and TAFS How
to understand the reports available via the weather pages
(meteorological airfield reports) give the wind, clouds, temperatures,
etc as a report
(terminal airfield forecasts) predict what is expected to happen
at a particular airfield
codes might seem daunting, but with familiarity, are really very straightforward.
Tafs and Metars follow similar codes.
than repeat everything, look at this Martin
Rowley website for good explanations.
the weather page, links are given to several sources
of Metars and Tafs
Metars and Tafs are not specifically for Gliding
is worth remembering that Tafs and Metars are prepared for general aviation
and not specifically for gliding.
note that CAVOK means (amongst other things) that there is no cloud below
5,000 feet. So when there is 8/8ths cloud cover at 6,000 feet (eg
approaching front), this is of no great consequence to an airliner, but
is vital to a glider pilot.
limitation for gliding is that Tafs do not forecast the rising cloud base
of cumulus during the morning.
Taf gives the lowest base expected during the period of the
forecast. By far the most accurate way to predict the final cumulus
base is by using the dewpoint (which is unlikely to change much) and the
forecast maximum temperature (Bradbury 400 ft / °C)
of note on the weather page is a link to look up metar history, eg for when
you were flying 'yesterday'
- example This
is a long range Taf that tells the whole story of a poor period ahead
you are uncertain of the ICAO code for any particular UK airfield, then
use the link ICAO < - > A/F name
reports can be accessed by country and can be quite fascinating
131031Z 131818 23012KT 9999 BKN020 TEMPO 0206 8000 -RA TEMPO 0618 3000
RADZ BKN004 PROB40 0818 22015G25KT=
with colour to aid explanation
0206 8000 -RATEMPO
BKN004 PROB40 0818
0206 8000 -RA
A/F with time of issue 13th at 1031Z
of forecast from 13th at 1800 Z to next day 1800Z
wind, 230° at 12 knots
greater than 9999 metres, ie 10 kms +
cloud (5-7/8s) at 2,000 feet above ground
(ie, not all the time) between 02 and 06Z visibility 8,000 metres with
between 06 and 18Z (that means tomorrow)
3,000 metres, rain & drizzle, broken cloud at 400 feet
probability between times 08Z and 18Z (tomorrow)
from 220° 15 knots gusting 25 knots
end of report, ie nothing accidentally omitted
practice, decoding becomes almost automatic It's a language that
you read and your brain interprets without going through any conscious