Weather
Bulletins
World METAREAS
METAREAS (Figure 1) are demarcated regions of the oceans, configured to facilitate coordinated transmission of meteorological information to mariners. These METAREAS form part of the Global Maritime Distress and Safety System Services (GMDSS). The global Maritime Distress and Safety System (GMDSS) provides the necessary communication support required to realize a global search and rescue plan. This system has been implemented by the world's maritime nations - including South Africa. The GMDSS utilizes both satellite and terrestrial radio services. Radio amateurs play a small but valuable role in facilitating safety at sea by transmitting marine weather bulletins to yachts equipped with a radio amateur transceiver. These maritime mobile stations can also provide the Maritime Mobile Net with their position, local weather conditions and other relevant information. Contact with land-based stations improves safety at sea, as the land based- radio amateur station operating within the Maritime Mobile Net can rapidly inform the appropriate Rescue Coordination Centre of any emergency situation. More information on the GMDSS can be found at International Maritime Organization. The South African Maritime Mobile Net (SAMMNet) transmits coastal and high seas marine weather bulletins as issued by the South African Weather Service (SAWS). METAREA VII covers the South Atlantic and Southern Oceans south of 6°S from 20°W to the coast of Africa, and then southward to the Cape of Good Hope and the South Indian Ocean and Southern Oceans south of 10°30’S from the Cape to 55°E, and then south of 30°S to 80°E. South Africa is responsible for the forecast of METAREA VII, with the exception of the forecast for the south-east sector of METAREA VII (30°S-50°E / 50°S-80°E) and tropical cyclone warnings which are prepared by La Réunion.
Figure 1. World map of Metareas, (source WMO, available at World map of METAREAS) .
Figure 2. Metarea VII, (adapted from WMO map, available at METAREA VII).
Weather bulletin for coastal areas (40 m band)
WEATHER BULLETIN FOR COASTAL WATERS UP TO 50 NAUTICAL MILES SEAWARD AS ISSUED BY THE SOUTH AFRICAN WEATHER SERVICE
The weather bulletins for coastal waters up to 50 nautical miles seaward as issued by the South African Weather Service are broadcast on 7120 kHz LSB. These transmissions of the coastal weather bulletins commence at 0635 UTC with an update at 1135 UTC.
Contents of the weather bulletin:
All alerts are broadcast as issued by the SAWS.
Warnings (e.g. gale force winds, very rough seas, poor visibility)
Note: Warnings are issued by the SAWS when dangerous conditions are present or imminent. Maritime mobile stations should immediately take appropriate action to ensure safety at sea.
Watches
Note: The SAWS issues a watch when conditions are favourable for a specific hazardous weather event to occur. Maritime mobile stations should immediately commence with appropriate preparations, do not wait until a warning is issued.
Severe Weather Advisories
Abnormal Wave Conditions
The area forecasts include the regions (see Figure 2):
CUNENE RIVER TO WALVIS BAY
WALVIS BAY TO ORANGE RIVER
ORANGE RIVER TO CAPE AGULHAS
CAPE AGULHAS TO EAST LONDON
EAST LONDON to MAPUTO
and the MOZAMBIQUE CHANNEL
Weather bulletin for the high seas for Metarea VII (20 m band)
WEATHER BULLETIN FOR THE HIGH SEAS FOR METAREA VII. AS ISSUED BY THE SOUTH AFRICAN WEATHER SERVICE
The high seas weather bulletins are broadcast on 14316 kHz USB. These transmission of the weather bulletin for the high seas as issued by the South African Weather Service commences at 0630 UTC with an update at 1130 UTC. Additional ad hoc bulletin transmissions are transmitted between 1500 UTC and 1530 UTC depending on HF propagation conditions and operator availability.
Contents of the weather bulletin:
GALE FORCE WARNINGS
SYNOPTIC CHART (high and low pressure zones, cold fronts)
The area forecast (wind, visibility and sea state) as issued by the SAWS covers the areas (see Figure 2):
ASCENSION (06S/15S, 00E/20W)
ANGOLA (06S/15S, 00E/WEST COAST)
ST HELENA (15S/30S, 00E/20W)
TRADES (15S/30S, 00E/WEST COAST)
TRISTAN (30S/40S, 00E/20W)
CAPE WEST (30S/40S, 00E/20E)
CAPE EAST (32.5S/40S, 20E/50E)
DURBAN EAST (32.5S/25S, EAST COAST/55E)
MOZAMBIQUE CHANNEL
MADAGASCAR EAST
MARION FORTIES EAST (40s/50s, 35e/50e)