Aerodrome Weather Warnings

What is the Aerodrome Weather Warnings Service?

As part of the Met Office services in the UK delivered on behalf of the Civil Aviation Authority (CAA), we have provided Aerodrome Weather Warnings for over ten years.

As inclement weather can have significant impacts, we issue warnings for a wide range of UK aerodromes. We provide concise information of meteorological conditions that could adversely affect aircraft on the ground, including parked aircraft, and the aerodrome facilities and services.

Aerodrome Weather Warnings are available to the widest possible range of aviation users, including airport operators, air traffic control units, and general aviation pilots. Warnings are displayed via the Aviation Briefing Service. Warning alerts by email are also available, ensuring that aviation users can be alerted in advance of conditions that may affect aerodrome operations in accordance with specified lead times.

What Aerodrome Weather Warnings are provided?

• Strong Wind (mean 20kt or more and/or gusts of 28 kt)
• Gale (mean 34kt or more and/or gusts of 43kt)
• Frost (Ground Frost, Air Frost, Ground and Air Frost)
• Snow
• Fog (including Freezing Fog)
• Thunderstorm (including Thunderstorm & Hail, Thunderstorm & Squall, Squall, Thunderstorm & Hail & Squall)
• Hail
• Freezing Precipitation (liquid precipitation freezing in contact with hard surfaces)
• Temperature Inversion (an increase in air temperature of 10C or more in the lowest 1000ft)

All warnings are provided in a standardised text format.

When are warnings issued?

Warnings are issued every six hours, four times per day* at the following times (UTC):

Time of update	Period of validity
0530-45	1200-1800
1130-45	1800-0000
1730-45	0000-0600
2330-45	0600-1200

The set times for updating the UK Aerodrome Weather Warnings Service allows the Met Office to provide appropriate lead times in order to provide advance notice of hazards relevant to aviation. This assists aerodromes and pilots planning to respond to these hazards.

All warnings have at least a six-hour lead time, with the exception of thunderstorm warnings that have a lead time of one hour. The warnings cover all or part of the six-hour periods.

*at a small number of airports, warnings will be issued as and when necessary.

How can I view the Aerodrome Weather Warnings?

The Aerodrome Weather Warnings issued can be accessed from the Met Office’s Aviation Briefing Service portal (free registration required). This service allows registered users to view warnings on a map-based view, (indicated by a red triangle) or when looking at the detail of an individual aerodrome location.

How can I be alerted about Aerodrome Weather Warnings for selected aerodromes?

In addition to viewing Aerodrome Weather Warnings on the Aviation Briefing Service, it is also possible to set your own preference to receive aerodrome warnings by email, for up to two aerodromes.  Select Settings under the Aerodrome Warning alerts menu option available in the Aviation Briefing Service.

NB. It is the registered user's responsibility to ensure their ability to receive email alerts. The Met Office does not guarantee delivery to individual end points.

Complementary information

The Aerodrome Weather Warning Service should be used as part of an overall weather monitoring routine. Users are expected to monitor weather as conditions dictate utilising all resources such as TAFS, METARs, Charts F214/F215 and other Met Office information as appropriate, including the National Severe Weather Warnings Service (NSWWS).

NSWWS warnings provide useful supplementary information to enhance situational awareness and to provide early indications of adverse weather helping to deliver the desired holistic approach.

Summary

Aerodrome Weather Warnings issued are available on the Met Office’s Aviation Briefing Service, supported by an optional, free to register, e-mail alert. The key aspects of the service are:

• Freely accessible at the point of use (subject to registration)
• Warnings issued routinely every 6 hours, 4 times per day (for selected airports this may be at other times as well)
• Maximum 6-hour validity period of warnings
• Minimum lead time of  at least 15 mins for thunderstorm warnings, and 6 hours for other warnings
• Warnings available on website map viewer and by email
• Integration and coherence with the Public Weather Service National Severe Weather Warning Service