Indonesia Weather Bulletin For Shipping

Berlaku tanggal : 29 Januari 2017

Part One :
WARNING NIL.
Part Two :
GENERAL SITUATION FOR JANUARY 28, 2016 12.00 UTC LOW PRESSURE AREA 990HPA IN WESTERN OF AUSTRALIA.
EDDY CIRCULATION AREA IN PASIFIC OCEAN NORTHERN OF HALMAHERA.
NORTHWESTERLY TO NORTHEASTERLY LIGHT TO MODERATE FLOW IN NORTHERN PART OF INDONESIA.
WESTERLY TO NORTHERLY LIGHT TO MODERATE FLOW IN SOUTHERN PART OF INDONESIA EXCEPT SOUTHEASTERLY TO SOUTHWESTERLY LIGHT TO MODERATE FLOW IN ARAFURU SEA AND BANDA SEA.
Part Three :
FORECAST

A. Weather :

1. HEAVY RAIN OCCURS IN ENGGANO � BENGKULU ISLAND WATERS, KARIMATA STRAIT, LINGGA ISLAND WATERS TO GELASA STRAIT, SOUTHERN OF KALIMANTAN WATERS, JAVA SEA, NORTHERN OF CENTRE JAVA TO EAST JAVA WATERS, SUMBAWA SEA, WESTERN OF SOUTH SULAWESI WATERS, SABALANA
� SELAYAR ISLAND WATERS, FLORES SEA, SOUTHERN OF EAST JAVA TO LOMBOK ISLAND WATERS, MANOKWARI WATERS, CENDRAWASIH GULF, AMAMAPARE � AGATS WATERS.
VISIBILITY REDUCING BELOW 2NM IN PRECIPITATION.

B. Winds Direction dan Speed From Surface Up To 3000 Feet :

WESTERLY TO NORTHWESTERLY 3 TO 4 BF OCCURS IN WESTERN OF SIMEULEU TO MENTAWAI ISLAND WATERS, KAI � ARU ISLAND WATERS, AMAMAPARE � AGATS WATERS, NORTHERN OF PAPUA WATERS. 4 TO 5 BF OCCURS IN WESTERN OF BENGKULU TO SOUTHERN OF SUMBA ISLAND WATERS, SAWU ISLAND TO KUPANG WATERS, SAWU SEA, KARIMATA STRAIT, JAVA SEA, SOUTHERN OF KALIMANTAN WATERS, EASTERN OF BENGKULU WATERS, NORTHERN OF JAVA WATERS, SOUTHERN PART OF MAKASSAR STRAIT, SUMBAWA SEA, SABALANA � SELAYAR ISLAND WATERS, FLORES SEA. 5 TO 6 BF OCCURS IN INDIAN OCEAN SOUTHERN OF CENTRE JAVA.

NORTHERLY TO NORTHEASTERLY 3 TO 4 BF OCCURS IN ANAMBAS � NATUNA ISLAND WATERS, NATUNA SEA, SOUTH CHINA SEA, MAKASSAR STRAIT, MOLUCCA SEA, NORTHERN OF RAJA AMPAT SORONG TO BIAK WATERS.

NORTHEASTERLY TO EASTERLY 3 TO 4 BF OCCURS IN MALACCA STRAIT, NORTHERN AND WESTERN OF ACEH WATERS, WESTERN PART OF SULAWESI SEA. CIRCULATION AREA 3 TO 4 BF OCCURS IN SOUTHERN OF ARU ISLAND WATERS.

C. State of Sea :

1. MODERATE SEA OCCURS IN WESTERN OF ACEH WATERS, WESTERN OF SIMELEU TO ENGGANO � BENGKULU WATERS, INDIAN OCEAN WESTERN OF ACEH TO BENGKULU, SAWU SEA, KUPANG TO ROTE ISLAND WATERS, SOUTH CHINA SEA, ANAMBAS TO NATUNA ISLAND WATERS, NATUNA SEA, NORTHERN OF BANGKA BELITUNG ISLAND WATERS, KARIMATA STRAIT, SOUTHERN OF KALIMANTAN WATERS, JAVA SEA, NORTHERN OF JAVA WATERS, SUMBAWA SEA, SOUTHERN PART OF MAKASSAR STRAIT, SABALANA � SELAYAR ISLAND WATERS, FLORES SEA, SANGIHE ISLAND WATERS, MOLUCCA SEA, HALMAHERA SEA, NORTHERN OF WEST PAPUA TO PAPUA WATERS.

