Our change in the weather and how the jet stream is driving it

13 12 2013

After a quiet spell of weather courtesy of a slow moving area of high pressure, we are now entering an unsettled period as a series of Atlantic depressions are expected to pass close to the northwest of Britain during the next week.

High pressure has now moved away and is settled over Europe and a powerful jet stream is developing over the Atlantic which will be the main driving force behind this spell of unsettled weather.

What is the jet stream?

The jet stream is a band of fast moving westerly winds high up in the atmosphere which circle around the pole in the northern hemisphere. It can feature winds of up to 200 knots (230 mph) or more, and these winds tend to guide wet and windy weather systems which come in off the Atlantic.

The jet moves around a fair bit and its position can have a big impact on weather here in the UK depending on where it is.

If the jet is over the UK or just to the south, we tend to get a lot of wet and windy conditions as it brings weather systems straight to us. If the jet is to the north of us, it guides that changeable weather away to the north to leave the UK with more settled conditions.

What’s the jet stream doing now?

Unsurprisingly given the outlook for the next week, with a succession of Atlantic depressions passing by to the northwest of Scotland, the jet is positioned to the northwest of the UK too.

As you can see from the picture below, the jet currently swoops east from Canada – swinging northeast over the Atlantic towards the UK.

Forecast position of jet stream at midday Saturday 14 December 2013

Forecast position of jet stream at midday Saturday 14 December 2013

Closer to the ground very cold air is also streaming south from Canada and meeting warm air moving north from the Caribbean. It is where these two air masses meet under the jet stream that powerful Atlantic depressions form and are blown across the ocean towards our shores.

It is these depressions that bring a significant risk of severe gales and heavy rain affecting at least the northwest of the UK at times.

What’s the weather outlook?

Currently, Met Office National Severe Weather Warnings have been issued for wind across some northwestern and northern areas for the weekend. Gusts of 60-70 mph are likely with a risk of gusts to 80 mph or more across exposed parts of northwest Scotland.

However, at this stage there remains uncertainty regarding the extent of the strongest winds and these warnings will be updated as the weather develops over the weekend.

Looking ahead, while we expect further depressions to develop it is not possible to say exactly how vigorous they may be or pinpoint where they will be in a week’s time. This means it is too early to say which areas will experience the strongest winds and heaviest rain, however there are indications that  areas further to the south of the UK may be affected at times.

You can stay up to date with what to expect with our detailed forecasts out to 5-days and our weather warnings, as well as a general view of what we expect out to 30 days and find out what to do in severe weather

You can find out more about the jet stream in our YouTube video.

 





UPDATED: Wind and rainfall data 4 to 5 December 2013

5 12 2013

UPDATED TO INCLUDE LATEST WIND SPEEDS AS AT 3PM, 5 DECEMBER 2013

As forecast, there have been severe gales with widespread gusts of between 60 and 80mph across Scotland and northern parts of England. Some very high level mountain sites have reported speeds of over 140mph, but these are in very exposed areas and not representative of the winds most people have experienced.

UK MAX HOURLY GUST SPEED 4 DEC 1800HRS – 5 DEC 0600HRS
SITE NAME AREA ELEVATION MAX GUST SPEED (MPH)
ALTNAHARRA SUTHERLAND 81 93
LOCH GLASCARNOCH ROSS & CROMARTY 269 92
DRUMALBIN LANARKSHIRE 245 90
SOUTH UIST RANGE WESTERN ISLES 4 89
HIGH BRADFIELD SOUTH YORKSHIRE 395 87
EMLEY MOOR WEST YORKSHIRE 267 86
STORNOWAY AIRPORT WESTERN ISLES 15 85
ORLOCK HEAD DOWN 35 84
KINLOSS MORAY 5 83
SPADEADAM CUMBRIA 285 83
ESKDALEMUIR DUMFRIESSHIRE 236 83
SKYE: LUSA WESTERN ISLES 18 83
TIREE ARGYLL 9 82
DUNSTAFFNAGE ARGYLL 3 82
 MOUNTAIN SITES MAX GUST SPEED 4 DEC 1800HRS – 5 DEC 0600HRS
SITE NAME AREA ELEVATION MAX GUST SPEED (MPH)
AONACH MOR INVERNESS-SHIRE 1130 142
CAIRNWELL ABERDEENSHIRE 928 137
BEALACH NA BA ROSS & CROMARTY 773 116
GREAT DUN FELL CUMBRIA 847 113
GLEN OGLE PERTHSHIRE 564 106

It has been very wet in some areas overnight as well with 50.8mm of rain being recorded at Tyndrum, Perthshire and 42.4mm at Cluanie Inn, Ross & Cromarty.





