Ex Hurricane Bertha: UK Update

As you may have seen, many of the newspapers are reporting that Hurricane Bertha is going to hit the UK, well its not at least as a hurricane. Ex Hurricane Bertha is heading across the Atlantic and will reach the UK on Sunday however this will be as an extra tropical cyclone and is expected to bring rain and strong winds to parts of the country.

Ex Hurricane Bertha, Satellite image August 6th 2014. Copyright NOAA

According to the National Hurricane Center in their 11AM update on Wednesday August 6, 2014, Hurricane Bertha is expected to be located just off the south west coast at 8AM on Sunday August 10, 2014.

Ex-Hurricane Bertha Track 6:8:14


This will bring strong winds and heavy rain to places and it is expected to travel across Southern Britain throughout Sunday. The Met Office has issued a Yellow Warning of Rain for much of the country on Sunday.

The Met Office Warning is as follows.

“There is the risk of severe weather during Sunday as a depression tracks over, or close to, the UK. At this stage there is more than average uncertainty in the forecast, but the public should be aware of the risk of heavy rain, strong winds and large waves, sufficient to disrupt transport and make outdoor activities dangerous.

This is a particularly volatile situation, and this warning is likely to be changed as the event approaches.”

The Met Offices Chief Forecaster Said

“The remains of hurricane Bertha, over the western side of the Atlantic on Thursday morning, will come steadily towards the UK. The transition from a tropical to an extra-tropical feature is a particularly hard one to forecast with confidence, and computer models continue to differ in the location and intensity of the resulting depression, which is expected to pass over, or close to, the UK from early on Sunday. There is the potential for widespread rainfall totals of more than 50 mm and coastal gusts of over 60 mph, along with large waves. However, the system may pass harmlessly to the south of the country. or spread heavy rain even further north, and the public are advised to keep up to date with warnings.”

EX Hurricane Bertha Weather Warning
UK Severe Weather Warning Valid 0015-2345 Sunday August 10, 2014. metoffice.gov.uk

There is a lot of uncertainty to the track of the extra tropical cyclone. The NMM 14KM model shows the centre of the depression to be located just south of Plymouth at 7AM on August 10 2014.

Photo courtesy of UK Weather Forecast
Copyright ukweatherforecast.co.uk

And at 1300h on August 10, 2014 the centre of the depression is located over Central Southern England.

Photo courtesy of UK Weather Forecast
Copyright ukweatherforecast.co.uk

The NMM 14KM is showing maximum wind gusts of 68mph along the Hampshire coast at 1300h on August 10 2014 and at 1600h, wind gusts of 68 mph on the East Sussex / Kent Coastlines with gusts of 56-60 mph here.

1300h August 10, 2014 NMM Max Wind Gusts Copyright ukweatherforecast.co.uk
1300h August 10, 2014 NMM Max Wind Gusts. Copyright ukweatherforecast.co.uk
1600h August 10 2014 NMM Max Wind Gust. Copyright ukweatherforecast.co.uk
1600h August 10 2014 NMM Max Wind Gust. Copyright ukweatherforecast.co.uk

The average wind speeds for 1300h are 48 mph south of Weymouth and 32 mph here in Littlehampton.

NMM 14KM Average winds at 1300h (1PM)  Copyright ukweatherforecast.co.uk
NMM 14KM Average winds at 1300h (1PM). Copyright ukweatherforecast.co.uk

The average wind speeds for 1600h are 48 mph along much of the Sussex Coastline.

NMM 14KM Average wind speed at 1600h (4PM). Copyright ukweatherforecast.co.uk
NMM 14KM Average wind speed at 1600h (4PM). Copyright ukweatherforecast.co.uk

With regards to rainfall, the current rainfall accumulation forecast suggests that the South West corner of the UK will be worst hit with possible flooding as of 1PM Sunday August 10, 2014 they have accumulations of up to 70mm, here in Littlehampton / East Preston we look to have rainfall accumulations of 3-4mm.

1PM Accumulated Rainfall. Copyright ukweatherforecast.co.uk
1PM Accumulated Rainfall. Copyright ukweatherforecast.co.uk

As of 4PM Sunday August 10, 2014 the Accumulative rainfall totals don’t increase that much for the South West but in the South East they have increased to 7-9mm and they don’t increase much after that.

4PM Accumulated Rainfall. Copyright ukweatherforecast.co.uk
4PM Accumulated Rainfall. Copyright ukweatherforecast.co.uk

The rainfall forecast shows that at 1PM the rain will be in South West England, Wales and the West Midlands with rainfall rates of up to 55mm per hour in parts of Wales and West Midlands, here in East Preston we have rainfall rates of 1mm per hour, as we look later in the day at 4PM, the rainfall has lightened and moved north east this time rainfall rates are around 8mm per hour in parts of the South West, here in East Preston we have rainfall rates of 2.5mm per hour.

1PM Rainfall Rates. Copyright ukweatherforecast.co.uk
1PM Rainfall Rates. Copyright ukweatherforecast.co.uk
4PM Rainfall rates. Copyright ukweatherforecast.co.uk
4PM Rainfall rates. Copyright ukweatherforecast.co.uk

The current forecast for the Hurricane Bertha is that it will bring heavy rain and strong winds towards the British Isles over the weekend, Sunday August 10 looks to be the worst day. Stay tuned for updates on our website and Facebook Page.