WEATHER BULLETIN FOR THE HIGH SEAS FOR METAREA VII.
ISSUED BY THE SOUTH AFRICAN WEATHER SERVICE ON THE
18th OF AUGUST 2026 AT 08:30 UTC.
FOR SOUTH-EAST SECTOR OF METAREA. VII, PREPARED BY REUNION, SEE AREA 2
BELOW.
NOTE: WX OBSERVATIONS.
======================
COULD ALL VESSELS EXPERIENCING UNEXPECTED, SEVERE WX/SEA STATE PLEASE
MAKE EVERY EFFORT TO REPORT THIS TO SAWS VIA CAPE TOWN RADIO.
AREA 1:
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FORECAST VALID FROM 181000 TO 191000 UTC:
WIND IN KNOTS, WAVE HEIGHTS IN METERS. NO SEA STATE GIVEN IF WAVES LESS THAN 3M.
NOTE THE WIND SPEEDS QUOTED HERE ARE THE EXPECTED AVERAGE SPEEDS.
INDIVIDUAL GUSTS MAY EXCEED THESE VALUES BY A FACTOR OF UP TO 1.5.
WAVE HEIGHTS ARE SIGNIFICANT WAVE HEIGHTS, WHICH MAY BE ACCOMPANIED BY INDIVIDUAL WAVES 1.5 TO 2.0 TIMES HIGHER.
GALE FORCE WARNINGS:
====================
1. TRISTAN: W to NW 35 in the south-east until mid-period, as well as in
the south-west from mid-period.
2. CAPE WEST: W to NW 35 in the south-west, spreading to the south-east by
end of the period, while moderating in the south-west.
3. MARION FORTIES EAST: W to SW 35 to 40 in the south until mid-period, but
NW 35 to 40 in the south-west from mid-period.
SYNOPTIC CHART 06:00Z
=====================
High 1028 hPa 33s12e High 1034 hPa 30s63e.
Low 1020 hPa 20s39e Low 1018 hPa 23s09w Low 996 hPa 44s46e
1. Cold front: 37s38e 42s45e into 44s46e
AREA FORECAST:
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ASCENSION (06S/15S, 00E/20W):
WIND : E to SE 10 to 20.
VIS : Good.
ANGOLA (06S/15S, 00E/00N):
WIND : S to SE 10 to 15 but SW 05 to 10 in the east.
VIS : Good.
ST HELENA (15S/30S, 00E/20W):
WIND : Variable 05 to 10 in the east, south-west and central parts,
otherwise S to SE 15 to 25.
VIS : Good in the north-east and south-west, otherwise moderate in
showers and thundershowers.
SEA STATE: 3.0 to 3.5m in the west, central and south-east, with S to SE
swell.
TRADES (15S/30S, 00E/WEST COAST):
WIND : Variable 05 to 10 in the west, otherwise S to SE 10 to 20 reaching
25 in the south-east until mid-period.
VIS : Good, but moderate in showers in the extreme south-west.
SEA STATE: 3.0m in places in the south and south-east, with SW swell.
TRISTAN (30S/40S, 00E/20W):
WIND : Variable 05 to 10 in the north, otherwise W to NW 15 to 25
reaching 30 to 35 in the south-east until mid-period, as well as
in the south-west from mid-period.
VIS : Good, but moderate in showers in the south and extreme north-east,
spreading to the west from mid-period.
SEA STATE: 3.0 to 4.0m in the south and east, reaching 4.5m in the south
until mid-period, as well as south-west by the end of the period,
with W to SW swell.
CAPE WEST (30S/40S, 00E/20E):
WIND : SE 15 to 25 in the north-east, otherwise variable 05 to 10 but W
to NW 15 to 25 in the south reaching 30 to 35 in the south-west,
spreading to the south-east by end of the period, while moderating
in the south-west.
VIS : Good in the north-east, otherwise moderate in rain and showers.
SEA STATE: 3.0 to 3.5m reaching 4.5 to 5.5m in the south, with W to SW swell.
CAPE EAST (32.5S/40S, 20E/50E):
WIND : W to NW 20 to 30 in the east until mid-period as well as in the
west from mid-period reaching 35 in the extreme south-west by end
of the period, otherwise SW 15 to 25, but reaching 30 in the
central south, spreading to the south-east by mid-period.
VIS : Good, but moderate in rain and showers in places in the south and
east.
SEA STATE: 3.0 to 4.0m in the south and west reaching 5.0m in south-west,
with W to SW swell.