2. ROUGH SEA OCCURS IN WESTERN OF LAMPUNG WATERS, SOUTHERN OF JAVA TO SUMBA ISLAND WATERS, INDIAN OCEAN WESTERN OF LAMPUNG TO SUMBA ISLAND, TALAUD ISLAND WATERS, NORTHERN OF HALMAHERA ISLAND WATERS, PASIFIC OCEAN NORTHERN OF HALMAHERA.

3. 1.25 TO 2.5 M SWELL OCCURS IN WESTERN OF SIMEULEU TO SOUTHERN OF SUMBA ISLAND WATERS, NORTHERN OF ANAMBAS - NATUNA ISLAND WATERS, SOUTH CHINA SEA, SANGIHE - TALAUD ISLAND WATERS, NORTHERN PART OF MOLUCCA SEA, HALMAHERA ISLAND WATERS, HALMAHERA SEA, NORTHERN OF WEST PAPUA TO PAPUA WATERS.
OTHER SEA AREAS GENERALLY ARE SEA SLIGHT AND SWELL LOW.

Indonesia Weather Bulletin For Shipping

Berlaku tanggal : 31 Januari 2017

Part One :

NIL

Part Two :

LOW PRESSURE AREA 999HPA IN INDIAN OCEAN WESTERN OF AUSTRALIA AND 1007HPA IN WESTERN PART OF ARAFURU SEA. CYCLONIC CIRCULATION AREA IN INDIAN OCEAN WESTERN OF ACEH.
EDDY CIRCULATION AREA IN SULAWESI SEA.
NORTHWESTERLY TO NORTHEASTERLY LIGHT TO MODERATE FLOW IN NORTHERN PART OF INDONESIA. WESTERLY TO NORTHWESTERLY LIGHT TO MODERATE FLOW IN SOUTHERN PART OF INDONESIA

Part Three :

WESTERLY TO NORTHWESTER 3 TO 5 BF OCCURS IN MENTAWAI ISLAND WATERS, NORTHERN PART OF SUNDA STRAIT, SOUTHERN OF EAST JAVA TO NUSA TENGGARA, SAWU SEA, KARIMATA STRAIT, EASTERN OF LAMPUNG WATERS, JAVA SEA, SOUTHERN OF KALIMANTAN WATERS, SUMBAWA SEA, BONE GULF, BURU TO CERAM SEA, MOLUCAS SEA, HALMAHERA ISLAND WATERS, HALMAHERA SEA, WEST PAPUA WATERS, NORTHERN OF PAPUA WATERS. 5 TO 6 BF OCCURS IN WESTERN OF BENGKULU TO LAMPUNG WATERS, SOUTHERN PART OF SUNDA STRAIT, SOUTHERN OF BANTEN TO CENTRE JAVA WATERS, FLORES SEA, BANDA SEA, ARAFURU SEA.

NORTHERLY TO NORTHEASTERLY 3 TO 4 BF OCCURS IN MALACCA STRAIT, ACEH WATERS. 4 TO 5 BF OCCURS IN SOUTH CHINA SEA, ANAMBAS TO NATUNA ISLAND WATERS, NATUNA SEA, RIAU ISLAND WATERS, BANGKA BELITUNG ISLAND WATERS.

SOUTHEASTERLY TO SOUTHERLY 3 TO 4 BF OCCURS IN MACASSAR STRAIT, WESTERN PART OF SULAWESI SEA.

