UK meteorologists are predicting no early end to the severe fog conditions that have disrupted domestic and European flights from London Heathrow for the past two days, with the possibility of beating an all-time record of nine days.

The Met Office, the branch of the UK defence ministry responsible for predicting and analysing weather conditions, says the current radiation fog, caused by a clear skies in recent days followed by a large high pressure front and very light wind, could remain in place for a further four days.

British Airways cancelled all domestic services to and from London Heathrow today and a large number of European services have also been cancelled, including significant numbers of services to Paris and Brussels. other airlines including BMI have followed suit as air traffic controllers have increased landing separation in light of ground visibility of around 200m (660ft).

Less dense fog hampered operations at the airport yesterday and have also affected flights from other London airports. However, the Met Office says there is a likelihood of continued high pressure and light winds until 26 December. "There is a sheet of strata-cumulus coming in tantalisingly close, where visibility is measured in kilometres rather than hundreds of metres, but with such light winds, it may not come our way for eight days," the office says.

The previous foggiest period in the airport's history was in December 1952, when nine continuous days of fog being reported at 09:00 were entered into the National Climate Report. Fog was reported at 09:00 on Tuesday 19 December, although it later cleared. If the fog continued on to 28 December it would equal the 1952 record.
The Met Office says the 1950s and 1960s were particularly bad for fog at Heathrow, as they preceded London's clean air act, banning open fires in the UK capital and thus reducing smog.

Heathrow is far from the most fog-prone airport in Europe, with northern German, Dutch, Polish and other Central European airports reporting tens of days of fog each year. However, due to the requirement at Heathrow to land aircraft every minute, the impact of adverse weather is greater. Italian national carrier was instrumental in moving Milan's main airport from Linate to Malpensa. The operations room at the former says 30 days of fog are not unusual.

Source: FlightGlobal.com