One metre of rain to fall in the Bay of Bengal

29 07 2015

Parts of the Ganges Delta have already seen over 240mm of rain in just 24 hours and coastal areas to the north of the Bay of Bengal are expected to receive over 1000mm over the coming 48 to 72 hours. The area will also see some strong winds, with gust of up to 60mph along the coast. This severe weather is likely to have significant impacts with a risk of flooding, landslides and damage to infrastructure.

Satellite image of monsoons over Pakistan, Bay of Bengal, and South China

Satellite image of monsoons over Pakistan, Bay of Bengal, and South China

After a break in monsoon rainfall across parts of India through much of July, the region is now experiencing a more active phase. Over the Bay of Bengal, a deep monsoon depression has developed, bringing a period of prolonged heavy rain and strong winds to coastal districts of northeast India, Bangladesh and northwest Myanmar. A monsoon depression is an area of low pressure which brings intense rainfall, and with other ingredients in place, can develop into a tropical cyclone.

The monsoon depression is expected to remain slow moving, tracking into Bangladesh over the next few days before gradually moving west across northeast India over the weekend.

Unusually, this is one of three monsoon depressions affecting South Asia. As well as the monsoon over the Bay of Bengal there is a monsoon bringing heavy rainfall to northwest India and Pakistan with as much as 430mm of rainfall falling in 24 hours. A third slow-moving depression is also affecting northeast Vietnam and southeastern China. 543mm 718mm has fallen in 42 66 hours in Mong Cai City on the border between Vietnam and China, an area that was affected by Tropical Storm Kujira last month.

Elsewhere in the world, the hot dry conditions which have affected southern Europe through much of July have led to some wildfires in Catalonia, Spain, and the Provence region of France. There is expected to be some respite from the high temperatures across Spain and France though in the coming days as a cold front pushes in from the north bringing a risk of heavy showers and thunderstorms to northeast Spain and Southern France by the weekend.

 





Are we set for record July rainfall?

27 07 2015

While July has seen a good deal of dry and bright weather, we’ve also seen a few periods of heavy rainfall.

Whether through intense thundery downpours or prolonged periods of rain such as seen in southern parts of the UK on Friday last week, these events have dramatically pushed up the rainfall totals for the month.

This has led to speculation about whether this July could be on course to be the wettest on record. However, a quick look at the statistics shows that while it has certainly been wet, we’re unlikely to break any national records this month.

Provisional rainfall statistics for July 2015 so far suggest that with 5 days of the month remaining much of the country has already received close to or above average rainfall for the month – but we’re some way off breaking the records for each country.

Table showing rainfall figures so far this month compared to average and the records:

Rainfall 1-26 Jul 2015 Current record July 1981 – 2010 average
UK 93 mm 146 mm (2009) 78 mm
England 70 mm 129 mm (2009) 63 mm
Scotland 128 mm 186 mm (1940) 100 mm
Wales 102 mm 241 mm (1939) 93 mm
Northern Ireland 95 mm 186 mm (1936) 81 mm

The wettest regions compared to average have so far this month been eastern Scotland, East Anglia and the south west of England. If records are going to be broken they will most likely be localised rather than national records.

Even those regional records are far from a sure thing. The weather is generally improving for most parts of the country and high pressure, bringing more settled conditions, is expected to build towards the back end of the week.

This means the last few days of this month are unlikely to add big rainfall numbers to the totals we have so far.

Map showing 1-26 July 2015 rainfall compared to the 1981-2010 average. Most places have received their full-month average (shown in white), while the darker blue areas have seen significantly more than average already.

Map showing 1-26 July 2015 rainfall compared to the 1981-2010 average. Most places have received their full-month average (shown in white), while the darker blue areas have seen significantly more than average already.





A wet getaway

24 07 2015

As many of us plan to head off on holiday, heavy rain and strengthening winds cross southern England today (Friday), persisting overnight in the east, before clearing on Saturday morning.

