Hurricane Joaquin lashes the Bahamas but will it hit the USA?

1 10 2015

In recent months attention has focused on the very active tropical cyclone season in the Pacific Ocean brought about primarily by the strong El Niño which has developed this year. Meanwhile, the Atlantic has been very quiet with most tropical storms remaining fairly weak and only two reaching hurricane strength until now.

However, Joaquin has become the third hurricane of the Atlantic season and the second to achieve ‘major’ status – category 3 or above on the Saffir-Simpson Hurricane Wind Scale. Joaquin is currently lashing the Bahamas with winds in excess of 100 mph near the centre of the hurricane. A storm surge of over two metres is possible and rainfall totals could be as high as 500 mm. Once the hurricane starts moving away from the islands the big question is whether it will make landfall over the US east coast.

Hurricane Joaquin at 1237 UTC on 01 October 2015 Image courtesy of the US Naval Research Laboratory [local copy at http://www-nwp/~frjh/tropicalcyclone/images/nhem15/joaquin_20151001_1237z.png]

Hurricane Joaquin at 1237 UTC on 01 October 2015
Image courtesy of the US Naval Research Laboratory

The forecasting conundrum

Joaquin is currently slow moving near the Bahamas and all computer models agree that a gradual turn north will happen in about two days time. However, beyond this point there is great uncertainty as to what will happen. Joaquin is being pulled in two directions. A developing trough of low pressure over the USA would act to pull Joaquin westwards towards the US coast. However, an area of low pressure to the east – including the remnants of Tropical Storm Ida – would act to pull Joaquin east away from the USA. The situation is finely balanced and any of several outcomes could happen.

One scenario is that Joaquin could make a turn north-westwards and make landfall near the Outer Banks of North Carolina at the weekend. Computer models are now mostly moving away from this as a likely outcome. Alternatively, Joaquin could take a mostly northwards track and reach New York and New England by early next week then continue up the eastern seaboard of Canada. Finally, a third scenario allows for the possibility that Joaquin could turn north-eastwards and avoid a US landfall altogether. We recommend that a close watch is kept on guidance issued by the National Hurricane Center in coming days for updates on which scenario is the most likely to occur.

Irrespective of whether or where Hurricane Joaquin makes landfall on the US east coast, large amounts of rain are expected in this area in the coming few days due to a slow-moving frontal zone. The impact of this will be exacerbated if Hurricane Joaquin does take a turn towards the USA in the next few days with further heavy rain accompanied by strong winds and a storm surge.

 Latest forecast track of Hurricane Joaquin from the National Hurricane Center

Latest forecast track of Hurricane Joaquin from the National Hurricane Center

Recent history of US landfalling hurricanes

Hurricane strikes on the USA have been fairly infrequent in recent years – particularly those at the stronger end of the scale. In 2014 Arthur crossed the Outer Banks of North Carolina as a category 2 hurricane. Going back to 2012, Isaac came ashore over Louisiana as a minimal category 1 hurricane. In 2011 Irene made landfall on the east coast of the USA also as a category 1 hurricane. The USA avoided hurricane strikes altogether in 2010 and 2009, but in 2008 three made landfall, the most significant of which was Hurricane Ike which caused a huge storm surge as it came ashore over Texas as a category 2 hurricane. However, you have to go back to 2005 to find the last ‘major’ hurricane strike on the USA (category 3 or above), when Hurricane Wilma hit Florida.

Hurricane Sandy (sometimes referred to as ‘Superstorm Sandy’) also caused much devastation to parts of the USA east coast in 2012. It is ranked as the second most costly hurricane in US history, although technically ceased to be a hurricane just prior to the time it made landfall.

Official warnings for the latest tropical cyclones in the Atlantic are produced by the US National Hurricane Center. 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. We also provide updates on current tropical storms via @metofficestorms on Twitter.

Will Joaquin affect the UK?

With the confidence around the exact track of Joaquin being so low, it is currently too early to tell if this system will affect the weather in the UK. There is, however, already high confidence that we will return to more autumnal and unsettled conditions across the UK early next week. Make sure you keep up-to-date with the Met Office five-day forecast.

Dry, sunny but cool September

30 09 2015

Two spells of settled weather during September have contributed to a rather dry and sunny but cool September.

Provisional statistics for the month show that after a wet end to August, September has been drier than average for much of the UK with figures up to the 28 September showing that there has been 53.3mm of rain, only 55% of the September average of 96.4mm.

Northern and western Scotland have been particularly dry with only 37% and 31% of the September average for rainfall having been recorded. In comparison, parts of eastern and southeast England have seen above average rainfall. Wales has seen 75mm of rain, 64% of average, while Northern Ireland recorded 51% of the September average for rainfall with a total of 47.1mm.

Many places have enjoyed a sunny month with 137 hours of sunshine recorded across the UK, this is 10% above the average for September.

However, despite the dry and sunny weather conditions, September has seen some rather cool days and nights. Mean temperatures across the UK up until the 28 September are 0.8C below normal with minimum temperatures across England and Wales around 1.5C below the September average. Five UK observing sites have already recorded their first frost of the season.

