Fan Brycheiniog - Twr y Fan Foel weather forecast.

Cloud-free timing: Around 67% early, improving to around 100% later.

A wild day on Fan Brycheiniog - Twr y Fan Foel: summit wind broadly 20-40 mph, with gusts 40-50 mph during the morning (gale-force winds). Much calmer lower down - generally 10-20 mph in the valley, rising towards the tops. Little or no rain expected. Cloud base is the least certain part of this - the models are only moderately agreed, so it could sit a couple of hundred metres either way.

Forecast confidence: Thunderstorm timing is inherently uncertain and may shift by several hours.

Cloud-free timing: Cloudy early, clearing later.

A mixed day on Fan Brycheiniog - Twr y Fan Foel: summit wind broadly 5-20 mph, with gusts 15-25 mph early in the morning (a moderate breeze). Thunderstorms are a significant hazard from the morning into the afternoon. Exposed summits and ridges are a poor choice while storms are nearby. Cloud base around 500–800 m in the morning, lifting to 900–1200 m around midday and 1400–1700 m by late afternoon. Summit cloud should lift later, bringing a better chance of clear views. Little or no rain expected.

Forecast confidence: Thunderstorm timing is inherently uncertain and may shift by several hours.

Cloud-free timing: Around 33% early, falling to around 0% later.

A rough, clagged-in day on Fan Brycheiniog - Twr y Fan Foel: summit wind broadly 20-35 mph, with gusts 35-45 mph during the evening (gale-force winds). Thunderstorms are a significant hazard from early morning into the evening. Exposed summits and ridges are a poor choice while storms are nearby. There could be a spate risk based on forecast rainfall. Burns and unbridged crossings may rise quickly. Most likely from around 05:00 until around 20:00. Much calmer lower down - generally 10-20 mph in the valley, rising towards the tops. Cloud base around 700-1000 m in the morning, lowering to 400-700 m around midday. Expect clag for much of the day, though a brief clearance is possible early in the morning. Cloud is likely to hang lowest on southern slopes; the northern side should see somewhat higher bases and better breaks. A persistently wet day is possible, with around 10-20 mm indicated; local totals could vary considerably. Confidence moderate (forecast models agree on the walking impact of the wind) - the summit peak could reasonably be 25-35 mph, so treat the headline as mid-range.

Forecast confidence: Thunderstorm timing is inherently uncertain and may shift by several hours.

A rough, clagged-in day on Fan Brycheiniog - Twr y Fan Foel: summit wind broadly 15-30 mph, with gusts 30-40 mph during the morning (strong winds). A meaningful thunderstorm risk is indicated from the morning into the evening. Avoid committing to exposed ridges if storms begin to build. The ground is likely to be wet after recent rain. There could be a spate risk based on forecast rainfall. Burns and unbridged crossings may rise quickly. Most likely from around 05:00 until around 20:00. Much calmer lower down - generally 10-20 mph in the valley, rising towards the tops. Cloud base mostly around 400–700 m through daylight. Expect the top to stay in cloud for most or all of daylight, with no dependable break. Cloud is likely to hang lowest on western slopes; the eastern side should see somewhat higher bases and better breaks. A persistently wet day is possible, with around 10-20 mm indicated; local totals could vary considerably. Confidence moderate (forecast models agree on the walking impact of the wind) - the summit peak could reasonably be 22-31 mph, so treat the headline as mid-range. Cloud base is the least certain part of this - the models are only moderately agreed, so it could sit a couple of hundred metres either way.

Forecast confidence: Thunderstorm timing is inherently uncertain and may shift by several hours.

A rough, clagged-in day on Fan Brycheiniog - Twr y Fan Foel: summit wind broadly 15-35 mph, with gusts 35-45 mph during the morning (gale-force winds). A meaningful thunderstorm risk is indicated from the morning into the evening. Avoid committing to exposed ridges if storms begin to build. The ground is likely to be wet after recent rain. There could be a spate risk based on forecast rainfall. Burns and unbridged crossings may rise quickly. Most likely from around 05:00 until around 02:00 the following day. Much calmer lower down - generally 5-15 mph in the valley, rising towards the tops. Cloud base mostly around 400–700 m through daylight. Expect the top to stay in cloud for most or all of daylight, with no dependable break. Cloud is likely to hang lowest on southwestern slopes; the northeastern side should see somewhat higher bases and better breaks. A persistently wet day is possible, with around 10-20 mm indicated; local totals could vary considerably. Confidence moderate (Summit wind could be roughly 22-41 mph, which changes how difficult exposed walking may feel) - the summit peak could reasonably be 22-41 mph, so treat the headline as mid-range.

Forecast confidence: Thunderstorm timing is inherently uncertain and may shift by several hours.

Cloud-free timing: Around 0% early, improving to around 40% later.

A rough, clagged-in day on Fan Brycheiniog - Twr y Fan Foel: summit wind broadly 20-35 mph, with gusts 35-45 mph during the evening (gale-force winds). Thunderstorms are a significant hazard from early morning into the evening. Exposed summits and ridges are a poor choice while storms are nearby. The ground is likely to be saturated after recent rain. Expect boggy paths and rapid runoff if more rain arrives. There could be a spate risk based on forecast rainfall. Burns and unbridged crossings may rise quickly. Most likely from around 08:00 until around 03:00 the following day. Much calmer lower down - generally 10-20 mph in the valley, rising towards the tops. Cloud base around 100–400 m in the morning, lifting to 700–1000 m around midday and 600–900 m by late afternoon. The top is likely to drift in and out of cloud, with the best chance of a view during the afternoon. Cloud is likely to hang lowest on southwestern slopes; the northeastern side should see somewhat higher bases and better breaks. A persistently wet day is possible, with around 10-20 mm indicated; local totals could vary considerably. Confidence moderate (Summit wind could be roughly 22-35 mph, which changes how difficult exposed walking may feel) - the summit peak could reasonably be 22-35 mph, so treat the headline as mid-range.

Forecast confidence: Forecast models disagree on whether meaningful rain reaches the hills during 10:00-16:00.

Cloud-free timing: Cloudy early, clearing later.

A mixed day on Fan Brycheiniog - Twr y Fan Foel: summit wind broadly 25-35 mph, with gusts 40-50 mph around midday (gale-force winds). The ground is likely to be wet after recent rain. There could be a spate risk based on forecast rainfall. Burns and unbridged crossings may rise quickly. Most likely from around 00:00 until around 17:00. Much calmer lower down - generally 10-20 mph in the valley, rising towards the tops. Cloud base around 400-700 m in the morning, lifting to 900-1200 m around midday. Summit cloud should lift later, bringing a better chance of clear views. Cloud is likely to hang lowest on western slopes; the eastern side should see somewhat higher bases and better breaks. Some rain is likely, with around 5-10 mm indicated; timing and local totals remain uncertain. Confidence moderate (Summit wind could be roughly 24-37 mph, which changes how difficult exposed walking may feel) - the summit peak could reasonably be 24-37 mph, so treat the headline as mid-range.