As Far As I Know, there is now NO Stevenson screen at LGW. We have 2 automated weather stations supplied by Vaisala and owned/operated by National Air Traffic Services (NATS). This data is fed to a PC in the Tower and also to the Met Office at Exeter. This forms the Semi Automated Met Observation System (SAMOS). An Assistant in the Tower looks at the data displayed on the screen to make sure that it makes sense compared with the view out of the window. This data is then allowed to update the Aerodrome Terminal Information System (ATIS). At this stage, any further remarks can also be added to the ATIS messge. The data transmitted to the Met Office becomes the MET Actual Report (METAR).
The lovely patch of grass that the Stevenson Screen stood on in front of the Met Observer's building is now a sea of mud and is occupied with garbage skips. The Met Observer is likewise long gone. Sic Transit Gloria Mundi.
Cheers,
TheOddOne