Snowdonia National Park

Includes all summits in the the northern half of Wales from Plynlimon northwards.

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Viewing Forecast For

Snowdonia National Park
Friday 30th October 2020
Last updated Friday 30th October 2020 at 8:07 AM

Summary for all mountain areas

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.

Headline for Snowdonia National Park

Windy at first. Rain clearing. Cloud base gradually lifting.

How windy? (On the summits)

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.

Effect of the wind on you?

Walking difficult and wind chill significant, before conditions ease markedly.

How Wet?

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.

Cloud on the hills?

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.

Chance of cloud free summits?

10% rising to 60%

Sunshine and air clarity?

Sunshine not expected. Visibility extensively very poor, although may well become excellent from northwest.

How Cold? (at 900m)

9C; may drop to 6C.

Freezing Level

Above the summits.

Viewing Forecast For

Snowdonia National Park
Saturday 31st October 2020
Last updated Friday 30th October 2020 at 8:07 AM

How windy? (On the summits)

Low confidence in this forecast: South veering southwesterly 50 to 70mph, strongest in morning.

Effect of the wind on you?

Walking, or any mobility, may be very difficult on higher areas, and wind chill severe. Sudden powerful gusts even lower slopes.

How Wet?

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.

Cloud on the hills?

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.

Chance of cloud free summits?

10%

Sunshine and air clarity?

Little or no sunshine. Visibility extensively very poor in rain.

How Cold? (at 900m)

8C

Freezing Level

Above the summits.

Viewing Forecast For

Snowdonia National Park
Sunday 1st November 2020
Last updated Friday 30th October 2020 at 8:07 AM

How windy? (On the summits)

Southwesterly 40 to 50mph, although perhaps 60mph higher tops post dawn and again pre dusk.

Effect of the wind on you?

Mobility difficult for periods and wind chill severe where exposed on higher areas.

How Wet?

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.

Cloud on the hills?

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.

Chance of cloud free summits?

20%

Sunshine and air clarity?

Rare sunshine, most likely east Wales. Extensively misty and at times very poor visibility.

How Cold? (at 900m)

4C

Freezing Level

Above the summits.

Planning Outlook

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.