Includes all summits in the the northern half of Wales from Plynlimon northwards.
Snowdonia National Park
Friday 30th October 2020
Last updated
Friday 30th October 2020 at
8:07 AM
A weak ridge of high pressure will bring a spell of relatively benign conditions to S Scotland and into England and Wales. However, showers will affect NW Scotland and there is uncertainty in the extent that strong winds, rain and low cloud clear from the NW across Wales.
Windy at first. Rain clearing. Cloud base gradually lifting.
Southwesterly 35 to perhaps 45mph after dawn. A transition to 20 or 25mph will extend southeast, probably during morning. By dusk, little wind at all.
Walking difficult and wind chill significant, before conditions ease markedly.
Heavy rain clearing; possible flooding
Overnight heavy or on some western mountains torrential rain will clear southwards during the morning although in mid Wales may persist until midday. Then dry. Expect flooding underfoot and of in spate steams & rivers.
Blanket fog across almost all hills morning; will tend to lift
Almost blanket fog, from many lower slopes up at first. Although timing uncertain, will improve from northwest; by afternoon most cloud confined above 800 to 1000m north Wales - before dusk may clear almost completely.
10% rising to 60%
Sunshine not expected. Visibility extensively very poor, although may well become excellent from northwest.
9C; may drop to 6C.
Above the summits.
Snowdonia National Park
Saturday 31st October 2020
Last updated
Friday 30th October 2020 at
8:07 AM
Low confidence in this forecast: South veering southwesterly 50 to 70mph, strongest in morning.
Walking, or any mobility, may be very difficult on higher areas, and wind chill severe. Sudden powerful gusts even lower slopes.
Heavy rain; risk flooding
Rain, sometimes heavy or torrential, particularly W Wales may fall most or perhaps all daylight, but one or two breaks. Widely saturated underfoot; some flooding of paths and in spate streams.
Threat almost blanket fog
Cloud base typically 450 to 650m, although toward and north of A5 most cloud above 750m with a few breaks to 900m.
10%
Little or no sunshine. Visibility extensively very poor in rain.
8C
Above the summits.
Snowdonia National Park
Sunday 1st November 2020
Last updated
Friday 30th October 2020 at
8:07 AM
Southwesterly 40 to 50mph, although perhaps 60mph higher tops post dawn and again pre dusk.
Mobility difficult for periods and wind chill severe where exposed on higher areas.
Frequent rain; flooding
One or two dry periods east Wales, but overall frequent sometimes heavy rain. Saturated conditions underfoot: flooding, perhaps extensive of paths, streams and rivers, particularly west Wales.
Very extensive
Rare breaks to higher areas east Wales, but overall extensive fog above 350 to 550m, although at times cloud forming on even coastal cliffs west Wales.
20%
Rare sunshine, most likely east Wales. Extensively misty and at times very poor visibility.
4C
Above the summits.
A series of deep Atlantic lows and their associated bands of rain and severe gale or storm force upland winds will affect Britain until early next week. It will then turn much drier, although some uncertainty as weak fronts may still affect northwest Scotland.