Sunday 15 Nov - Tuesday 24 Nov

During this period unsettled conditions are likely in the northwest, bringing spells of rain and wind, perhaps strong winds and gales at times. More settled conditions may establish in the southeast and later into central areas where it will be mainly dry and sometimes bright. Temperatures look to be mild and at times very mild at first with a reduced risk of night frosts. There is a chance that drier brighter conditions may extend UK-wide for a time, where fog patches could prove persistent in places. Although uncertain, later during this period temperatures look to turn cooler, closer to the seasonal average with an increased risk of overnight frosts especially in central and south-eastern areas.

Tuesday 24 Nov - Tuesday 8 Dec

The end of November is likely to be generally settled with high pressure set to dominate, with settled conditions expected to be more prolonged in central and south-eastern areas. However, occasional unsettled periods do remain possible, although likely to be short-lived and mostly affecting north-western areas of the UK. Temperatures are probably remaining around average at first, feeling mild, before possibly turning colder than average into December with increased risk of overnight frosts. The chance of wintery precipitation could also be increasing into December, notably for northern higher ground.

https://www.metoffice.gov.uk/

 

BBC monthly outlook

Summary

Often mild and westerly. Strong winds at times.

_________________________________

Wednesday 11 November – Sunday 15 November

Very mild for mid-November. Wettest in north-west

A massive area of high pressure has developed across most of continental Europe over recent days. It's not expected to be move too far over the next few days. The UK is positioned on the very mild western side of this high pressure area, with winds from south-westerly direction. Over recent days, temperatures have peaked at 16C or 17C.
More very mild weather will feature during the rest of this week.

However, a few changes will occur that will allow episodes of wetter and windier weather to extend a bit further east over England and Wales than we have seen recently.
This will start on Wednesday 11th, when a deeper area of low pressure over Ireland and western Scotland will drive a squally band of heavy rain and strong winds slowly east across the UK by the end of the day. Eastern areas will have a lot of dry weather for most of the day, with the squally rain band arriving during the first half of Wednesday night.

Thursday will offer a drier and sunnier day for many areas, especially across the southern half of the UK, as a transient high pressure ridge scoots from west to east. However, before the day is out, more cloud, wind and rain will advance eastwards over western Scotland and Northern Ireland. The weekend will be very changeable, but often quite windy, as another Atlantic low pressure area gets close to the UK. The most sustained wet weather will be across the north and west.

Monday 16 November – Sunday 22 November

Mild conditions continuing. Wettest in north-west.

The most likely outcome during this week is for a huge area of high pressure to remain situated across much of continental Europe. The UK will once again be located on the milder western side of this high pressure ridge. Atlantic fronts running into western and northern fringes of the UK. Milder than average conditions will continue, including a very mild night on Tuesday 17th into Wednesday 18th. The risk of frost is very low, even in Scotland. A distinct north-west to south-east split in rainfall totals and wind speeds.
The south and east again experiencing less rainfall and wind than would typically occur in mid-November.

Towards the end of this week, high pressure is expected to decline over the near continent and low pressure areas will start to intensify close to Scotland. Westerly winds strengthening more widely over the UK, with periods of heavy rain making their presence felt across many parts by the weekend of 21st and 22nd. After the very mild weather for much of the week, don't be surprised if a brief blast of cold winds from the north-west races into Scotland during the weekend.

Monday 23 November – Sunday 6 December

Often windy and quite wet. Short cold snaps.

The latest forecast signals for the end of November and into December continue to suggest that the threat of a widespread and sustained cold spell over the UK is low and seems unlikely. Deep areas of low pressure frequently passing eastwards across the north Atlantic, between Scotland and Iceland, and then into southern Scandinavia will prevent a sustained period of cold Arctic winds from firmly establishing.

Brisk westerly winds and fast moving frontal systems racing across the UK will feature, with short-lived periods of drier, brighter and sunnier weather between them. Wettest over western areas, especially western Scotland. Some very strong winds are possible on a few days, perhaps leading to some disruption. High pressure will be closest to Wales and the southern and western half of England, so a few drier and less windy days are most likely here.

