Severe Tropical Cyclone Hamish

[Somerset Squall]

Hamish continues to slowly weaken. The eye remains small and well defined, but the convective coverage overall has continued to shrink. Shear is increasing over Hamish so further weakening is predicted. Intensity has decreased to 120kts, so Hamish remains an intense system so weakening could be quite slow as shear will take a while to punch into that strong core. Hamish will continue to move south-southeastwards over the next 24hrs. What happens after this is open to question. If shear is strong enough to significantly weaken Hamish, he will respond more to the low level steering which would force the weakened system southwestwards towards land. BOM are favouring this solution. If Hamish remains a strong system however, if shear doesn't get strong enough to significantly weaken the core, then Hamish will continue to be steered by the upper levels- southeastwards out to sea. JTWC favour this solution. It really is a case of wait and see. Either way, Hamish will get quite close to Hervey Bay and neighbouring communities so we certainly aren't out of the woods with Hamish yet.

Edited March 8, 2009 by Somerset Squall

[Cookie]

Storm Alert issued at 9 Mar, 2009 12:00 GMT

Intense Tropical Cyclone HAMISH is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert Country(s) or Province(s)

Australia

probability for CAT 1 or above is 30% within 12 hours

probability for TS is 100% currently

Yellow Alert City(s) and Town(s)

Bundaberg (24.9 S, 152.3 E)

probability for TS is 85% within 12 hours

Maryborough (25.5 S, 152.5 E)

probability for TS is 55% within 12 hours

Green Alert City(s) and Town(s)

Gladstone (23.9 S, 151.2 E)

probability for TS is 45% currently

Note that

Yellow Alert (Elevated) is CAT 1 or above to between 10% and 30% probability, or TS to above 50% probability.

Green Alert (Low) is TS to between 31% and 50% probability.

CAT 1 means Tropical Cyclone strength winds of at least 74 mph, 119 km/h or 64 knots 1-min sustained.

TS means Tropical Storm strength winds of at least 39 mph, 63 km/h or 34 knots 1-min sustained.

[Somerset Squall]

Hamish continues to be an intense system today, and intensity is still at 110kts. However, northwesterly shear is impinging on the cyclone, which is clear to see from latest satellite imagery, which shows convection deepest to the southeast and very little banding to the northwest. Shear will persist which will cause further weakening. JTWC and BOM are still in big disagreement where this storm will go, as are the models. JTWC continue to predict an eastward turn out to sea as the ridge to the east moves away, and BOM are forecasting a weakened Hamish to move back northwestwards, steered by low level steering winds. It is very uncertain what will happen track wise, it's really going to be a case of wait and see. Whether Hamish goes east or west, it will weaken as shear is high in the area in general.

You can see how much BOM and JTWC differ in forecast track. Here's JTWC's:

Edited March 9, 2009 by Somerset Squall

[Cookie]

thanks for the great updates mate

[Cookie]

Large waves generated by the cyclone may produce elevated sea levels and minor

flooding along the foreshore south of Sandy Cape. People living in areas likely

to be affected by this flooding should take measures to protect their property

as much as possible and be prepared to help their neighbours.

Details of Severe Tropical Cyclone Hamish at 7:00 am EST:

.Centre located near...... 24.0 degrees South 154.4 degrees East

.Location accuracy........ within 19 kilometres

.Recent movement.......... towards the southeast at 11 kilometres per hour

.Wind gusts near centre... 230 kilometres per hour

.Severity category........ 4

.Central pressure......... 950 hectoPascals

People on the northern part of Fraser Island should stay calm and remain in a

secure shelter while the damaging winds continue.

sounds bad out their.

[Cookie]

Storm Alert issued at 10 Mar, 2009 0:00 GMT

Tropical Cyclone HAMISH is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert Country(s) or Province(s)

Australia

probability for TS is 100% currently

Green Alert City(s) and Town(s)

Maryborough (25.5 S, 152.5 E)

probability for TS is 50% currently

Bundaberg (24.9 S, 152.3 E)

probability for TS is 45% currently

Note that

Yellow Alert (Elevated) is CAT 1 or above to between 10% and 30% probability, or TS to above 50% probability.

Green Alert (Low) is TS to between 31% and 50% probability.

