About Marine Weather Services

Marine weather services

The Bureau of Meteorology provides the Australian and international maritime communities with weather forecasts, warnings and observations for coastal waters areas and high seas around Australia. Generally most of these services are provided routinely throughout the day, while marine weather warnings may be issued at any time when the need becomes apparent.

Because of the complex nature of the sea, the Bureau of Meteorology uses advanced computer models to predict the physical characteristics of the ocean.

These computer forecasts are used by meteorologists in the preparation of marine forecasts and warnings. The forecasts include wind, weather, sea and swell and are intended to describe the average conditions over specified areas.

Marine forecasts have been enhanced by the inclusion of ocean currents and sea-surface temperature forecasts through the BLUElink ocean forecasting initiative.

Marine weather warnings

About marine weather warnings | Marine warnings

Warnings for coastal waters are issued whenever strong winds, gales, storm force or hurricane force winds are expected. The initial warning attempts to provide around 24 hours lead-time and warnings are renewed every 6 hours.

Warnings to shipping on the high seas are issued whenever gale, storm force or hurricane force winds are expected. The initial warning attempts to provide around 24 hours lead-time and warnings are renewed every 6 hours.

Marine forecasts

About marine forecasts | Coastal & local waters forecasts | High seas forecasts

Coastal waters forecasts are for areas within 60 nautical miles of the coast (see map for coastal waters areas). Coastal waters and local waters forecasts are issued twice daily and monitored continuously for changes which may occur. Updates may be issued at other times.

High seas forecasts are issued twice daily for the areas beyond the coastal waters surrounding Australia.

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Forecasts of winds

The Bureau forecasts of wind speed and direction are average (or mean) values over a 10 minute period at a height of 10 metres. Wind speeds usually increase with height above the sea-surface. When there are expected variations along a coastal area a range may be given, for example 15 to 25 knots.

Forecasts of gusts are not included as routine, however statistically it is estimated that gusts typically exceed the average wind speed by about one third. For example, if the forecast (average) wind speed is 15 knots, and one third of 15 is 5, gusts of around 20 knots can be expected. Gusts are generally associated with showers, thunderstorms and fronts.

Figure 1 Wind trace from an anemograph. This shows a recording of instantaneous wind speed. The dark blue trace illustrates the variability (gustiness) of wind speed. The higher wind speeds are typically one-third above the average. Squalls are also evident. These may have occurred as showers or thunderstorms passed over the recording site.

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Sea and swell forecasts

Forecasts of sea and swell in coastal waters forecasts are given in metres and describe the height, which is the average height of the highest one-third of the waves (see definitions and terminology).

Some waves will be higher and some lower than the forecast and observed height.

The Bureau of Meteorology does not forecast maximum wave heights in routine forecasts.

Statistically it is estimated that about one in every 2000 to 3000 waves (three to four times a day) will be approximately twice the height of the significant wave. Forecasts for high seas describe sea and swell using terms such as slight, moderate, rough etc. in place of wave heights in metres.

Figure 2 Significant and Maximum wave heights at Cape Sorell, west coast of Tasmania. The recording illustrates that maximum wave heights can be twice the significant wave height. It shows a maximum wave height of two and a half times the significant wave height (4am, 3 April 2004). This is sometimes referred to as a Rogue or King wave.

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Marine weather observations

About coastal weather observations | Marine weather observations

Latest coastal weather observations for states and territories show the most currently reported weather conditions at weather stations near or on the coast. Some stations also include sea and swell information.

Ocean services

Bureau Oceanographic services include tide prediction, tsunami warnings and ocean forecasts including sea surface temperature, sea surface salinity, currents and sea level anomaly via the BLUElink ocean forecasting project. These are linked below the Marine menu.
See: Oceanographic services

General weather services

In addition to specific marine weather information, other general weather information is relevant to mariners. A selection of general weather services are linked from the marine website.

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Definitions and terminology

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Ways to get weather information

VHF voice radio
The marine transport and safety agencies of the State and Territory governments provide maritime safety information, including weather information, for small craft on VHF radio: contact your State/Territory government for details.
Details: VHF marine radio weather services

Recorded telephone services*
The Bureau provides recorded forecasts, warnings and reports for mariners. Dial 1900 926 113*
List of local phone and fax numbers

Telephone – weather by fax*
The Bureau operates a polling fax service* providing current weather charts, satellite images, coastal waters forecasts and tropical cyclone threat maps. Set your fax in ‘Poll Receive’ mode and dial 1902 935 200 for a directory of services . Access is also available via Inmarsat. Contact your Satcom provider for details.

Public radio/TV broadcasts
The Bureau distributes coastal waters forecasts and warnings to various television and radio networks.

Satellite communications
As part of the Global Maritime Distress and Safety System (GMDSS) the Bureau transmits via Inmarsat SafetyNET marine weather warnings and forecasts. High seas forecasts and warnings are broadcast over the Pacific Ocean satellite, whilst the Western area is broadcast over the Indian Ocean satellite. Some coastal waters forecasts are broadcast via SafetyNET and currently include Northern Territory, Western Australia and Bass Strait forecasts.
Details: Inmarsat C (SafetyNET)

*Call costs apply (correct at time of print): for 1900 services, 77c per minute; for 1902 polling fax services, $1.38 per minute. (Call costs include GST and are higher from mobile and public phones).

HF voice radio
Marine warnings are broadcast every hour, on the hour UTC while forecasts and reports are broadcast on a fixed schedule repeated every four hours.
Schedules

VMC Broadcasts on Frequencies (kHz)
Daytime (7am–6pm) EST	4426, 16546
Night-time (6pm–7am) EST	2201, 6507
Anytime	8176, 12365
VMW Broadcasts on Frequencies (kHz)
Daytime (7am–6pm) WST	4149, 16528
Night-time (6pm–7am) WST	2056, 6230
Anytime	8113, 12362

HF radiofax
The Bureau transmits weather charts and warning summaries (not including routine forecast text or satellite images) on a schedule repeated every 24 hours. Reception requires a marine fax unit attached to your HF radio or a personal computer connected through an HF modulator.
Schedules

 

VMC Broadcasts on Frequencies (kHz)
Daytime (5am–7pm) EST	20469
Night-time (7pm–5am) EST	2628
Anytime	5100, 11030, 13920
VMW Broadcasts on Frequencies (kHz)
Daytime (5am–7pm) WST	18060
Night-time (7pm–5am) WST	5755
Anytime	7535, 10555, 15615

High seas and coastal waters forecast areas map | Metarea 10 map

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For further information

Bureau of Meteorology telephone contacts
Brisbane	07 3239 8700
Sydney	02 9296 1555
Melbourne	03 9669 4000
Hobart	03 6221 2000
Adelaide	08 8366 2600
Perth	08 9263 2222
Darwin	08 8920 3800