This week’s Deep Dive explores the evolving weather across the UK as we transition from the dramatic impacts of Storm Amy to a period dominated by high pressure.
Drawing on the latest observations, records, and meteorological insights, we’ll examine the significance of recent weather events, the science behind the patterns, and what the coming days may hold.
Storm Amy: a record-breaking event
The week began with the aftermath of Storm Amy, a system that left a significant mark on the UK’s weather records. As the storm swept through on Friday and into Saturday, it brought strong winds and heavy, thundery rain to much of the country. Notably, the centre of the low pressure dropped to 944 hectopascals (or millibars), with a reading of 947.9 hectopascals recorded in northern Scotland, a new October record for the region.
Northern Ireland also experienced its strongest October gust on record, with McGilligan recording a gust of 92 miles per hour. Across Scotland, Northern Ireland, and even parts of northern England, numerous weather stations reported their highest October gusts, with some records stretching back nearly half a century. For example, Lossiemouth’s records go back 49 years, underscoring the rarity of such an event.
Tyree in northern Scotland registered a gust of 96 miles per hour before a power cut interrupted further measurements. It is possible that even stronger gusts occurred, but data is currently unavailable to confirm this. The widespread breaking of October wind records highlights the exceptional nature of Storm Amy.
Storm Amy has been record breaking⚠️
— Met Office (@metoffice) October 4, 2025
An air pressure of 947.9 hPa was recorded at Baltasound, Shetland, provisionally setting a new UK lowest pressure record for October.
Northern Ireland provisionally recorded its strongest October wind gust on record, with a gust of 92 mph… pic.twitter.com/26RyHFLrki
Winter months, particularly January and February, tend to see a higher frequency of strong gusts, while summer months are much quieter. Storm Amy stands out as an outlier for early October, joining the ranks of other unseasonable storms such as Floris Aug 2025) and Ali (Sept 2018). The event is best described as a “one-in-a-year” occurrence, with its early timing in the autumn making it even more unusual.
The transition to high pressure
With Storm Amy behind us, the UK’s weather has shifted to a regime dominated by high pressure. High pressure is currently centred across the south of the UK, with a front making its way southwards. The jet stream, which was strong and positioned over the UK last week, has weakened and shifted further north, resulting in quieter and more settled conditions.
Despite the calmer weather, there are still some notable features. Earlier in the week, parts of Scotland experienced their warmest October day in years, with temperatures reaching the low 20s. Wick, for example, set a new October temperature record. However, as the week progresses, temperatures are expected to return to more typical levels for the time of year.
Cloud, fog, and the challenge of forecasting
One of the key features of the current high-pressure system is the prevalence of cloud and fog. While high pressure often brings clear skies and sunshine, this is not always the case. This week, the high is expected to produce quite a bit of cloud, with some areas experiencing locally dense fog, particularly overnight and in the early morning.
The presence of cloud and fog is influenced by several factors, including the source of the air mass and the structure of the atmosphere. The current air mass has an Atlantic origin, bringing moisture that becomes trapped under the high-pressure system. Light winds contribute to the stagnation of this moisture, leading to persistent cloud and fog in some areas.
READ MORE: Mist, fog, and haze: What's the difference?
The science behind the cloud: Capping inversions
A key meteorological concept at play this week is the capping inversion. Normally, air temperature decreases with height, allowing warm air to rise and clouds to develop. However, a capping inversion is a layer of warmer air above cooler air near the surface, which prevents vertical mixing and traps moisture and cloud below.
This weekend, a capping inversion is expected to form and confine moisture to a relatively thin layer of the atmosphere, resulting in extensive low cloud.
The presence or absence of cloud has a significant impact on daily weather conditions. During the day, cloud cover can keep temperatures cooler, while clear spells allow for warmer conditions, especially with light winds. At night, cloud acts as a blanket, keeping temperatures milder, whereas clear skies can lead to rapid cooling and the risk of frost, particularly in rural areas.
Forecasting cloud cover is particularly challenging in this setup. The thin layer of cloud is difficult to resolve in weather models, which divide the atmosphere into discrete layers. Small changes in the model can have a large impact on the forecast, making it harder to predict exactly where and when cloud or clear spells will occur.
The capping inversion not only affects lowland areas but also has implications for those venturing into the hills and mountains. With the inversion set at around 1,000 metres, peaks higher than this, such as Ben Nevis at 4,400 feet, may rise above the cloud layer. This creates the possibility for those climbing higher peaks to experience sunny skies above a sea of cloud, a phenomenon that can make for spectacular views and excellent conditions for hillwalking.
READ MORE: Understanding the Foehn effect and its impacts
The weekend and beyond
Forecast models show a high probability of high pressure persisting through the end of this week, the weekend, and into the start of next week. The Met Office’s probabilistic pressure trend indicates a very high chance of high pressure dominating from Friday to Monday, with only a slight decrease in confidence as we move further ahead. Even by the following weekend, the likelihood remains high, suggesting that settled weather will continue for some time.
As we move into the weekend, high pressure is expected to remain the dominant feature across the UK. While there will be some spots of rain, particularly in northern areas where winds are stronger and fronts may try to push in, much of the country will experience calm and settled conditions. However, it will not be wall-to-wall blue skies, and cloud and fog will continue to be a feature.
There is some potential for cooler air to move in from the north or east, depending on the exact position of the high. If this happens, temperatures could drop further, with the possibility of frost in rural areas. However, confidence in this scenario is low, and it is more likely that the high will remain in place, keeping conditions relatively mild by day and calm overall.
Beyond that, there are signs that a more mobile and unsettled pattern may develop, particularly across the south of the UK, as we approach the end of October. However, this is still some way off, and the focus for now remains on the current high-pressure regime.
With the combination of high pressure, light winds, and moisture, fog is likely to be a recurring issue in the coming days. Fog warnings are notoriously difficult to issue far in advance, as the development of fog depends on subtle changes in cloud cover and temperature. The Met Office will be monitoring conditions closely and issuing short-notice warnings as needed.
Tropical developments in the Atlantic
In addition to the local weather, attention is also focused on developments in the Atlantic. The National Hurricane Centre has highlighted a low-pressure system with a 90% chance of developing into a tropical storm. This follows recent activity, including Imelda and Humberto, the latter of which developed into a hurricane and contributed energy to Storm Amy.
While there are similarities between the current system and Humberto, the latest forecasts suggest that the blocking high over the UK will prevent the new system from having a direct impact. Although there is a potential for it to approach the UK, it is unlikely to bring significant effects like those seen with Storm Amy. The situation will continue to be monitored, but for now, the blocking high remains the dominant feature.
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