Topic: 1st low of the 2010/11 Australian season : Tropical Cyclone Anggrek

[Colin Maitland]

The first low for the Australian cyclone season of 2010/11 has formed way off the WA coast. Although a long way from the Australian Mainland Cocos Islands are in the track path hence the warning has been issued.

It has also been interesting reading over the last few weeks of the possible season that lays ahead for Australian waters with La Nina dominating our weather pattern.

Advice from BOM regarding the low

TROPICAL CYCLONE ADVICE NUMBER 1
Issued at 9:12 am WST on Saturday 30 October 2010

A Cyclone WATCH has been declared for a developing tropical low for the Cocos
(Keeling) Islands.

At 8:00 am WST a Tropical Low was estimated to be
530 kilometres north of Cocos Island and
moving west at 11 kilometres per hour.

The low is forecast to develop into a tropical cyclone today or early on
Sunday. Although it is currently moving westwards, it is expected to take a
southwards turn, and is likely to pass close to Cocos Island on Tuesday.
Conditions are favourable for intensification and Cocos Island is at risk of
impact from a Severe Tropical Cyclone.

Gales are not expected on the islands during the weekend, but may develop by
sunrise on Monday as the system moves closer and intensifies.

Details of Tropical Low at 8:00 am WST:
.Centre located near...... 7.5 degrees South 96.0 degrees East
.Location accuracy........ within 75 kilometres
.Recent movement.......... towards the west at 11 kilometres per hour
.Wind gusts near centre... 85 kilometres per hour and INTENSIFYING
.Severity category........ below cyclone intensity
.Central pressure......... 1002 hectoPascals

[Colin Maitland]

All the latest technical reports indicate that the tropical low has favorable conditions to form into a cyclone today (Sunday.) The latest track path has it heading straight towards Cocos Island as A cat.3 storm.

Quoting from one of the tech threads:

Shear conditions are forecast to become more favourable during Sunday and the
system will remain over SSTs>28C. The mid latitude system passing to the south
erodes the mid level ridge and results in a recurvature to the southeast during
Sunday. This also brings the system into light shear and by Sunday evening the
system should be experiencing quite favourable conditions. The development of
the system in the South China Sea should not be detrimental to this system, so
based on the expected conditions, and consistent with the trend in STIPS
intensity guidance it is forecast to reach hurricane force on Monday.

Col

[Colin Maitland]

The tropical low has now formed into a Cat. 1 cyclone named  Anggrek.

TROPICAL CYCLONE ADVICE NUMBER 7
Issued at 2:48 pm WST on Sunday 31 October 2010

A Cyclone WARNING continues for people on the Cocos (Keeling) Islands.

At 2:00 pm WST (12:30pm Cocos local time) Tropical Cyclone Anggrek, Category 1,
was estimated to be
405 kilometres north of Cocos Island and
moving south southeast at 7 kilometres per hour.

Tropical Cyclone Anggrek is expected to intensify overnight as it moves
southwards towards the Cocos Islands. Gales are not expected on the islands
during Sunday, but may develop during Monday as the system moves closer and
intensifies. The period of greatest risk will commence on Monday evening, with
the system likely to pass close to the islands during Tuesday.

Overnight conditions will become favourable for intensification and there is a
significant risk that people on the Cocos Islands will experience VERY
DESTRUCTIVE wind gusts.

Details of Tropical Cyclone Anggrek at 2:00 pm WST:
.Centre located near...... 8.6 degrees South 96.3 degrees East
.Location accuracy........ within 55 kilometres
.Recent movement.......... towards the south southeast at 7 kilometres per hour
.Wind gusts near centre... 95 kilometres per hour and INTENSIFYING
.Severity category........ 1
.Central pressure......... 998 hectoPascals

[Antonio (stormboy)]

Looks like it is now a cat 1 and will be heading towards 3 soon

Tropical Cyclone Anggrek is expected to intensify this morning as it moves southwards towards the Cocos Islands. Gales may develop during Monday as the system moves closer and intensifies. The period of greatest risk will commence on Monday evening, with the system likely to pass close to the islands during Tuesday.

During this morning conditions will become favourable for intensification and there is a significant risk that people on the Cocos Islands will experience VERY DESTRUCTIVE wind gusts during Tuesday.

The Australian Federal Police advise a YELLOW ALERT for communities on Home and West Island

Antonio.

[Colin Maitland]

Cyclone Anggrek is now a cat.2 storm system with a central pressure of 988 HPa.and moving to the southeast at 9 Km/h.

Col

[Antonio (stormboy)]

also is gaining rotation look here

http://cimss.ssec.wisc.edu/tropic/real-time/shemi/movies/gmsswir/gmsswirjava.html

Antonio.

[Colin Maitland]

Anggrek has lost some intensity today, downgrading to a cat 1 storm. The latest update from BOM


Tropical Cyclone Anggrek has weakened to a Category 1 system during today, and
is now located to the east southeast of the Cocos Islands and moving
southwards. The cyclone may strengthen a little again overnight and return to
Category 2 intensity.   

The cyclone is expected to curve and take a southwestwards track during the
remainder of Tuesday, which may take it a little closer to Cocos. Squalls on
the islands will continue, with a period of gale force winds possible later on
Tuesday as the cyclone passes to the south.


Details of Tropical Cyclone Anggrek at 2:00 pm WST (12:30pm Cocos local time):
.Centre located near...... 12.5 degrees South 98.1 degrees East
.Location accuracy........ within 85 kilometres
.Recent movement.......... towards the south at 9 kilometres per hour
.Wind gusts near centre... 120 kilometres per hour
.Severity category........ 1
.Central pressure......... 992 hectoPascals

[Antonio (stormboy)]

Tropical Cyclone ANGGREK is still going despite the wonky shape of it on the maps

Remarks:

Tropical Cyclone Anggrek is currently a Category 1 cyclone. The system is now located to the southeast of the Cocos Islands and is moving further away with gales no longer expected to affect the Cocos Islands.

In the longer term the system is expected to continue to move to the south west and weaken.
The Australian Federal Police advise that All Clear With Caution has been declared.


Antonio.

[Colin Maitland]

EX tropical cyclone  has Anggrek weakened to a tropical low early on the 4th of November. As the system continues to move in a west/south west direction it will maintain a weakening pattern. Currently estimated winds within the storm are about 30 knots. The system will be closely monitored for any signs of regeneration.

Col.