I am in the Western Balkans, where in some weeks you can hear the rumbling of thunder every night, and it is sometimes difficult to predict how close the storm will come to you for the purposes of camping.
The night before last I survived a windy storm in my two-season Lanshan 2 tent. The lightning was very frequent, sometimes several times per minute, for most likely over an hour. The rain was extremely heavy, and sometimes seemed to be raining sideways (but fortunately didn't develop into hail). One of my trekking poles fell over, so that the tent partially collapsed. I decided to pull the part of the tent that collapsed down with my hand instead of holding it up (to give my tent a smaller profile in the wind, kind of like what the Lanshan 1 has, and hopefully disrupt the airflow), and I felt the wind sucking that part of the tent upwards so strongly (causing that side to billow outwards from my hand in a doughnut shape) that I was constantly worrying that the whole tent could get pulled upwards into the air with me in it. If the earth had been less sticky I believe the wind would have pulled out some pegs (as it was it only undid a knot in a guyline, causing it to come loose, and stretched my tent's silnylon fabric). The whole tent was flapping in and out by up to 50cm for an hour, and this felt like the closest thing to a violent storm in two months of trekking the Balkans.
I have already been out camping in an electric storm during a severe weather warning before in a forest in a steep valley, but this time was much, much worse due to the wind. This time I was on a grassy plain (Obstina Zabljak in Montenegro, which a relatively flat basin surrounded by hills and mountains), which is getting very warm during the day (perhaps warmer than the mountains, resulting in higher air density over the mountains than the plain by evening, ripe for it to rush down the slopes during a storm?). Is a flat grassy basin which is fully or partially surrounded by hills/mountains at risk of higher winds during a storm, in the same way that a sea of coastline adjacent to mountains might be subject to unusually strong katabatic winds (eg the Bora on the Montenegrin coastline)?
Is an area of younger trees in a forest (small enough not to attract lightning or cause injury if their branches fall on you) safer during a storm due to the wind protection?
Me and two passing bikepackers agreed that the problematic windy storm the night before last was not in the 3-hourly forecast for Zabljak (which is a town near where I was camping). One of them recommended I use the Windy app for richer forecasts, however I am not sure that it has any layer for hail. Is there any weather forecasting map which will allow me to see whether hail specifically is forecast in any particular hour?
3, 4 and 5 illustrate the stretched fabric (note that silnylon does not rip when it gets damaged; it just gets stretched and stretched and stretched but it genuinely is damaged when stretched so far that it won't return to its original form, as seems to be the case here)
8, 9, and 10 show the rain from the storm in radar as it was moving over me. 11 is a zoomed in version of 9. If anybody knows how to find the historical speed of gusts of wind on Opstina Zabljak at that day/time please do share, I would be very interested because I believe that as Alex J. suggested that this could have been a violent "supercell" (which is the kind of storm which is capable of among other things spawning tornadoes). The way it was battering my tent really did seem very violent, I don't think I have ever been outside in such weather let alone in a tent. I genuinely felt under severe threat, I couldn't quite believe at this time I was in that situation, I thought at the time that there was little chance my tent would stay guyed or unflooded; it was horrendous. Edit: according to https://en.wikipedia.org/wiki/2023_European_heat_waves#Storms, the July 2023 Balkan Supercells have been a newsworthy phenomenon, with gusts over 100km/h, large hailstones, and they have killed people as well. Just to make clear what I'm up against in an ultralight tent!
11 shows that Opstina Zapljak is a high basin surrounded by hills and mountains.