A. Weather :

1. HEAVY RAIN OCCURS IN MENTAWAI ISLAND TO WESTERN OFLAMPUNG WATERS, SUNDA STRAIT, SOUTHERN OF JAVA TO SUMBAWA ISLAND WATERS, SUMBA ISLAND WATERS, SAWU SEA, KUPANG TO ROTE ISLAND WATERS, NATUNA SEA, KARIMATA STRAIT, EASTERN OF LAMPUNG WATERS, JAVA SEA, SOUTHERN PART OF MAKASSAR STRAIT, FLORES ISLAND WATERS, FLORES SEA, BANDA SEA, BURU TO CERAM SEA, SERMATA TO TANIMBAR ISLAND WATERS, KAI TO ARU ISLAND WATERS, ARAFURU SEA, WEST PAPUA WATERS, NORTHERN OF PAPUA WATERS.

VISIBILITY REDUCING BELOW 2NM IN PRECIPITATION

C. State of Sea :

1. MODERATE SEA OCCURS IN NORTHERN OF SABANG ISLAND WATERS, WESTERN OF ACEH TO BENGKULU WATERS, INDIAN OCEAN WESTERN OF ACEH TO NIAS ISLAND WATERS, SOUTHERN OF BALI TO SUMBA ISLAND WATERS, SOUTHERN PART OF BALI STRAIT � LOMBOK STRAIT � ALAS STRAIT, SAWU SEA, FLORES ISLAND WATERS, KUPANG TO ROTE ISLAND WATERS, INDIAN OCEAN SOUTHERN OF BALI TO NUSA TENGGARA, ANAMBAS TO NATUNA ISLAND WATERS, NATUNA SEA, KARIMATA STRAIT, JAVA SEA, NORTHERN OF CENTRE JAVA WATERS, SUMBAWA SEA, SELAYAR ISLAND WATERS, SOUTHERN OF BAUBAU WATERS, FLORES SEA GRADUALLY INCREASSING BECOMING ROUGH SEA IN THE MIDDLE OF NIGHT, SERMATA TO LETTI ISLAND WATERS, SOUTHERN OF BURU TO CERAM ISLAND WATERS, CERAM SEA, SANGIHE TO TALAUD ISLAND WATERS, MOLUCAS SEA, NORTHERN OF HALMAHERA ISLAND WATERS, HALMAHERA SEA, NORTHERN OF WEST PAPUA TO PAPUA WATERS, AMAMAPARE TO AGATS WATERS.

2. 1.25 TO 2.5 M SWELL OCCURS IN WESTERN OF SUMATRA WATERS, SOUTHERN PART OF SUNDA STRAIT, SOUTHERN OF JAVA TO SUMBA ISLAND WATERS, NORTHERN PART OF BANDA SEA, TALAUD ISLAND WATERS, NORTHERN OF HALMAHERA ISLAND WATERS, NORTHERN OF WEST PAPUA TO PAPUA WATERS. OTHER SEA AREAS GENERALLY ARE SEA SLIGHT AND SWELL LOW

3. ROUGH SEA OCCURS IN SOUTH CHINA SEA, WESTERN OF LAMPUNG WATERS, SOUTHERN PART OF SUNDA STRAIT, SOUTHERN OF JAVA, INDIAN OCEAN WESTERN OF MENTAWAI ISLAND TO SOUTHERN OF JAVA, BANDA SEA, BABAR TO TANIMBAR ISLAND WATERS, KAI TO ARU ISLAND WATERS, ARAFURU SEA.

ISSUED BY BMKG AT 02:30 UTC THURSDAY, FEBRUARY 09, 2017
FORECAST VALID FOR 24 HOURS FROM 0300 UTC THURSDAY, FEBRUARY 09, 2017

PART I WARNING

NIL.

PART II GENERAL SITUATION FOR FEBRUARY 08, 2016 12.00 UTC

LOW PRESSURE AREA 984HPA IN WESTERN AUSTRALIA, 1006HPA IN PASIFIC OCEAN EASTERN OF PHILIPPINES AND CARPENTARIA GULF.

WESTERLY TO NORTHERLY LIGHT TO MODERATE FLOW IN NORTHERN PART OF INDONESIA.