Although it will often be quite mild, the low pressure track will occasionally dip southwards over central Europe towards the Alps and Italy. This will pull in winds from the north or north-west into the UK, leading to colder snaps, with night frosts and squally wintry showers. The greatest likelihood of snowfall will be over the hills in the north and west, especially in Scotland. A couple of these short cold snaps might be expected to occur during the course of this two week period. But they will not last more than about 2 or 3 days, before the mild westerlies return.

Further ahead

We'll update on the threat of strong and damaging wind events and short cold snaps during late November and early December, and see if the chance for these has increased or decreased.

https://www.bbc.co.uk/weather/outlook

 

Monday 16 Nov - Wednesday 25 Nov

During this period unsettled conditions are likely in the northwest, bringing spells of rain and wind, perhaps strong winds and gales at times. More settled conditions may establish in the southeast and later into central areas where it will be mainly dry and sometimes bright. Temperatures look to be mild and at times very mild at first with a reduced risk of night frosts. There is a chance that drier brighter conditions may extend UK-wide for a time, where fog patches could prove persistent in places. Although uncertain, later during this period temperatures look to turn cooler, closer to the seasonal average with an increased risk of overnight frosts especially in central and south-eastern areas.

Wednesday 25 Nov - Wednesday 9 Dec

The end of November is likely to be generally settled with high pressure set to dominate, with settled conditions expected to be more prolonged in central and south-eastern areas. However, occasional unsettled periods do remain possible, although likely to be short-lived and mostly affecting north-western areas of the UK. Temperatures are probably remaining around average at first, feeling mild, before possibly turning colder than average into December with increased risk of overnight frosts. The chance of wintery precipitation could also be increasing into December, notably for northern higher ground.

https://www.metoffice.gov.uk/

 

Wednesday 18 Nov - Friday 27 Nov

Unsettled weather by Wednesday bringing outbreaks of rain, heavy at times, for the North and the northwestern parts of the country. During the rest of the week unsettled conditions continue with spells of rain followed by brighter, showery interludes. In the northwest, rain, strong winds and gales at times. During late November more settled conditions may establish in central and southeastern areas where it will be mainly dry and sometimes bright. Temperatures look to be mild on Wednesday, but they are likely to return to near the seasonal average by the end of next week, with an increased risk of overnight frosts. There is a chance that drier brighter conditions may extend UK-wide at times. Although uncertain, temperatures are looking to become colder by the end of this period.

Friday 27 Nov - Friday 11 Dec

By the end of November and middle of December it is likely settled conditions could develop more widely with high pressure set to dominate. However, occasional unsettled interludes are still likely with outbreaks of rain and strong winds mostly affecting northwestern areas of the UK. Temperatures are probably remaining around average at first, before possibly turning colder than average into December with increased risk of overnight frosts. The chance of wintry precipitation could also be increasing into December, notably for northern higher ground.

https://www.metoffice.gov.uk/

 

Thursday 19 Nov - Saturday 28 Nov

Unsettled weather by Wednesday bringing outbreaks of rain, heavy at times, for the North and the northwestern parts of the country. During the rest of the week unsettled conditions continue with spells of rain followed by brighter, showery interludes. In the northwest, rain, strong winds and gales at times. During late November more settled conditions may establish in central and southeastern areas where it will be mainly dry and sometimes bright. Temperatures look to be mild on Wednesday, but they are likely to return to near the seasonal average by the end of next week, with an increased risk of overnight frosts. There is a chance that drier brighter conditions may extend UK-wide at times. Although uncertain, temperatures are looking to become colder by the end of this period.

Saturday 28 Nov - Saturday 12 Dec

By the end of November and into the middle of December it is likely settled conditions could become more wildly developed, with high pressure set to dominate. However, occasional unsettled periods are still possible with outbreaks of rain and strong winds most likely to affect northwestern areas of the UK. Temperatures are probably remaining around average at first, before possibly turning colder than average into December with an increased risk of overnight frosts. The chance of wintry precipitation could also be increasing into December, notably for northern higher ground.

https://www.metoffice.gov.uk/

 

BBC monthly outlook

Summary

Mild weather less sustained. Short cold snaps.

