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Terry Scholey's Monthly weather outlook. Terry is a midlands meteorologist and forecaster.
December 2013 Final Update
Persistent high pressure at this time of year can often lead to cold northerly outbreaks and this seems to be the case towards the end of the first week. Another weather type more likely in the second half of December is a ‘blocking’ or partially ‘blocking’ anticyclone either to the east or south. Both will cause the ‘Jet Stream’ to fluctuate perhaps sometimes quite wildly, bringing short but noticeable unsettled intervals that could be windy and occasionally wintry.
The effect of this could produce some stark temperature variations, in probably a colder than average month in the north and east that may also be drier than normal in most parts. Confidence is only medium due to placement problems and the extent of ‘blocking’ later.
December 1st to 4th: High pressure gives mainly dry, quiet weather, with patchy fog and frost under clear skies at night. Later it turns somewhat unsettled from the north west, with a few showers mostly over Scotland and Ireland. Top temps 4 to 9C. Min temps –3 to +3C.
December 5th to 9th: The first of those promised cold northerly outbreaks, with blustery showers particularly in the north and east turning wintry. Some snow is likely over Scotland and probably mostly on hills farther south, before it becomes mainly dry and quieter again as pressure rises. This will give sunny spells by day but very cold nights, with moderate frost and also a few freezing mist or fog patches. Max temps 2 to 6C. Min temps –5 to +3C.
December 10th to 13th: Becoming windy, milder and unsettled over Scotland, Ireland and in the west. In the east and south high pressure may ‘hang on’ giving further mainly weather, with night frost and still the risk of patchy fog. Top temps 2 to 5C in the east and south and 7 to 10C in the north and west. Min temps 4 to 7C in the west and –2 to +2C in the east.
December 14th to 22nd: An unsettled probably cold period seems likely, but temperatures will vary particularly in the south. Occasional rain or showers are expected between brief drier, brighter intervals. Another cold northerly outbreak could give some snow mostly in the north. Max temps say 2 to 7C, with min values mostly in the range –2 to +4C.
December 23rd to 27th: A quieter, finer spell seems likely into Christmas, but it could be a cold one particularly in the east and south with frost and patchy fog perhaps freezing. Scotland, Ireland and the north west should turn milder, breezier and unsettled through the holiday, this probably spreading to most parts later. Max temps 5 to 9C but locally only 1 or 2C in the east where fog lingers. Min temps –3 to +4C at first then somewhat milder nights.
December 28th to 31st: Unsettled and windy, but probably much milder for a time. Towards the New Year it may turn colder from the north with perhaps ice and snow ice particularly over Scotland. Top temps 8 to 11C for a while, with min values 3 to 7C then colder.