WESTERLY TO NORTHWESTERLY LIGHT TO MODERATE FLOW IN SOUTHERN PART OF INDONESIA. MODERATE TO STRONG FLOW IN EASTERN PART OF JAVA SEA, SUMBAWA SEA, BALI TO NUSA TENGGARA WATERS, FLORES SEA, INDIAN OCEAN SOUTHERN OF EAST JAVA TO NUSA TENGGARA.

PART III FORECAST

WESTERLY TO NORTHWESTERLY 3 TO 4 BF OCCURS IN NIAS TO MENTAWAI ISLAND WATERS, SOUTHERN PART OF MAKASSAR STRAIT, BONE GULF, BANDA SEA, BURU SEA, SULAWESI SEA, SANGIHE TALAUD ISLAND WATERS, MOLUCAS SEA, NORTHERN OF HALMAHERA ISLAND WATERS, HALMAHERA SEA, NORTHERN OF WEST PAPUA TO PAPUA WATERS. 4 TO 6 BF OCCURS IN BENGKULU TO LAMPUNG WATERS, SUNDA STRAIT, SOUTHERN OF JAVA TO SUMBA ISLAND WATERS, SUMBA STRAIT, SAWU SEA, KUPANG TO ROTE ISLAND WATERS, TIMOR SEA, JAVA SEA, SOUTHERN OF KALIMANTAN WATERS, NORTHERN OF JAVA WATERS, BALI SEA, NORTHERN OF BALI TO FLORES ISLAND WATERS, SELAYAR ISLAND WATERS, FLORES SEA, ARAFURU SEA, YOS SUDARSO TO MERAUKE WATERS. 6 TO 7 BF OCCURS IN SUMBAWA SEA, INDIAN OCEAN SOUTHERN OF CENTRE JAVA.

NORTHWESTERLY TO NORTHERLY 3 TO 4 BF OCCURS IN MALACCA STRAIT, ACEH WATERS, EASTERN OF SUMATRA WATERS, ANAMBAS TO NATUNA ISLAND WATERS, RIAU ISLAND WATERS, NORTHERN AND SOUTHERN PART OF MAKASSAR STRAIT, EASTERN OF  KALIMANTAN WATERS. 4 TO 5 BF OCCURS IN NATUNA SEA, BANGKA BELITUNG ISLAND WATERS, KARIMATA STRAIT, WEST KALIMANTAN WATERS.

MODERATE SEA OCCURS IN WESTERN OF ACEH WATERS, WESTERN OF SIMEULUE TO MENTAWAI ISLAND WATERS, BENGKULU WATERS, INDIAN OCEAN WESTERN OF ACEH TO BENGKULU, ANAMBAS TO NATUNA ISLAND WATERS, NATUNA SEA, KARIMATA STRAIT, WESTERN AND CENTRE PART OF JAVA SEA, NORTHERN OF WEST JAVA TO EAST JAVA WATERS, BALI SEA, SOUTHERN PART OF MAKASSAR STRAIT, SELAYAR ISLAND WATERS, SOUTHERN OF FLORES ISLAND WATERS, NORTHERN PART OF SAWU SEA, SERMATA TO TANIMBAR ISLAND WATERS, SOUTHERN PART OF BANDA SEA, SOUTHERN OF ARU ISLAND WATERS, ARAFURU SEA, SANGIHE TALAUD ISLAND WATERS, NORTHERN OF HALMAHERA ISLAND WATERS, HALMAHERA SEA, NORTHERN OF WEST PAPUA TO PAPUA WATERS, PASIFIC OCEAN NORTHERN OF HALMAHERA TO PAPUA.

ROUGH SEA OCCURS IN SOUTH CHINA SEA, ENGGANO ISLAND TO WESTERN OF LAMPUNG WATERS, SOUTHERN PART OF SUNDA STRAIT, SOUTHERN OF JAVA TO SUMBA ISLAND WATERS, SOUTHERN PART BALI-LOMBOK-ALAS STRAIT, SOUTHERN PART OF SAWU SEA, KUPANG TO ROTE ISLAND WATERS, INDIAN OCEAN SOUTHERN OF LAMPUNG TO EAST NUSA TENGGARA, TIMOR SEA SOUTHERN OF KUPANG, EASTERN PART OF JAVA SEA, NORTHERN OF MADURA ISLAND TO KANGEAN ISLAND WATERS, SUMBAWA SEA, NORTHERN OF SUMBAWA TO FLORES ISLAND WATERS, FLORES SEA.

