HMS Ocean tracks weather as she speeds to hurricane zone

HMS Ocean is heading into the 'Atlantic hurricane conveyor belt' at top speed as she races to deliver crucial aid to Britons in the Caribbean.

Filled with aid from the UK and Gibraltar Governments - trucks, food, temporary shelters, building materials and toys - the helicopter carrier is following in the wake of Hurricane Maria, the latest storm to smash its way through the islands of the Caribbean.

Ocean is due to reach the region at the end of the week, which has meant the staff of her Hydrographic Meteorological Office - known simply as the Met Office by the crew of Britain's biggest warship - are keeping an even closer eye of the weather than usual.

"Everyone is interested in the weather especially now as HMS Ocean is heading into the hurricane conveyor belt," Lieutenant Commander Gordon Jones, Senior Meteorologist Officer aboard HMS Ocean.

"A hurricane is a local name for tropical storms in the Atlantic. They usually die down when they lose their drive such as when moving over cold water. Hurricanes need moisture and heat going in which comes from the sea.

“To some extent you can predict the force of it but predicting the full force and the direction is very challenging."

 

The balloon will send us lots of important data such as what height the clouds are, whether the atmosphere is stable or unstable and if there is a weather front coming through

Able Seaman Thea Puttick, hydrographic & meteorological specialist on HMS Ocean

The National Hurricane Centre in Miami is the official forecasting centre for the Atlantic and East Pacific areas and is also responsible for the storms' names.

"Once Hurricane Maria has dissipated the next named hurricane will be Nate as the boys and girls names are alternated," explained Lt Cdr Jones.

One of the weapons in Gordon's forecasting armoury is his weather balloons, a traditional form of data collection which is still valuable in the modern age. Launched from the ship's flight deck, each balloon is inflated with helium and released into the atmosphere.

23-year-old Able Seaman Thea Puttick from St Ives in Cambridgeshire is one of Lt Cdr Jones' team of hydrographic/meteorological specialists. It is her job to release the balloon.

She said, "Attached to the weather balloon is a radiosonde which feeds data back to our computer.

"The balloon will send us lots of important data such as what height the clouds are, whether the atmosphere is stable or unstable and if there is a weather front coming through."

The balloon, which is specifically designed to be aircraft safe, is usually launched once a week but more can be launched if needed. The data from the balloon is downloaded on to the meteorological computer where Thea and her shipmates translate the information.

"We wait for the balloon to get to its optimum height before we get the data off.  We often have a sweepstake to guess how high the balloon will go - the height depends on when it expands to such a size that it pops and falls back to the sea," said Thea.

"The balloon and radiosonde attached to it are designed to have a minimal impact on the environment."

Some have been known to reach 48,000ft - nine miles, or three miles higher than the altitude commercial airliners typically fly at.

The balloon that Thea sent up might not have set any records but it did provide the team with reams of weather data, allowing HMS Ocean's meteorologists to confirm the accuracy of the computer-based information that they are dependent on for forecasting.