A Yellow warning has been issued for southeast England and East Anglia, valid from Friday afternoon to 11am Saturday because of the potential impacts the heavy rain and wind could have.

 

Weather warning 24.07.15

As an area of low pressure is crossing northeastwards across the UK today (Friday), close to southern England, it deepens into quite an intense feature for this time of year and is expected to bring disruptive rain and wind, particularly within the warning area.

More than 30 mm of rain is expected quite widely, but there is a chance some isolated locations could well see more than 70 mm of rain. Wind gusts are also expected to be strong across the warning area, with northerly winds gusting to 45 mph inland and around 55 mph along coasts. This combination of factors could bring the risk of disruption to outdoor activities and heavy holiday traffic.
Highways England has launched a website especially for drivers heading to the South West of England to help plan their journey.





A summer forecasting challenge for Friday

22 07 2015

Forecasting rainfall for the UK during the summer has always posed a more difficult challenge than other times of year – and the weather for this Friday is a perfect example.

The various computer models the Met Office uses to forecast the weather differ on how a low pressure system forming to the west of the UK will behave.

We know that it will bring some wind and rain to the southern half of the UK, but there is no consensus on exactly which track it will take across the country and precisely when it will arrive.

Below you can see the area most likely to see some persistent rain during Friday and into Saturday. There is a 30% chance that rainfall could extend further north than this. The system is likely to bring up to 15-25 mm of rain and winds of up to 30 mph, mainly in exposed areas.

Forecast uncertainties 24-25-July

Currently there are no plans to issue a weather warning for this event, but clearly it has the potential to affect people’s plans for Friday now summer holidays are in full swing.  You can hear more about Friday’s forecast in the video below.

We’ll be keeping a close eye on the situation as it develops to ensure everyone has the clearest picture of what’s likely for Friday, so it’s worth staying up to date with the forecast over the next couple of days.

The current situation is a good example of why summer is tricky because at this time of year the details are vitally important.

Will the showers be inland or at the coast, when will low cloud clear to let warm sunshine through? In winter this might not be so important, but in summer when many are outside making the most of all the UK has to offer it can make a huge difference to your day.

Familiar features of our landscape such as hills, valleys or the sea can cause subtle variations in heat and moisture and therefore dominate the local weather outcome.  This can result in big differences in the weather in quite small areas, it can be sunny on the beach but raining inland or a village fair could be rained off while the next village down the road is dry.

At this time of year it’s always a good idea to keep a close eye on the forecast as the situation can change from day to day.

We’re always harnessing new science and technology to make forecasting ever more accurate and summer forecasting is a major focus for future gains.





Early July sees big rainfall contrasts

20 07 2015

After a hot and humid start to the month, when record daily maximum temperatures were recorded at several stations across the country on 1 July, it has been a fairly average month so far for the UK as a whole. However, on a regional scale there are some contrasts.

Using figures up to 15 July, mean temperatures have been close to or above average, with counties in eastern and southeastern England highest relative to average.

Meanwhile, for rainfall there are more notable variations, with eastern parts of England having received around or less than half the amount of rainfall that would be expected by mid-month. For example, Surrey and Sussex have both recorded less than 20% of the month’s average rainfall with 7.8mm and 9.9mm respectively. By the 15th of the month you would normally expect around 48% of the whole-month average.

This is in comparison with parts of Eastern Scotland where some places have already recorded more rainfall than the whole-July average. Aberdeenshire and Kincardineshire have already seen rainfall in excess of July’s average at 79mm and 106.6mm.

After the hot, sunny start to the month there have been periods of unsettled weather, with weather systems arriving from the Atlantic bringing rain or showers at times. This has been interspersed with drier, sunny spells.

With west or southwesterly winds dominating, there have been some rather cloudy days in the south, leading to mild nights.

The table below shows figures for the 1-15 July. You would normally expect about 48% of the full-month average for sunshine and rainfall at this point in the month.