1.25 TO 2.5 M SWELL OCCURS IN NORTHERN OF NATUNA ISLAND WATERS, SOUTHERN OF JAVA TO SUMBA ISLAND WATERS, SAWU SEA, KUPANG TO ROTE ISLAND WATERS, TIMOR SEA, NORTHERN OF TALAUD ISLAND WATERS, NORTHERN OF HALMAHERA WATERS.

2.5 TO 3.5 M SWELL OCCURS IN INDIAN OCEAN SOUTHERN OF JAVA TO EAST NUSA TENGGARA.

OTHER SEA AREAS GENERALLY ARE SEA SLIGHT AND SWELL LOW.

HEAVY RAIN OCCURS IN BENGKULU AND LAMPUNG WATERS, BANGKA BELITUNG ISLAND WATERS, KARIMATA STRAIT, SUNDA STRAIT, SOUTHERN OF BANTEN TO CENTRE JAVA WATERS, NORTHERN OF JAVA WATERS, JAVA SEA, SUMBAWA SEA, BALI TO SUMBAWA ISLAND WATERS, FLORES SEA, BANDA SEA, BURU ISLAND WATERS, TIMOR SEA, ARAFURU SEA, YOS SUDARSO TO MERAUKE WATERS.

VISIBILITY REDUCING BELOW 2NM IN PRECIPITATION.

THE NEXT WEATHER BULLETIN FOR SHIPPING WILL BE ISSUED AT 02.30 UTC FRIDAY.

BROADSCALE ENVIRONMENT - LARGE SCALE CONDITIONS

•Tropical waves (MJO, ER waves)

•Monsoon or trade wind surges

•Upper trough within 25 deg to the west or retrogressing upper low

•Broad scale outflow channels – fanning of cirrus

BROADSCALE ENVIRONMENT  -  NEAR SUSPECT AREA

•low to mid level trough

•light upper winds

•weak shear in area, stronger shear further away

•deep moist air in all sectors

DEVELOPMENT OF EXISTING DISTURBANCE - CIRCULATION

•identifiable cyclonic circulations (low/mid level circulation centre = cloud lines)

•vertically stacked circulation (surface – 500 hPa)

•significant (vertically stacked & round) mid level circulation (850-500 hPa ,15-25 kt)

DEVELOPMENT OF EXISTING DISTURBANCE - DEEP CONVECTION

•deep convection (cold cloud tops <-65C) < 2 degree radius, persisting 6-12 hrs.

•Pressure falls > 2 hPa within 3 degree of centre

A.Is the MJO active in our longitudes ?
MJO OLR anomalies | Real time Multivariate MJO Index

B.Are there any tropical/easterly waves currently propagating towards the suspect area?
All Mode OLR anomalies | Tropical Wave Forecast

C.Are there any strong low-level monsoon or trade flows feeding into the suspect area now? (Not necessarily a surge but a maintenance of strong flow).
CIMMS | Quickscat | TXLAPS 850hPa

D.Is there a low/mid level trough in the suspect area now?
CIMMS | Gradient 00Z | Gradient 12Z | TXLAPS 900hPa | TXLAPS 850hPa

E.Are the winds at 200/250 hPa over the suspect area < 20 knots?
CIMMS | 200 hPa 00Z | 200 hPa 12Z | TXLAPS 200hPa

F.Is there low (5-15 kt) 850-200 hPa vertical shear near the area and stronger (>15 kt) shear away (5-10°) from the suspect area?
CIMSS | TXLAPS 850-200hPa shear

G.Is there a synoptic feature creating strong upper divergence above the suspect area? For example an upper trough or retrogressing upper low within 25 degrees to the west, or a strong equatorial jet with the ridge centre over the area.
CIMSS | TXLAPS 200hPa Div

H.Is there evidence on satellite imagery or upper streamline charts of at least one outflow channel?
GOES-9 | 200 hPa 00Z | 200 hPa 12Z

I.Is there evidence of two outflow channels or fanning of cirrus (equatorward and eastward of CDO)? If so consider rapid development potential.
GOES-9

J.Is the suspect area being fed by deep moist air in all sectors?
SSMI Precip Water | GOES-9 WV | Darwin | Gove | Weipa | Broome | TXLAPS 850hPa RH | TXLAPS 700hPa RH | TXLAPS 500hPa RH

Vortical towers

Cores of deep Cb convection forming in a vorticity rich pre-hurricane environment.

