HS 015

========= weather bulletin for the high seas for Metarea VII.East of 20e. Issued by the South African Weather Service on the 11th February 2012 at 08:30 UTC.

For southeast 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: ======= forecast valid from 111000 to 121000 utc:

Wind in knots, wave heights in metres. 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.

Tropical cyclone 9 (giovanna): ==============================

0.A warning number: 9/9/20112012 1.A intense tropical cyclone 9 (giovanna)

2.A position 2012/02/11 at 0600 utc: within 10 nm radius of point 17.0 S / 59.4 E (seventeen decimal zero degrees south and fifty nine decimal four degrees east) movement : west 6 kt

3.A Dvorak analysis: 5.0/5.5/W 0.5/6 h 4.A central pressure: 945 hpa 5.A Max average wind speed (10 mn): 95 kt radius of maximum winds (rmw) :7 km

6.A extension of wind by quadrants (km): 28 kt ne: 160 se: 220 sw: 220 nw: 160 34 kt ne: 120 se: 130 sw: 130 nw: 120 48 kt ne: 60 se: 60 sw: 60 nw: 60 64 kt ne: 30 se: 30 sw: 30 nw: 30

7.A first closed isobar (pressure / average diam): 1006 hpa / 1000 km 8.A vertical extension of cyclone circulation : deep

1.B forecasts: 12h: 2012/02/11 18 utc: 17.5 S / 58.4 E, Max wind=090 kt, intense tropical cyclone 24h: 2012/02/12 06 utc: 17.6 S / 57.0 E, Max wind=095 kt, intense tropical cyclone 36h: 2012/02/12 18 utc: 17.7 S / 54.9 E, Max wind=100 kt, intense tropical cyclone 48h: 2012/02/13 06 utc: 18.0 S / 52.0 E, Max wind=100 kt, intense tropical cyclone 60h: 2012/02/13 18 utc: 18.4 S / 49.8 E, Max wind=095 kt, intense tropical cyclone 72h: 2012/02/14 06 utc: 18.8 S / 47.5 E, Max wind=030 kt, inland

2.B longer-range outlook : 96h: 2012/02/15 06 utc: 21.3 S / 42.7 E, Max wind=025 kt, tropical disturbance 120h: 2012/02/16 06 utc: 22.5 S / 38.6 E, Max wind=045 kt, moderate Tropical Storm

2.C additional informations: t=5.0+ et ci=5.5+

Last avalaible Micro-wave imagery show an ongoing eyewall replacement cycle. Last trmm imagery show a still vigorous inner eyewall

System is tracking westwards until the end of the night ... a transcient mid-level trough should pass to the south of the system later this afternoon ... on this timeframe, a more southwestwards track is still possible. Tonight, with the rebuilding of the deep high pressure cell south-east of Madagascar, a due westwards motion is still expected.

The current erc should cause intensity fluctuations ... but within favourable environmental conditions, the system should remain an intense one and could significantly strenghen again.

On and after Monday, giovanna should undergo a weak to moderate easterly vertical wind shear on the northern side of rebuilding upper level high pressures. A slight weakening is possible before the landfall on the eastern coast of Madagascar Monday night

... But giovanna is expected to remain a dangerous and powerful system by that time.

The residual centre should come back over seas in the Mozambique Channel on Wednesday within a favourable environment.

Unhabitants of mascareignes islands and eastern coasts of Madagascar (tamatave area) should continu to monitor the progress of this dangerous system.

Gale warnings: ============== 1. Cape east: SW to W 35 to 40 from the west spreading eastwards by end of the period.

2. Marion forties east: E to NE 35 in the South-West by end of the period.

Synoptic situation at 06:00 UTC =============================== high 1026 hpa 33s13w high 1030 hpa 43s17w high 1018 55s43e low 1002 hpa 51s10e low 994 hpa 40s37e

1. Cold front: 36s07w 40s03e 45s11e 51s10e. 2. Cold front: 27s33e 30s34e 35s36e 40s35e 40s37e

Area forecast: ==============

Cape east (32.5s/40s, 20e/50e) wind : NW 15 to 25 in the east, otherwise SW to W 30 to 40 spreading eastwards by end of the period. Vis : poor in rain and showers. Sea : 4 to 5m in the west spreading to the central parts, SW swell.

Durban east (25s/32.5s, East Coast/55e) wind : N to NW 10 to 20, but S to se 15 to 20 in the South-West. Vis : good, but poor in thundershowers in the west. Sea state: 2.5 to 3m in the extreme west, SW swell.

Mozambique channel: wind : NW 10 to 15 in north, otherwise NE 15 to 25. Vis : moderate in showers and thundershowers in the north, otherwise good.

Madagascar east: wind : E to se 10 to 15 in the south, otherwise S to SW 15 to 25. Vis : poor in showers and thundershowers.

Marion forties east: (40s/50s, 35e/50e) wind : E to NE 20 to 30 reaching 35 in the South-West by end of the period, becoming NW 25 to 25 in the north- west. Vis : poor in rain and showers. Sea state: 2.5 to 3.5m reaching 4.0m in the south, se swell.

Area 2 ======= marine meteorological bulletin from Meteo-France/La Reunion on area ack (amsterdam-Crozet-kerguelen)

Date: 12/02/11 at 0500utc averaged wind speed on Beaufort scale. (Wind gusts may be about 40% stronger than the averages given here.)

Part 1: warning: nil.

Part 2: general synopsys, 12/02/11 at 0000 utc:

Low 1010 hpa near 37s/71e, moving eastsoutheastward 15 kt. Warm front wf 39s/80e, 37s/73e, 39s/85e. Cold front cf 29s/62e, 33s/67e, 37s/72e.

Low 1002 hpa near 48s/55e with warm front wg 51s/58e, 51s/64e, 50s/68e. Cold front cg 40s/54e, 43s/60e, 48s/63e, 50s/59e moving eastward 30/35 kt.

Page 1/2 part 3: forecast for 24 hours from 12/02/11 at 0600 UTC to 12/02/12 at 0600utc:

Wam (30s/40s, 50e/65e): frontals rain and showers cg over far southern. Wind : anticlockwise 3/5 to locally 6 over far southern. Sea : moderate, locally slight. Vis : good but poor over far southern.

Ams (30s/40s, 65e/80e): frontals rain and showers wf and cf then cg. Wind : clockwise 4/6 setting up westerly 3/5 behind cf. Sea : moderate locally rough. Vis : poor in precipitations.

Cro (40s/50s, 50e/65e): frontals rain and showers wg and cg. Wind : clockwise 4/5 to locally 6 over far southern, setting up NE 5/6 over western at end. Sea : moderate to rough. Vis : poor in precipitations.

Ker (40s/50s, 65e/80e): frontals rain and showers wg and cg. Wind : nortwesterly 3/4 increasing 5/6 ahead cg then becoming clockwise 4/6 from western at end. Sea : moderate to rough. Vis : poor in precipitations.