Spring has sprung

5 03 2014

Warmer, drier weather is on the way for parts of the country.  As we move through the week a north–south divide develops across the UK with Scotland, Northern Ireland, northern England and parts of Wales being changeable and windy. However in the south high pressure will dominate  bringing dry weather for the weekend, with the best of the weather in the Southeast.

Temperatures are expected to reach mid to high teens in the South this weekend (8th – 9th March), while northwest England and Scotland are likely to see spells of strong winds and rain and there is a risk of overnight frosts.

This is in sharp contrast to the record breaking winter we have just experienced.  It was the wettest winter for the UK, England, Wales and Scotland, and the second wettest winter for Northern Ireland in the record series dating from 1910. It was the stormiest UK weather for 20 years with at least 12 major winter storms affecting the UK in two spells from mid-December to early January, and again from late January to mid-February.

For a time early next week the temperatures are expected to return to nearer normal, or slightly above, the average for the time of year (9 °C).  High pressure is again expected to dominate through next week leaving largely settled conditions it should continue to feel “spring like” with some sunshine around and light winds.

When does Spring start?

Meteorologically speaking spring stretches from 1 March to the end of May. Astronomically, spring typically starts on the day of spring equinox, around the 20 March in the Northern Hemisphere.

Weather in spring is often calm and dry with temperatures rising in the day but staying cool at night.





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.

 





Overnight minimum temperatures

11 12 2013

As forecast, last night Scotland saw warmer temperatures than any other part of the country, with overnight maximum temperatures of 16.2 °C recorded in Ross and Cromarty. In fact, many parts of Scotland saw warmer temperatures overnight than they did during the daytime.

Maximum overnight temperatures Tuesday 11 December 2013

Location Area Temperature (°C)
Achnagart Ross & Cromarty 16.2
Kinlochewe        Ross & Cromarty 15.2
Altnaharra No 2   Sutherland 14.6
Kinloss  Moray 14.3
Lossiemouth Moray 14.2
Cluanie Inn No 3  Ross & Cromarty 14.2
Drumnadrochit Inverness-shire 14.1
Aultbea No 2      Ross & Cromarty 14
Resallach    Sutherland 13.8
Skye, Lusa Western Isles 13.7

Not everywhere was so warm with some areas in the southern part of the UK recording several degrees below freezing.

Lowest minimum temperatures Tuesday 11 December 2013

Location Area Temperature (°C)
Pershore Hereford & Worcester -3.1
Shoreham Airport West Sussex -3.1
Goudhurst Kent -3.0
Wiggonholt West Sussex  -2.9
Frittenden Kent  -2.6
Hurn Dorset -2.2
Kew Gardens Greater London  -2.0
Northolt Greater London -2.0
Charlwood Surrey -1.9
Odiham Hampshire -1.9

More mild temperatures are forecast in Scotland over the next few nights, before it becomes slightly more unsettled, particularly in the North of the UK. See your local forecast and temperature range on our website.





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.





Cold snap expected

3 12 2013

The UK is going to see a very short, sharp, cold snap.  From Wednesday night (4th Dec) into Thursday morning (5th Dec) Scotland, northern England and Northern Ireland will see some strong winds, while Scotland will see some wintry showers and snow.  However temperatures will return to normal as we head through the weekend, and be more in line with what should be expected for December.

A rapidly deepening Atlantic depression is expected to move in an easterly direction to the north of Scotland bringing westerly gales, with gusts of 60 to 70 mph extending southwards across northern and some central parts of the UK on Wednesday night and Thursday.  Northern Scotland could see gusts of 80mph, and potentially 90mph for a time.

Because of this the Met Office has issued a Yellow Severe Weather Warning for strong winds. The public should be aware of possible disruption to travel, especially across Scotland, parts of Northern Ireland and Northern England.

The winds are expected to veer northerly and bring the colder arctic air southwards across northern areas before easing into Friday. The winds could exacerbate high tides and may increase the risk of coastal flooding in the Northern and Western Isles and along the East Coast of England.

A Yellow warning for snow is also in place. It runs from 6am Thursday to 12 noon on Friday, covering the northern half of Scotland, snow showers are expected to be most frequent across the Northern Isles, the North Highlands and northern Aberdeenshire.  Low laying areas could see 2 – 5cms of snow and higher altitudes 10 – 20cms. In addition the strong winds could lead to some drifting of snow and possibly blizzard conditions on higher ground.  Icy conditions may also develop on some roads across Scotland on Thursday night and Friday morning.

