Is Tropical Storm Bertha heading for the UK?

4 08 2014

Update: The latest update about the whether ex-Bertha will affect the UK can be found in our news release

A Tropical Storm called Bertha, which is currently in situated off the east coast of the US, could head towards Europe over the next week – so what’s the outlook?

Forecast tracks for Bertha, which was a hurricane but has now been downgraded to a tropical storm, suggest it will head north – staying offshore from the eastern coast of the US before turning to track east across the Atlantic.

Forecast track for Bertha from StormTracker shows it heading north off the east coast of the US before turning east.

Forecast track for Bertha from StormTracker shows it heading north off the east coast of the US before turning east.

While all forecast models suggest the storm will head in the general direction of UK and continental Europe, there remains a lot of uncertainty about exactly what it will do.

One certainty is that as the storm heads north away from the very warm seas which drive its power, it will lose strength and become what’s known as an extra-tropical storm – so we won’t be seeing a ‘hurricane in Europe’, but there is a chance we could see a fairly active summer storm.

The development of hurricanes and extra tropical storms can present complexities for meteorologists, and Bertha is a good example of that.

Here at the Met Office we use several world-leading forecast models as well as our own, and this gives an indication of how certain a forecast is. If all the models agree, there’s higher certainty, if they diverge, we know the atmosphere is finely balanced and there are several possible outcomes.

Satellite image of Bertha in the Caribbean taken at 11.45am on Monday, 4 August 2014 (Picture from NOAA)

Satellite image of Bertha in the Caribbean taken at 11.45am on Monday, 4 August 2014 (Picture from NOAA)

In the case of Bertha each of the models we use gives a very different picture of what the storm will do. This ranges from Bertha heading towards France as a weak feature which will completely miss the UK, to it arriving as a fairly active summer storm.

In terms of timing, there’s also a spread of possibilities – but it looks likely that the earliest Bertha would affect the UK would be on Sunday or into the start of next week.

As time progresses, different models normally come more in to line with each other and uncertainty decreases. The Met Office will be keeping an eye on how this situation develops over the next few days to give everyone in the UK the best advice on what Bertha is likely to do.

Given the time of year and the potential heavy rain, strong winds and large waves Bertha could bring if it does head to the UK, we’d advise everyone to stay up to date with the latest forecasts and warnings from the Met Office over the next few days.

You can also see the forecast track for Bertha and other tropical storms on our StormTracker pages.

NOTE – story updated to reflect Bertha’s status after being downgraded to a tropical storm.





Guest blog: RNLI lifeguards warn of beach dangers after winter storms

17 04 2014

Brett Shepherd, Lifeguard Manager, provides some timely advice for those planning a trip to the beach as the Easter weekend approaches.

As many of our RNLI lifeguards head back to British beaches this weekend, I’m hoping for some lovely weather to herald the start of the season. But the affect winter storms have had around the coast mean that many of the country’s most popular beaches are looking very different to this time last year.

Unprecedented storms over the winter have changed the make-up of some beaches, with sand dunes in some areas being washed away leaving sheer sand cliffs. On other beaches, access points to and from the beach have changed and shifting sand has left deep channels that in turn create strong rip currents.

Our RNLI lifeguards, who have been patrolling the country’s beaches since 2001, will be keeping visitors safe on 33 beaches across the UK over the Easter bank holiday weekend. Whilst we’re hoping lots of people head out to enjoy our glorious coast, there are a couple of easy safety steps we’re urging people to take following the winter storms.

Firstly, always head to lifeguarded beaches; they are far safer environments and will help offer you peace of mind. You can download a special ‘Beach Finder’ app from our website which will tell you where the nearest lifeguarded beaches are, or check with local authorities. We’d also urge people planning on visiting a beach to check local information in advance, as the beach environment may have changed dramatically since your last visit.

Swimmers should ensure that they swim between the red and yellow flags, which mark out the safest area to swim and are patrolled by lifeguards. Lifeguards are always on hand to offer beach safety information and advice, and please take heed of local safety signage.

By highlighting the dangers before visitors arrive at the beach, we hope that we can avoid potential incidents and everyone can enjoy their time on the beach in safety.

RNLI lifeguard rescue. Copyright Nigel Millar

RNLI lifeguard rescue. Copyright Nigel Millar





Strong winds, big waves and a storm surge

9 10 2013

A relatively deep area of low pressure is tracking past the north of Scotland today and is then expected to head south into the North Sea tomorrow.

This will bring some strong winds to northern Scotland tonight, then to the east coast of England tomorrow – particularly through the afternoon.

These northerly winds are expected to gust up to 50-60mph, which is unlikely to cause any wind damage but could generate some big waves in the North Sea.

Forecast surface pressure chart for Midnight tonight.

Forecast surface pressure chart for Midnight tonight.

The Met Office has issued a warning this possibility as the big waves could combine with a storm surge to overtop sea walls and potentially flood some coastal roads.

A spokeswoman for the Environment Agency said: “Strong winds and large waves could cause minor disruption along the North Sea coast on Thursday from Yorkshire to Essex. Spray and waves may overtop sea walls and people are urged to stay safe and avoid coastal paths and promenades. The high winds and localised flooding on roads could make driving conditions difficult in coastal areas.”

But what is a storm surge?

Essentially this is a very localised rising of sea level – independent of tides – related to the track of an area of low pressure (storm) and its accompanying winds.

The storm causes this surge of water in two ways. Firstly, strong winds push water in their direction of travel, causing water to ‘pile up’ on coasts facing into the wind.

The second element of a storm surge relates to differences in air pressure. Areas of low pressure are always relative, meaning the air surrounding them must be at a higher pressure.

These areas of high pressure push down on the surface of the ocean, forcing water towards areas of lower pressure to create bulges in the sea level. For each 1 hPa drop in pressure, sea levels rise by up to 1 cm.

Bulges move with a low pressure as it tracks across the sea. North Sea areas are particularly prone to storm surges because water flowing south cannot escape through the narrow Dover Strait and the English Channel.

When storm surges combine with higher tides and big waves they can cause localised issues along coasts.








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