Yr Wyddfa / Snowdon Summit (Gwynedd) weather

Headline:

Storm Bert to bring possible disruption this weekend.

This Evening and Tonight:

Dry but chilly evening. Cloud building overnight ahead of Storm Bert's arrival with rain becoming widespread and brief hill snow across Eryri. Patchy frost abating as the rain arrives. Minimum temperature 1 °C.

Saturday:

Storm Bert bringing a widely unsettled and potentially disruptive day with heavy, persistent rain and gales, severe along coasts. Turning noticeably milder, resulting in a rapid melt of lying snow. Maximum temperature 15 °C.

Outlook for Sunday to Tuesday:

Early rain clearing through Sunday with showers and brighter spells on Monday and Tuesday. Strongest winds easing but staying blustery. Mild on Sunday then temperatures returning to the seasonal average.

Probably a quieter interlude to start this period for much of the UK as high pressure builds across the north with a return of night frosts. However there is still a risk of some rain across southern parts of the country on Wednesday, although the northern extent of this is uncertain. The high is likely to migrate eastwards during the second half of next week, potentially allowing some outbreaks of rain to move into some some northwestern areas along with some stronger winds. Into December, and while signals are mixed it looks most likely that high pressure may re-assert itself close to or over the UK, with temperatures generally near average, but some overnight frost is likely, and rather cold by day where any fog persists.

The start of this period looks like being largely settled, with high pressure close to if not over the UK. However as we move further into December there are signs that it will become less settled with west or northwesterly types preferred, These will bring some wetter and windier interludes with a risk of some snow, especially for hills in the north. These conditions look more likely to dominate towards the middle of December. Temperatures generally close to average through the period.