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Posts tagged Learmonth

Probability for Tropical Cyclone Near Australia Upgraded to “Good”

February 27th, 2009 Category: Tropical Cyclones

Area of convection near Australia - February 27th, 2009

Area of convection near Australia - February 27th, 2009

Multispectral imagery © JTWC

Multispectral imagery

The area of convection is located approximately 545 nautical miles east-northeast of Learmonth, Australia.

Formation of a significant tropical cyclone is possible within 155 nautical miles either side of a line from 17.2S 123.3E to 19.4S 117.5E within the next 12 to 24 hours.

Available data does not justify issuance of numbered tropical cyclone warnings at this time, although the possibility for formation has been upgraded from fair, yesterday, to good.

The color image on the left shows the eastern part of the system, while the multispectral image to the right, taken a few hours later, shows the entire area. The system is moving southwestward at 17 knots.

Winds in the area are estimated to be 25 to 30 knots. METSAT imagery indicates that a circulation center is located near 17.6S 122.4E.

Animated multispectral satellite imagery indicates that the low level circulation center (LLCC) that had previously been tracking over land is beginning to move over water.

Sea surface temperatures will be very favorable for the LLCC to continue to develop as it tracks to the southwest.

Upper level analysis indicates low vertical wind shear and good outflow as the LLCC is just equatorward of an upper level subtropical ridge.

Mid-level ridging over Australia will be the dominant steering influence tracking the LLCC towards Learmonth. Maximum sustained surface winds are estimated at 25 to 30 knots. Minimum sea level pressure is estimated to be near 1002 mb. Due to the LLCC moving over water into a favorable environment and beginning to consolidate, the potential for the development of a significant tropical cyclone within the next 24 hours is good.

North West Cape and Ningaloo Reef, Australia

February 20th, 2009 Category: Snapshots

Peninsula, Australia - February 19th, 2009

Peninsula, Australia - February 19th, 2009

North West Cape is a large peninsula of land in the north west coast of Western Australia. It includes the towns of Exmouth and Learmonth.

Cape Range, a national park, runs down the spine of the peninsula and Ningaloo Reef runs along the western edge.

Ningaloo Reef is a fringing coral reef,  of 280 kilometers in length. It is Australia’s largest fringing coral reef and the only large reef positioned very close to a landmass.

In 1987 the reef and surrounding waters were designated as the Ningaloo Marine Park.

It is known for its seasonal feeding concentrations of the whale shark, and the conservation debate surrounding its potential tourism development.

Although most famed for its whale sharks which feed there from March to June, the reef is also rich in coral and other marine life.

During the winter months, the reef is part of the migratory routes for dolphins, dugongs, manta rays and humpback whales.

The beaches of the reef are an important breeding ground of the loggerhead, green and hawksbill turtles. They also depend on the reef for nesting and food.

The Ningaloo supports an abundance of fish (500 species), corals (300 species), mollusks (600 species) and many other marine invertebrates. The reef is less than half a kilometer offshore in some areas, such as Coral Bay.

Area of Convection Near Australia

February 16th, 2009 Category: Tropical Cyclones

Area of convection near Australia - February 16th, 2009

Area of convection near Australia - February 16th, 2009

Convective area - enhanced image

Convective area - enhanced image

The area of convection previously located near 18.0S 116.0E is now located near 18.0S 115.0E, approximately 255 nautical miles north-northeast of Learmonth, Australia.

Animated infrared satellite imagery and an AMSU image depict a monsoon depression low pressure area with multiple fully-exposed low-level circulation center (LLCC) rotating around a centroid.

Imagery also shows a persistent area of deep convection along the convergent southern periphery of the low.

A QUIKSCAT image indicated 15 to 20 knot core winds with stronger (25 to 30 knot) winds along the southern periphery.

The Learnmonth radar shows weak banding over the southeast and south quadrants with moderate to heavy thunderstorms just north of Exmouth.

The broad LLCC is located north of the subtropical ridge axis and is under strong easterly vertical wind shear.

Maximum sustained surface winds are estimated at 25 to 30 knots. Minimum sea level pressure is estimated to be near 998 mb.

The LLCC is expected to remain within an unfavorable environment for the next 24 hours, therefore, the potential for the development of a significant tropical cyclone within the next 24 hours remains poor.

source JTWC

Tropical Cyclone 14S (Freddy) Weakens

February 10th, 2009 Category: Tropical Cyclones

Tropical Cyclone 14S (Freddy) - February 9th, 2009 © JTWC

Tropical Cyclone 14S (Freddy) - February 9th, 2009

Tropical Cyclone 14S (Freddy), located approximately 615 nautical miles west-northwest of Learmonth, Australia, has tracked southwestward at 11 knots over the past six hours.

Maximum significant wave height is 13 feet.

Animated water vapor imagery indicates the system has lost a significant amount of convection around the low level circulation center, which has become partially exposed.

Environmental analysis indicates that TC 14S remains in an area of moderate vertical wind shear and cooler sea surface temperatures.

These factors are contibuting to the gradual dissipation of the cyclone.

The Joint Typhoon Warning Center will issue no further warnings on this system, though it will be closely monitored for signs of regeneration.

source JTWC

Tropical Cyclone 14S (Freddy) Expected to Weaken

February 9th, 2009 Category: Tropical Cyclones

Tropical Cyclone 14S (Freddy) - February 9th, 2009

Tropical Cyclone 14S (Freddy) - February 9th, 2009

Tropical Cyclone 14S (Freddy), located approximately 525 nautical miles west-northwest of Learmonth, Australia, has tracked west-southwestward at 13 knots over the past 6 hours.

The system is tracking toward a weakness in the low to mid-level subtropical steering ridge induced by a midlatitude shortwave to the Southwest.

Generally west-southwestward motion will continue through the forecast period as the subtropical ridge remains the dominant steering influence.

Persistent easterly vertical wind shear and passage over cooler water are weakening the system.

Shear is expected to remain unfavorably high as along-track sea surface temperatures drop during the next 36 hours. Therefore, the maximum sustained wind speed is expected to fall below the 35 knot warning threshold by TAU 36.

Maximum significant wave height is 14 feet.

source JTWC