lights do not make a stopped vehicle safe; they make it a visible obstruction.
- Get fully off the right of way, all four wheels, clear of the white line with room to spare.
- Confirm it is legal. Interstate shoulders are for emergencies in most states, and module 11 covers the law properly.
- Look at the shoulder before you commit to it. Soft ground, a ditch, a culvert or a drop-off will take your vehicle out of service in exactly the conditions where you need it.
- Look before you open the door, and get out on the side away from traffic if there is any traffic at all.
Two people, two jobs
This is the single highest-value countermeasure in the module and it costs nothing but a passenger.
- The driver
- Drives. That is the entire job. Does not look at radar, does not type, does not work a net, does not take photographs. If the driver needs to see something, the vehicle stops first.
- The navigator
- Everything else. Radar, maps, the escape route, the net, the report, the clock. Also has the authority to say the words "we are leaving", which matters more than any of the rest of it.
Which gives the hard rule this platform works to: a report is never composed while driving. Not typed, not dictated into a form, not photographed. Module 7 said the report carries the time the event happened rather than the time you sent it, and that is precisely what makes it safe to stop first and send afterwards. The time stamp does not degrade while you find somewhere to pull off.
Fuel, and other boring things that end trips
- Top up before half a tank, not when the light comes on. Stations close, and after a damaging storm they lose power and cannot pump at all. Half a tank is your reserve to drive out of an area.
- Tyres, including the spare, and something to change it with. Debris on the road after a storm is mostly nails, glass and wire.
- Wipers and lights that actually work. Replace wipers before the season, not during the storm that revealed they were finished.
Crowds
Where spotters and chasers converge on one storm, the road network stops working. This is documented rather than theoretical: the Service Assessment for El Reno found that a mass evacuation by car led to traffic jams and accidents that day. A blocked road is a blocked escape route, and it blocks emergency vehicles trying to reach people the storm has already hit.
Fatigue is a weather hazard
Severe weather happens in the late afternoon and overnight, after a working day, and the drive home is the most dangerous part of the outing. OSHA, citing the sleep science literature, puts the impairment from being awake 17 hours at roughly the equivalent of a 0.05 blood alcohol concentration, and 24 hours at about 0.10.
So the last decision of the night is a real decision, not an afterthought: can I drive home, or should I stop? Nobody has ever regretted sleeping in a car park for two hours.
You are alone, driving, and you see a wall cloud with clear rotation. What do you do first?
One of these takes about forty extra seconds. Module 7 explains why those seconds cost the report nothing.Stop first, always, and alone that is not negotiable because you are already doing two jobs. The report carries the time the event happened rather than the time you sent it, so pulling over costs the report nothing at all. Voice reporting while driving is still reporting while driving.