_________________________________

Saturday 14 November – Sunday 22 November

Very mild until middle of next week. Unsettled.

The weekend of 14th and 15th November will be very unsettled over the UK, due to a large low pressure area from the north Atlantic passing slowly eastwards overhead. Saturday will feature overcast skies for nearly all of us, with bands of rain pushing north-eastwards. Some heavy and prolonged in western and south-western areas.
Fresh to strong south-westerly winds for us all, helping to remove quite a few more autumn leaves. Turning more showery on Sunday, with a few sunny intervals between the showers. Staying windy, especially across the south. Some of the showers will contain hail and thunder as they pass over the southern and western coasts and hills of the UK.

The first half of next week will be very mild, as we see yet another surge of south-westerly winds, transporting warmth and moisture towards us from the sub-tropical Atlantic.
Temperatures peaking at 12 to 15C widely on Tuesday, locally 16C in some northern and eastern areas, downwind of hills and mountains. Tuesday night will be extremely mild too, with temperatures falling no lower than 12C or 13C in some southern locations. Wet weather will especially affect the north and west, heavy and prolonged for a time, but this will clear the UK late on Wednesday.

A change by Friday, as winds swing into the north-west. Colder air moving in for a couple of days, so the threat of some frost in the north and some wintry showers. More wet weather will sweep east across England and Wales on 21st and 22nd.

Monday 23 November – Sunday 29 November

Less mild than recent weeks. Staying unsettled.

A low pressure track near or overhead the UK is very likely during the final week of November. So we can all expect some more rain, alongside some blustery winds. However, the fine detail for this particular week has been tricky to pin down over the last few days, with forecast computer models showing a lot of variability in where they expect the focus of the low pressure track to be.

The most likely outcome is that high pressure will only occasionally influence the weather over the far south and south-west of the UK. So the best chance for a few drier and brighter days will be here. Low pressure areas from the Atlantic should extend their influence widely on many days. The trend in the computer models has been wetter and windier weather more widely. There will also be some cold air digging in from the north for a few days too.

Temperatures variable, but the week will probably end up close to average as the mild spells cancel out the colder days. After the very mild mid-November period, there is a greater likelihood of some frost in places and some wintry showers over northern hills.

Monday 30 November – Sunday 13 December

Often windy and quite wet. Short cold snaps.

A severe and sustained cold spell over the UK in the first half of December currently seems unlikely. Deep areas of low pressure frequently passing eastwards between Scotland and Iceland, into Scandinavia, will prevent a sustained period of cold Arctic winds from firmly establishing. Nevertheless, we should be wary of a couple of short-lived cold snaps, when winds swing into the north for a few days.

This weather pattern most recently occurred in December 2017. There were several dramatic swings in temperature during that month, from very mild to colder than average in just 2 or 3 days. For example, on 7th December 2017, temperatures across the southern half of England were very mild and widely above 10C. Just 3 days later, midday temperatures over Wales and the Midlands were hovering around freezing, with 15-20cm of snow lying on the ground!

While this is a dramatic example of how UK weather patterns can flip during winter westerly spells, don't be too surprised to see swings in temperature during this December, rather than sustained mild conditions. Sharp frost and scattered sleet and snow showers are possible on a few days, especially over northern areas. The silver lining with westerly Decembers is that they can actually be quite sunny! This is especially true over southern and eastern parts of the UK when the monthly averaged wind direction is a little to the north of west. Rain bearing weather fronts tend to be fast moving, with sunny breaks between them.

December 2011 was a very westerly month over the UK and sunshine amounts were above average quite widely in the east, despite it also being quite wet.
Winds from the south and south-west in December often result in much more extensive cloud cover, mist, hill fog and periods of prolonged rain and drizzle.