This winter storm is not expected to be as powerful as those in January 2012 and December 2011

This is expected to be a short-lived cold snap, with temperatures quickly recovering to near normal over the weekend.

Our video explains what to do during a Yellow warning for wind. You can also download a weather warnings widget for your website.





June set to be slightly drier and sunnier than average

28 06 2013

Provisional Met Office early June figures suggest that it has been drier than average and slightly sunnier than usual so far this month.

Rainfall for the UK from 1-26 June was 37.8 mm. At this stage we would expect to have seen about 87 % of the full month average, however we have only seen 52 %.

Up to the 26th we have seen 163 hours of sunshine in the UK, which is 96 % of the full month average – suggesting we are on track for a sunnier than average month.

However, the mean UK temperature up to the 26th has been recorded at 12.7 °C which is -0.3 °C below the 1981-2010 long-term average for the month.

The average maximum temperature so far this June is 17.1°C which is very close to the long-term average of 17.3 °C.

Looking at the individual countries, Scotland and Northern Ireland have had slightly above average temperatures so far.  Scotland’s mean temperature has been 11.5 °C (0.2 °C above average) and Northern Ireland’s has been 13.0 °C (0.2 °C above average).

Wales had the most sunshine with190.6 hours, already above the full-month long-term average.

Northern Ireland has had the most rain so far with 79.8 mm compared with England’s below average 27.5 mm and Scotland’s 45.3 mm.

Temperatures of 26.4 °C at Herstmonceux, East Sussex (19 June) and Mickleham, Surrey (20 June) are the hottest days in the UK so far.

The hottest day in Wales so far this year was at Usk (25.1°C on 19 June).

Scotland’s hottest day was at Glenlee (24.5 °C on 8 June) and Northern Ireland’s hottest day of the year so far was on 9 June (24.5 °C) at Magilligan.

Mean Temperature Sunshine hours Rainfall
1-26 June Actual Diff from Avg Actual % of Avg Actual % of Avg
degC degC hours % mm %
UK 12.7 -0.3 163.0 96 37.8 52
England 13.4 -0.7 168.2 92 27.5 44
Wales 12.7 -0.5 190.6 110 45.9 54
Scotland 11.5 0.2 148.9 99 45.3 51
N Ireland 13.0 0.2 150.4 100 79.8 105




April drier and colder than average

2 05 2013

After the wettest April on record in 2012, provisional full-month Met Office figures show this April has been slightly drier than average in the UK.

Rainfall throughout the UK was 64 mm this year, compared to the 1981-2010 average of 72.7 mm. That’s considerably less than the 128 mm we saw last year.

There were big regional differences in April rainfall this year. Scotland saw 121.2 mm of rain which is above the 91.1 mm average and Northern Ireland saw 75.2mm, almost spot on the 75.0 mm average.

However, both England and Wales saw well below average rainfall. Wales had 50.3mm, compared to an average of 89.3mm, and England saw 30.4mm, compared to an average of 58.7 mm.

The month was characterised by generally cold and dry weather, following on from the theme set in March. Despite this, April registered as only slightly colder than average with a mean UK temperature of 6.3 °C, which is 1.1 °C below the 7.4 °C long-term average.

This is the same mean temperature as recorded in April 2012. To find a colder April than the last two years, you have to go back to 1989 – which saw a mean temperature of 5.5 °C.

Scotland saw the coldest temperatures compared to country specific averages, with a mean temperature of 4.8 °C, which is 1.3 °C below average – and is the same temperature as recorded in 1998.

The warmest day of the month was 25 April at Faversham in Kent when the temperature recorded was 23.1°C.

In terms of sunshine, Scotland was sunnier than the rest of the UK with hours of sunshine totalling 170.9, followed by Northern Ireland with 168.0, England at 167.7 and Wales at 162.7 hours.

This compares with only 127.9 hours of sunshine in April last year throughout the UK. The sunniest April in the last 10 years was 2007 with 203.5 hours.

Mean Temperature Sunshine hours Rainfall
Apr-13 Actual Diff to Avg Actual Diff to Avg Actual Diff to Avg
degC degC hours % mm %
UK 6.3 -1.1 168.4 114 64 88
England 7.2 -0.9 167.7 108 30.4 52
Wales 6.4 -1.2 162.7 105 50.3 56
Scotland 4.8 -1.3 170.9 127 121.2 133
N Ireland 6.5 -1.1 168 115 75.2 100




This week’s snowfall captured by rainfall radar

13 03 2013

The rainfall radar network is a great way of looking back at how weather systems affect the UK.

