Category Archives: Australian Region

Tropical Cyclone Olwyn Near Carnarvon, Australia

The center of Tropical Cyclone Olwyn has been moving roughly parallel to the coast of Western Australia and it is near Carnarvon.  At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Olwyn was located at latitude 24.6°S and longitude 113.4°E which put it about 20 miles northwest of Carnarvon and about 100 miles north of Denham, Australia.  Olwyn was moving toward the south-southwest at 15 m.p.h.  The maximum sustained wind speed was 100 m.p.h. and there were gusts to 120 m.p.h.  The minimum surface pressure was 959 mb.  Earlier on Thursday the airport at Learmonth measured sustained winds to 84 m.p.h. and a pressure of 970 mb when the center of Olwyn passed just to its west.

Olwyn is being steered southward by a subtropical ridge to its east.  The projected path takes the center of circulation inland and then moves it parallel to the coast.  When Olwyn moves inland it will start to weaken.  However, if there is a slight deviation of the track to the west which keeps the center of circulation over water for a longer period of time, it would keep the circulation stronger.  The latter possibility would extend the risk for wind damage farther south along the coast.  In either case, the clockwise rotation around the center and the shape of the coast could produce a significant storm surge in Shark Bay.  There is also a potential for locally heavy rainfall and flooding near the coast.

Tropical Cyclone Olwyn Intensifying near Western Australia

An eye appears to be forming in the center of Tropical Cyclone Olwyn and it is near hurricane intensity.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Olwyn was located at latitude 18.5°S and longitude 114.8°E which put it about 210 miles northwest of Karratha and about 250 miles north-northeast of Exmouth, Australia.  Olwyn was moving toward the south-southwest at 9 m.p.h.  The maximum sustained wind speed was 70 m.p.h. and there were gusts to 90 m.p.h.  The minimum surface pressure was 978 mb.

The circulation around Olwyn became increasingly well organized on Wednesday and and eye appeared to develop.  The stronger thunderstorms are on the western side of the eye and the circulation could be pulling in a little drier air on the eastern side.  Olwyn is over warm Sea Surface Temperatures and the upper level winds are light.  So, further intensification is possible before Olwyn makes landfall.

A subtropical ridge is steering Olwyn in a generally southerly direction and that steering pattern is expected to continue.  The projected track brings the center of Olwyn near Exmouth on the coast of Western Australia in about 18 to 24 hours.  Owlyn has the potential to bring strong winds and a significant storm surge near the point of landfall.  In addition it could bring locally heavy rainfall and the potential for floods as it moves inland.

Tropical Cyclone Nathan Lingering Off Coast of Queensland

Tropical Cyclone Nathan moved slowly toward the northern coast of Queensland on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Nathan was located at latitude 13.5°S and longitude 145.3°E which put it about 110 miles north of Cooktown, Australia and about 70 miles east of Cape Flattery.  Nathan was moving toward the west at 4 m.p.h.  The maximum sustained wind speed was 65 m.p.h. and there were gusts to 85 m.p.h.  The minimum surface pressure was 982 mb.

The eastern half of the circulation around Nathan was being affected by some of the upper level outflow from large Tropical Cyclone Pam to the east.  The outflow from Pam was creating vertical wind shear over the eastern half of Nathan and inhibiting convection on that side of the circulation.  In addition, Nathan is close enough to the coast of Queensland that interaction with land could be affecting some of the circulation on the western side of the storm.  Despite those negative influences, Nathan is over warm Sea Surface Temperatures and the wind speeds increased slightly on Wednesday.

Numerical guidance continues to suggest that a near equatorial ridge will build north of Nathan and stop its westward motion.  The ridge is projected to eventually push Nathan back toward the east later this week.  The center of Nathan is within 70 miles of the coast of Queensland, and even if it turns back toward the east it could bring high winds and a storm surge to a portion of the coast near Cape Flattery.

Tropical Cyclone Olwyn Organizing Quickly Near Western Australia

A low level circulation is organizing quickly in an area of thunderstorms northwest of Western Australia and the system has been classified as Tropical Cyclone Olwyn.  At 8:00 a.m. EDT on Wednesday the center of Olwyn was located at latitude16.6°S and longitude 116.1°E which put it about 280 miles north of Karratha and about 390 miles north-northeast of Exmouth, Australia.  The maximum sustained wind speed was 45 m.p.h. and there were gusts to 60 m.p.h.  The minimum surface pressure was 996 mb.

