One year on – A look back to last winter

17 02 2015

This weekend marked the one-year anniversary of the Valentine’s Day storm, which also marked the end of a particularly stormy three-month period. A new review article – ‘From months to minutes – exploring the value of high-resolution rainfall observation and prediction during the UK winter storms of 2013/2014’ – written by 16 Met Office co-authors reviews the accuracy of our forecasting and warning of severe weather during winter 2013-14, and assesses its performance.

The paper concludes that the “prolonged period of high impact weather experienced in the United Kingdom during the winter of 2013/14 was very well forecast by the operational tools available across space and time scales.”

Here Huw Lewis, the paper’s lead author, and Derrick Ryall, Head of the Public Weather Service, look at the extreme weather last year and the role of the Met Office in communicating severe weather through the National Severe Weather Warning Service.

Analysis chart 1200 GMT 26 January 2014

Analysis chart 1200 GMT 26 January 2014

Winter 2013/2014 in the United Kingdom was remarkable. The country was battered by at least 12 major winter storms over a three month period and was officially assessed as the stormiest period that the United Kingdom has experienced for at least 20 years.

The series of storms resulted in the wettest winter in almost 250 years (according to the England and Wales precipitation series from 1766), significantly wetter than the previous wettest winter in 1914/1915.

Snapshot of UK rain radar surface rainfall rate for 2200 GMT on 23 December 2013

Snapshot of UK rain radar surface rainfall rate for 2200 GMT on 23 December 2013

The extreme weather caused widespread flooding throughout Southern England and coastal damage – most notably in the South West and Norfolk coasts. The impact of the severe winter storms on individuals, businesses and the government were substantial, including several fatalities, widespread power cuts and damaged infrastructure.

Recent advances in forecasting, technology and the scientific developments in meteorology have been considerable. These developments and improvements in accuracy mean that a four-day weather forecast is as accurate as a one-day forecast was just thirty years ago. During the course of last winter, the Met Office was able to use these forecasts to warn of any severe weather well in advance. In the case of the St Jude’s Day storm at the end of October 2013 warnings went out to the Government and the public five days before the storm even existed.

rainfall

As the accuracy of weather forecasts has evolved, so has the communication of the potential impacts of severe weather. The National Severe Weather Warning Service enables more ‘weather decisions’ which in turn help to minimise the consequences of severe weather. The Met Office was at the heart of the government response to the storms, providing advice on weather impacts through the National Severe Weather Warning Service and Civil Contingency Advisors. The Met Office also worked very closely with both the national and regional media, who in turn played a key role in ensuring that the public were fully informed about the potential impacts of any up-coming weather.

In addition to the Public Weather Service, commercial partners and customers were also provided with detailed updates throughout the period in order for them to plan effectively for logistical issues. Together, these advanced warnings helped authorities, businesses and individuals to be better prepared to take mitigating actions.

Driving further improvements in accuracy and therefore reducing the lead time and increasing the detail of severe weather warnings is one of the Met Office’s key priorities . The ultimate aim is to improve the potential for users to plan preventative measures for severe weather events much further ahead. Underpinning all of these developments is a continuing programme of scientific research and access to enhanced supercomputing over the next few years.





Strongest winds overnight 14 – 15 January 2015

15 01 2015

As expected, a powerful low pressure system affected the UK yesterday evening and overnight bringing gales and heavy rain to many areas.

The low pressure system will continue to affect the UK today, bringing sunny spells and blustery, heavy showers with the chance of thunderstorms and snow over high ground. Severe gales are again expected around western and northwestern coasts, with the strongest winds likely over Northern Ireland and southwest Scotland, extending to northern Scotland later. You can see detail on this on our forecast and warnings pages.

Below are some of the strongest gust speeds recorded at Met Office observing sites between 7pm yesterday and 7am today.

