First half of November sticks with mild theme

18 11 2014

Early statistics up to the 16th of November show that month so far has followed the generally warm theme of 2014. Some areas have also been very wet.

Map shows the UK mean temperature for 1-16 November compared to the whole month average.

Map shows the UK mean temperature for 1-16 November compared to the whole month average.

The mean temperature for the UK was 8.1C, which is 1.9C above the long-term (1981-2010) average for the whole month.

As we’re heading towards winter, which starts for meteorologists on 1 December, we would normally expect the first half of the November to be warmer than the second half – but even still, the month so far is above average. There have been few air frosts.

The mildest places compared to average have been in the South East of England and East Anglia – which are both around 2.5C above average.

Perhaps more significant is the rainfall so far this month. After 16 days of the month you’d expect about 53% of the full-month average to have fallen in a ‘normal’ November, but the UK has already seen 77% (93.1mm).

Northern Ireland has already had more than its full-month average with 150.8mm so far compared to the November average of 112.5mm. This is more than it had through the whole of October.

Looking at regions, some parts of southern England, south Wales and eastern Scotland have also received around their whole-month average rainfall after just 16 days. South-eastern parts of Northern Ireland have recorded over 200% of their average.

Overall, the UK is on course for a mild and wet month – but it’s too early to say exactly where we’ll end up after the full-month figures are included.

  Mean temp Sunshine Rainfall
1-16 Nov Deg C Diff to avg Hours % of Nov Avg Actual mm % of Nov Avg
UK 11.0 1.8 32.9 57 93.1 77
England 11.8 2.0 36.6 57 74.1 84
Wales 11.3 1.7 37.7 67 130.9 81
Scotland 9.5 1.8 24.2 53 104.3 63
N Ireland 10.6 1.2 39.3 73 150.8 134

Data from the Met Office’s UK digitised records dating back to 1910. You can explore our climate data on our website.





Dual Warnings

12 11 2014

Today for the first time we have issued a new dual National Severe Weather Warning for wind and rain.

What is a Dual Warning?

A dual warning is one warning, covering one geographical area, over one period of time in the way a single warning does – but it combines two different types of severe weather. They would only be combined if they were both at the same warning level.

Any of the five types of weather warnings, Wind, Rain, Snow, Ice and Fog, can form a dual warning in any combination. So in theory Wind and Snow could be a dual warning. In practice there are certain weather types that are more likely to form a dual warning; the most likely is Wind and Rain, which is what we see today.  More information on our dual warnings can be found at the bottom of our Weather Warning page.

These new dual warnings have been developed following extensive two-way conversations with emergency responders and feedback we have recieved from the public over the past twelve months.

Until now, we would have issued multiple severe weather warnings to cover the range of warnings in place. Quite often however, situations arise where multiple impacts occur and these can now be shown on one map. This should make the information we issue easier to access.

Today’s Warning

Dual wind and rain warning

Dual wind and rain warning

The warning for wind and rain issued today covers Southwest England, Western Scotland and the Irish Sea between 07.00 and 23.45 on Thursday 13 November. A small area of low pressure will move quickly northwards throughout the day bringing a short-lived period of gales and severe gales and spells of heavy rain.

We encourage everyone to keep up to date with the latest forecasts and national severe weather warnings and to stay weather aware this winter by following the Met Office on Twitter, Facebook, Google+ and YouTube for the latest weather information. You can also sign up for severe weather alerts from us through the Twitter Alerts programme, providing critical information directly to your phone. Find out more about how to sign up for Met Office Twitter alerts.





Warm and wet, but October is no thriller

30 10 2014

Early Met Office figures up to the 28th of October show it has been a warm and rather wet month compared to average, but it’s not going to break any records.

The UK mean temperature for the month so far is 11.0C, which is 1.5C above the long-term (1981-2010) average.

Map showing the UK mean temperature for 1-28 Oct compared to the long-term (1981-2010) average.

Map showing the UK mean temperature for 1-28 Oct compared to the long-term (1981-2010) average.

