Weather Information

Introduction

Knowledge of weather conditions likely to be encountered during flight is essential to the safe operation of aircraft. However, weather conditions change and therefore a convenient system to supply the latest information is required. To be effective these sources and the terms used must be globally understood.

Sources of Weather Information

Sources

A pilot in flight can gain weather information from several sources; the main sources are:

ATC ATIS VOLMET

In all of these, standard met terms should be used and the information is transmitted slowly and enunciated clearly, so that the data can be written down by the flight crew.

Request from ATC

For example, when returning to Oxford from Cardiff, you might be receiving a radar service from Brize Radar. In order to decide how you will approach Oxford, you could request the weather from Brize.

“Brize Radar, Oxford 94 request Oxford weather”

“Oxford 94, the Oxford 0950 weather, surface wind 360 degrees 5 knots, visibility 10 km, Nil weather, scattered 2500 feet. Runway 02 in use, QNH 1010”

ATIS (AutomaticTerminal Information Service)

In order to reduce the workload on controllers, a recorded message is transmitted continuously on a discrete VHF frequency or on a VOR frequency. Pilots are expected to listen to the report before contacting the appropriate aerodrome controller. Every time the data is changed, a new code letter is allocated.

Oxford has its own ATIS on 121.950, a typical example sounds like this:

“Oxford Departure information Bravo at 0830 Zulu. Surface wind 210 degrees 10 knots. QNH 1019 QFE 1009. Brize Norton outside air temp 15 dewpoint 14. Call 121.950 for taxi and report QNH and information Bravo”

Information Code. On initial contact the pilot should state the information code that he has received so that the controller can update the information if necessary.

“Oxford Ground, GBODA with Information Bravo QNH 1019 request taxi”

Weather Information 4

Information Weather 4

Volmet

Frequencies for Volmet information can be found in the Aeronautical Information Publication (AIP) or en route booklets such as Aerad. Each Volmet transmits a met information for a group of aerodromes at set times past the hour.

Contents ofVolmet

Volmet broadcasts (and other met transmissions) should follow a standard format. You should study the information on Met Reports in UK AIP MET so that you are familiar with terms and the units of measurement. A Volmet broadcast would include the following items and units of measurement: