Mountain weather

Bannau Brycheiniog / Brecon Beacons

Bannau Brycheiniog / Brecon Beacons Mountain weather forecast table

Confidence

High for the mobile nature of the westerly weather patterns, but lowering for the transitional timing detail.

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.

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.
hazard Thunderstorms
Lightning is a significant mountain hazard which can result in serious injury or death. Mountain terrain often leaves one highly exposed to lightning strikes. Hail may give unpleasant conditions with torrential rain and localised flash flooding also possible, mainly in Summer months.
hazard Heavy Persistent Rain
Heavy and persistent rain can lead to drenched clothing and footwear with waterproofs often becoming soaked through, especially if accompanied by strong winds. This can lead to significant loss of body heat and an increased likelihood of hypothermia. Terrain may turn increasingly boggy underfoot while streams can flood and become impassable. There may also be a risk of flooding in valleys or glens. If there is snow cover, a heightened avalanche hazard is possible and avalanche reports should be consulted where available.

Mountain weather forecast

Cloudy to overcast with increasing chance of showery rain. Fresh winds.

Time 06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 600m)
Cloudy Fog Cloudy Light rain Cloudy Cloudy
Chance of precipitation
(at 600m)
60% 40% 30% 70% 60% 30%

Wind direction and speed (mph)
Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
600m S
14
S
13
S
13
SW
11
SW
11
SW
13
300m SE
2
SE
6
S
7
SW
7
SW
6
SW
6
Valley N
2
E
2
SE
4
SW
6
SW
4
SW
4
Wind gust (mph)
Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
600m 18 16 17 14 15 18
300m 9 12 13 13 14 15
Valley 3 4 9 12 12 13

Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
600m
300m
10°
10°
Valley
10°
11°
Freezing Level
1,800m
1,700m
1,700m
1,700m
1,600m
1,400m

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

Additional weather information

Meteorologist's view

Poor visibility in cloud making navigation difficult for the morning.

Weather

A cloudy to overcast day with occasional rain, most of this patchy and light, but the chance of some limited brightness, also some brief heavier outbreaks appearing mid to late afternoon, with low chance of lightning.

Chance of cloud-free hill tops

10% becoming 25% during the afternoon

Low cloud and visibility

Moderate or poor at first becoming good by late morning, but moderate or poor in rain, very poor within cloud, which will be quite extensive from 300m through the morning, before thinning and lifting a little during the afternoon.

Recent rainfall

Location: Neuadd (Near Pontsticill)
Altitude: 353m
Last 24 hoursLast 48 hoursLast 72 hours
0.6mm0.6mm1.8mm
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

Rather cloudy with some patchy light rain about, but most of this will be focused in the west. Band of occasionally heavy rain arriving from the west during the evening. Strong southerly summit winds developing.

Chance of cloud-free hill tops

60%.

Maximum wind speed expected

South to southwest increasing mean 30-35mph from late afternoon, with gusts reaching 45mph across more exposed ridges and summits.

Temperature

  • At 600m Plus 4 Celsius increasing 7 Celsius for the afternoon
  • Valley Plus 5 Celsius increasing 12 Celsius for the afternoon
  • Freezing level Above summits

Low cloud and visibility

Good or very good becoming moderate or poor in rain, very poor within cloud, which will be occasionally lower to 600m.

Mountain weather information

Wed 11 Mar

Sunrise:
Sunset:

Chance of early rain, otherwise mainly dry with bright spells. Strong westerly summit winds bringing a severe wind chill at height. Freezing level above summits.

Thu 12 Mar

Sunrise:
Sunset:

Cloudy with occasional rain, turning heavier and more persistent at times, particularly late in the day. Gale to severe gale summit winds. Freezing level above summits.

Fri 13 Mar

Sunrise:
Sunset:

Rather cloudy with occasional light showers. Strong summit winds bringing severe wind chill at height. Freezing level 700m.

Updated at:

Summit specific forecast

Mountain summit forecast map

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