Overnight lows and the latest snow depths

19 01 2013

As forecast temperatures fell well below zero across the UK last night and the heaviest of the snow started to ease in most areas.

The lowest temperature recorded at a Met Office observing station was Edinburgh, Gorgarbank, at -4.3 C and at 9am this morning the deepest snow cover was 27 cm at Lough Fea, Londonderry.

Lowest temperatures overnight 18 to 19 January 2013:

Location Area Temperature (Celsius)
Edinburgh Gogarbank                 Midlothian           -4.3
Lake Vyrnwy             Powys                -4.3
Pennerley                           Shropshire           -4.0
Tredegar Bryn Bach Park     Gwent                -3.5
Crosby                              Merseyside           -3.4
Libanus                             Powys                -3.4
Leek, Thorncliffe                   Staffordshire        -3.3
Little Rissington                   Gloucestershire      -3.3
Sennybridge                    Powys                -3.2
Carterhouse                         Roxburghshire        -3.1
Salsburgh                           Lanarkshire          -3.1
Keele                               Staffordshire        -3
Emley Moor                     West Yorkshire       -2.9
Astwood Bank                        Hereford & Worcester -2.8
Winterbourne                  West midlands        -2.8
Aviemore                            Inverness-shire      -2.7
Bingley                        West Yorkshire       -2.7
Liscombe                            Somerset             -2.7
Pateley Bridge Ravens Nest          North Yorkshire      -2.7
Spadeadam                     Cumbria              -2.7

Snow depths at 9am Saturday 19 January 2012:

Location Area Elevation Snow depth (cm)
Lough Fea              Londonderry          225 27
Sennybridge       Powys                307 22
Little Rissington      Gloucestershire      210 20
Loftus                 Cleveland            158 16
Liscombe               Somerset             348 16
Filton                 Avon                 59 16
Brize Norton           Oxfordshire          82 12
Hereford, Credenhill   Hereford & Worcester 76 11
Nottingham, Watnall    Nottinghamshire      117 11
Larkhill               Wiltshire            132 11
Albemarle              Northumberland       142 10
Cranwell               Lincolnshire         63 10
Benson                 Oxfordshire          57 10
Leconfield             Humberside           7 10
Redesdale Camp         Northumberland       211 9
Middle Wallop          Hampshire            90 9
Boscombe Down          Wiltshire            126 8
Aboyne            Aberdeenshire        140 8
Wittering              Cambridgeshire       73 8
Coningsby              Lincolnshire         6 7
Leek, Thorncliffe      Staffordshire        298 7
Northolt               Greater London       33 7
Leeming                North Yorkshire      33 6
Marham                 Norfolk              21 6
Shawbury               Shropshire           72 6
Bingley          West Yorkshire       262 6
Waddington             Lincolnshire         68 6
Odiham                 Hampshire            118 6
Eskdalemuir            Dumfriesshire        236 5
Hurn                   Dorset               10 5
Scampton               Lincolnshire         57 5
Charlwood              Surrey               67 5
Coleshill              Warwickshire         96 5
Wattisham              Suffolk              89 4
Boulmer                Northumberland       23 4
Dyce                   Aberdeenshire        65 4
Bedford                Bedfordshire         85 3
Trawsgoed              Dyfed                63 3
Church Fenton          North Yorkshire      8 3
Linton on Ouse         North Yorkshire      14 3
Heathrow               Greater London       25 3
Edinburgh, Gogarbank   Midlothian           57 3
St Athan               South Glamorgan      49 3
Herstmonceux, West End East Sussex          52 2

The cold weather is set to continue for the remainder of the weekend and ice is expected to be a major hazard, keep up to date with your local forecast for the latest update.