While well above average, that’s well short of the record of 12.2C set in 2001 and would currently rank 11th warmest in our digitised national records dating back to 1910.

Last year’s October (11.2C), and that of 2011 (11.3C), were both warmer than this year’s early figure.

As ever there are regional variations within the UK for this year, with the far north west of the UK hardly above normal while much of England has seen mean temperatures around 2C above normal.

This October continues the theme of above average temperatures for 2014. Nine out of the ten months this year have seen above average mean temperatures, with only August having been below average.

It’s a similar story with UK rainfall in that it is wetter than average, but with no chance of breaking any records.

There has been 148.1mm of rain for the UK up to the 28th of the month, which is 116% of the long-term full-month average (you’d expect about 91% of the average after 28 days in a ‘normal’ month).

This would rank it around mid-table in the records – nowhere near the October record of 194.8mm set in 2000. While the rainfall will go up when the final few days are added, it’s not going to top that.

Again there are regional variations, with some parts of Scotland, the Isle of Man and Cumbria much wetter than average while some parts are slightly drier than average.

Sunshine hasn’t been too remarkable, with figures below average for most areas.

  Mean temp Sunshine Rainfall
1-28 Oct Deg C Diff to avg Hours % of Oct Avg Actual mm % of Oct Avg
UK 11.0 1.5 77.8 84 148.1 116
England 12.2 1.8 86.6 84 100.8 110
Wales 11.4 1.6 73.1 79 160.2 94
Scotland 9.2 1.2 62.6 83 226.7 129
N Ireland 10.3 0.9 86.7 99 124.0 104




What is the wettest city in the UK?

20 10 2014

We often get asked the question about where is the wettest town or city in the UK – and there are some news stories on this subject circulating in the media at the moment.

While the current stories use some of our figures, this isn’t an analysis by us and wasn’t done using our complete records from across the UK.

When it comes to answering what, on the face of it, is a relatively straightforward question – the reality is that it’s a lot more tricky than it first seems.

First of all, which measure should you use? There are rain days, which denote every day which sees more than 1mm of rain. Then there is total rainfall, which denotes the total accumulated rainfall over a period of time.

Which gives the better picture of a rainy city? There’s certainly room for debate.

Secondly, we have thousands of weather observation sites spread across the UK providing data on temperature, rainfall and other factors.

Map shows the 1981-2010 average annual UK rainfall based on individual station data - but it doesn't highlight individual towns and cities.

Map shows the 1981-2010 average annual UK rainfall based on individual station data – but can’t be used to make conclusions about individual towns and cities.

Towns and cities are generally quite large features on a map and one area could potentially have numerous weather stations.

Let’s take Huddersfield as an example. There are two rain gauges in the town that we have averages for – one on the west side sees 1028 mm a year, while another station further east sees 843 mm a year.

This demonstrates the fact that local features such as hills, or even mountains, as well as coasts and other features can all play a role in local rainfall – so there may be differences across a town or city.

It is possible to do a detailed analysis, but this would always require a clear basis for comparison.

It’s a lot more straightforward to look at individual stations. Using this data, we can see that the UK rain gauge in our archive with the highest average annual rainfall total is Crib Goch (Gwynedd) with 4635 mm of rain followed by Styhead (Cumbria) at 4562 mm.

For rain gauges located at elevations below 200 m the wettest place is Glenshiel Forest (Ross and Cromarty) at 3778 mm, but none of these are located in major towns or cities.

You can explore more about UK climate averages and statistics in our UK Climate pages.





Cool, wet August ends fairly average summer

29 08 2014

After a dry and warm start, summer 2014 is set to end on a rather average note – with temperatures and rainfall close to normal levels for the season.

Using figures up to 27 August and then assuming average conditions for the final few days of the month, Met Office statistics show the UK mean temperature for this summer will be around 14.8C. This is just 0.5C above the long term average (1981-2010).