Strongest gusts 7 pm 14 January 2015 – 7 am 15 January 2015
Date / time Site Max Gusts (mph)
15/01/2015 00:00 CAPEL CURIG GWYNEDD 96
15/01/2015 03:00 WIGHT: NEEDLES OLD BATTERY ISLE OF WIGHT 93
15/01/2015 00:00 ABERDARON GWYNEDD 83
14/01/2015 23:00 MUMBLES HEAD WEST GLAMORGAN 81
15/01/2015 02:00 BERRY HEAD DEVON 77
15/01/2015 02:00 AVONMOUTH AVON 76
15/01/2015 03:00 ISLE OF PORTLAND DORSET 75
14/01/2015 23:00 CULDROSE CORNWALL 73
15/01/2015 04:00 TIREE ARGYLL 73
15/01/2015 01:00 LOFTUS CLEVELAND 70
15/01/2015 01:00 PLYMOUTH, MOUNTBATTEN DEVON 70
14/01/2015 23:00 SCILLY: ST MARYS AIRPORT ISLES OF SCILLY 70
15/01/2015 04:00 SOLENT HAMPSHIRE 69
15/01/2015 01:00 LAKE VYRNWY POWYS 69
14/01/2015 23:00 NORTH WYKE DEVON 68
14/01/2015 23:00 SENNYBRIDGE POWYS 68
15/01/2015 06:00 ISLAY: PORT ELLEN ARGYLL 68
15/01/2015 00:00 PEMBREY SANDS DYFED 68
14/01/2015 21:00 DRUMALBIN LANARKSHIRE 67
15/01/2015 07:00 EDINBURGH, BLACKFORD HILL MIDLOTHIAN 67

Below are some of the highest rainfall totals recorded at Met Office observing sites between 7pm yesterday and 7am today.

Highest rainfall 7pm 14 January to 7am 15 January 2015
Site Rain (mm)
ACHNAGART ROSS & CROMARTY 40.8
TYNDRUM PERTHSHIRE 39.0
TREDEGAR, BRYN BACH PARK GWENT 35.8
KESWICK CUMBRIA 35.0
THREAVE KIRKCUDBRIGHTSHIRE 31.8
LIBANUS POWYS 31.8
SHAP CUMBRIA 31.6
ESKDALEMUIR DUMFRIESSHIRE 28.2
SKYE: LUSA WESTERN ISLES 27.8
USK MONMOUTHSHIRE 27.4
OKEHAMPTON, EAST OKEMENT FARM DEVON 27.1
STRATHALLAN AIRFIELD PERTHSHIRE 25.6
GOUDHURST KENT 25.4
BLENCATHRA CUMBRIA 25.2
TULLOCH BRIDGE INVERNESS-SHIRE 24.2
WHITECHURCH DYFED 24.0
NORTH WYKE DEVON 23.6
CAPEL CURIG GWYNEDD 23.4
MIDDLE WALLOP HAMPSHIRE 23.4
CAMBORNE CORNWALL 23.0

You can share the weather you have experienced through the ‘Weather Impacts’ section of WOW

The stormy weather we have seen over the last couple of weeks is now coming to an end and conditions over the weekend and into next week look calmer but colder with frosts at night and wintry mix of showers.





Typhoon Hagupit still on course for the Philippines

5 12 2014

In yesterday’s blog we reported on the formation of Typhoon Hagupit and its potential threat to the Philippines. At that time, winds averaged over one minute were estimated to be near 180 mph. During the last 24 hours Hagupit has weakened slightly, but winds are still estimated to be above 140 mph and the typhoon still shows an impressive structure as seen in the latest satellite image.

Typhoon Hagupit seen on 5 December 2014 Satellite image courtesy of Naval Research Laboratory

Typhoon Hagupit seen on 5 December 2014
Satellite image courtesy of Naval Research Laboratory

Forecasting the track of Typhoon Hagupit has been very problematic. Three possible scenarios were described in yesterday’s blog. One of these – that Hagupit would turn north and not make landfall – is considered highly unlikely now. It seems likely that Typhoon Hagupit will make landfall on the coast of the Philippine island of Samar. However, some uncertainties still remain.

One possible scenario is that landfall occurs during Saturday and Hagupit takes a fast and westward track across the Philippines. This is likely to result in structural damage due to strong winds and a storm surge of a few metres along the coast of Samar Island.

An alternative scenario is that Hagupit slows its forward motion as it approaches the Philippines and makes a slight northwards turn. Landfall will still occur, but not until Sunday. The effects of strong winds and several hundred millimetres of rain will be felt in a broad swath including areas as far north as Manila and central Luzon. The heavy rain could last for days and would have the potential to cause significant flooding and landslides.

Below is the latest projection of the typhoon produced by the Japan Meteorological Agency (JMA):

The latest projection of the typhoon produced by the Japan Meteorological Agency (JMA)

The latest projection of the typhoon produced by the Japan Meteorological Agency (JMA)

As reported yesterday, Met Office scientists have been working closely with counterparts at the Philippines weather service PAGASA. We are providing the latest information on computer model predictions and are discussing the range of possibilities, highlighting which of the possible forecast outcomes is the most likely; this is helping PAGASA to manage their risks. We have also been providing information to Government departments such as FCO and DFID on the likely impacts of Typhoon Hagupit.