The towers contain a lot of vorticity, they are inertially stable.

So latent heat generated becomes trapped in the rotating convective cores.

Their lifetime is of the order of one hour.

First Stage – Preconditioning Phase

Vortical hot towers compete for CAPE and angular momentum.

Vorticity generated by the towers (updraft) passes to the environment after the towers decay. 

Environmental vorticity increases.

Second Stage - Multiple Merger and Axisymmetrization Phase

Hot towers coalesce in an environment of enhanced vorticity (diabatic mergers).

This coalescence quadruples the horizontal scale of relative vorticity.

Tangential winds increase, and warming at low levels.

The TC is born (model data indicates the vortex merger stage lasts from 27-36hrs)

Upon Receipt of Warning:
1. Plot the current and forecast 24 hour storm  positions and forecast radius of 35 kt winds.
2. Using a compass extend the radius of the forecast 24 hour 35 kt wind area by 100 NM.
3. Draw tangents relative to the direction of the storm from the 35 kt radius (current position) to the outermost radius at the 24 hr forecast position.  Avoid the DANGER AREA
4. Use the same procedure for the 48 and 72 hr forecast positions, however, use 200 and 300 NM radii/respectively.
   Avoid the DANGER AREA.



TROPICAL CYCLONE EVASION

- Meteorological elements are not uniformly distributed throughout a tropical
Storm is divided into left/right semicircles and quadrants, relative to the direction of motion
Usually strongest winds are on right side in N.H. (added to motion)

- Ship in the “Dangerous” (right) semi-circle:
1.  Maneuver ship so relative wind is from 045 degrees to starboard.
2.  Continually hold course with respect to relative wind, making best way possible.

- Ship in the “Less Dangerous” (left) semi-circle:
1.  Maneuver ship so that relative wind is from 135 degrees to starboard.
2.  Hold course with respect to relative wind, and make best SOA.

- Never cross the “T”:    Do not plan to cross the track of a hurricane.

NEVER LEFT TO RIGHT!  Respect the negative effects that heavy weather places on vessel speed/handling. Sudden accelerations in hurricane motion can ultimately place a vessel in conditions not originally expected, resulting in disaster! 

Adjustments to course & speed in order to remain clear of the danger area in a hurricane are the most prudent navigation decisions a mariner can make in these instances. 

If it becomes necessary to cross the “T” right to left, ensure you are at least 300NM from the center. 

Follow the 1 – 2 – 3 Rule

- Monitor warnings and advisories to prevent an encounter.

Forecast Track Tendencies:  Comparison of the most recent NHC forecast track with forecast tracks from the past 24 hours can be useful for determining a trend in the forecast motion of a hurricane. 

For instance, a comparison of forecast tracks issued every 6 hours over the last 24 hours, may show a noticeable shift right or left (with respect to storm motion) in the forecast track of a hurricane. This information may provide some indication as to how the forecast & actual hurricane track are trending and provide more guidance in navigation planning for avoidance, particularly in the 2-3 day forecast range & beyond.

Stay Inport or Ride it out at Sea?
Factors to consider!
The decision to leave port for hurricane avoidance must be made very early, and must be balanced with a number of other factors

-  Storm Intensity, Size, Strength, and Speed.  
-  Port Facilities, Berthing & Shelter Requirements 
-  24 hours prior to onset of gale force winds.
-  Probability of Hit (angle of approach)
-  Vessel, size, speed, engineering status
-  Time window to clear last vessel
-  Vessel Route (safe, heavy seas, etc...)


* Early decisions to leave port in an attempt to avoid hurricanes are crucial.*