Monthly Archives: February 2015

Tropical Cyclone Glenda Forms South of Diego Garcia

A low level circulation consolidated quickly in a large area of thunderstorms over the south central Indian Ocean and the system was classified as Tropical Cyclone Glenda.  At 11:00 p.m. EST on Tuesday the center of Tropical Cyclone Glenda was located at latitude 17.3°S and longitude 69.8°E which put it about 670 miles south of Diego Garcia and about 1040 miles east-northeast of La Reunion.  Glenda was moving toward the west-southwest at 10 m.p.h.  The maximum sustained wind speed was 65 m.p.h. and there were gusts to 75 m.p.h.  The minimum surface pressure was 982 mb.

Glenda is over warm Sea Surface Temperatures and it has well developed upper level outflow.  The outflow is pumping out mass and the pressure has been decreasing steadily.  Glenda is like to remain in a favorable environment for another 48 hours.  It will likely reach hurricane intensity on Wednesday and it could become the equivalent of a major hurricane on Thursday.

Glenda is being steered to the west-southwest by a subtropical ridge located southeast of it.  This motion is likely to continue for another 24 to 36 hours.  When it approaches the western end of the ridge, it will turn more toward the south.  The projected track keeps Glenda well south of Diego Garcia and has it turning southward well to the east of La Reunion.  As a result, Glenda poses no current threat to any land area.

 

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.

 

Severe Cyclone Lam Reaches Hurricane Intensity Near Wessel Islands

Tropical Cyclone Lam reached hurricane intensity near the northern coast of Australia and was upgraded to Severe Cyclone status.  At 10:00 p.m. EST on Tuesday the center of Severe Cyclone Lam was located at latitude 11.1°S and longitude 137.0°E which put it near the Wessel Islands, about 80 miles north of Nhulunbuy and about 110 miles northeast of Elcho Island, Australia.  Lam was moving toward the west at 8 m.p.h.  The maximum sustained wind speed was 75 m.p.h. and there were gusts to 100 m.p.h.  The minimum surface pressure was 976 mb.

Lam remains over very warm Sea Surface Temperatures and the vertical wind shear is modest.  So, it has the potential to intensify further as long as the center remains over water.  A subtropical ridge is steering Lam westward and that motion is expect to continue for another 8 to 16 hours.  When it reaches the western edge of the ridge, Lam is expected to turn toward the southwest and it could make a landfall west of Elcho Island in 24 to 36 hours.  Lam is strong enough to pose a risk of a significant storm surge and it could also produce locally heavy rainfall and flooding as it moves inland.

 

Tropical Cyclone 13P Forms Northeast of Australia

A second tropical cyclone formed near the coast of Australia when a center of circulation developed in a cluster of thunderstorms northeast of Queensland.  At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone 13P was located at latitude 16.5°S and longitude 155.9°E which put it 385 miles east of Willis Island and about 800 miles north of Brisbane, Australia.  It was moving toward the south at 7 m.p.h.  The maximum sustained wind speed was 40 m.p.h. and there were gusts to 50 m.p.h.  The minimum surface pressure was 996 mb.

Tropical Cyclone 13P is near the western end of a subtropical ridge and moderately strong northerly winds are blowing over the top of the circulation, especially over the eastern half of it.  As a result, more thunderstorms are forming in the western half of the circulation.  The tropical cyclone is over Sea Surface Temperatures that are warm enough to support intensification.  The upper level northerly winds are enhancing outflow to the south of the circulation and so some intensification is possible.

The subtropical ridge is expected to steer Tropical Cyclone 13P in a generally southwesterly direction, which will move it toward the east coast of Australia.  A landfall near Gladstone could occur in 36 to 48 hours.

 

Cyclone Lam Developed Rapidly Over the Northern Gulf of Carpentaria

A well defined center of circulation developed rapidly on Monday in an area of thunderstorms over the northern Gulf of Carpentaria and the system was classified as Cyclone Lam.  At 10:00 p.m. EST on Monday the center of Lam was located at latitude 11.6°S and longitude 139.4°E which put it about 180 miles east-northeast of Nhulunbuy, Australia and about 260 miles northeast of Alyangula.  Lam was moving toward the west at 5 m.p.h.  The maximum sustained wind speed was 60 m.p.h. and there were gusts to 80 m.p.h.  The minimum surface pressure was 989 mb.

Lam is an environment that favors intensification.  The Sea Surface Temperatures (SSTs) in the northern Gulf of Carpentaria are near 30°C.  There are light east-southeasterly winds in the upper levels, which are creating some vertical wind shear, but there is well-developed upper level outflow on the western side of the circulation.  The upper level divergence is pumping out mass and the surface pressure is decreasing.  The circulation is tightening up around the core and further intensification is likely.  Given the warm SSTs, rapid intensification is possible if the magnitude of the wind shear remains at a modest level.

A subtropical ridge to the south of Lam is steering it slowly toward the west.  Lam is expected to continue moving westward for another 18 to 24 hours until it reaches the western end of the subtropical ridge.  When Lam reaches the western edge of the ridge, it is expected to move toward the southwest.  The timing of that turn is very important.  If the turn occurs a few hours later than expected, Lam could make landfall in northern Australia near Nhulunbuy.  If Lam turns southwestward sooner, it could remain over the Gulf of Carpentaria longer and make landfall closer to Groote Eylandt.  Lam has the potential to create dangerous storm surges when it makes landfall.  There is also the potential for wind damage, locally heavy rainfall and flooding.

 

Higos Weakening Rapidly East of Saipan

After intensifying rapidly into a strong but small typhoon on Monday, vertical wind shear caused Higos to begin a rapid weakening trend on Tuesday.  At 11:00 p.m. EST on Tuesday the center of Typhoon Higos was located at latitude 15.3°N and longitude 152.9°E which put it about 450 miles east of Saipan and about 880 miles west-southwest of Wake Island.  Higos was moving toward the west-northwest at 7 m.p.h.  The maximum sustained wind speed was 80 m.p.h. and there were gusts to 90 m.p.h.  The minimum surface pressure was estimated to be 974 mb.

Strong southwesterly winds in the upper levels are blowing over the top of Higos.  Those strong winds have blown the upper half of the circulation off to the northeast of the lower half of the circulation.  The lower portion of the circulation consists of a tight center with spiral bands of shallower clouds rotating around the center.  The wind shear is preventing deep thunderstorms from forming near the center and it is causing Higos to weaken rapidly.  Unless the shear lets up, which is unlikely, the lack of deep convection to remove mass will cause the surface pressure to increase and the circulation to spin down.

Since Higos consists primarily of a lower level circulation it is likely to be steered by winds in the lower portion of the atmosphere.  A subtropical ridge to the east of Higos is likely to steer it to the north-northwest until the wind shear causes it to spin down.