CAT 1 means Tropical Cyclone strength winds of at least 74 mph, 119 km/h or 64 knots 1-min sustained.

TS means Tropical Storm strength winds of at least 39 mph, 63 km/h or 34 knots 1-min sustained.

[Cookie]

Tropical Cyclone HAMISH is forecast to strike land to the following likelihood(s) at the given lead time(s):

Green Alert Country(s) or Province(s)

Australia

probability for TS is 35% in about 36 hours

Note that

Green Alert (Low) is TS to between 31% and 50% probability.

TS means Tropical Storm strength winds of at least 39 mph, 63 km/h or 34 knots 1-min sustained.

[Somerset Squall]

Strong northwesterly shear continues to weaken Hamish. The eye is no longer visable on satellite imagery and the cloud pattern has become rather shapeless. However, it's estimated that sustained winds of 75kts are still occuring near the centre, so Hamish is still a cat 1 on the SS scale. Further weakening is expected in this hostile environment.

JTWC have come into much better agreement with BOM as regards to the future track of Hamish. Hamish is currently moving eastwards but it is expected to move back on itself towards the northwest as the subtropical steering ridge to the east weakens and a ridge to the southwest becomes the dominant steering influence. As Cookie's warning shows, Hamish may well wander near the east coast again, but it is likely to be severely weakened by this point. Still worth watching though as more rain is likely for areas already affected by the storm. Hamish is likely to dissipate in a few days time.

[Cookie]

thanks for the updates

interesting image

[Somerset Squall]

Indeed Cookie, that image clearly shows the convection being stripped away by shear leaving the LLC exposed. This has continued to happen overnight and Hamish has weakened to 50kts. The storm barely qualifies as a tropical cyclone any more as the convection is now very seperate from the weakening and totally exposed LLC. The LLC is drifting west-northwestwards and the convection is detaching itself from the system by moving southeastwards, driven in this direction by heavy northwesterly shear. Shear is expected to remain very strong, so Hamish isn't long for this world, and will probably dissipate soon, probably well before it reaches the east coast of Australia.

[Cookie]

Hamish is no more.

[Somerset Squall]

Yes, BOM are now classifying him as an ex-cyclone. However, it's worth noting that despite the total absence of convection, Hamish's circulation is still strong, and sustained winds are still at 45kts. The LLC should slowly wind down over the next day or so. It will take a little time as of course Hamish was once a very intense system. Hamish has jogged to the north today, and is moving along the eastern periphery of a low level ridge over Australia. Hamish will then round the periphery of the ridge and move towards the coast, however- winds should be below gale force by then. However, there is still a small risk of gales affecting the coastline so there are gale warning out in the Yeppoon area.

[Cookie]

A couple of fishermen killed

http://www.abc.net.au/news/stories/2009/03/12/2513737.htm

[Cookie]

http://www.cnn.com/2009/WORLD/asiapcf/03/1...lick/index.html

(CNN) -- Australian authorities have declared several coastal areas near Brisbane disaster zones after a massive oil spill earlier this week, according to the Queensland government.

"This is a very serious situation," Queensland Premier Anna Bligh said, according to a news release on Friday. "It appears the volume of oil involved is much greater than originally reported by the Pacific Adventurer. And the effect of the oil spill is more widespread."

The Pacific Adventurer sustained damage early Wednesday when Cyclone Hamish struck the waters of eastern Australia with more than 125 kph (77 mph) winds. The cargo ship lost 30 of its 50 containers of ammonium nitrate about 13 kilometers (8 miles) off the coast of Cape Moreton. Those containers are still missing.

The damaged ship also spilled a large amount of oil that is covering at least 60 kilometers (37 miles) of beach in and around Brisbane, according to Australian Broadcasting Corporation (ABC). Watch sludge washing up on shorelines »

The ship's owner, Swire Shipping, initially said no more than 42,000 liters (11,100 U.S. gallons) of oil escaped from the ship, but now says that "substantially more oil was spilled," ABC reported Friday.

The ship is currently in the custody of Australia's Maritime Safety Authority in Brisbane, as the investigation into the spill continues.

A massive clean-up effort is also under way. So far, 13 oil-covered birds have been recovered, according to the Queensland government.