Weather Wise

If you see something the size of a man floating out of a Portakabin into the sky, trailing what looks like a box of chocolates, don't worry. Even if it inflates to the size of a detached house, then bursts, there is no cause for concern. For this is the new automatic weather balloon made in Finland called Autosonde, which the Met Office is using to monitor conditions at inland locations.

Until now, most of the weather balloons released by the Met Office have been launched from eight coastal sites. For more detailed information about local conditions - particularly where measurements are needed at differing altitudes - the new device will be very helpful. The balloons and weather sampling equipment (known as radiosondes) are loaded into their Portakabins, then at pre-programmed times the balloon inflates, the radiosonde is calibrated, then the complete rig is ejected for an hour-long trip into the atmosphere.

They will be launched from eight sites around the country, four times a day at each site. Quite apart from improving the accuracy of weather forecasts, they should keep UFO-spotters entranced for some time.

More data from the Met Office: we have just experienced the wettest April this century, but unless an average of 6cm of rain fell over the country in the last 24 hours, the all-time record of 139mm in 1782 still stands. April 1998 was, however, only the fifth time this century that April has been colder than March. It happened before in 1903, 1936, 1957 and 1990.