Rainfall overall is close to average, with the UK having seen 246.7mm of rain – which is just over the long-term average of 241.0mm. Rainfall from the final few days of August will add to this number, so overall the summer will be slightly wetter than average.

As ever when looking over a whole season, the statistics mask some big variations between each month.

June and July were both characterised by drier and warmer than average conditions across the UK which meant the summer was already one of the best we’ve seen in recent years.

UK rainfall as a percentage of the long-term (1981-2010) average

Map showing August UK rainfall as a percentage of the long-term (1981-2010) average for the month

August bucked that trend, however, with cooler and wetter than average weather. Taken together, this has led to the fairly average final statistics for summer.

Looking specifically at the early August figures, also released today, the UK mean temperature up to the 27th of the month is 13.8C which is 1.1C below the long-term average. This ranks it as currently the coolest August since 1993, but that could change when the final few days of the month are added.

August is also the first month since November 2013 to have been cooler than average, breaking an eight month run.

In terms of rainfall, August has been much wetter than average, with 127.1mm of rain which is 142% of the long-term average (89.5mm). This makes it the 18th wettest August in the records, but it may climb higher when the figures for the whole month are available.

 

Mean Temperature Rainfall
Summer* Actual (°C)
Diff from Avg Actual (mm)
% of Avg
UK 14.8 0.5 258.2 107
England 15.9 0.4 211.6 109
Wales 14.8 0.3 257.5 90
Scotland 13.1 0.6 338.4 111
N Ireland 14.3 0.4 244.6 96

*Please note these are projected numbers that include statistics from 1 June to 27 August, then assume average conditions for the final few days of the season. They may not accurately represent the final full-season figures.

 

Mean Temperature Sunshine hours Rainfall
August** Actual (°C)
Diff from Avg Actual (hours)
% of Avg Actual (mm)
% of Avg
UK 13.8 -1.1 154.2 95 127.1 142
England 14.9 -1.2 169.7 93 103.4 149
Wales 13.9 -1.0 152.3 91 128.2 119
Scotland 11.9 -1.1 132.4 99 169.0 145
N Ireland 13.3 -1.0 134.2 99 112.8 116

** Please note these are preliminary statistics from 1-27 August. The final figures will change once statistics from the final few days of the month are included.





A wet start to August

15 08 2014

The UK has already seen nearly its entire ‘normal’ rainfall for August in the first half of the month.

Figures up to the 13th of August show there has been 86.1mm of rain so far in the UK, just short of the 89.5mm long-term (1981-2010) average.

Looking at individual countries, Scotland has already seen more than its full-month average with 121.4mm of rain so far compared to the average of 116.7mm. The Inverness and Moray areas have been particularly wet, with significant flooding from ex-hurricane Bertha on 10 to 11 August.

Rainfall for England and Northern Ireland so far is just under the full-month average, while Wales has been the driest relatively speaking – with 83.2mm of rain making up 77% of its full-month average. Normally at this stage you would expect about 42% of the average to have fallen.

With regards to temperatures and sunshine, the month has been much closer to average so far.

The UK mean temperature is currently 15.2C, which is 0.3C above the full-month average.

UK sunshine hours are at 77.8 hours, which is 48% of the full-month average – so just ahead of where we’d expect after 13 days of the month.

While these figures are interesting, they don’t tell us where the month will end up overall – we’ll have to wait until the full-month figures are in before deciding where this August fits in to the records.

As we head in to next week there should be a good deal of drier weather but with northerly winds bringing in cooler air it will feel colder than of late, especially at night.

This will feel noticeably cool in the wind, so people heading out in the evening may want to take a few extra layers.

Mean temperature Sunshine Rainfall
1 – 13 August 2014 Actual

Diff from 81-10 average

Actual % of 81-10 average Actual % of 81-10 average
Celsius Celsius hours % mm %
UK 15.2 0.3 77.8 48 86.1 96
England 16.5 0.4 91.8 50 64.7 93
Wales 15.3 0.3 85.1 51 83.2 77
Scotland 13.2 0.2 55.3 41 121.4 104
N Ireland 14.5 0.2 61.9 46 92.7 95




Mild wet winter continues in early January figures

16 01 2014

Provisional half-month statistics up to the 15th of January show a continuation of the generally mild and wet theme of the UK’s winter thus far.

