The Met Office and lightning

Courtesy of the UKMO

The yellow thunderstorm warning issued yesterday to cover Monday and Tuesday by the UKMO, has now been tweaked again and extended to cover Wednesday next week. I am not sure what the point of most of the warnings they issue is, but this one seems even more pointless, they will occur somewhere in the UK during these three days, we don’t know where and we don’t know when. Here are some useful pointers from the Met Office about what to do in the event that you are caught out by one of them, rather surprisingly it says nothing about sheltering under a tree, but does warn that you should squat rather that to lie on the ground.


Before the thunderstorm

  • Lightning can cause power surges, unplug any non-essential appliances if not already using a surge protector.
  • Seek shelter if possible. When you hear thunder you are already within range of where the next ground flash may occur, lightning can strike as far as 10 miles away from the centre of a storm.

During the thunderstorm

  • Telephone lines can conduct electricity so try to avoid using the landline, unless in an emergency
  • If outside avoid water and find a low-lying open place that is a safe distance from trees, poles or metal objects
  • Avoid activities such as golf, rod fishing or boating on a lake
  • Be aware of metal objects that can conduct or attract lightning, including golf clubs, golf buggies, fishing rods, umbrellas, motorbikes, bicycles, wheelchairs, mobility scooters, pushchairs, wire fencing and rails. If you are in a tent, try to stay away from the metal poles
  • If you find yourself in an exposed location it may be advisable to squat close to the ground, with hands on knees and with head tucked between them. Try to touch as little of the ground with your body as possible, do not lie down on the ground
  • If you feel your hair stand on end, drop to the above position immediately

After the thunderstorm

  • Avoid downed power lines or broken cables
  • If someone is struck by lightning, they often suffer severe burns. The strike also affects the heart, so check if they have a pulse.

Driving in a thunderstorm

If you are caught out in thunder and lightning it is advised that you wind up the windows and stay inside your car. This is because in the vast majority of cars with a metal roof and frame, the frame will act as a conductive Faraday cage, passing the current around the passengers inside and on to the ground.

  • Soft-top convertibles, with their fabric roofs, are the most at risk and could catch fire if struck by lightning
  • Be aware that current can travel through other parts of many modern cars, including GPS and radio systems. Cars with metal interior handles, foot pedals and steering wheels can also carry current
  • Cars can be damaged both internally and externally by lightning strikes

Thunderstorms can also bring a risk of sudden gusty winds, those most at risk would include cyclists, motorcyclists and high sided vehicles.

  • Remember to give vulnerable road users including cyclists, motorcyclists and pedestrians more room than usual. They are more likely to be blown around by side winds – always keep a safe distance.
  • Keep your speed down, lowering your speed will lower the distance you travel when buffeted around by the wind.

Hail storms can be extremely dangerous to drive in reducing your ability to see and be seen, as well as causing damage to your vehicle. If hail is severe, stop and pull over to a safe place and remain inside the vehicle


A care less national weather service

I would have thought that if the Met Office were truly concerned about the safety of the public in the UK during thundery weather they would display a real time interactive map of where the latest lightning flashes were occuring on their website just like Blitzortung and who put the Met Office to shame.

I do realise that the Met Office do have a map to display SFERICs on a map, it’s well hidden on their website and it doesn’t feature in their smart app, but crucially unlike Blitzortung it’s only updated every five minutes and not in real time. It would take very little work to incorporate a lightning display into their smart app, which could then alert you as soon as lightning were detected in a 5 mile radius of your postcode – hands up if you think I’m asking too much of our national weather service.

If the Met Office can’t be bothered to provide this service then they should at least free up the one minute data they jealously guard from their ATD system so that others can. But I suppose until that happens we’ll just have to put up with current system they use to warn of thunderstorms and lightning, and don’t get me going on why the warnings always seem to be yellow and never amber or red!

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