Aviation Digital Data Service (ADDS)

Output produced by TAFs form (1553 UTC 23 April 2017)
found at http://www.aviationweather.gov/adds/tafs/
 
Forecast for: EGLL (LONDON/HEATHROW , GB)
Text: TAF EGLL 231055Z 2312/2418 25008KT 9999 SCT035
Forecast period: 1200 UTC 23 April 2017 to 1800 UTC 24 April 2017
Forecast type: FROM: standard forecast or significant change
Winds: from the WSW (250 degrees) at 9 MPH (8 knots; 4.2 m/s)
Visibility: 6 or more miles (10+ km)
Clouds: scattered clouds at 3500 feet AGL
Weather: no significant weather forecast for this period
Text: PROB30 2401/2406 9000
Forecast period: 0100 to 0600 UTC 24 April 2017
Forecast type: PROBABLE: 30 percent likelihood of the following during this time
Visibility: 6 miles (9 km)
Weather: no significant weather forecast for this period
Text: PROB30
Forecast period: 1200 to 1800 UTC 24 April 2017
Forecast type: TEMPORARY: The following changes expected for less than half the time period
Visibility: 5 miles (8 km)
Weather: -SHRA  (light rain showers)