Tropical Storm Malou

[Somerset Squall]

The very active phase of the West Pacific typhoon season continues with another tropical depression forming, the fourth in as many days. 10W consists of concentrated, deep convection loosely wrapping around a developing LLC. This system is still very much in the formative stages, so strengthening from the initial intensity of 25kts could be quite slow. This is despite low shear, warm sea temps and good outflow which suggests intensification. Once 10W consolidates, some rapid intensification could occur as waters remain very warm and the upper level environment good. 10W will move northwestward over the next few days along the southwestern periphery of a subtropical ridge to the northeast (the same one that steered Kompasu). Beyond this, 10W is expected to recurve northeastwards and begin extratropical transition in a similar way to Kompasu.

[Somerset Squall]

10W continues to move northwestwards in a similar region to where Typhoon Kompasu existed. The depression has become a little better organised with convection wrapping around an increasingly well defined LLC and also there is some signs of limited banding, particularly in the southern quadrant of 10W. Accordingly, the intensity has increased to 30kts.

Now the system has taken on the look of well developed tropical depression, strengthening should occur proper, and the system may even become a tropical storm later today. The upper level environment remains very favourable with low shear and good radial outflow. Waters are very warm on the northwesterly track which should support further development. JTWC are keen on this one becoming a typhoon, with peak intensity currently estimated at 80kts.

There is a little model spread with where 10W will end up. The steering pattern remains largely the same as when Kompasu was moving through a couple days ago, with a subtropical ridge anchored just south of Japan. 10W should round the western periphery of this ridge and turn towards the north. The timing of this turn is crucial- the later it happens, the increased risk of landfall near Shanghai, China. An early turn will ensure 10W misses China, runs into the higher shear that was responsible for killing Kompasu and weakens prior to landfall in South Korea. In the middle of the two possibilities is that 10W follows Kompasu's track and misses South Korea and China and recurves to hit North Korea instead. All three places need to monitor 10W.

Edited September 2, 2010 by Somerset Squall

[Cookie]

[Cookie]

[Somerset Squall]

10W has been upgraded to Tropical Storm Malou, with intensity rising to 35kts. Malou continues on a general northwestwards heading, with the track forecast being practically the same as before. A northward turn should materialise soon.

Malou should continue to strengthen in low shear, warm sea temps and good outflow. Because of the slow initial strengthening of the system, JTWC forecast a peak just below typhoon strength as the agency doesn't think Malou will have enough time to become one before running into higher shear. Strengthening into a typhoon cannot be ruled out however as Malou is now quite a compact storm which could intensify quickly.

Edited September 3, 2010 by Somerset Squall

[peterf]

hi iceberg,big thanks to you for all the info regards earl and danielle.

much appreciated mate.

[Cookie]

hi iceberg,big thanks to you for all the info regards earl and danielle.

much appreciated mate.

wrong thread ?

[Somerset Squall]

Malou has not behaved as expected. Firstly, it has not intensified as much as originally anticipated, despite a favourable environment. Secondly, though Malou has roughly followed the predicted track, the storm's motion has been very erratic. Both of these things have been caused by the storm developing multiple circulations, causing wobbles in the track and slowing intensification due to the LLC's competing with each other for resources. The intensity has only risen to 40kts.

Malou is nearing South Korea. The storm could intensify a little more prior to landfall. Afterwards, extratropical transition will occur as the storm veers eastwards into the Sea Of Japan.

[Somerset Squall]

Malou peaked at 45kts, and also veered east sooner than expected, missing South Korea. Extratropical transition is well underway in the Sea Of Japan.

[Somerset Squall]

Malou became extratropical over Japan but is now moving southeastwards away from Tokyo, into warmer water. As a result, convection has increased. However, the core is still analysed as cold, meaning the system is still extratropical. There is a small chance of re-generation if Malou continues southeast but most models are forecasting the extratropical remnant of Malou to continue eastwards or even east-northeastwards.