5 replies to this topic

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Off the Coast of Madagascar

[Somerset Squall]

Looks like a really well organised system which has spun up quite rapidly. Very late too, especically as the season formally ended almost two weeks ago. Latest imagery shows Joel looking almost fully tropical with deep convection over the LLC and even an eye like feature forming. However, as Joel is moving southeastwards into colder waters, he cannot survive long. Shear is already high over Joel, so it is rather surprising he has managed to become as strong as he has to begin with. As Joel is a small cyclone, it is unlikely to bring any significant impact to southern Madagascar before moving away.

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Still hanging in out there

[Somerset Squall]

Yup, Joel is still looking well organised. The convection is quite shallow but persistant. Joel is still classified subtropical, which is not surprising as sea temps are only 24-25C and 40kts of shear is still pounding the system. Subtropical cyclones tend to survive and prosper better in strong shear than fully tropical systems. Joel is moving slowly eastwards at present but is expected to turn towards the southeast where shear rises steeply to 60+kts, and this should kill off Joel or force him to become extratropical. Looks neat on satellite imagery I think! A very small storm indeed!

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why do the survive better?

[Somerset Squall]

I don't understand fully, but basically as subtropical cyclones form from extratropical cyclones and are, in part, like an extratropical storm they are more resistant to wind shear.