September 2015 rainfall amount

September 2015 rainfall amount

September 2015 sunshine anomaly

September 2015 sunshine anomaly












PROVISIONAL mean temperature sunshine duration precipitation
Sep-2015 Act Anm (8110) Act Anm (8110) Act Anm (8110)
degC degC hours % mm %
UK 11.9 -0.8 137.2 110 53.3 55
England 12.6 -1.1 152.5 111 52.8 76
Wales 11.8 -1.1 151.9 119 75.0 64
Scotland 10.8 -0.1 112.0 106 49.3 36
N Ireland 11.7 -0.7 113.9 100 47.1 51


The outlook for the first few days of October is for the fine, settled weather to continue before we see a transition towards more changeable weather next week with rain at times. Check out our five day forecast for more details.

Dry start to September for many

18 09 2015

You may think September has been a wet month so far but according to early provisional Met Office statistics, the month has started out drier and sunnier than average for many across the UK.

However the picture has been varied, some parts of southern and eastern England have already had over three quarters of their whole-month average rainfall for September. While northern and western areas have been drier, with little in the way of rain so far for much of Northern Ireland and Scotland away from eastern coasts.

Figures up to 16th September show there has been almost 30mm of rain across the UK, which is just 31% of the September average of 96mm. We would normally expect about half of the average monthly rainfall to have fallen by this point in the month. While there has been almost 72 hours of sunshine, 58% of the monthly average of 125 hours, with some north-western areas being especially sunny so far this month.

01 -16 Sept 2015 Rainfall Amount

01 -16 Sept 2015 Rainfall Amount

Looking at individual countries, Scotland has been the driest with almost 21mm of rain, 15% of average, followed by Northern Ireland with almost 24mm of rain, 26% of average. England is the wettest country so far with almost 34mm 49% of average.  There was a dry anticyclonic spell for the UK lasting from 5th until 11th, since then there have been some noticeable falls of rain.

The UK mean temperature so far has been 12.2C, which is 0.4C below the full-month average.

EARLY mean temperature sunshine duration precipitation
Sep-2015 Act Anm (8110) Act Anm (8110) Act Anm (8110)
degC degC hours % mm %
UK 12.2 -0.4 71.8 58 29.8 31
England 13.0 -0.8 78.2 57 33.8 49
Wales 12.3 -0.6 73.2 57 42.2 36
Scotland 11.0 0.1 63.6 61 20.9 15
N Ireland 12.2 -0.2 56.1 49 23.9 26


While these figures are interesting, they don’t tell us where the month will end up overall. A few days of wet or cold weather could drastically alter the statistics, so we’ll have to wait for the full-month figures before making any judgements.

Meanwhile this weekend is looking fine and dry, with good spells of sunshine for many on Saturday and many places seeing settled weather continuing well into Sunday evening. Check out our five day forecast for more details.

So what happened to our summer?

28 08 2015

Our Chief Scientist Professor Dame Julia Slingo OBE FRS reflects on this summer’s weather and what has influenced it:

No-one can deny that we have had a pretty disappointing summer with a lot of unsettled weather and only a few warm spells, especially through July and August. Our weather has been dominated by low pressure over and to the west of the country that has brought us periods of heavy rain from the south – what we call the Spanish Plume. So what has been happening?

If we look beyond our shores there have been some big changes in the global climate this year. El Niño is in full flight, disturbing weather patterns around the world. The low pressure that has dominated our weather is part of a pattern of waves in the jet stream around the world that has brought crippling heat waves to places like Poland and Japan. And, looking back over past El Niños, you could have expected that a more unsettled summer might be on the cards for the UK. Closer to home the North Atlantic is more than 2 degrees colder than normal. It seems quite likely that the unusually cold North Atlantic has strengthened and pushed our jet stream south, also contributing to the low pressure systems that have dominated our weather.

So could all this have been anticipated? Seasonal forecasts for this summer suggested that temperatures and rainfall would be near normal. However, as the season progressed all the leading models around the world failed to capture the signal for unsettled weather over the UK. We all know that forecasting months and seasons ahead is still in its infancy and much more research needs to be done. On the other hand our day-to-day forecasts have been really successful in allowing us to warn of bad weather, highlighting yet again the benefits of our research that has delivered year-on-year and decade-by-decade improvements in forecasting skill. Our 5-day forecast is now as accurate as our 1-day forecast was when I started my career. This enables us to make so many decisions that keep us safe, protect our property, keep our infrastructure running and even when to go out and enjoy the sunshine!

All of this cannot happen without improvements to research and technology, and this week the first phase of our new supercomputer went live, five weeks ahead of schedule. This will enable us to provide even more accurate and relevant weather and climate forecasts to all of us, our government, emergency responders, and our many other customers at home and abroad.