Official warnings of west Pacific tropical storms are produced by the Japan Meteorological Agency. The Met Office routinely supplies predictions of cyclone tracks from its global forecast model to regional meteorological centres worldwide, which are used along with guidance from other models in the production of forecasts and guidance.

Met Office StormTracker provides a mapped picture of tropical cyclones around the globe with access to track history and six-day forecast tracks for current tropical cyclones from the Met Office global forecast model and latest observed cloud cover and sea surface temperature. We also provide updates on current tropical storms via @metofficestorms on Twitter.





Typhoon Hagupit threatens the Philippines

4 12 2014

The typhoon season in the western North Pacific usually peaks in September and October. However, late season typhoons are not rare and this year Typhoon Hagupit has formed in December and poses a threat to the Philippines.

Hagupit developed in the open waters of the western Pacific becoming a tropical storm on 1 December. As it strengthened into a typhoon, it passed south of the Yap Islands and north of the island of Palau. In the last day, it has intensified rapidly and Typhoon Hagupit now has winds averaged over one minute of near 180 mph.

Typhoon Hagupit seen on 4 December 2014 Image courtesy of Naval Research Laboratory

Typhoon Hagupit seen on 4 December 2014
Image courtesy of Naval Research Laboratory

With the effects of Typhoon Haiyan in November 2013 still fresh in the memory there is obvious concern of a possible repeat as Hagupit moves towards the Philippines. However, unlike for Haiyan, there is much more uncertainty as to the precise track and intensity of the typhoon in the coming few days.

One possible scenario is that Hagupit continues moving westwards and makes landfall on Saturday as a strong typhoon in a similar location to Typhoon Haiyan in 2013. Another scenario suggests that Hagupit will slow and make a slight turn north, but still makes landfall over the Central Philippines on Sunday. Yet another scenario predicts a marked turn northwards with the eye of the typhoon staying offshore altogether.

At this stage, the latter scenario seems the least likely outcome. Thus landfall somewhere over the Central Philippines seems likely to happen at some stage during the weekend. Below is the projected track of the storm from the Japan Meteorological Agency.

Forecast track of Typhoon Hagupit from the Japan Meteorological Agency

Forecast track of Typhoon Hagupit from the Japan Meteorological Agency

As ever with tropical cyclones, there are multiple hazards associated with landfall. With winds expected to remain well above 100 mph for the time being, there is the potential for significant structural damage if Hagupit makes landfall. Storm surge was a major hazard associated with Typhoon Haiyan and depending on the precise track of the storm could be again with Typhoon Hagupit. This would threaten coastal communities with flooding to the depth of several metres. One additional hazard which needs to be considered is heavy rain. If Hagupit reduces its speed of motion it could take a long time to cross the Philippines which would increase the threat from heavy rain, flooding and landslides.

In the last couple of years the Met Office has been working with the Philippines weather service PAGASA to help improve its weather forecasting capabilities with a particular emphasis on tropical cyclones, which are a regular threat to the country. In the last few days, our meteorologists have been providing advice on the latest predictions of the track and intensity and likely impacts of Typhoon Hagupit to counterparts in PAGASA.

Official warnings of west Pacific tropical storms are produced by the Japan Meteorological Agency. The Met Office routinely supplies predictions of cyclone tracks from its global forecast model to regional meteorological centres worldwide, which are used along with guidance from other models in the production of forecasts and guidance.

Met Office StormTracker provides a mapped picture of tropical cyclones around the globe with access to track history and six-day forecast tracks for current tropical cyclones from the Met Office global forecast model and latest observed cloud cover and sea surface temperature. We also provide updates on current tropical storms via @metofficestorms on Twitter.





Severe weather around the world

26 11 2014

While the UK is currently experiencing relatively benign weather for the time of year, extreme conditions are expected in some other parts of the world.

Morocco and Spain

Last Saturday, Agadir in Morocco saw 90mm of rain fall in just 24 hours, which is around twice the monthly November average for the region of just 50mm. The subsequent flooding resulted in more than 30 fatalities.

Unfortunately, more severe weather is expected through Friday and into the weekend across Morocco, but particularly around the southwest of the country.

A combination of a deep area of low pressure, relatively warm sea temperatures and strong winds will bring heavy rainfall. 100-150mm of rain could fall across SW Morocco on Friday with further heavy rain likely on Saturday, and totals could be enhanced over higher ground. Conditions should improve into Sunday.

Through the weekend, the same area of low pressure is expected to bring very heavy rain across North East Spain. Rainfall totals for both days could reach 150-300mm, locally 400mm over higher ground, with a gradual improvement into start of next week.

Both areas could experience flooding and landslides from the intensity and duration of rainfall, as well as the rain that has already fallen in recent days.

