8th May 1993: 1030mb+ pressure but heavy thundery rain.

[Weather-history]

Something "odd" happened on the 8th May 1993. Pressure was highest over Scotland but during the early hours, heavy thundery rain broke out across central Lowlands and slowly moved southwards before dying out.

So what caused this? Upper level trough?

Michael Fish forecast

The forecast for the previous day suggested maybe a few showers but did not expect the extent of the rain nor thundery nature.