Brecon Beacons mountain area forecast

Hazards

High risk of Severe chill effect: Strong winds will combine with low temperatures to give a severe chill effect.

Medium risk of Gales: Northwesterly winds may reach gale force over the highest summits.

Medium risk of Thunderstorms: Showers may be heavy at times with a risk of hail and thunder

Medium risk of Strong sunlight: Risk of sunburn in any lengthy sunny spells between showers.

No risk of Blizzards; Heavy snow; Storm force winds; Persistent extensive hill fog; Heavy persistent rain;

Weather summary and probability of precipitation for Thursday

Dawn to 0900		Sunny intervals	20% chance of precipitation
0900 to 1200		Light rain showers	40% chance of precipitation
1200 to 1500		Light rain showers	70% chance of precipitation
1500 to dusk		Light rain showers	70% chance of precipitation

Thursday

Weather

A much windier day and feeling cold, especially at height where temperatures will be low. After a bright start with some sunshine and isolated showers, the showers will become more frequent by afternoon with perhaps the odd heavy one, with the risk of hail and thunder. There is a risk of showers turning wintry above 800 metres. Winds will strengthen, perhaps reaching gale force over exposed ridges and summits during the afternoon.

Visibility

Generally very good or excellent, but moderate in showers.

Hill fog

Nil expected.

Maximum winds above 400m

NW 50 mph during the afternoon.

Temperature

Valleys: Plus 4 Celsius rising to plus 10 Celsius.
800 m: Zero Celsius rising to plus 2 Celsius.
Freezing level: 800 metres.

Friday

Weather

Very windy with north or northwesterly gales possible at lower levels, becoming northeasterly later. It will also be rather cloudy with outbreaks of rain or showers and occasional hill fog above around 700 metres. The freezing level will be around 800 metres initially so some of the rain could turn wintry. Some bright spells developing later but with showers too.

Visibility

Generally good but moderate in rain or showers, becoming very good between showers later.

Hill fog

Occasional hill fog above 700 metres especially over north facing hills, but tending to lift clear during the afternoon between showers.

Maximum winds above 400m

NW 40-45 mph becoming NE later.

Temperature

Valleys: Plus 4 Celsius rising to plus 11 Celsius.
800 m: Zero Celsius rising to plus 4 Celsius.
Freezing level: 800 metres rising above the summits by afternoon.

Outlook

Saturday

Conditions much better than on Friday with lighter winds and some decent sunny spells. It will be a chilly start with some mist and fog patches in the valleys, but these will soon clear to leave a dry day and with the sunshine it will feel much warmer than previous days.

Sunday

After another chilly start with some mist and fog patches it will be a mostly dry day with some bright or sunny spells and light or moderate northwesterly winds. Turning cloudier later.

Monday

Cloudy and breezy with outbreaks of rain arriving later, becoming persistent and heavy at times with occasional hill fog. Significant wind chill developing in the wind and rain.