Forecast Chart 1200 Sat 29 Nov 2014

Forecast Pressure Chart for Midday on Saturday 29th November

North East America

A rapidly deepening area of low pressure is bringing heavy rain and snowfall across parts of the Eastern Seaboard of North America, with the storm quickly moving northeast over the coming days.

The weather has been caused by an extreme temperature contrast between the warm weather of the Gulf Coast and the bitter cold across inland parts of North America.

While heavy rain is expected on the coast, snow is likely inland, mainly but not exclusively over higher ground. As tomorrow is Thanksgiving, this system poses a risk of travel disruption to what is normally one of the busiest holiday periods in the States. Over 4 inches of snow could fall over parts of the northeast, before the weather improves into the weekend.





Strong winds and heavy rain affect parts of the UK

6 10 2014

After an exceptionally dry September, the UK has seen its first bout of widespread heavy rain and strong winds so far this autumn. An area of low pressure centred close to Iceland has driven a cold front eastwards across Britain, bringing unsettled weather, particularly in the west.

Highest rainfall totals

Some of the highest rainfall totals are shown below (between 10pm (5th October) to 10am (6th October):

SITE NAME AREA RAINFALL (mm)
CAMBORNE CORNWALL 44.8
LLYNFRYNACH POWYS 43.8
SOUTH UIST WESTERN ISLES 41.4
CARDINHAM CORNWALL 40.2
KATESBRIDGE COUNTY DOWN 34.6

Strongest wind gusts

There have been some strong wind gusts in parts, particularly across exposed western areas. The highest gusts are below:

DATE/TIME SITE NAME AREA WIND GUST (MPH)
06/10/2014 03:00 SOUTH UIST RANGE WESTERN ISLES 84
06/10/2014 05:00 ALTNAHARRA NO 2 SUTHERLAND 78
06/10/2014 02:00 TIREE ARGYLL 77
06/10/2014 05:00 MACHRIHANISH ARGYLL 75
06/10/2014 01:00 MAGILLIGAN NO 2 LONDONDERRY 70

Earlier rainfall image across the UK:

Featured image

Weather outlook

The rain will continue to move east across the UK during the rest of today with drier conditions following for a time, before showers follow in places overnight. Although winds will tend to ease for most areas, further gales are expected across northeast Scotland through tomorrow. During this unsettled weather we’d encourage everyone to keep up to date with the latest forecasts and national severe weather warnings.





Heavy rainfall and floods in India and Pakistan

10 09 2014

Heavy rainfall has devastated parts of India and Pakistan in recent days, leading to some of the worst flooding in decades.

The extreme conditions were caused by a tropical depression associated with the ongoing monsoon season which tracked northwards across the countries, bringing exceptional rainfall totals over short time periods.

In the Punjab province of Pakistan, some areas saw around 300mm (12 inches) of rain falling in less than 24 hours. This is close to the amount of rainfall we would expect through the whole of the winter in the UK.

Although the heaviest of the rain has now eased, water levels in some parts of the countries are continuing to rise.

Hundreds of people are thought to have died as a result of the floods, with officials saying that around 400,000 people are stranded in Indian-administered Kashmir. Around 700,000 people have also been told to leave their homes in Pakistan due to rising water levels.





Latest wind and rain data as ex-hurricane Bertha crosses the UK

10 08 2014

As forecast ex-hurricane Bertha is crossing the UK today (10 August 2014) bringing heavy and strong, gusty winds.

ex-hurricane Bertha crosses the UK on 10 August 2014

ex-hurricane Bertha crosses the UK on 10 August 2014

 

The heaviest rainfall overnight was recorded at Balatasound in Shetland where 48.8mm of rain was recorded as a previous low pressure system moved away from the UK, while Bute Park in Cardiff saw 40.6mm as the remnants of ex-hurricane Bertha move in from the southwest.

The highest hourly total was 18.4mm at Wisley in Surrey between 9 and 10am this morning and Coventry in the West Midlands seeing 18.2mm in the same time.

The table below shows a selection of the rainfall recorded at Met Office observing sites across the UK between 10pm on Saturday 9 August and 10am on Sunday 10 August 2014.

