The balloon will be launched twice a day during the pre-monsoon months of April, May, and June

STORM: An upper air observation service, that will allow more accurate weather forecasts, was officially launched by the Department of Hydro Met Services and Department of Air Transport (DAT) at Paro international airport, yesterday.

The upper air observation service, which will be conducted in the pre-monsoon months of April, May, and June, is carried out by launching a hydrogen filled balloon that lifts a piece of equipment called a radiosonde.

A radiosonde records features like temperature, rainfall, humidity, air pressure, wind direction and speed, among others, and transmits this information back to a ground station located at the airport every five seconds. This information is then displayed on a personal computer to be observed.

Once launched, the balloon rises five metres a second until it reaches the stratosphere or between 35-40km above earth, and bursts.

Senior meteorologist, Tayba B Tamang, said information provided by the radiosonde would provide realtime data on the weather above and around Paro airport, such as wind speed and directions, and would be useful to air traffic control in directing aircraft in or out of the airport.

For the hydro-met department, Tayba B Tamang said that such data would aid in validating their forecasts to provide more accurate models.

However, one of the primary uses of the service would be to scientists at the SAARC Meteorological Research Centre who are studying weather in the region so that they can better predict its patterns and be able to provide warnings and advisories to the public when the weather could turn bad in the region.

The service will be carried out only during the pre-monsoon months as this is when the weather is most volatile. Balloons carrying radiosondes would be launched twice a day from Paro airport during these months.

The SAARC project covers the four countries mostly affected by this volatile weather: Bhutan, Bangladesh, India, and Nepal.

The project has also installed 10 ground weather stations in Bhutan, 24 in Nepal and 50 in Bangladesh.

The three-year project, which is costing Nu 2.9 million for a year, is funded by SAARC through the STORM (Severe Thunderstorm Observation and Regional Modelling) programme which is monitoring and studying the life cycle of severe thunderstorms in the region.

Severe weather predicted in next 48 hours

The hydro-met department has forecast strong gusty winds of over 30m/second in the northern and some parts of north-west Bhutan from Saturday night to Sunday morning. This covers recently affected Lunana, and northern parts of Thimphu, Paro and Haa.

Senior meteorologist, Tayba B Tamang said all concerned authorities had already been informed of the forecast.

The department has also forecast a possibility of light rain over western, central, and eastern Bhutan today and tomorrow. There is also a possibility of light snow fall in the high passes and areas located above 3,000m.

Gyalsten K Dorji