Issued: 17/01/2017 11:53:00
Start: Wednesday 18 January
Finish: end of Wednesday 18 January
Pollution Band: Moderate
With an area of high pressure becoming established over the near-continent, cold and settled conditions are expected in Greater London.
Light winds and low temperatures throughout the day will inhibit the dispersal of locally-emitted pollutants. Consequently, 'Moderate' levels of PM10 & PM2.5 particulates and Nitrogen Dioxide are likely close to busy roads.
Air mass back trajectories indicate that, for at least some of Wednesday, air arriving in Greater London will have passed over the industrialised region of North-Western France.
London's local pollution burden is therefore likely to be exacerbated by some imported particulates. However, should this incoming feed of polluted air become more prolonged and established, 'Moderate' levels of PM10 and PM2.5 particulates may also occur widely at urban background locations.
Air pollution is expected to remain ‘Low’ throughout the forecast period for the following pollutants: