There is currently an industry consultation underway regarding the changes
of TAFs and METARs.

Brief details as follows:

TAF changes are expected wef 5 Nov 2008.

Each airfield in future will only have one TAF - i.e there will be no
issuing of the long and short ones for the same airport.

- Introduction of 30 hour TAF with date fields:
i.e TAF EGLL 160500Z 1606/1712 13018KT 9999 FEW012 BECMG 1606/1608 SCT015CB
TEMPO 1608/1618 17025G45KT 1000 TSRA BKN010CB TEMPO 1703/1707 4000 BR=

All TAFs will be effective from 1 hour after issue ie the 1200-1800 next day
TAF will be issued at 1100Z

EGBB, EGCC, EGLL & EGSS 30 hour TAFs
EGPD, EGAA, EGGD, EGFF, EGBE, EGNX, EGPH, EGPF, EGNM, EGGP, EGKK
(surprisingly although I think this will become 30hr after consultation),
EGGW, EGNT & EGPK 18 hour TAFs
All the rest 9hour TAFs only

METARs from 7 Nov 2007
Auto Metars will be used to initiate TAF production.
Prevailing vis - introduced in 2005 - Minimum vis will only be reported when
the vis is different from the prevailing vis and less than 50% of the
prevailing vis AND less than 5000m.

METARs from 5 Nov 2008
Reporting of 5kt gusts in local reports when noise preferential runways are
in use.
TCU cluds will be included as significant clouds i.e if they are present
CAVOK cannot be reported.

METARs (no sure intro date)
Introduction of additional AUTO unidentified precipitation (UP) parameters
i.e SHUP, TSUP & FZUP.

Good Luck Jon!

Phil
--
www.layton.me.uk/meteo.htm

"Phil Layton" wrote in message
...

Good Luck Jon!

Phil

Yes... thanks, Phil ! Interesting times ahead. The addition of date groups
will, on occasion, make the 30 hour TAFs quite long.

Do you know when the issues times will be and at what frequency, e.g. will
the 9 hour TAFs be issued every 3 hours and 18/30 hour TAFs every 6 ?

Jon.

"Jon O'Rourke" wrote in message
...
Do you know when the issues times will be and at what frequency, e.g.
will
the 9 hour TAFs be issued every 3 hours and 18/30 hour TAFs every 6 ?


The 30hr TAFs
Issued 2300 Valid 0000-0600
Issued 0500 Valid 0600-1200
Issued 1100 Valid 1200-1800
Issued 1700 Valid 1800-0000

TAFs with a validity period of less than 12 hours will be updated every 3
hours, while those of 12 hours or more every 6 hours.

Phil

I have just looked at a typical 24 hour Taf:

EGGW 181621Z 190024 22011KT 9999 SCT035 BECMG 0205 10005KT TEMPO
0407 6000 BECMG 1316 07015G27KT PROB40 TEMPO 1622 6000 RA
BECMG
2123 21010KT TEMPO 2123 BKN012=

In simple language, what the f*** will the conditions be at 0700
tomorrow? SCT cloud with rain? A tad improbable. But I presume I
have misinterpreted this Taf due to my advancing years!

It's long and complicated enough as it is, but 30 hours with tempo
this, prob that, etc, is a recipe for confusion.

Jack (retired professional pilot, but)

wrote in message
oups.com...
I have just looked at a typical 24 hour Taf:

EGGW 181621Z 190024 22011KT 9999 SCT035 BECMG 0205 10005KT TEMPO 0407
6000 BECMG 1316 07015G27KT PROB40 TEMPO 1622 6000 RA
BECMG 2123 21010KT TEMPO 2123 BKN012=

In simple language, what the f*** will the conditions be at 0700
tomorrow? SCT cloud with rain?

Looks fairly straightforward for that time to me, i.e. 9999 SCT035 with a
TEMPO of a bit of HZ between 0400 and 0700. The PROB for the rain doesn't
start until 16Z.

Jon.

What is really needed is to break things up into simple time blocks
rather than tempo this, and prob that.

eg
period 0006 weather ABC

period 0612 XYZ (even though that might be exactly the same, but a
damn site easier to read if presented in this way)

etc

Jack