Further ahead

Getting a fix on the timing and magnitude of any upcoming cold snaps will remain our key focus, especially as November has been very mild so far!

https://www.bbc.co.uk/weather/outlook

 

Friday 20 Nov - Sunday 29 Nov

Unsettled weather by Wednesday bringing outbreaks of rain, heavy at times, for the North and the northwestern parts of the country. During the rest of the week unsettled conditions continue with spells of rain followed by brighter, showery interludes. In the northwest, rain, strong winds and gales at times. During late November more settled conditions may establish in central and southeastern areas where it will be mainly dry and sometimes bright. Temperatures look to be mild on Wednesday, but they are likely to return to near the seasonal average by the end of next week, with an increased risk of overnight frosts. There is a chance that drier brighter conditions may extend UK-wide at times. Although uncertain, temperatures are looking to become colder by the end of this period.

Sunday 29 Nov - Sunday 13 Dec

By the end of November and into the middle of December it is likely settled conditions could become more wildly developed, with high pressure set to dominate. However, occasional unsettled periods are still possible with outbreaks of rain and strong winds most likely to affect northwestern areas of the UK. Temperatures are probably remaining around average at first, before possibly turning colder than average into December with an increased risk of overnight frosts. The chance of wintry precipitation could also be increasing into December, notably for northern higher ground.

https://www.metoffice.gov.uk/

 

Saturday 21 Nov - Monday 30 Nov

Spells of rain will spread southwards across England and Wales on Saturday with brighter, showery conditions in Scotland and Northern Ireland. Sunny spells are expected in the south of the UK on Sunday with blustery showers across the north. For the remainder of November conditions will begin to become more widely settled, especially across the south and east where there will be an increased risk of slow clearing fog. Unsettled interludes bringing spells of rain and strong winds are still likely at times, especially in the north and west. Temperatures look to be around average with increasing incidence of overnight frost, as is typical for this time of year, as well as bringing an increasing chance of wintry precipitation.

Monday 30 Nov - Monday 14 Dec

Heading into the middle of December, high pressure is likely to become the dominant weather pattern across the UK, bringing settled conditions to many parts. Occasional unsettled periods with outbreaks of rain and strong winds are still likely at times, these most likely to affect northwestern areas of the UK. Temperatures will probably be close to or below average with an increasing chance of wintry precipitation, notably for higher ground in the north.

https://www.metoffice.gov.uk/

 

Sunday 22 Nov - Tuesday 1 Dec

Sunny spells are expected over central areas of the UK on Sunday with blustery showers across the north. Monday will see generally fine and settled conditions. However, clear spells and light winds provide potential for fog patches and morning frost. For the remainder of November, conditions will begin to become more widely settled, especially across the south and east where there will be an increased risk of slow clearing morning fog. Unsettled interludes bringing spells of rain and strong winds are still likely at times, especially in the north and west. Temperatures look to be around average with increasing incidence of overnight frost, as is typical for this time of year, as well as bringing an increasing chance of wintry precipitation over high ground.

Tuesday 1 Dec - Tuesday 15 Dec

Heading into the middle of December, high pressure is likely to become the dominant weather pattern across the UK, bringing settled conditions to many parts, and an increased chance of fog. Occasional unsettled periods with outbreaks of rain and strong winds are still likely at times, these most likely to affect northwestern areas of the UK. Temperatures will probably be close to or below average with an increasing chance of wintry precipitation and overnight frost, notably for higher ground in the north.

https://www.metoffice.gov.uk/

 

BBC monthly outlook

Summary

Unsettled conditions continuing. Short cold snaps.

_________________________________

Wednesday 18 November – Sunday 22 November

A short cold spell on Thursday. Otherwise mild.

Wednesday will be another unusually mild mid-November day, with maximum temperatures climbing to 16C, perhaps even 17C in a few areas. After a dry and locally bright start over eastern England, it will be windy and unsettled again, as another low pressure area moves in. Wednesday night will see winds peak in strength across the UK, with gusts of 55-65mph over exposed western and northern areas. Even across sheltered inland parts of England, maximum gusts will get close to 40mph.

