Christmas weather

Libby Greenhalgh looks forward to today's (26 Dec) and this weekend's weather while analysing what happened last weekend in the UK

Merry Christmas everyone. I am sure you are all enjoying Christmas and gearing up for your Boxing Day Race. So what is the weather going to do?

Christmas Day has been exceptionally mild with no snow in sight as expected and Boxing Day will continue with mild temperatures across the country. The morning will start off damp as a low pressure system pushes across central UK producing rain with the occluded system. The wind direction will change from the south east overnight to the south by morning with a further change in direction in the mid-morning as the low centre to the west of Ireland pushes across. This will cause the wind to veer to the south west in the mid morning, but towards midday the direction will return to the south as a second low pressure system follows. The wind strength will oscillate around 15-18 knots with no significant with an increase as the wind goes west in the morning, otherwise remaining fairly constant as a second low pressure system follows on behind bringing further wet weather.

Weekend Outlook

If you are considering getting a quick sail in before the New Year at the weekend may I suggest the Saturday, which will be drier and not as windy as the Sunday. With between 12-16knots form the west o the Saturday. Sunday will see the wind strengthen slightly to between 15-18 knots and back to the southwest as a low pressure system passes to the north of Scotland. Key features to identify will be the location of the frontal systems, which will bring a change in direction and strength.


Weekend Analysis 20th-21st December

Well last weekend the forecast was for good wind on the Saturday between 15-18knots and little to no wind on the Sunday. Anyone who was out and about would have noticed it was the complete opposite.

The fog horns could be heard all Saturday as a weak low pressure centre sat over the south of the UK producing calm conditions reaching only 3 knots at some stations along the coast. The occluded front provided the low cloud and the generally damp and drizzly conditions. The forecast had predicted this situation for the Sunday.

Sunday provided winds between 15-18 knots in the morning from the south that decreased across the afternoon, as the low pressure system tracked across from the Atlantic. These conditions were what were expected on the Saturday.

This was due to the low pressure system expected to provide better conditions for Saturday moving off over Friday night and effectively the forecast jumping on a day.

Satellite images provided some of the best images of the lack of the expected low pressure system as can be seen (see below). The small patch of cloud over the south of the UK represents the weak low pressure centre and the associated occluded front, while to the west the larger cloud represents the approaching frontal systems of the low pressure that provided stronger winds on the Sunday.