Mean temperature Sunshine duration Rainfall
1-15 July
Act (°C) Diff from avg (°C) Act (hrs) % of avg Act (mm) % of avg
UK 15.5 0.4 88.0 51 46.9 60
England 17.0 0.7 103.7 54 30.5 49
Wales 15.4 0.2 89.2 50 56.4 61
Scotland 13.3 0.0 66.8 47 71.9 72
N Ireland 14.2 -0.4 57.7 41 45.9 57

 





Mixed bag for the start of June

17 06 2015

It has been a very varied weather picture so far this month.

It’s been dry and warm for the south east of the UK, with some places around London having received less than 5 mm of rainfall so far and areas such as Essex, Hertfordshire, Suffolk and Cambridgeshire receiving less than 20% of the month’s average in places.

This year’s highest UK temperature so far, 26.8 °C, occurred at Kew Gardens (Greater London) on the 12 June.

Much of the rest of the UK has seen temperatures in general noticeably below average for June, continuing on from the rather cool May.  While rainfall totals are already close to the whole-month average in the central Scottish Highlands and in Nottinghamshire.

MeanTemp June

June began with two very unseasonal days, due to a deep low-pressure system to the west of the UK, bringing large amounts of rain and some strong winds to the UK, particularly southern areas. Apart from this, and some showery rain on the 5th/6th,

June so far has been relatively settled, especially over southern areas, although we saw a period of thundery outbreaks on 12th June affecting mainly southern areas due to a plume of very humid and warm unstable air moving in from France/Spain.

Mean temperatures for the UK so far this month have been 2 °C below normal in most areas, but colder in the far north-west of the UK and a little closer to normal in southern England. While the minimum temperatures have been well below average, by as much as 3 °C over some northern areas.

mean temperature sunshine duration rainfall
1-15 June 2015 Act (°C) Diff from avg (°C) Act (hrs) % of avg Act (mm) % of avg
UK 11.2 -1.8 117.6 69 31.3 43
England 12.5 -1.6 128.3 70 23.1 37
Wales 11.6 -1.6 121.6 70 41.8 49
Scotland 9.3 -2.0 99.3 66 43.9 49
N Ireland 10.3 -2.5 114.3 76 21.4 28

We would expect figures to be around 50% of the average figures by the mid month point.

For the latest weather forecast go to www.metoffice.gov.uk/weather





Summer returns but no heatwave

2 06 2015

There have been some stories in the press that a heatwave is on the way later this week.  Although we are expecting temperatures to rise over the coming days with some pleasant early summer weather, any very warm weather will be fairly short-lived.

After an unseasonably cold, wet and windy start to June and the meteorological summer, high pressure is expected to build across southern parts of the UK from Wednesday, resulting in a much quieter and more pleasant spell of weather.

By Friday, a plume of hot air from the continent could bring temperatures in the mid 20s°C  across south eastern parts of the country, but this in turn is likely to trigger some thundery showers. So although temperatures are likely to peak on Friday, this may not necessarily be accompanied by blue skies and sunshine, as a good deal of cloud is possible along with rather humid and hazy conditions.

Deputy Chief Meteorologist Martin Young said “although things will be a good deal warmer than of late, there still remains considerable uncertainty about how hot it will be and exactly where will see the highest temperatures on Friday, and the public should keep in touch with the latest forecasts”.

This coming weekend is likely to see temperatures a little lower than Friday’s in the south east, but plenty of pleasantly warm sunshine is expected across much of the UK with temperatures widely in the high teens, and reaching the low 20s°C  in parts of the south.





Sunny and dry April

30 04 2015

UPDATE: YOU CAN SEE AN UPDATED STORY ON APRIL’S WEATHER ON OUR WEBSITE.

The early April figures (1st – 28th April) show it was a sunny and warm month over all, with well above average sunshine almost everywhere. At the moment it ranks as the fifth sunniest April across the UK as a whole. Some locations, particularly in the East of the country, have so far seen almost 50% more sunshine than average.  East Scotland has had its sunniest April on record, beating 1942’s 200 hours of sunshine by 2 hours and it was the second sunniest for England East and NE with 212.4 – just behind 2011 with 216.9 5 hours.

