Autumn & the start of Winter 2016
Updated 22nd September 2016
After some record breaking warmth in September, October is expected to see
temperatures generally closer to the norm for the time of year, the
southwest of England potentially bucking that trend though. The air pressure
anomaly shown below does show slightly higher than average pressure across
the north of the British Isles, but this is a fairly weak anomaly so isn't
forecast to have too much of an impact on the rainfall patterns. Western
Scotland, Northern Ireland and perhaps also Southeast England are forecast
to be wetter than average, with other regions nearer to normal.
October Air Pressure
Into the final month of Autumn, and slightly higher than average pressure
anomalies are still in play - generally to the north and also east of the
British Isles. Should it occur (and bearing in mind that confidence always
falls away as we move through the long range forecast), then a fairly
blocked month is on the cards, with rainfall amounts seeing a west to east
split - wettest, and wetter than average in the west. Temperatures are
currently forecast to be close to, or milder than the seasonal norm.
November Air Pressure
Winter - December
Exceptionally low confidence at this stage, with a lot of uncertainty around
the global drivers and likely pattern as we move into Winter. Currently
though, the long range model is again going with slightly higher than
average pressure to the north of the Britain and Ireland. It's a weak
anomaly though, which is to be expected with this amount of uncertainty, but
the phrase 'Northern Blocking' may be used come the winter should something
similar to this play out.
More on this in the next update, plus of course in the full winter forecast
issued during November.
December Air Pressure
UK Winter Forecast:
December: A month dominated
by high pressure. Temperatures close to the average for the UK, with high
pressure dominating across Scandinavia, providing chilly Easterly winds. A
frosty, cold month with light rain showers for the East Coast, which at times
will be wintry. A drier month for Central Britain, however at times the Atlantic
will bring rain and wind for Western Scotland and the West of Northern Ireland.
January: A Colder, Wetter and Wintrier Month.
January is likely to be dominated by low pressure, bringing cold North Westerly
winds, wintry showers and generally fairly wet weather for many areas. At times,
winds will rotate to the NE as high pressure builds over Iceland, providing
chilly Easterly winds, which increases risk of disruptive weather. Temperature: At
or Slightly Below average.Precipitation: Slightly
February - Very Uncertain, chances of dominant blocking.
In weather forecasting, long range forecasts are always experimental. However
signs are that blocking could become even more dominant this month, giving drier
weather than experienced earlier in the winter.
The United Kingdom is positioned on the boundary of major air masses, these air
masses interact with each other in a volatile sense, therefore it is difficult
to predict long range weather. Further updates will be provided, however a
combination of La Nina (jet stream weakening), (and the jet stream provides
usual "wet and windy" weather), lower solar activity (sunspot numbers), is
causing the polar vortex (an area of very cold air over the pole), to be
displaced, this means that for Winter 2016/17, there is a higher risk of cold
air sinking south and affecting mid latitude areas.
The jet stream will still have some strength, and is still likely to poise a
threat, meaning there will be "cold spells" this winter, and in January, these
could be significant. Please stay tuned for further updates, the weather team.