Brief periods of heavy hail showers with thunder (could have also featured soft hail and sleet) due to a deep trough directing cold air over the Islands (the previous 7 days had also been colder than average). This trough was further accompanied by very unstable air (as indicated in red) which traveled over warmer seas that made it even more unstable (represented as thermal in the weather sounding). Air temperature was only between +4°C and +5°C during this hail storm while sea temperature was around +15°C. The weather sounding showed that such Wintry precipitation was possible. The first thumbnail is another photo of the same hail storm.