A significant change in temperature will occur during Thursday, as a colder north-westerly wind sets in. But there will also be widespread sunny spells for many of us, and only a few showers. In northern Scotland, the showers will be heavy and frequent, falling readily as sleet and snow as a cold Arctic blast arrives. Some local snow accumulations are likely, even at low levels. Widespread clear spells and winds easing on Thursday evening will lead to the coldest night since early November. Eastern areas will see a frost. A new frontal system will push cloud, rain and milder air raidly into many western and northern areas during the second half of the night. Snow for a time over the Scottish high ground before it turns milder.

The rest of the week will be mild and windy, as a deep Atlantic low pressure area returns strong westerly winds. Wettest over western Scotland, Cumbria and north-west Wales, while the south and east of the UK will have some drier weather with a few sunny intervals.

Monday 23 November – Sunday 29 November

Milder than average. Wet and windy.

A low pressure track near or overhead the UK is very likely during the final week of November, so we can all expect some more rain coupled with blustery winds. The fine detail for this particular week has been tricky to pin down over the last few days, with forecast computer models showing a lot of variability in where they expect the focus of the low pressure track to be.

The most likely outcome is that high pressure will be quite extensive over the near continent, more than we predicted in the previous update. This high pressure influence will help to steer the jet stream and its associated Atlantic low pressure areas just to the north and west of the UK on many days, with winds often blowing in from a mild south-westerly direction.

This means that cold snaps are less likely and mild weather patterns should predominate, even at night. If we do see a cold snap it will just be for one or two days and most likely over northern and eastern areas of the UK. Further bands of heavy rain and brisk south-westerly winds will feature. Gales are possible in the north during the second half of the week. North-western areas will be wetter than average, while rainfall amounts across the south and east will be closer to average, with most of the rain falling in the second half of the week.

Monday 30 November – Sunday 6 December

Westerly winds and unsettled. Brief cold snaps.

The latest forecast guidance continues to indicate that winds from a westerly direction will dominate the first half of December. This means that UK temperatures will be close to, or a little above the seasonal average for this 2 week period as whole. The prospect of a sustained and very cold weather pattern, with severe frosts and widespread lowland snowfall, as we saw in December 2010, is very unlikely.

Nevertheless, we should be wary of a couple of short-lived cold snaps, when winds swing into the north for a few days. This weather pattern most recently occurred in December 2017. There were several sharp swings in temperature during that month, from very mild to cold in just 2 or 3 days. For example, on 7th December 2017, temperatures across the southern half of England were mild and widely above 10C. Just 3 days later, midday temperatures over Wales and the Midlands were hovering around freezing, with 20cm of snow lying on the ground! While this a rare and dramatic example of how UK weather patterns can flip during winter westerly spells, don't be too surprised to see a few sharp swings in temperature during this December, rather than sustained mild conditions. Sharp frost and scattered sleet and snow showers are likely on a few days, especially over northern areas.

The silver lining with westerly Decembers is that they can actually be quite sunny! This is especially true over southern and eastern parts of the UK when the monthly averaged wind direction is a little to the north of west. Rain bearing weather fronts tend to be fast moving, with sunny breaks between them. December 2011 was a very westerly month over the UK and sunshine amounts were above average quite widely in the east, despite it also being quite wet.

Further ahead

The lead up to Christmas will soon be in the forecast range! We'll be focussing our attention on pinning down the detail for December and identifying the most likely time for a pre-Christmas cold snap.

https://www.bbc.co.uk/weather/outlook

 

Sunday 22 Nov - Tuesday 1 Dec

Sunny spells are expected over central areas of the UK on Sunday with blustery showers across the north. Monday will see generally fine and settled conditions. However, clear spells and light winds provide potential for fog patches and morning frost. For the remainder of November, conditions will begin to become more widely settled, especially across the south and east where there will be an increased risk of slow clearing morning fog. Unsettled interludes bringing spells of rain and strong winds are still likely at times, especially in the north and west. Temperatures look to be around average with increasing incidence of overnight frost, as is typical for this time of year, as well as bringing an increasing chance of wintry precipitation over high ground.