April Sunshine Anomaly 1981-2010

April Sunshine Anomaly 1981-2010

Mean temperatures for the month have been also mostly above average. The mean temperature for the UK was 8.0 C, which is 0.6C above the long-term (1981-2010) average for the whole month. Daytime temperatures rose above average in many areas, especially in the south, with the year’s highest temperature so far (25.6 °C) recorded at Faversham (Kent) on the afternoon of the 15th. This is the highest April temperature anywhere in the UK since 2011.

However, in contrast, under often clear skies, minimum temperatures have been near or below average, particularly in Northern Ireland and parts of northern England and southern Scotland. Katesbridge (County Down) recorded -8.0 °C on 27th April.

Mean Temperature Sunshine hours Rainfall  
 April 2015
Actual Diff to Avg Actual % of Avg Actual % of Avg
  degC degC hours % mm %
UK 8.0 0.6 199.2 135 41.6 57
England 8.9 0.8 209.1 135 23.3 40
Wales 8.5 0.9 203.3 132 32.4 36
Scotland 6.4 0.3 183.0 136 72.2 79
N Ireland 7.7 0.1 193.2 132 52.8 70

April has been a dry month, particularly across the southern half of the UK with only a third, to a half, of normal rainfall quite widely and less than 20% in some places.

Data from the Met Office’s UK digitised records dating back to 1910. You can explore our climate data on our website. Clearly these are early month figures and the statistics at the end of the month will change somewhat.





Intense storm threatens Sydney

22 04 2015

Parts of New South Wales in southeast Australia have had severe flooding and wind damage over the past few days due to an intense low pressure system. Parts of the region have already seen more than 300mm (around a foot) of rainfall. Areas around Sydney have been affected, with flooding claiming three lives and causing evacuations of properties, as well as disrupting power and transport. Officials warned that hundreds of homes in the city are under threat from rising river levels, and it has been reported that the State Emergency Service (SES) have received nearly 10,000 calls for help and carried out more than 100 rescues.

Analysis chart from Austrlian Bureau of Meteorology

Analysis chart from Austrlian Bureau of Meteorology

The storm is now weakening and moving away southeastwards into the Tasman Sea, so conditions are expected to improve over the next 24 hours, however remnants of the system are likely to bring a further 50 to 75mm of rainfall to some coastal parts today, before conditions gradually become quieter.

Rapid Response image from NASA

Rapid Response image from NASA

For more information on current warnings and forecasts across New South Wales, visit the Australian Bureau of Meteorology website.





A very sunny winter on the cards

18 02 2015

Early figures show that while this winter is on track for fairly average temperatures and rainfall, it could be among the sunniest in our UK record dating back to 1929.

If we have average sunshine for the rest of February, it’s likely to be in the top few sunniest winters and could potentially beat the 2001 record of 189 hours.

Between 1 Dec -16 Feb many areas have already received more than their long-term average winter sunshine for the full season (1 Dec – 28 Feb), especially parts of the Midlands, eastern Scotland and north-east England.

December and January were both sunny across much of the country – especially eastern areas, while northern England and eastern Scotland have had a sunny February so far.

As we near the end of winter it looks as though temperatures will be close to the long-term average with December warmer than average, January near average and February so far being just below.

For many it has been a dry winter so far across southern, eastern and north-east England but relatively wet across Scotland, with the north-west having a wet December and January.

Dry start to February

The first half of February has seen some dry settled weather thanks to high pressure dominating the weather for much of the period.

Using figures from 1-16 February, temperatures have generally been around 1 to 1.5 °C below normal across the UK as a whole and clear skies have allowed fog and frosty conditions to develop at times.

Many areas have been on the dry side, with less than 20 percent of expected rainfall so far across large swathes of the country – we’d normally expect around half of the monthly average to have fallen by now.

Sunshine amounts have been variable but parts of northern England and eastern Scotland have already received almost the whole-month average.

 








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