High pressure brings a dry, calm week to Birmingham, but watch out for fog

High pressure is firmly in charge of the weather as the new week begins, bringing Birmingham a run of mostly dry, calm days. The Met Office says the main thing to plan around this week is not rain but fog.

Forecasters have strong confidence in the settled spell. The most likely pattern for Monday gives a 91% chance of high pressure dominating the UK, with a 75% probability for Tuesday, when pressure could reach around 1040 hPa in some areas. That is unusually high, and a sign of a large, slow-moving area of calm weather sitting over the country.

Dry through to Bonfire Night

High pressure is expected to keep influencing the weather through Wednesday, Thursday and Friday, covering Bonfire Night on Thursday, 5 November. Confidence naturally falls further ahead, and the Met Office says it may not be completely dry everywhere, with the possibility of some light showers reaching eastern and south-eastern areas. But the overall message is one of "high pressure, light winds and very limited rainfall for much of the UK".

Where the sunshine breaks through and winds stay light, it could feel pleasantly warm for early November. Places stuck under low cloud, mist or fog could feel much colder. Temperatures are expected to fall gradually over the coming days as the still air settles over the country.

A week of fog

With clear skies and light winds, fog is likely to be one of the main weather themes, and it could be locally dense where skies clear overnight.

The Met Office explains that fog forms when moist air cools to its dew point, the temperature at which water vapour condenses into tiny droplets. In public forecasts, fog generally means visibility below about 180 metres. Dense fog is visibility below 100 metres, when journeys become considerably more difficult, and severe disruption to road transport can happen below 50 metres.

Fog can also be very patchy, clear in one place and thick a short distance away, and some fog clears soon after sunrise while in calmer, colder conditions it can linger into the afternoon.

Driving in fog

The forecaster's advice for drivers is to check the latest forecast before setting off and allow extra time where poor visibility is expected. The Highway Code says headlights must be used when visibility is seriously reduced, generally when you cannot see for more than 100 metres, and motorists should check their lights, including fog lights, are working before they travel.

For the morning school run and commute, that means leaving a little earlier, keeping a safe distance from the vehicle in front and slowing down where fog thickens, particularly on open roads and motorways around the city.

Change by the weekend?

Looking towards the first full weekend of November, the Met Office sees signs of a return to more changeable conditions, although uncertainty is greater that far ahead.

Until then, the outlook is about as kind as early November gets. Anyone planning to go to a firework display this week can look forward to a good chance of dry weather, but should wrap up warm, as clear, calm evenings can turn cold quickly.