Mountain weather

Mountain weather

Bannau Brycheiniog / Brecon Beacons

Confidence

High for overall picture through the period but moderate with respect to location of heaviest showers through Tuesday.

Mountain hazards

Mountain weather hazards

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

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.
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.

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.
Strong Sunlight
Harmful UV levels from sunlight increase with altitude giving a greater risk of sunburn and eye damage, even on some overcast days. On breezy days, the cooling effect of wind on exposed skin may disguise any feeling of sunburn until it is too late. If there is snow cover, glare increases the effect of UV rays especially on the eyes. It is advisable to wear sun block, protective clothing such as a long-sleeved top and hat and have good quality eye protection.

Mountain weather forecast

Heavy and persistent rain clearing eastward with brighter spells and showers to follow, these potentially heavy at times.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Heavy Rain Heavy Rain Cloudy Heavy Rain Heavy Rain Heavy Rain
Chance of
precipitation
(at 800m)
Chance of precipitation
40%
60%
60%
60%
60%
40%

Wind direction and speed

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
600m
600m SW 19mph knots
SW
19mph
SW 21mph knots
SW
21mph
SW 23mph knots
SW
23mph
SW 23mph knots
SW
23mph
SW 24mph knots
SW
24mph
SW 25mph knots
SW
25mph
300m
300m SW 10mph knots
SW
10mph
SW 13mph knots
SW
13mph
SW 16mph knots
SW
16mph
SW 17mph knots
SW
17mph
SW 16mph knots
SW
16mph
SW 15mph knots
SW
15mph
Valley
Valley SW 9mph knots
SW
9mph
SW 11mph knots
SW
11mph
SW 14mph knots
SW
14mph
SW 16mph knots
SW
16mph
SW 14mph knots
SW
14mph
SW 13mph knots
SW
13mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
600m
600m 27mph 29mph 33mph 33mph 35mph 35mph
300m
300m 21mph 26mph 31mph 32mph 31mph 30mph
Valley
Valley 21mph 25mph 30mph 32mph 30mph 29mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
600m
600m 5 degrees Celsius 5 degrees Celsius 6 degrees Celsius 5 degrees Celsius 4 degrees Celsius 3 degrees Celsius
300m
300m 9 degrees Celsius 9 degrees Celsius 10 degrees Celsius 10 degrees Celsius 8 degrees Celsius 7 degrees Celsius
Valley
Valley 10 degrees Celsius 10 degrees Celsius 11 degrees Celsius 10 degrees Celsius 9 degrees Celsius 8 degrees Celsius
Freezing Level Freezing Level
1900m
2000m
1900m
1900m
1800m
1900m

Additional weather information

Meteorologist's view

Heavy and persistent rain followed by showers, again potentially heavy will allow for surfaces to remain wet and slippery for much of the day meaning appropriate footwear is advised. Waterproof clothing is also advisable throughout the day.

Weather

A band of heavy and persistent rain is expected to arrive from the west overnight into Tuesday, this will bring a wet and rather blustery start to the day before gradually clearing to the northeast. Once clear scattered showers are expected to develop once again, these potentially heavy with a low risk of thunder at times.

Chance of cloud-free hill tops

20% gradually rising to 70% by late morning.

Low cloud and visibility

Widespread cloud above 400-600m initially, gradually rising to 600-800m through the morning before lifting above highest peaks. Moderate or poor visibilities initially in heavy rain and cloud and potentially very poor in any hill hog. Visibilities gradually improving to very good or good with views of distant hills possible, temporary deterioration in any heavy showers.

Ground conditions

No recent ground conditions report available.

Summit specific forecast