Mountain weather

Bannau Brycheiniog / Brecon Beacons

Yellow warning

Yellow weather warning in force for Bannau Brycheiniog / Brecon Beacons

Bannau Brycheiniog / Brecon Beacons Mountain weather forecast table

Confidence

Generally high throughout the forecast period with the main uncertainties around cloud amounts and height of the cloud inversion.

Sunrise:
Sunset:

This evening forecast

Dry but cloudy with hill fog this evening, although cloud may lift off the summits towards midnight. Strong northeast winds gusting around 35-40 mph across the summits, and feeling cold with the freezing level around 400m.

Sunrise:
Sunset:
Mountain hazards

Mountain weather hazards

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

hazard Gales
Gale force winds (gusts over 50mph) make walking difficult and strenuous with a potential to be blown over by gusts. There is often a marked increase in winds through cols or on exposed ridges and summits. Distances can take longer to cover and compass bearings become harder to follow accurately.

hazard Severe Chill Effect
Wind significantly lowers the ‘feels-like’ temperature relative to the actual temperature, with even moderate winds significantly adding to the chilling effect. Strong winds can result in a severe and debilitating wind chill many degrees below the actual temperature. This effect will be enhanced in rain or wet snow. Without protection, prolonged exposure could result in frost nip or frostbite on exposed parts of the body and/or hypothermia.

Mountain weather forecast

Cold and windy with a chance of summit gales, but dry and sunny.

Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 600m)
Overcast Mist Partly cloudy (night) Sunny day Sunny day Sunny day Clear night Clear night
Chance of precipitation
(at 600m)
<05% <05% 00% 00% 00% 00% 00% 00%

Wind direction and speed (mph)
Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
600m NE
24
NE
25
NE
31
NE
30
NE
30
NE
29
NE
27
NE
26
300m NE
15
NE
15
NE
18
NE
16
NE
19
NE
18
NE
16
NE
15
Valley NE
13
NE
14
NE
17
NE
17
NE
17
E
15
E
14
E
15
Wind gust (mph)
Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
600m 33 34 43 42 41 41 38 37
300m 29 29 36 34 37 35 33 32
Valley 28 30 37 38 36 33 31 34

Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
600m
-1°
-1°
-2°
-2°
-1°
-1°
-2°
300m
Valley
Freezing Level
300m
300m
300m
200m
300m
400m
200m
200m

Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
600m
-8°
-9°
-10°
-11°
-9°
-8°
-9°
-10°
300m
-3°
-4°
-5°
-5°
-4°
-3°
-5°
-6°
Valley
-2°
-3°
-4°
-4°
-2°
-2°
-4°
-5°

Additional weather information

Meteorologist's view

Gusts are likely to reach 50-55 mph over the higher summits, perhaps 60 mph late afternoon, giving a bitterly cold wind chill and a risk of being blown over.

Weather

Low cloud lifts and breaks through the early hours. Then dry and sunny on Christmas day, but bitterly cold on the tops in strong to gale force summit winds. Clear skies in the evening, perhaps a little patchy cloud towards midnight.

Chance of cloud-free hill tops

90% or more

Low cloud and visibility

Patchy summit cloud will disperse before dawn to give excellent visibility with no cloud on the hills.

Recent rainfall

Location: Neuadd (Near Pontsticill)
Altitude: 353m
Last 24 hoursLast 48 hoursLast 72 hours
0.8mm9.4mm14.8mm
Measurement date:

Rainfall data provided by Natural Resources Wales. The Met Office is not responsible for content provided by third parties and may remove this data without warning.

Sunrise:
Sunset:

Mountain weather information

Weather

Cloud lowering through the early hours to give a dry but dull day in the valleys and lower slopes. The higher summits are likely to be above the cloud in the morning, but a chance that cloud rises to envelop the summits in the afternoon. Little change in the evening, but a chance of clearing skies by midnight.

Chance of cloud-free hill tops

60% in the morning, 30% in the afternoon.

Maximum wind speed expected

East-northeast 30 gusting 40 mph

Temperature

  • At 600m Minus 3 Celsius rising to around zero Celsius, but the higher summits plus 1 Celsius in the morning falling to minus 1 Celsius in the afternoon.
  • Valley Minus 2 Celsius rising to plus 3 Celsius.
  • Freezing level 200m rising to 600m.

Low cloud and visibility

Very poor visibility in cloud on lower slopes in the morning, but very good visibility above 700-750m with summits above the cloud. Cloud bases rising to around 600m in the afternoon giving good visibility at lower levels, but occasionally poor visibility on the summits as cloud tops rise.

Mountain weather information

Sat 27 Dec

Sunrise:
Sunset:

Dry and sunny but cold with strong to gale force east or northeast winds. Freezing level around 500m to start but soon above the summits. Low cloud spreads west late evening.

Sun 28 Dec

Sunrise:
Sunset:

A dull day with hill fog and a little patchy light drizzle at times, although a chance that the highest summits could be above the cloud at times. Moderate to fresh easterly winds. Freezing level 700m.

Mon 29 Dec

Sunrise:
Sunset:

Most likely a drier brighter day than Sunday, but still some patchy low cloud. Moderate easterly winds. Freezing level 500m.

Updated at:

Summit specific forecast

Mountain summit forecast map

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