Tuesday 1 Dec - Tuesday 15 Dec

Heading into the middle of December, high pressure is likely to become the dominant weather pattern across the UK, bringing settled conditions to many parts, and an increased chance of fog. Occasional unsettled periods with outbreaks of rain and strong winds are still likely at times, these most likely to affect northwestern areas of the UK. Temperatures will probably be close to or below average with an increasing chance of wintry precipitation and overnight frost, notably for higher ground in the north.

https://www.metoffice.gov.uk/

 

Sunday 22 Nov - Tuesday 1 Dec

Sunny spells are expected over central areas of the UK on Sunday with blustery showers across the north. Monday will see generally fine and settled conditions. However, clear spells and light winds provide potential for fog patches and morning frost. For the remainder of November, conditions will begin to become more widely settled, especially across the south and east where there will be an increased risk of slow clearing morning fog. Unsettled interludes bringing spells of rain and strong winds are still likely at times, especially in the north and west. Temperatures look to be around average with increasing incidence of overnight frost, as is typical for this time of year, as well as bringing an increasing chance of wintry precipitation over high ground.

Tuesday 1 Dec - Tuesday 15 Dec

Heading into the middle of December, high pressure is likely to become the dominant weather pattern across the UK, bringing settled conditions to many parts, and an increased chance of fog. Occasional unsettled periods with outbreaks of rain and strong winds are still likely at times, these most likely to affect northwestern areas of the UK. Temperatures will probably be close to or below average with an increasing chance of wintry precipitation and overnight frost, notably for higher ground in the north.

https://www.metoffice.gov.uk/

 

We shall see then?

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Wednesday 25 Nov - Friday 4 Dec

Outbreaks of rain are expected to cross the UK on Wednesday, with western areas receiving the heaviest rain. Blustery heavy showers are also likely to affect the far north of Scotland. Thursday and Friday could see further rainfall and strengthened winds for the north and west, but elsewhere the weather is likely to become more settled and colder, increasing the risks of frosts and morning fog. For the remainder of November and start of December, conditions will likely become more unsettled, with successive weather systems bringing rain and strong winds to the UK. Temperatures look to be around average for this time of year during this period, feeling reasonably cold with snow only likely on mountains, but it will turn mild at times when rain and cloud are present.

Friday 4 Dec - Friday 18 Dec

Heading into the middle of December, the UK's weather it is likely to remain changeable and unsettled, resulting in a mixture of rainy days and days with spells of sunshine and showers. The northwest is expected to receive the most rain and could see gales or severe gales at times. The south of the UK is expected to see the driest and brightest weather during this period, though still seeing rain at times. It will become more settled in the south going into the second half of December, with fog patches and frosts likely. Temperatures will probably be close to or below average with an increasing chance of wintry precipitation, especially over higher ground in the north.

https://www.metoffice.gov.uk/

 

A tangible change to the December outlook. The Met Office are now saying it will remain largely changeable and unsettled. More settled in the south. I can already see that big fat high pressure sat over mainland Europe ....

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A tangible change to the December outlook. The Met Office are now saying it will remain largely changeable and unsettled. More settled in the south. I can already see that big fat high pressure sat over mainland Europe ....

The interesting thing is that while they have dropped their thoughts of more settled weather in December, they don't seem to have altered their thoughts much if at all wrt temperatures. It looks to me as if they may be expecting zonality of the cool or cold type as opposed to the very mild stuff.

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Anyone see the weather for ben Nevis and Cairngorm!?

Looks like it could be a snowy one for the Scot Mountains with cold zonality ruling the roost.

https://www.metoffice.gov.uk/weather/forecast/gfjkvjeuz#?date=2020-11-22 

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Anyone see the weather for ben Nevis and Cairngorm!?

Looks like it could be a snowy one for the Scot Mountains with cold zonality ruling the roost.

https://www.metoffice.gov.uk/weather/forecast/gfjkvjeuz#?date=2020-11-22

If only we all lived at over 4000ft asl it would be wintry most winters. 

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Anyone see the weather for ben Nevis and Cairngorm!?

