Malta getting sunnier, and wetter

It may not be apparent to those who are not too attentive, but more rain is falling in the Maltese islands, according to the chief meteorological officer at the Met. office in Luqa, Saviour Porter.

Rainfall records during the past 30 years kept by the Met. office indicate that the number of rainless days has gone up but the amount of rain is heavier on rainy days.

That means that the chances of flooding are greater and rising. However, although the trend may continue, no one could be sure it would, Mr Porter said.

The Met. office in Luqa is equipped with state-of-the-art equipment which provides raw data from three computer systems, two in the UK and one in Spain.

The raw data provides the Met. office with values of temperature, humidity, wind, pressure and rainfall.

Using these three sources, forecasters monitor what goes on at the surface and the various levels of the atmosphere.

The weather model starts with a picture of the whole globe in order to get to know the starting conditions as a basis for the local forecast.

Every three hours, an observation is made in most parts of the globe, including details about temperature, type of cloud, and visibility.

This data is included in grids by forecasters all over the world to be used as forecast formulas.

There are six forecasters at Luqa, two of whom have more than 20 years' experience.

"We need a Met. office for Malta because the area around the island has unique characteristics. This central part of the Mediterranean is influenced by mountains to the west and the desert to the south. Overall, the island is in an area of high humidity and a climatology of its own.

"We are entrusted by the government to provide aviation services to all inbound and outgoing aircraft and to the armed forces.

"We also have an international commitment to provide weather reports for the Flight Information Region in an area ranging from Greece, on to the north of Libya, on to the east of the Tunisian border and to the south of Sicily".

Aircraft passing through this region would be notified about severe icing - the deposit of ice on the wings of a plane; thunderstorms; volcanic ash from Etna; and air turbulence.

"We also do a shipping forecast every six hours over a 50- nautical mile radius of Malta which is broadcast by Valletta Radio and internationally by Maltacom.

"On a daily basis, the Met. office broadcasts a rudimentary five-day forecast; a detailed three-day forecast intended mainly for shipping; and a detailed 24-hour forecast that is updated three times a day and more if necessary; a six-day UV index and a heat stress forecast."

The heat stress is the heat people actually feel. The cooling mechanism of a person depends on the ability to transfer heat into the atmosphere through perspiration.

If the air is dry, the perspiration dries up quickly and the temperature of the body cools. When it is humid, the perspiration does not dry out.

The heat index shows the heat a person feels compared with the temperature on the thermometer.

With the cooperation of the health department, the Met. office website includes information about how one can cope with heat stress. The Met. office has seven automatic weather stations spread over Malta and Gozo, including Benghajsa, Birkirkara, Valletta, Dingli, Selmun, Kercem and Xewkija.

A number of these stations measure the direction and speed of the wind, while others measure the sun energy.

The high temperatures in Europe followed by intense rainfall a few weeks ago could have been due to any one or a number of several factors. One reason could be the natural cycle of heating and cooling of the earth's atmosphere that takes place over a long period of time.

Another factor could be the emission of greenhouse gases into the atmosphere resulting in warmer days. Another reason could be a high pressure area or an anti-cyclone where air comes down vertically and heats up by compression.

The air over Europe did not become warmer because of global warming as such but because of localised conditions.

Another factor was the warm air from the desert moving towards Europe, which increased the amount of heat which was displaced to the east as cooler air came in from the Atlantic, which led to the formation of rain.

Big differences in temperature cause thunderstorms.

The Met. office, which today forms part of Malta International Airport, has weather records going back to 1922. Last month, its website www.maltairport.com was visited 122,694 times.