Olwyn is over warm Sea Surface Temperatures and it is in an area where the upper level winds are very weak.  The favorable environment has allowed thunderstorms to grow rapidly and the circulation has developed upper level outflow which is pumping out mass and allowing the pressure to decrease.  Owlyn is expected to remain in a favorable environment until it makes landfall in Western Australia.  It should continue to intensify and a period of rapid intensification is possible.

Olwyn is moving around the western end of a subtropical ridge which is steering it toward the south.  That general steering pattern is expected to continue for the next several days.  On its projected track, Olwyn could approach the coast of Western Australia between Onslow and Exmouth in a about 36 hours.

Olwyn has the potential to cause significant wind damage and generate a storm surge near where the center makes landfall.  In addition, it could produce locally heavy rainfall and the potential for floods as it moves inland.

Tropical Cyclone Nathan Forms Over the Coral Sea

Another tropical cyclone formed in an elongated trough of low pressure over the southwestern Pacific Ocean.  At 10:00 p.m. EDT on Tuesday the center of Tropical Storm Nathan was located at latitude 13.8°S and longitude 146.8°E which put it about 150 miles northeast of Cooktown, Australia and about 250 miles south of Port Moresby, Papua New Guinea.  It was moving toward the west-southwest at 9 m.p.h.  The maximum sustained wind speed was 60 m.p.h. and there were wind gusts to 80 m.p.h.  The minimum surface pressure was 989 mb.

Nathan is over warm Sea Surface Temperatures, but it is being partly influenced by some of the upper level outflow from large Tropical Cyclone Pam which is located farther east.  The wind shear is reducing the rate of intensification, but the environment is favorable enough that continued intensification is likely during the next day or two.

The track forecast for Nathan has a high degree of uncertainty.  It is currently being steered to the west-southwest by a subtropical ridge that is north of the circulation center.  That ridge is predicted to weaken and westerly winds are expected to turn the tropical cyclone back toward the east.  However, the timing of that turn is important.  The center of Nathan could come very close to the coast of Queensland.  If the turn does not occur, Nathan could bring high winds and heavy rain to portions of northern Queensland.

 

Strong Tropical Cyclone Marcia Moving Over Eastern Queensland

Strong Tropical Cyclone Marcia made landfall a few hours ago on the east coast of Australia northwest of Yeppoon in Queensland.  Marcia is moving roughly parallel to the coast about 25 miles inland from the Pacific Ocean.  At 9:00 p.m. EST on Thursday the center of Tropical Cyclone Marcia was located at latitude 22.9°S and longitude 150.5°E which put it about 25 miles northwest of Yeppoon, about 85 miles northwest of Gladstone and about 340 miles north-northwest of Brisbane, Australia.  Marcia was moving toward the south at 12 m.p.h.  The maximum sustained wind speed was 110 m.p.h. and there were gusts to 150 m.p.h.  The minimum surface pressure was 948 mb.

Marcia is beginning to weaken.  It will initially weaken slowly because it is still near the ocean and the circulation has well developed upper level outflow.  As Marcia moves farther south, it will encounter more vertical wind shear.  Increased wind shear and more time over land, will speed up the rate of weakening in 12 to 24 hours.

Marcia is still strong enough to contain damaging winds.  The center of circulation will pass near Rockhampton in a few hours.  It could produce a significant storm surge on the portion of the coast where the winds are blowing toward the coastline.  Marcia could also generate locally heavy rainfall and the potential for flooding.

 

Tropical Cyclone Lam Moving Farther Inland and Weakening

Tropical Cyclone Lam made landfall earlier today just to the southwest of Elcho Island on the north coast of Australia.  Lam is continuing to move farther inland in the Northern Territory.  At 9:00 p.m. EST on Thursday the center of Lam was located at latitude 13.1°S and longitude 134.4°S which put it 40 miles north of Bulman and about 75 miles south-southwest of Milingimbi, Australia.  It was moving toward the southwest at 10 m.p.h.  The maximum sustained wind speed was 65 m.p.h. and there were gusts to 90 m.p.h.  The minimum surface pressure was 985 mb.

Lam will continue to weaken as it moves farther into the interior of Australia.  The weakening will occur slowly because the circulation is moving over relatively flat terrain.  Lam could produce locally heavy rainfall and the potential for flooding along its path.  The winds and waves along the coast should continue to lessen and the water levels should decrease.

