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A foggy start: How does fog form?

09:45
14 November 2022

A foggy start
How does fog form?

foggy field

It's been a foggy start for many of us this morning, but how does it form and will it affect your commute?

Autumn and winter is the perfect time for fog to develop, especially in periods of high pressure dominated weather, with weaker winds allowing dense fog to settle, even for days at a time.

This morning's fog that is largely dominating the east of the UK formed under a ridge of high pressure, and will likely be quite slow to budge through the morning. You can find out if it's affecting your area on the WeatherRadar.

There are several types of fog that form in different ways, including valley fog, radiation fog and advection fog. To learn more on exactly how and why fog forms, check out our Weather Explained video below:

Because of the many factors involved, forecasting the arrival and exact location of fog is actually quite tricky. If just one aspect of the development is out of sync, fog is unlikely to form. Cloud cover, wind speeds, temperature, moisture levels, and daylight hours all play a role.

A different type of fog can also occur in sub-zero temperatures, this is called freezing fog and will become a more likely occurrence in the depths of winter, rather than autumn. If you capture any atmospheric shots be sure to send them in via our dedicated uploader.

Foggy mornings

Did you know? The BBC's first bulletin 100 years ago today covered a fog warning!

Weather & Radar editorial team
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