SSEN's Weather Watch for December 2019
The southerly displaced jet stream during November gave us an unusual rainfall distribution. The Met Office map - illustrated above - shows the wet and dry precipitation anomalies; blue being wetter than average and the brown shading shows drier than normal. November was the sixth consecutive month to be wetter than average in England.
Not surprisingly, the ground is generally wetter than normal for the time of year. The soil moisture anomaly map (in the summary image) is for the week ending 25th November and shows wet soils in west and north of Europe, but dry soils in parts of eastern Europe and across Turkey. Any heavy rainfall events coming to northwest Europe in December will enhance the flooding risk, as the ground is mostly saturated.
Looking to December, we are expecting a very changeable month in terms of weather. The first few days will start colder than average with night frosts and fairly light winds but mostly sunny days, the we'll see a rapid change during the period of 5th December to 8th December, as a strong westerly wind from the Atlantic brings some cloudy and wet spells. After a long dry period in western Scotland, they too can expect a few days of heavy rain, most notable around the 6th December.
It’s also possible the highest recorded wind power in Great Britain could be broken on 6th December, due to the strong and steady winds across the country.
The week commencing 9th December could see another change as the jet stream starts to sink to the south once again. If this were to happen as expected, we’ll find it turning colder and less windy from the north, and just before mid-month there could be some snow to the higher ground. It would be best to check your local forecasts nearer the time to see how the weather patterns are expected to play out.
Just after mid-month the weather could turn wet and windy again with relatively mild and cloudy weather coming in from the nearby Atlantic. It should also become frost-free for most of us.
To summarise, it’s looking typically changeable for December with temperatures, rainfall and wind speeds to come in close to average for the month as a whole.
For more weather information you can follow our meteorologist, Simon Cardy on twitter @weather_king.