I just got back from a guided walking trip to high mountains. There was one day when we encountered a thunderstorm - and the guide advised we are OK to proceed with the day's walking, instead of turning round. He gave an explanation, and I wonder if you think it is reasonable?
The situation was as follows: the forecast said 'possibility of thunderstorms', for just-about all the foreseeable future. We set off from our overnight stay up the valley, heading for a high mountain pass. We then heard the thunderstorm coming, staying about 1.5-3 km (1-2 miles) away from us, as deduced from timing between lightning and thunder.
Now, the guide said he is happy to proceed up the valley and up to the col, because
he was monitoring the pressure (with a gauge in his GPS), and it was stable - indicating that the storm was going remain where it was, and not migrate / descend towards us.
Does that make sense?
More generally, the advice I have been given was that if you hear a thunderstorm, you unconditionally turn around and seek solid shelter (mountain hut etc.). Is that too conservative, and if so, what are the mitigating circumstances? I understand you are never 100% safe from lightning outside solid buildings.