DURBAN EAST (32.5S/25S, EAST COAST/55E):
WIND : E to SE 10 to 20 in the north, otherwise variable 05 to 10, but S
10 to 20 in the south-west.
VIS : Good but moderate in showers and thundershowers in the north-east
at first.
MOZAMBIQUE CHANNEL:
WIND : S to SE 05 to 15.
VIS : Good, but moderate in showers in the north from mid-period.
MADAGASCAR EAST (10S/25S, EAST COAST/55E):
WIND : E to SE 10 to 20, but NE 10 to 15 in the south.
VIS : Moderate in showers and thundershowers in places.
MARION FORTIES EAST (40S/50S, 35E/50E):
WIND : W to SW 20 to 30 reaching 35 to 40 in the south until mid-period.
It will become NW 20 to 30 in the west from mid-period, while
reaching 35 to 40 in the south-west.
VIS : Moderate to poor in showers and possible snow showers in the
south, while clearing over the central and northern parts towards
the end of the period.
SEA STATE: 4.0 to 5.0m, reaching 6.0 to 7.0m in the south-west towards the
end of the period, with W to NW swell.
AREA 2:
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MARINE METEOROLOGICAL BULLETIN FROM METEO-FRANCE/LA REUNION ON AREA ACK (AMSTERDAM-CROZET-KERGUELEN)
26/08/18 AT 0500UTC
AVERAGED WIND SPEED ON BEAUFORT SCALE. (WIND GUSTS MAY BE ABOUT 40% STRONGER THAN THE AVERAGES GIVEN HERE).
PART 1: WARNING
- STORM FORCE 10 OVER CRO- SRONG GALE FORCE 9 OVER KER.
PART 2: GENERAL SYNOPSIS, 26/08/18 AT 0000UTC
- COLD FRONT (CF) AXIS 41S/36E, 43S/50E, 45S/65E, 49S/74E, 60S/66E,, MOVING EASTWARD.- DEEPENING LOW, 1004 HPA NEAR 42S/40E, EXPECTED OVER CRO, 986 HPA NEAR 46S/51E AT FIRST.- HIGH 1032 HPA NEAR 32S/59E MOVING SLOWLY NORTHEASTWARD.
PART 3: FORECAST FOR 24 HOURS FROM 26/08/18 AT 0600UTC TO 26/08/19 AT 0600UTC
WAM (30S/40S, 50E/65E)
SCATTERED SHOWERS THEN FRONTAL RAIN AND SHOWERS OVER SOUTHERN
LATER.
WIND: ANTICLOCKWISE 3 TO 4 AT TIMES 5, INCREASING 6/7 OVER SOUTHERN AT FIRST. GUSTS.
SEA: MODERATE TO ROUGH FROM NORTH TO SOUTH. SW SWELL 2 TO 3 M ABATING.
VIS: POOR IN PRECIPITATION.
AMS (30S/40S, 65E/80E)
SCATTERED SHOWERS.
WIND: BECOMING ANTICLOCKWISE 2 TO 4 OVER NORTHERN AND W 5/6 AT TIMES 7 OVER SOUTHERN AT END.
SEA: ROUGH TO VERY ROUGH BECOMING MODERATE TO ROUGH OVER NORTH-WESTERN AREA AT END. SW SWELL 3 TO 5 METERS ABATING.
VIS: GOOD.
CRO (40S/50S, 50E/65E)
FRONTAL RAIN AND SHOWERS UNDER CF.
WIND: W TO NW 6 TO 7 WITH GUSTS TEMPORARILY VARIABLE 3 TO 4 OVER SOUTHERN AND INCREASING AT FIRST 7/8 AT TIMES 9 AND VERY LOCALLY 10 AT END BY WESTERN AREA.
SEA: ROUGH TO VERY ROUGH BECOMING HIGH OVER EASTERN AT END. W SWELL 2 TO 4 METERS.
VIS : POOR IN PRECIPITATION.
KER (40S/50S, 65E/80E)
FRONTAL RAIN AND SHOWERS UNDER CF.
WIND: W 6 TO 7 AT TIMES 8 LOCALLY 9 OVER SOUTH-EASTERN DECREASING TEMPORARILY W 3 TO 5 BY WESTERN AREA SOON, INCREASING AT END 7/8 LOCALLY 9 BY WESTERN. GUSTS.
SEA: VERY ROUGH TO HIGH. W SWELL 4 TO 6 METERS INCREASING 6 TO 8 METERS OVER SOUTH-EASTERN SOON.
VIS: POOR IN PRECIPITATION.