The mean UK temperature up to the 15th of January is 5.1 °C, which is 1.5 °C above the long-term (1981-2010) average.

The mild January so far follows on from a mild UK December, which had a mean temperature of 5.7 °C, which is 1.8 °C above the long-term average – making it the eighth mildest December in records dating back to 1910, and the mildest since 1988.

It’s a similar story with UK rainfall. We’d normally expect about 48% of the January average rainfall by the 15th of the month, but the UK has seen 87.9mm so far – which equates to 72% of the January average.

As usual, there are regional varations. England has been particularly wet so far this month, having already seen close to its full-month average, and Wales is not too far behind. Scotland and Northern Ireland, however, are closer to the ‘normal’ amount of rain we’d expect at this stage.

The wet January so far once again follows the theme set in December, which saw 184.7mm of rain – which is 154% of the average for the month.

While this means January, and winter, so far have been mild and wet, it doesn’t mean they will finish that way. We often see half-month or half-season figures which then change dramatically by the end of the period. So the message is, it’s too early to judge how January 2014 or winter 2013/4 will finish up.

The main reason for the mild and wet weather so far is that we have seen a predominance of west and south-west winds, bringing in mild air from the Atlantic – as well as generally unsettled conditions.

The table below shows provisional figures from 1-15 of January, with actual figures so far compared to full-month averages. We would normally expect rainfall and sunshine to be about 48% of the full-month average at this stage.

Mean Temperature Sunshine hours Rainfall  
January 1-15
Actual Diff from Avg Actual % of Avg Actual % of Avg
  degC degC hours % mm %
UK 5.1 1.5 26.1 55 87.9 72
England 6.0 1.9 34.7 64 80.4 97
Wales 5.8 1.7 20.6 42 137.7 88
Scotland 3.6 1.0 15.4 43 91.2 51
N Ireland 4.4 0.2 14.6 33 62.8 54




October set for top ten warmest

1 11 2013

5 November 2013 Update – The full month figures are available in our latest blog

Early statistics for October up to the 28th of the month suggest this October is likely to be one of the warmest in records dating back to 1910.

Map showing relative warmth of October temperatures across the UK.

Map showing relative warmth of October temperatures across the UK.

The mean temperature for the UK from the 1st to the 28th is 11.6 °C, which is 2.1 °C above the long-term (1981-2010) average. It’s currently ranked joint fifth warmest in the records, but this could change once the final three days of data have been included.

Mild temperatures were experienced across all parts of the UK – with October currently being in the top ten warmest for England, Wales, Scotland and Northern Ireland. However, it was particularly mild in Wales, with this October currently ranked as the joint warmest on record alongside 2001.

There were no autumn heat waves through October, just a persistence of mild conditions – particularly mild nights – and frost has been rare through the month.

October 2013 is also notable because it was dull and, for most places, relatively wet. Sunshine hours are currently below the long-term average, while rainfall is already above ‘normal’ levels for everywhere apart from Scotland – which is about average.

Below are figures from 1-28 October, and we’ll update on the full-month figures early next week.

Below is a table showing statistics for 1-28 October, and we’ll update with full-month statistics early next week.

Mean temp Sunshine Rainfall
October 1-28 Actual (°C) Diff to Avg Actual (hrs) % of Avg Actual (mm) % of Avg
UK 11.6 2.1 67.3 73 147.6 116
England 12.6 2.2 74.4 72 131.6 143
Wales 12.3 2.4 66.7 72 208.9 123
Scotland 9.7 1.8 52.7 70 157.9 90
N Ireland 11.2 1.8 84.1 96 145.6 122




UK’s unsettled weather and the jet stream

21 10 2013

The UK is set to see unsettled weather throughout this week as heavy rain and windy conditions are expected to affect many areas, whilst temperatures will remain mild for the time of year.