The news that the BBC has decided that the Met Office won’t be their main weather provider when the current contract ends has raised the question of where will the new provider get their information from. It’s important to understand that no weather forecasting organization, whether it is a National Met Service like the Met Office or an independent company, can provide a service without a forecast, and that it is the leading meteorological agencies, like the Met Office, that build and deliver those forecasts. So whoever the BBC chooses to deliver their weather services in future, you can be sure that Met Office observations and forecasts will continue to be at the heart of them. We are committed to driving forward the skill and usefulness of our forecasts and ensuring that all of us benefit from the advances the Met Office makes in the coming years with our new supercomputer.

Typhoon heads for Japanese volcano

23 08 2015

Typhoon Goni, which was located just east of Taiwan on Sunday morning, is expected to track across the western side of Kyushu Island in SW Japan through Monday.  There is a risk it could bring up to 200mm of rainfall in 24 hours across Kyushu, leading to a risk of flooding and landslides along with the threat of Hurricane Force winds and a storm surge.  This comes as the Japanese Meteorological Agency issues a level 4 alert for a major volcanic eruption on Mount Sakurajima.

Mount Sakurajima is one of 16 ‘Decade Volcano’ around the globe, meaning that it is a potentially destructive volcano close to populated areas. The level of alert suggests that the local population should prepare for evacuation, which would be made more difficult by a Typhoon impact.

Satellite image courtesy of National Oceanic and Atmospheric Administration

Satellite image courtesy of National Oceanic and Atmospheric Administration

Typhoon Goni has already bought heavy rainfall and Typhoon strength winds across the NE tip of Luzon in the northern Philippines.  Goni is expected to remain a Strong Typhoon (equivalent of a Category 2 Hurricane) with sustained winds of 80 knots and gusts to 115 knots, tracking steadily north through the rest of Sunday and Monday across the eastern East China Sea.  There is a risk of a storm surge and coastal flooding up through Kagoshima Bay in southern Kyushu.

Once Goni passes across western Japan, it is likely to lose its tropical characteristics, but could still bring flooding rains to the Korean Peninsula on Tuesday.


Summer downpours on the way

11 08 2015

The weather forecast for later this week is presenting a challenge for our meteorologists.

All the ingredients are present to produce significant rainfall on Thursday and Friday, but complex interactions in the atmosphere make it difficult to say with certainty where the rain will be most intense.

An area of low pressure is expected to develop and push north across the Bay of Biscay and western France on Wednesday night and into Thursday, arriving across southern England on Thursday morning. As it comes north, very warm air over the continent is expected to be drawn into the low pressure’s circulation, making it feel very humid across central and southern areas of the UK


Forecast pressure chart valid for 1am on Friday showing the location of the low pressure system over the southeast of the UK.

Warmer air can carry more moisture, and as such some very heavy rain is possible. However, this type of situation is difficult to forecast accurately a few days ahead and there is some uncertainty about which areas will see the heaviest rainfall. Current indications are that central and southern England and Wales are most likely to be affected. We may also have hail and thunder, this is most likely early on Thursday and then again Friday afternoon.

As we have already seen this summer, this type of weather situation has the potential to cause sudden, localised surface water flooding and hazardous travelling conditions.

Met Office National Severe Weather Warnings have been issued and these will be updated over the next few days as confidence in where and when we will see the heaviest rainfall increases.

Looking further ahead, the whole system is expected to clear away to the east during Saturday, with drier, fresher weather following to all parts with some sunshine.

Wet and dull July

31 07 2015

UPDATE: The figures below have now been updated to include data from the 1-31 July 2015.

July 2015 was cool, dull and wet across the UK according to Met Office statistics for 1-31 July.

The month began with a record-breaking heatwave, with hot, humid air moving in from the continent.  36.7 °C was recorded at Heathrow 1 July, the highest recorded temperature in the UK since August 2003.

However the rest of the month has been characterized by cooler and often more unsettled conditions, particularly in the north, as a result of a westerly Atlantic air flow.  Rainfall has been above average in most areas, particularly across parts of East Anglia, central and eastern Scotland.

MeantempJuly2015 RainfallJuly2015

minimum temperature mean temperature sunshine duration precipitation
Jul 1 – 31 2015 Act (°C)   Diff from avg (°C)   Act (°C) Diff from avg (°C) Act (hrs) % of avg Act (mm) % of avg
UK 10.3 -0.6 14.4 -0.7 164.8 96 109.5 140
England 11.2 -0.4 15.8 -0.5 191.9 99   82.3 131
Wales 10.8 -0.3 14.4 -0.8 175.1 98 112.4 121
Scotland 8.7 -0.9 12.2 -1.0 125.3 89 152.4 153
N Ireland 9.6 -1.1 13.3 -1.3 117.4 84 116.8 144

The south-east has seen some drier and more settled weather with temperatures near average, although there has also been some changeable weather here with over 20mm of rain falling on the 24 July and some cooler temperatures and strong winds on 26 and 27 July.

Elsewhere temperatures have been below average, particularly in the west and north, and it has been a rather dull month with sunshine totals being below average across much of the country.

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

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.


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