Lam and Marcia Equivalent of Major Hurricanes As They Affect Australia

Both Severe Cyclone Lam and Severe Tropical Cyclone Marcia intensified rapidly during the past few hours and both storms are now the equivalent of major hurricanes.  Lam is making landfall on the north coast of Australia just to the southwest of Elcho Island.  The motion of Marcia has slowed, but it is approaching the coast of Queensland.

At 8:00 a.m. EST on Thursday the center of Lam was located at latitude 12.0°S and longitude 135.4°E which put it about 12 miles west-northwest of Galiwinku and about 35 miles east-northeast of Milingimbi, Australia.  Lam was moving toward the southwest at 5 m.p.h.  The maximum sustained wind speed was 115 m.p.h., which makes Lam the equivalent of a Category 3 hurricane on the Saffir-Simpson Scale.  It was estimate that there were wind gusts to 160 m.p.h. and the minimum surface pressure was 963 mb.

At 8:00 a.m. EST on Thursday the center of Marcia was located at latitude 20.8°S and longitude 150.6°S which put it about 150 miles east of Mackay and about 160 miles north of Yeppoon, Australia.  Lam was moving toward the west-southwest at 7 m.p.h.  The maximum sustained wind speed was 120 m.p.h., which makes Marcia the equivalent of a Category 3 hurricane on the Saffir-Simpson Scale.  It was estimated that there were wind gusts to 165 m.p.h. and the minimum surface pressure was 956 mb.

Both tropical cyclones are capable of causing significant wind damage.  They are also capable of generating a significant storm surge near where the center makes landfall.  Locally heavy rainfall and the potential for flooding exists, as the storms move inland.

 

Tropical Cyclone Marcia Intensifying Quickly as It Nears Australia

The circulation around Tropical Cyclone Marcia is organizing rapidly as it moves toward eastern Australia.  An eye is apparent on visible satellite imagery and Marcia rapidly intensified to hurricane intensity.  At 1:00 a.m. EST on Thursday the center of Marcia was located at latitude 20.5°S and longitude 151.0°E which put it about 125 miles east-northeast of Mackay and about 180 miles north-northeast of Yeppoon, Australia.  Marcia was moving toward the west-southwest at 16 m.p.h.  The maximum sustained wind speed was 95 m.p.h. and there were gusts to 135 m.p.h.  The minimum surface pressure was 956 mb.

Marcia has developed an eye and thunderstorms completely surround it.  The core of Marcia is symmetrical which indicates a well organized storm.  As Marcia moved toward the southwest, it moved west of the strongest upper level winds, which reduced the vertical wind shear.  Marcia was over warm Sea Surface Temperatures and the more favorable environment allowed it to intensify quickly.  It will remain in a favorable environment until it makes landfall and further intensification is possible.

Marcia is near the western end of a subtropical ridge which is steering it to the southwest.  Once the system moves inland, it is likely to move in more of a southerly direction, but it should be weaker by that time.

Marcia could make landfall in around 12 hours near the Northumberland Isles between Mackay and Yeppoon.  The rapid organization of the circulation increased the destructive potential of Marcia.  It is strong enough to cause wind damage and it could cause a storm surge near where the center makes landfall.  The stronger circulation could also produce locally heavy rainfall and the potential for flooding as it moves inland.

 

Severe Cyclone Lam Approaching North Coast of Australia

Severe Cyclone Lam is located just to the west of the Wessel Islands.  It is moving slowly southwestward toward the north coast of Australia.  At 10:00 p.m. EST on Wednesday the center of Severe Cyclone Lam was located at latitude 11.5°S and longitude 135.9°E which put it about 40 miles north-northeast of Elcho Island and about 75 miles northwest of Nhulunbuy, Australia.  Lam was moving toward the southwest at 5 m.p.h.  The maximum sustained wind speed was 85 m.p.h. and there were gusts to 120 m.p.h.  The minimum surface pressure was 967 mb.

Lam is moving over Sea Surface Temperatures that are warmer than 30°C.  The upper level winds are relatively light and there is little vertical wind shear.  Since the environment is favorable, some further intensification is possible before Lam makes landfall in about 12 hours.

Lam is expected to make landfall on the north coast of Australia just to the southwest of Elcho Island.  It is a strong tropical cyclone capable of causing wind damage.  A weather station near Cape Wessel measured a sustained wind speed of 80 m.p.h. and wind gusts to 100 m.p.h. when the eyewall passed over the station.  The intensity and slow movement of Lam are also creating the potential for a significant storm surge near where the center makes landfall.  The slow motion will also create the potential for locally heavy rainfall and flooding as Lam moves inland.