Looks like it could be a snowy one for the Scot Mountains with cold zonality ruling the roost.

https://www.metoffice.gov.uk/weather/forecast/gfjkvjeuz#?date=2020-11-22

Certainly an exciting development to see snow forecast on Nevis and Cairngorm in late November.  

PS:  quick...there's a dusting at the Ptarmigan

https://www.cairngormmountain.co.uk/weather-webcams/live-webcams/

 

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BBC monthly outlook

Summary

Continued westerly pattern, through to December

_________________________________

Saturday 21 November – Sunday 29 November

A similar week to the one we are just ending!

A deep Atlantic low pressure area will pass eastwards close to northern Scotland this weekend. Its warm front crossed the UK on Friday daytime, and brought all of us some wet weather, but also a return to milder air, after the short cold snap on Thursday night. A narrow band of rain, the cold front, will move south-east during the day.
But there will be a few sunny intervals over eastern England ahead of it and sunny spells and scattered showers in its wake.

Sunday will be a less windy day in the south, with sunny spells. Scattered showers across the north, where brisk westerly winds will continue. Next week is actually looking very similar to the week just gone! Very mild south-westerly winds between Monday and Wednesday will bring rain to all parts, heaviest in the north and west, while the south-east has much less rain. A change to cooler air on Thursday, but lingering showery rain will affect southern and eastern England for a time, as it did last Thursday. A brief colder snap on Thursday night with some frost, before wet and windy weather sets back in by next Friday evening and the weekend.

Monday 30 November – Sunday 6 December

Wet and windy spells. Squally showers.

High in the atmosphere around the North Pole, a belt of strong westerly winds is predicted to become very strong during this week. Each autumn a 'Stratospheric Polar Vortex' develops, as the column of air above North Pole receives less and less daylight and then no daylight at all for a few months, so it rapidly cools. The polar vortex forms around the edge of this mass of cold polar air, but it can vary in strength and sometimes breakdown. The changes in its strength can have some influence on our weather during the winter.

When the Polar Vortex becomes stronger than average in the winter, it can help to intensify the low pressure track across the north Atlantic and facilitate its longevity. This process occurred last winter, in February 2020, when the UK was bombarded by frequent wind storms in. And it seems to be occurring again at the start of this winter. Expect to see frequent, deep Atlantic low pressure areas moving eastwards near to the UK, pushing rain bands eastwards at regular intervals. Short-lived 'shots' of cold polar air will occasionally sweep out of Greenland and over the UK, especially Scotland. This will bring cold and showery days, with some hail, sleet and upland snow in the north and west.
But milder winds from the west and south-west will be most frequent, keeping many days of this week slightly warmer than the long term average.

Monday 7 December – Sunday 20 December

Westerly pattern will continue, stormy at times.

The latest forecast guidance continues to indicate that winds from a westerly quadrant will continue throughout mid-December. The prospect of a sustained and very cold weather pattern, with severe frosts and widespread lowland snowfall, as we saw in December 2010, is very unlikely. Nevertheless, we should be wary of a couple of short-lived cold snaps, when winds swing into the north-west for a few days, before flicking back around to a milder south-westerly direction. These rapid changes in temperature and forecast hazards certainly keep the forecasters on their toes, but they can also be hazardous for travelling.

A very wet spell, followed by a couple of cold and frosty nights means that even after the roads and pavements have been treated with salt, water running off from nearby saturated fields can dilute the salt or sometimes even wash it off. This can lead to an increased risk of some ice by the end of the night. This changeable mild to cold weather pattern most recently occurred in December 2017 - a mild westerly month overall. But still with some cold snaps and a couple of locally heavy snow events that led to some disruption. The most likely weather hazards during this period will be strong winds and heavy rainfall, especially during the week of Monday 13th to Sunday 20th. The latest forecast models predict a higher probability of stormy conditions. Already there are some strong signals in the forecast guidance for gales to feature in December.

Further ahead

The lead up to Christmas is getting into forecast range! We'll be focussing our attention in getting the detail for December correct and identifying the most likely times for hazardous weather.

https://www.bbc.co.uk/weather/outlook

 

Well, that's just piddled on the bonfire. 

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