Wednesday 17 December

The day started with a fierce lightning storm just after midnight. The path of the storm was easily mapped, when the lightning began to strike the electricity pylons which run into the Arnish Substation from the south. Some of the discharges were within half a mile of my position (as it took less than 3 seconds between lightning and thunder). The final bolt was accompanied by half-inch hailstones. Winter is the most likely time we're likely to see thunder; it occurs when the temperature in the cloudtops is 40 degrees C lower than down at groundlevel. At the moment, there is heavy rain and strong winds (force 7). The ferry is not sailing; at present it is tied up at Ullapool. The 5.15 sailing out of Ullapool is under review. Judging by the forecast (winds up to force 9), it will probably be cancelled as well.