We talk about the jet stream quite a bit in the UK because it has such a big influence on our weather, and this week is no exception as it’s playing a leading role in determining the unsettled outlook.

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 this week, the jet is positioned more or less directly over the UK – but it’s the detail of its track which is important.

As you can see from the picture below, the jet currently swoops south from western Canada – moving over the Atlantic before taking a sharp turn north to head over the UK.

Forecast chart showing  expected position of the jet stream at 1pm on Tuesday 22 October

Forecast chart showing expected position of the jet stream at 1pm on Tuesday 22 October

This means relatively cool air is being dragged south then over the Atlantic, where warmer seas heat the air from below. This causes the air to warm and rise – creating instability and generating cloud and rain.

By the time weather systems reach they UK they have picked up a lot of rain and relatively warm air, bringing us the wet but mild conditions we are currently seeing.

What’s the weather outlook?

Currently unsettled weather looks set to impact the UK through the week, with heavy rain affecting many areas at times.

There may be more settled conditions on Thursday, and perhaps again on Saturday, but looking further ahead into the start of next week the outlook is for unsettled weather to continue.

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.

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





Guest blog – How the Atlantic may influence wet summers

19 06 2013

This morning there has been a lot of media coverage following a workshop held here at the Met Office HQ in Exeter on a recent run of unusual seasons in the UK.

Much of this centred around recent research by the University of Reading, presented at the workshop yesterday, which suggested Atlantic ocean cycles – specifically one known as the Atlantic Multidecadal Oscillation (AMO) – can have an influence on UK summer weather.

Here Professor Rowan Sutton, from the University of Reading, explains that research in a bit more detail:

 

“Last year, Buwen Dong and I at the National Centre for Atmospheric Science published a paper in Nature Geoscience about the link between slow changes in the temperature of the North Atlantic Ocean and weather patterns.

In particular, we presented evidence of a link between warm surface temperatures in the North Atlantic and a higher frequency of wet summers in the UK and Northern Europe.

This research built on earlier research I published with another colleague, Dan Hodson, in Science in 2005 and an important study by Jeff Knight and colleagues at the Met Office, which was published in 2006.

In our 2012 paper we showed that a rapid warming of the North Atlantic Ocean which occurred in the 1990s coincided with a shift to wetter summers in the UK and northern Europe and hotter, drier summers around the Mediterranean. The pattern identified matched that of summer 2012, when the UK had the wettest summer in 100 years.

Observational records show that the surface temperature of the North Atlantic has swung slowly between warmer and cooler conditions, and the present warm phase has a similar pattern to warm conditions that persisted throughout the 1930s, 40s and 50s. During the 1960s, 70s and 80s cooler conditions prevailed.

Computer simulations suggest that these changes in ocean temperature affect the atmosphere above. Warmth in the North Atlantic causes a trough of low pressure over western Europe in summer and steers rain-bearing weather systems into the UK.

An important question of interest to many people is how long will the current pattern of wet summers in northern Europe persist? This is a key research question and we don’t yet have precise answers.

In our 2012 paper we stated: “Our results suggest that the recent pattern of anomalies in European climate will persist as long as the North Atlantic Ocean remains anomalously warm.”

How long might this be?  There is strong evidence linking the swings in the Atlantic Ocean surface temperature to the “overturning” or “thermohaline” circulation of the Atlantic.

This circulation appears to have intensified in the 1990s. Following such a strengthening, a subsequent weakening is expected, as various feedbacks exert their influence.

For example, the surface warm waters transported northward by the overturning circulation have relatively low density which inhibits their tendency to sink, and acts to slow the circulation. Such a slowing cools the North Atlantic.

The time scales involved are in the range between a few years and a decade or two.  Progress in Decadal Forecasting, such as the pioneering work at the Met Office, and critical observations such as from the NERC-funded “RAPID” array, should help us to reduce this large range of uncertainty, but it is a challenging problem and advances may take some years.”








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