Mountain weather

Eryri / Snowdonia

Eryri / Snowdonia Mountain weather forecast table

Confidence

High confidence in low cloud and patchy drizzle developing through the evening, but low confidence in exact timing of the change.

Sunrise:
Sunset:

This evening forecast

Some early clear spells, especially in the south, but low cloud cover soon increasing from the north with some patchy drizzle developing. Light north or northwest winds.

Sunrise:
Sunset:
Mountain hazards

Mountain weather hazards

Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.

hazard Poor Visibility
Poor visibility presents challenging route finding conditions. Visibility could be significantly less than 50 metres in all directions with few or no visual references, especially on featureless moors or plateaux. Distances become hard to judge and cliff or cornice edges can be difficult to recognise. These conditions require good navigational skills. There is a risk of white-out conditions when mist or fog is combined with extensive snow cover.

Mountain weather forecast

Mainly cloudy and dry. Fresh northerly winds at first, becoming light from late morning.

00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Fog Fog Fog Cloudy Fog Fog Fog Fog
Chance of precipitation
(at 800m)
40% 40% 30% 20% 10% 10% 10% 10%

Wind direction and speed (mph)
Altitude above mean sea level
00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m N
21
N
23
N
15
NE
10
E
6
N
6
NE
5
E
4
600m N
12
N
14
N
10
N
6
NW
6
N
5
E
3
S
3
300m NW
6
N
9
N
5
N
3
N
4
N
3
E
2
SE
2
Valley NW
7
N
9
N
5
N
3
N
3
N
3
E
2
SE
2
Wind gust (mph)
Altitude above mean sea level
00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m 26 28 19 13 9 7 7 5
600m 16 19 14 9 9 6 4 5
300m 13 17 9 7 6 5 3 3
Valley 15 16 9 6 6 5 3 3

Altitude above mean sea level
00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m
600m
300m
10°
10°
10°
10°
10°
Valley
11°
11°
10°
10°
11°
11°
10°
10°
Freezing Level
2,700m
2,700m
2,600m
2,600m
2,600m
2,600m
2,500m
2,500m

Altitude above mean sea level
00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m
600m
300m
10°
10°
Valley
10°
10°
11°
11°
10°

Additional weather information

Meteorologist's view

Temperatures will be around average for November, but with light winds during the afternoon it should feel reasonably pleasant below to the cloud layer, and in any brightness.

Weather

Extensive low cloud will affect much of the area through the morning, bringing a risk of some patchy drizzle at times, though it will be dry with some brightness in sheltered southern and western areas. Cloud should lift at lower levels by afternoon, though still affecting mid-level hills and peaks. The highest peaks (above 800-1000m) may see clear skies as they sit above the cloud. Similar conditions persisting into the evening, but with cloud bases lowering again.

Chance of cloud-free hill tops

20-40%. Medium confidence at best for clear skies above the inversion, with its height expected around 800-1000m.

Low cloud and visibility

The cloud layer will generally sit between 500 and 1000m, but could extend as low as 200m during the morning and evening. Very poor visibility in cloud, moderate to poor in any drizzle, otherwise good.

Ground conditions

Please see - https://yrwyddfa.live/

Sunrise:
Sunset:

Mountain weather information

Weather

Cloudy with intermittent drizzle, perhaps persistent on some northern hills. Cloud bases generally in the region of 400-600m, though perhaps lifting to around 800m at times, especially in the south. Light winds at first, but fresh to strong south-westerlies developing through the day.

Chance of cloud-free hill tops

20-40%. The temperature inversion at around 800-1000m will give a chance of cloud-free hill tops on some of the highest peaks.

Maximum wind speed expected

Southwesterly 15-20mph with gusts 25-30mph, but gusts locally reaching as high at 40mph near temperature inversion on the highest summits.

Temperature

  • At 800m Plus 4.
  • Valley Plus 8 increasing plus 12 Celsius by afternoon.
  • Freezing level Above summits.

Low cloud and visibility

Generally moderate to poor in outbreaks of drizzle, but occasionally good in any drier spells. Very poor within cloud at mid and higher elevations.

Mountain weather information

Sat 16 Nov

Sunrise:
Sunset:

Cloudy with occasional rain or drizzle, heavy at times. Fresh to strong west or southwest winds. Freezing level above summits.

Sun 17 Nov

Sunrise:
Sunset:

Cloudy and wet, becoming brighter with scattered showers through the day. Some showers heavy, with a risk of hail and thunder, falling as snow on the highest peaks. Strong winds and increasing wind chill.

Mon 18 Nov

Sunrise:
Sunset:

Cold with strong northerly winds and blustery showers, some heavy with a risk of hail and thunder, falling as snow above 500m.

Updated at:

Summit specific forecast

Mountain summit forecast map

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