Be weather aware with our Windows Phone 8 app

13 12 2012

The Met Office has launched its latest addition to mobile forecasts with a specially designed app for Windows Phone 8.

Since it’s launch in the last two weeks it has garnered some very positive reviews with Windows Phone Central saying:

“We’re always pleased to see official apps hit the platform but even more so when those apps are truly useful. … this [app] stands out for a few reasons. The Met Office is the UK’s National Weather Service and is therefore the trusted supplier of weather information to everyone from the military or the man on the street”.

In addition All About Windows Phone said:

“The standout feature of the Met Office app is the quality of the data on offer…. it’s hard to think of another weather app, for Windows Phone, that provides this amount of detail for those in the UK. …Given that the Met Office app is a free download, we would strongly recommend that anyone living in the UK download it… There’s a good chance that you’ll make your friends living outside the UK rather jealous!”

The new Met Office Windows Phone 8 weather app is the latest addition to our range of products for smart phone users and provides easy access to the latest weather forecasts and warnings wherever you are, 24 hours a day.

The App gives you three hourly forecasts and five day weather predictions. In addition to the likelihood of rain or snow, sunshine, cloud coverage and temperature, it gives the “feels-like” temperature – ideal if it’s 10 °C but will actually feel like 3 °C accounting for the wind chill factor.

As well as users having access to local, up to date forecasts from the Met Office, the new weather app includes a number of features unique to Windows Phone 8. These include ‘live tiles’ reflecting the current weather at your saved location and the use of ‘augmented reality’ to overlay forecast data on the camera image of where you are facing.

The Windows 8 Toast (notification) feature also means that you will never miss a weather warning for your area, helping you to stay weather aware so that you can prepare, plan and protect yourself from the impacts of severe weather.

The Met Office Windows Phone 8 weather app is available free of charge from the Windows Phone 8 app store. We also provides Apps for Android and iPhone, available from the Apple app store and the Android Market.





24 – 25 November rainfall update

25 11 2012

Overnight rainfall recorded at Met Office observing stations from 6pm Saturday 24 November to 8am Sunday 25 November:

Station     Amount
Fylingdales, North Yorkshire 36.6 mm
Pershore, Hereford & Worcester 32.6 mm
Sheffield, South Yorkshire 32.6 mm
Gingley-on-the-Hill 31.8 mm
Leek, Staffordshire 31.6 mm
High Mowthorpe, North Yorkshire 31.4 mm
Exeter Airport, Devon 31.2 mm
Dunkeswell, Devon 30.8 mm
Scarborough, North Yorkshire 30.6 mm
Normanby Hall, Humberside 30 mm

Below are the highest rainfall totals recorded at Met Office observing stations between midnight on Saturday and 8am this morning:

Station     Amount
St Mary’s Airport, Isles of Scilly 58.2 mm
Plymouth, Devon 56.8 mm
Cardinham, Cornwall 49.2 mm
Exeter Airport, Devon 48 mm
Dunkeswell, Devon 47.8 mm
Camborne, Cornwall 44.6 mm
Culdrose, Cornwall 41 mm
Pershore, Hereford & Worcester 40.6 mm
Astwood Bank, Hereford & Worcester 39.6 mm
Liscombe, Somerset 38.4 mm

 





Stormy November weekend

24 11 2012

As forecast, unsettled weather continues across the UK, with more heavy rain and strong winds expected to affect many areas at times through the weekend and into next week.

The Met Office and the Environment Agency are warning the public to be prepared for possible travel disruption and flooding as some areas see up to 60 mm on top of the rain that has already fallen over this week.

Eddy Carroll, Met Office Chief Forecaster, said: “The current very unsettled run of weather is set to continue with further spells of wet and windy weather expected across the country over the next few days.

“The southwest of England and parts of southeast Wales are expected to see the heaviest rain on Saturday with between 30 to 40 mm of rain in many parts and up to 60 mm of rain in some areas. Further rain moving in from the west on Sunday continues the risk for further flooding and travel disruption. We urge everyone to keep up to date with forecasts and warnings and be prepared for what the weather will bring.”

