Aonach Beag (Alder) weather forecast.

Cloud-free timing: Around 100% early, falling to around 40% later.

A mixed day on Aonach Beag (Alder): summit wind broadly 15-30 mph, with gusts 30-40 mph during the afternoon (strong winds). Much calmer lower down - generally 5-15 mph in the valley, rising towards the tops. Cloud base around 3000–3300 m in the morning, lowering to 1100–1400 m around midday and 900–1200 m by late afternoon. The top is likely to drift in and out of cloud, with the best chance of a view from early morning into around midday. Little or no rain expected.

Forecast confidence: A low thunderstorm risk remains difficult to time precisely.

A grey, cloudy day on Aonach Beag (Alder): summit wind broadly 10-25 mph, with gusts 25-35 mph early in the morning (fresh and blowy). Thunderstorms are possible from the morning into the afternoon. Keep an escape route from exposed ridges and descend if thunder develops. Much calmer lower down - generally 0-10 mph in the valley, rising towards the tops. Cloud base around 400–700 m in the morning, then around 800–1100 m around midday and 400–700 m by late afternoon. Expect the top to stay in cloud for most or all of daylight, with no dependable break. Cloud is likely to hang lowest on northern slopes; the southern side should see somewhat higher bases and better breaks. Some rain is likely, with up to around 2 mm indicated; timing and local totals remain uncertain.

Forecast confidence: A low thunderstorm risk remains difficult to time precisely.

A grey, cloudy day on Aonach Beag (Alder): summit wind broadly 5-15 mph, with gusts 10-20 mph early in the morning (a moderate breeze). Thunderstorms are possible from the morning into the afternoon. Keep an escape route from exposed ridges and descend if thunder develops. Cloud base around 300–600 m in the morning, then around 600–900 m around midday and 400–700 m by late afternoon. Expect the top to stay in cloud for most or all of daylight, with no dependable break. Some rain is likely, with around 2-5 mm indicated; timing and local totals remain uncertain. 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: Around 0% early, improving to around 80% later.

A grey, cloudy day on Aonach Beag (Alder): summit wind broadly 10-25 mph, with gusts 20-30 mph during the evening (fresh and blowy). Thunderstorms are a significant hazard from the morning into the evening. Exposed summits and ridges are a poor choice while storms are nearby. Cloud base around 300–600 m in the morning, lifting to 400–700 m around midday and 1300–1600 m by late afternoon. The top is likely to drift in and out of cloud, with the best chance of a view from late afternoon into the evening. Cloud is likely to hang lowest on southern slopes; the northern 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 14-26 mph, which changes how difficult exposed walking may feel) - the summit peak could reasonably be 14-26 mph, so treat the headline as mid-range.

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

Cloud-free timing: Best around midday at about 25%; around 0% early and 0% later.

A rough, clagged-in day on Aonach Beag (Alder): summit wind broadly 10-40 mph, with gusts 45-55 mph during the evening (gale-force winds). A meaningful thunderstorm risk is indicated from early morning into the evening. Avoid committing to exposed ridges if storms begin to build. 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 03:00 the following day. Much calmer lower down - generally 5-15 mph in the valley, rising towards the tops. Cloud base around 300–600 m in the morning, then around 800–1100 m around midday and 300–600 m by late afternoon. Expect clag for much of the day, though a brief clearance is possible around midday. 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. Cold on top: air temperature broadly 4 to 8°C, feeling around -2 to 2°C in the wind - wrap up. Low confidence (Summit wind could be roughly 23-56 mph, which changes how difficult exposed walking may feel) - the summit peak could be anywhere from 23 to 56 mph; check again nearer the time.

Forecast confidence: Summit wind could be roughly 24-45 mph, which changes how difficult exposed walking may feel.

A rough, clagged-in day on Aonach Beag (Alder): summit wind broadly 25-40 mph, with gusts 45-55 mph early in the morning (gale-force winds). The ground is likely to be wet after recent rain. Much calmer lower down - generally 5-15 mph in the valley, rising towards the tops. Cloud base around 400–700 m through the morning, lifting to 700–1000 m by late afternoon. Expect the top to stay in cloud for most or all of daylight, with no dependable break. Cloud is likely to hang lowest on northwestern slopes; the southeastern 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. Cold on top: air temperature broadly 2 to 6°C, feeling around -6 to -2°C in the wind - wrap up. Confidence moderate (Summit wind could be roughly 24-45 mph, which changes how difficult exposed walking may feel) - the summit peak could reasonably be 24-45 mph, so treat the headline as mid-range.