There’s still considerable uncertainty over the likelihood of the Western Isles seeing impacts from thunderstorms forecast for the whole of the UK over the next few days (Monday 10 – Thursday 13 August).
On Friday the Met Office issued a warning of thunder, lightning, rain and hail covering all parts of the UK, with Monday the earliest point at which effects could be expected in the islands.
That warning’s now been cancelled for the islands on Monday and, as of this evening (7pm Sunday 9 August), the strongest likelihood of impacts is now predicted for Tuesday and Wednesday this week, as thunderstorms move north and north-westwards across the whole of the UK.
The Met Office warning currently in force says: “At present the west of Scotland seems less likely to be affected than other areas, but still could not be ruled out. Where the storms occur, rainfall totals of 30-40mm could fall in an hour.”
You can read the whole warning for Tuesday at: https://www.metoffice.gov.uk/weather/warnings-and-advice/uk-warnings
In their blog today (https://westernislesweather.com/2020/08/09/thunderstorm-risk-for-the-western-isles-sunday-9th-august-update/?fbclid=IwAR0U6Mhc-ncsG1beiGf1XvFbmtERR2rPi8zg00hcLmShMs09IONqgkGLxJQ) , Western Isles Weather said: “It is really important here to stress that this does not rule out us seeing thunderstorms entirely. We could still see thunderstorms. However, the judged risk by the Met Office has now reduced for our area and no longer meets the impact criteria to warrant a warning.”
The Met Office warnings for Tuesday and Wednesday cover the whole of the UK, from Cornwall to Shetland, with the warning giving: “Significant uncertainty in location and timing.”
Where impacts are felt, the Met Office warns of flooding, lightning strikes, coastal spray and power failures as well as local disruption to transport.