Here we see rainfall radar imagery from 00:00 GMT on Sunday 10 March to 09:00 GMT on Tuesday 12 March. It shows snow showers affecting much of the UK while an area of heavier snowfall affects northern France, the Channel Islands and the far south-east of England.

radar_animation

What’s particularly interesting is that it shows really well how the showers and the heavier snowfall across the south were moving in totally different directions. The snow showers can be seen moving in from the North Sea on north-easterly winds. Meanwhile, the heavier and more persistent snowfall was moving in from the south-west as an area of low pressure tracked across France. You can see how these two systems collided over Sussex and Kent, resulting in the heavy snowfall here.

At the very end of the sequence the wind changes direction again over the north of the UK, with the snow showers being blown across Scotland from the north.

You can see current observations from our rainfall radar on our website.





The worst storm in years?

28 01 2013

Various articles in the news today said that the weather over the weekend was the worst storm to hit the UK in years, and that there is more to come this week. There was indeed a very deep area of low pressure in the Atlantic over the weekend. At its deepest, on Saturday 26 January, the central pressure of the depression was 932 millibars and it was sitting some 1,800 nautical miles west of the UK. It came closest to the UK during the day yesterday with a central pressure of 950 millibars but was still around 600 nautical miles to the north west of Scotland.

Satellite image from 26 January 2013

Satellite image from 26 January 2013

To put this into context, the storm that affected the UK on 3 January 2012 had a central pressure of 953 millibars but was centred right on the west coast of Scotland and brought winds in excess of 80 mph to the Central Belt and a gust of over 100 mph in Edinburgh. Property was damaged, as well as trees, and there was disruption on the road network and with ferry crossings. Power supplies were also affected significantly.

The storm in January 2012 was therefore much more disruptive and severe than any wet and windy weather we have seen so far this year.

Much of the recent severe weather has been attributed to the phrase “Weather Bomb”, which is not a perfect meteorological term but is defined as an intense low pressure system with a central pressure that falls 24 millibars in a 24-hour period. This happened to the depression over the Atlantic during the weekend but as it was miles away from the UK its impacts were minimal. A better description can be more directly linked to the meteorological phenomena known as rapid cyclogenesis. This is where dry air from the stratosphere flows into an area of low pressure. This causes air within the depression to rise very quickly and increases its rotation, which in turn deepens the pressure and creates a more vigorous storm.





How wet has 2012 been? Is it a record breaker?

27 12 2012

Provisional figures from the Met Office from 1 January to 26 December 2012 show that some parts of the UK have already had their wettest year on record.

New records have been set in England (1095.8 mm), northern England (1253 mm), E and NE England (1042.1 mm), Midlands (1048.2 mm), and East Anglia (788 mm), in a series that goes back to 1910.

A further 46 mm of rain is needed from 27 to 31 December for this to be the wettest year on record for the UK overall – the UK has had 1291.2 mm of rain from 1 January to 26 December. The wettest year on record for the UK is 2000 with 1337.3 mm.

2012 rainfall anomaly 1 Jan to 26 Dec

2012 rainfall anomaly 1 Jan to 26 Dec

In terms of temperature and sunshine the year as a whole is set to be unremarkable, both being around normal. However, overall 2012 is set to be cooler than 2011, but warmer than 2010.

  mean temperature sunshine duration precipitation
1 January to 26 December 2012 Actual Difference from 1981-2010 average Actual Percentage of 1981-2010 average Actual Percentage of 1981-2010 average
  degC degC hours % mm %
UK 8.7 -0.1 1354.1 99 1291.2 112
England 9.5 -0.1 1467.1 98 1095.8 128
Wales 9.1 -0.1 1354.0 97 1649.5 113
Scotland 7.3 -0.1 1186.8 100 1546.3 98
N Ireland 8.9 0.0 1234.0 98 1134.8 100
England & Wales 9.5 -0.1 1451.5 98 1172.2 125
England N 8.7 -0.1 1357.0 99 1253.0 129
England S 9.9 -0.1 1525.4 98 1012.6 128

More about the record breaking year of 2012








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