Background
In accordance with proposed changes to ICAO Annex 3, Amendment 74, Civilian TAF issue and validity times will change, as of 0001 UTC on Wednesday 5 November 2008.
A review of current practice is given initially, with the change in procedures following.
Current practice
Currently, the nominal Civilian TAF issue cycle is:
| 'Short' 9 hour TAFs (strictly, a 'short' TAF is one that is less than 12 hours) | |||
|---|---|---|---|
| Issue time | Valid time | ||
| ~0005 | 0110 | ||
| ~0305 | 0413 | ||
| ~0605 | 0716 | ||
| ~0905 | 1019 | ||
| ~1205 | 1322 | ||
| ~1505 | 1601 | ||
| ~1805 | 1904 | ||
| ~2105 | 2207 | ||
| 'Long' TAFs (strictly, a 'long' TAF is equal to or greater than 12 hours, i.e. 24 hours, or 30 hours) | |||
|---|---|---|---|
| Issue time | Valid time | ||
| ~1630 | 0024 | ||
| ~2230 | 0606 | ||
| ~0430 | 1212 | ||
| ~1030 | 1818 | ||
In addition, both a long TAF and a short TAF may be issued for the same airport, i.e. Heathrow EGLL currently has a short (9 hour) TAF and a long (24 hour) hour TAF.
'Short' TAFs are issued 55 minutes in advance of start of the TAF.
'Long' TAFs are issued ~7 ½ hours in advance of start of the TAF.
Practice as of 0001 UTC Wednesday 5 November 2008
From 0001 UTC Wednesday 5 November 2008 the cycle will change:
| 'Short' 9 hour TAFs (strictly, a 'short' TAF is one that is less than 12 hours): | |||
|---|---|---|---|
| Issue time | Valid time | For example | |
| ~2305 | DD00/dd09 | 1600/1609 meaning 00 UTC on 16th to 09 UTC on 16th | |
| ~0205 | DD03/dd12 | 1603/1612 meaning 03 UTC on 16th to 12 UTC on 16th | |
| ~0505 | DD06/dd15 | 1606/1615 meaning 06 UTC on 16th to 15 UTC on 16th | |
| ~0805 | DD09/dd18 | 1609/1618 meaning 09 UTC on 16th to 18 UTC on 16th | |
| ~1105 | DD12/dd21 | 1612/1621 meaning 12 UTC on 16th to 21 UTC on 16th | |
| ~1405 | DD15/dd24 | 1615/1624 meaning 15 UTC on 16th to 24 UTC on 16th | |
| ~1705 | DD18/dd03 | 1618/1703 meaning 18 UTC on 16th to 03 UTC on 17th | |
| ~2005 | DD21/dd06 | 1621/1706 meaning 21 UTC on 16th to 06 UTC on 17th | |
* where 'DD' refers to day of month at start of TAF, 'dd' refers to day of month at end of TAF.
Example 30 hr TAF:
| 'Long' TAFs (strictly, a 'long' TAF is equal to or greater than 12 hours, i.e. 18 hours, 24 hours or 30 hours) | |||
|---|---|---|---|
| Issue time | Valid time | For example | |
| ~2305 | D00/dd06 | 1600/1706 meaning 00 UTC on 16th to 06 UTC on 17th | |
| ~0505 | DD06/dd12 | 1606/1712 meaning 06 UTC on 16th to 12 UTC on 17th | |
| ~1105 | DD12/dd18 | 1612/1718 meaning 12 UTC on 16th to 18 UTC on 17th | |
| ~1705 | DD18/dd24 | 1618/1724 meaning 18 UTC on 16th to 24 UTC on 17th | |
* where 'DD' refers to day of month at start of TAF, 'dd' refers to day of month at end of TAF.
Example 24 hr TAF:
| 'Long' TAFs (strictly, a 'long' TAF is equal to or greater than 12 hours, i.e. 18 hours, 24 hours or 30 hours) | |||
|---|---|---|---|
| Issue time | Valid time | For example | |
| ~2305 | D00/dd00 | 1600/1700 meaning 00 UTC on 16th to 00 UTC on 17th | |
| ~0505 | DD06/dd06 | 1606/1706 meaning 06 UTC on 16th to 06 UTC on 17th | |
| ~1105 | DD12/dd12 | 1612/1712 meaning 12 UTC on 16th to 12 UTC on 17th | |
| ~1705 | DD18/dd18 | 1618/1718 meaning 18 UTC on 16th to 18 UTC on 17th | |
* where 'DD' refers to day of month at start of TAF, 'dd' refers to day of month at end of TAF.
In addition, airports will no longer have a long TAF and a short TAF issued. That is, an airport with 24 or 30 hour TAF will no longer have a 9 hour TAF issued. i.e. Heathrow EGLL will only receive 30 hour TAFs, no 9 hour TAFs will be issued.
Both 'Short' and 'Long' TAFs will be issued between 55 and 35 minutes in advance of start of the TAF.
| Aerodromes proposed TAF arrangements from Nov 2008 | |||
|---|---|---|---|
| Airport | 9 Hour TAF | 24 Hour TAF | 30 Hour TAF |
Aberdeen |
|
X |
|
Belfast Aldergrove |
|
X |
|
Belfast City |
X |
|
|
Benbecula |
X |
|
|
Biggin Hill |
X |
|
|
Birmingham |
|
X |
|
Blackpool |
X |
|
|
Bournemouth |
X |
|
|
Bristol |
|
X |
|
Bristol Filton |
X |
|
|
Cambridge |
X |
|
|
Campbeltown |
X |
|
|
Cardiff |
|
X |
|
Carlisle |
X |
|
|
City Of Derry |
X |
|
|
Coventry |
|
X |
|
Cranfield |
X |
|
|
Doncaster Sheffield |
X |
|
|
Dundee |
X |
|
|
Durham |
X |
|
|
East Midlands |
|
X |
|
Edinburgh |
|
X |
|
Exeter |
X |
|
|
Farnborough |
X |
|
|
Glasgow |
|
X |
|
Gloucestershire |
X |
|
|
Hawarden |
X |
|
|
Humberside |
X |
|
|
Inverness |
X |
|
|
Islay |
X |
|
|
Kirkwall |
X |
|
|
Leeds/Bradford |
|
X |
|
Liverpool |
|
X |
|
London City |
X |
|
|
London Gatwick |
|
|
X |
London Heathrow |
|
|
X |
London Luton |
|
X |
|
London Stansted |
|
|
X |
Lydd |
X |
|
|
Manchester |
|
|
X |
Manston |
X |
|
|
Newcastle |
|
X |
|
Norwich |
X |
|
|
Plymouth |
X |
|
|
Prestwick |
|
X |
|
Scatsta |
X |
|
|
Scilly Isles |
X |
|
|
Shoreham |
X |
|
|
Southampton |
X |
|
|
Southend |
X |
|
|
Stornoway |
X |
|
|
Sumburgh |
X |
|
|
Tiree |
X |
|
|
Wick |
X |
|
|
Notes:
- The precise validity time of TAFs will be dependent upon Airport opening hours, and availability of METAR/AutoMETAR data of sufficient regularity and quality.
- TAFs of less than 12 hours ('short' TAFs), will be routinely updated on a 3 hourly basis.
- TAFs of equal to or greater than 12 hours ('long' TAFs), will be routinely updated on a 6 hourly basis.
- All TAFs will be monitored and may be re-issued as Amendments at any time.