12hr UK RAINFALL 10pm 9 Aug to 10am 10 Aug 2014
SITE NAME AREA Rainfall (MM)
BALTASOUND SHETLAND 48.8
CARDIFF, BUTE PARK SOUTH GLAMORGAN 40.6
MILFORD HAVEN CONSERVANCY BOARD DYFED 37.0
SCOLTON COUNTRY PARK DYFED 35.4
ST ATHAN SOUTH GLAMORGAN 34.4
PERSHORE COLLEGE HEREFORD & WORCESTER 28.2
USK NO 2 MONMOUTHSHIRE 27.6
ASTWOOD BANK HEREFORD & WORCESTER 26.0
PERSHORE HEREFORD & WORCESTER 23.6
MURLOUGH DOWN 23.2
TREDEGAR, BRYN BACH PARK GWENT 22.8
KILLOWEN DOWN 22.4
WHITECHURCH DYFED 22.2
CHIVENOR DEVON 22.0
COVENTRY, COUNDON WEST MIDLANDS 21.8
WISLEY SURREY 21.2

The winds have picked up as well with a gust of 53mph being recorded at Berry Head, Devon betwen 5am and 6am this morning. The table below shows the wind speeds recorded between 1am and 10am today.

UK MAX GUST SPEED 10 AUG 1am to 10am
DATE / TIME SITE NAME AREA MAX GUST (MPH)
10/08/2014 0600 BERRY HEAD DEVON 53
10/08/2014 0300 BALTASOUND SHETLAND 52
10/08/2014 0800 SCILLY: ST MARYS AIRPORT ISLES OF SCILLY 51
10/08/2014 0900 CULDROSE CORNWALL 48
10/08/2014 0200 SELLA NESS SHETLAND 48
10/08/2014 1000 WIGHT: NEEDLES OLD BATTERY ISLE OF WIGHT 46
10/08/2014 0800 MUMBLES HEAD WEST GLAMORGAN 44
10/08/2014 0300 LERWICK SHETLAND 44
10/08/2014 0900 CAMBORNE CORNWALL 43
10/08/2014 0900 SOLENT HAMPSHIRE 41

The rain will continue to move north across the UK during the rest of today and the winds will stay strong and gusty and we encourage everyone to keep up to date with the latest forecasts and national severe weather warnings.





Thunderstorms bring intense rainfall to parts of England

28 07 2014

This morning has seen some intense downpours across parts of south east England.

They developed across parts of East Anglia in the early hours of the morning, with further areas of heavy showers across Sussex, Surrey, Kent and the south of London following later.

The showers were very heavy in places with thunderstorms, hail, and torrential rain reported, giving high rainfall totals and localised flooding in some areas.

The high rainfall totals were caused by an area of low pressure and a plume of warm air that moved in from the near continent accompanied by light winds, meaning that the showers were slow moving.

Several spots have seen more than half of their average monthly rainfall for the whole of July in just one hour.

Below you can see some of the highest recorded hourly rainfall totals from Environment Agency rain gauges through the morning of Monday 28th July 2014:

Great Dunmow Essex 43 mm (4am to 5am)
Isfield Sussex 37 mm (8.30am to 9:30am)
Ardingly Sussex 35 mm (8.30am to 9:30am)
Santon Downham Suffolk 33mm (4am to 5am)
Weirwood Sussex 28 mm (9am to 10am)
Northolt London 20mm (7am to 8am)

 

The band of showery rain is now easing, but a yellow warning for rainfall remains in place for the south east of the UK as the risk of seeing some further isolated downpours remains.

In addition, the far south east of England could see further persistent and perhaps locally heavy rain later today and overnight, with parts of Kent and Sussex most at risk. Conditions across all areas should then improve through tomorrow.





Balkan flooding

19 05 2014

Over 100mm of rainfall was recorded over Bosnia and Serbia during Wednesday and Thursday last week (14th & 15th May 2014), with media reports of much higher rainfall accumulations in places.

The heavy rainfall was caused by a slow moving area of low pressure through the whole depth of the atmosphere

The subsequent flooding was reported to be the worst in 120 years in Bosnia since records began in 1894. A state of emergency has been declared in 18 towns and cities, including Belgrade. The Serbian Prime Minister declared this the greatest flooding disaster ever, with more than four months worth of rain falling on one day. Rivers across the region are now believed to be at record levels.

The system that caused the heavy rainfall has now moved away eastwards with predominately dry weather expected for the rest of this week. Temperatures are expected to be close to normal for the time of year with relatively light winds.  However the longer range forecast shows the potential for further heavy rainfall next week.

There have been reports in the media that the flooding has sparked a mass evacuation with fears that flooding and mudslides could expose landmines left by the Bosnian war.

River gauges show many of the rivers have peaked, but despite the dry forecast for the next few days there are concerns (from local hydromet departments) that river levels may rise again on Tuesday evening (20th May) and Wednesday morning(21st May) on the River Sava and River Danube.  Further flooding could threaten a major power station on the River Sava.








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