Issued: 1900hrs Sunday 30th December 2007
Duty forecaster: Simon Keeling
Short winter cold snap on the way this week, could be some snow
So, we're all getting ready for the New Year festivities, can you believe it has been a week since Christmas?
This time last week the GFS showed the first signs of a wintry snap coming up. I have to be honest and admit that I didn't take much notice of it then, but as time has gone on and the model has consistently hinted at a colder spell coming through later this week, I have taken more notice. You see, sometimes computer models go off on stange patterns of their own, and the trick in forecasting is deciding when to believe them. This time, the GFS looks about to be proved right.
So, how much of a wintery spells will this be? Well as I type it's probably the short-lived Variety. Things start to hot up, (or should that be cool down) through the day on Tuesday. By Wednesday we'll notice a big difference as the winds become easterly and daytime maximums struggle to 2C in parts of the Midlands and eastern England. Add the effect of that wind and it will feel raw. By Thursday daytime maximums are nearer 1C and that easterly wind is still around.
The GFS has a cold pool at 500hPa moving into the North Sea by midday on Thursday. This highlights the fact that preceipitation is likely to be increasing through the day, soe I think we could start to see some snow flurries overnight into Thursday through eastern coasts of England, these running into the Midlands. Bear in mind that parts of eastern and the higher ground of Scotland may see some snow through Wednesday too.
Latest hints are that the cold pool splits to the north and south of the UK, effectively letting in warmer Atlantic air during the course of the weekend. However, I am not convince by this, I suspect that we might see more of a cold pool linger through the Iberian Peninsula or France for a while, making the easterly winds more persistent and the cold spell then lasting into early next week. I do think Scotland will become milder though.
Let's see what the next run of the models brings.
Simon
Email me at simon.keeling@weatheronline.co.uk