Aviation Digital Data Service (ADDS)

Output produced by TAFs form (2307 UTC 04 September 2015)
found at http://www.aviationweather.gov/adds/tafs/
 
Forecast for: EGLL (LONDON/HEATHROW , GB)
Text: TAF EGLL 041657Z 0418/0524 35006KT 9999 SCT040
Forecast period: 1800 UTC 04 September 2015 to 0000 UTC 06 September 2015
Forecast type: FROM: standard forecast or significant change
Winds: from the N (350 degrees) at 7 MPH (6 knots; 3.1 m/s)
Visibility: 6 or more miles (10+ km)
Clouds: scattered clouds at 4000 feet AGL
Weather: no significant weather forecast for this period
Text: PROB40
Forecast period: 0400 to 0900 UTC 05 September 2015
Forecast type: TEMPORARY: The following changes expected for less than half the time period
Visibility: 5 miles (8 km)
Ceiling: 800 feet AGL
Clouds: broken clouds at 800 feet AGL
Weather: -RA -DZ  (light rain, light drizzle)