Mountain weather

Bannau Brycheiniog / Brecon Beacons

Bannau Brycheiniog / Brecon Beacons Mountain weather forecast table

Confidence

High for the changeable conditions this week, lower for day to day details.

Sunrise:
Sunset:

This evening forecast

The last of the persistent heavy rain will clear during the evening, though a few showers will follow later, perhaps turning wintry on the highest summits towards midnight. Strong to gale southwesterly winds also starting to ease down.

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.

Mountain weather forecast

A few bright or sunny intervals but often cloudy, witrh occasional showers which will be wintry on the highest hills, and with a small chance of lightning.

Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 600m)
Light shower (night) Heavy shower (night) Heavy shower (night) Sunny intervals Overcast Heavy rain Heavy rain Fog
Chance of precipitation
(at 600m)
30% 50% 30% 30% 20% 60% 50% 40%

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 SW
19
SW
20
SW
18
SW
16
SW
16
SW
13
S
10
S
13
300m SW
11
SW
11
SW
10
SW
8
SW
9
SW
7
SW
6
SW
7
Valley SW
9
SW
9
SW
9
SW
7
SW
8
SW
6
SW
5
SW
5
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 26 27 24 21 21 17 14 17
300m 24 24 22 18 18 14 12 15
Valley 23 22 22 19 17 13 12 14

Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
600m
300m
Valley
Freezing Level
1,100m
1,100m
1,000m
1,100m
1,100m
1,100m
1,000m
1,000m

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

Additional weather information

Meteorologist's view

Poor underfoot conditions due to the recent very wet weather with some fast flowing rivers especially at first, and some flooding in car parks and access roads,

Weather

Bright or sunny intervals and a few showers in the morning then cloudier in the afternoon with more frequent showers, some heavy with the chance of thunder, and perhaps some sleet or wet snow above 800m.

Chance of cloud-free hill tops

60% in morning falling 30% in afternoon.

Low cloud and visibility

Broken or occasional cloud at 600-700m in morning becoming more extensive in afternoon with the odd patch to 450m especially in the south. Visibility occasionally good away from cloud and showers, but falling moderate to poor in the showers, and very poor in hill fog above the cloud line and in wet snow.

Recent rainfall

Location: Neuadd (Near Pontsticill)
Altitude: 353m
Last 24 hoursLast 48 hoursLast 72 hours
2.4mm29.8mm33.2mm
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

Clear or sunny intervals and occasional showers, wintry on summits in early hours, with perhaps more extensive cloud in the morning. More persistent rain arriving later in the evening.

Chance of cloud-free hill tops

20% rising 50% in afternoon

Maximum wind speed expected

Southwesterly 20 gusts 30mph.

Temperature

  • At 600m Plus 2 rising to Plus 4 Celsius
  • Valley Plus 5 rising to Plus 9 Celsius
  • Freezing level 900m rising above summits before morning

Low cloud and visibility

Broken to overcast cloud in morning bases 500-700m with the odd lower patch, becoming more broken in the afternoon with bases rising to nearer 700-800m, still a few lower patches though. Visibility below the cloud, often good but moderate briefly poor as showers pass through.

Mountain weather information

Thu 4 Dec

Sunrise:
Sunset:

Mainly cloudy with frequent showers, falling as snow above 600-700m. Moderate to fresh southwesterly winds.

Fri 5 Dec

Sunrise:
Sunset:

A dry morning with sunny spells and patchy valley fog. Becoming cloudier in afternoon then rain and strong winds in the evening. Low confidence.

Sat 6 Dec

Sunrise:
Sunset:

Confidence remains low, but most likely a showery day with strong to gale force westerly winds.

Updated at:

Summit specific forecast

Mountain summit forecast map

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