Along with the heavy rain strong winds may add to the potential for travel disruption, especially across southern Britain overnight Saturday into Sunday. Winds gusting to 50 or 60 mph are expected across southern counties of England overnight Saturday and into Sunday with severe gale or possibly storm force winds over the English Channel.

Rain spreading north across the UK Saturday 24 November 2012

Rain spreading north across the UK Saturday 24 November 2012

John Curtin, Head of Incident Management at the Environment Agency, said: “We would urge people to continue to be prepared for flooding, sign up for Environment Agency flood warnings, keep up to date with the latest situation, and stay away from dangerous flood water.

“Our teams have been out around the clock over the last few days to minimise the risks and prepare for flooding and we are continuing to deploy teams across the country to keep communities safe.”

Looking a little further ahead the weather is expected to become drier and colder in most areas by the middle of next week, however overnight frost may then bring the risk of some icy roads after the recent rain.

The public can keep up to date with the latest forecasts and warnings for their area on our website and with forecasts on TV and radio during this unsettled spell. You can also be #weatheraware by following us on Twitter @metoffice





Heavy rainfall across the UK

7 07 2012

As forecast heavy rain has fallen across large parts of the UK causing flooding and disruption to travel and outdoor events.

Here is a selection of rainfall totals recorded at Met Office observation sites on Friday 6 July 2012:

UK RAINFALL 6 JULY 2012 1am – 7 JULY 1am

 
 

Location

Area

Rainfall        (mm)

 
EMLEY MOOR

WEST YORKSHIRE     

56.6

 
RYHILL                       

WEST YORKSHIRE     

52.6

 
HOLBEACH

LINCOLNSHIRE       

44.8

 
NORMANBY HALL                

HUMBERSIDE         

43.6

 
MARKET BOSWORTH, BOSWORTHPARK

LEICESTERSHIRE     

41.6

 
BINGLEY

WEST YORKSHIRE     

40.2

 
LOFTUS                       

CLEVELAND          

39.4

 
BOSCOMBE DOWN                

WILTSHIRE          

38.6

 
SHAWBURY                      

SHROPSHIRE         

36.6

 
SHEFFIELD                    

SOUTH YORKSHIRE    

36.2

 
COTON-IN-THE-ELMS            

DERBYSHIRE         

36

 
NEWPORT(SALOP)              

SHROPSHIRE         

36

 
BRADFORD                     

WEST YORKSHIRE     

36

 
PORTHMADOG                   

GWYNEDD            

35.2

 
SCARBOROUGH                  

NORTH YORKSHIRE    

34.6

 
ABERDARON                    

GWYNEDD            

33.6

 
NANTWICH, REASEHEATH HALL    

CHESHIRE           

32.6

 
NOTTINGHAM, WATNALL           

NOTTINGHAMSHIRE    

32.4

 
KEELE                        

STAFFORDSHIRE      

32

 
FYLINGDALES                  

NORTH YORKSHIRE    

31.8

 
LLYSDINAM                    

POWYS              

31.2

 
ISLE OF PORTLAND             

DORSET              

30.4

 
SHOBDON AIRFIELD             

HEREFORD&WORCESTER

30.2

 

Overnight into Saturday the heaviest rain fell across the southwest of England and parts of southern Scotland:

UK RAINFALL 6 July 7pm – 7 July 10am

 
 

Location

Area

Rainfall (mm)

 
DUNKESWELL AERODROME               

DEVON         

45

 
ISLE OF PORTLAND                   

DORSET        

42.4

 
EXETER AIRPORT                     

DEVON         

41.8

 
NETTLECOMBE, BIRDS HILL            

SOMERSET      

38

 
CAMBORNE                           

CORNWALL      

37.8

 
CHARTERHALL                        

BERWICKSHIRE  

37.6

 
PLYMOUTH, MOUNTBATTEN              

DEVON         

35.2

 
LISCOMBE                           

SOMERSET      

34.6

 
EDINBURGH,ROYAL BOTANIC GARDEN

MIDLOTHIAN    

33.4

 
CULDROSE                           

CORNWALL      

31.8

 
CARDINHAM, BODMIN                   

CORNWALL      

28.6

 
ST ATHAN                           

SOUTH GLAMORGAN

26

 
STORMONT CASTLE                    

DOWN          

25.4

 

 








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