Tropical Cyclone Ken

[Somerset Squall]

Invest 95P has developed into Tropical Cyclone Ken, with initial intensity at 35kts. Banding has continued to improve, and Ken is sat in a very favourable environment for further intensification. The system is located west of Rarotonga, and is moving south-southeastwards and this motion is expected to continue. This will bring Ken into colder waters in about 60 hours, but he has ample oppurtunity to strengthen before then. How much is really open to question, how well will he make use of the good environment?

[Somerset Squall]

Satellite image of the south Pacific, with Ken clearly visible near the centre of the image:

[Cookie]

ken come on thats hardly an exotic name,

its a bit old this image but gives you an idea of the track

[Cookie]

shear taking hold

[Somerset Squall]

Ken is struggling. Shear is beginning to increase, and the system has accelerated southeastwards much quicker towards cooler waters which Ken will be moving over soon. In addition, the moderate shear currently over the system is cutting off poleward outflow, meaning that the exhaust mechanism for the storm is being choked, and instead of a column of rising, condensing, unstable air within the system which also causes pressure to drop, we have the opposite as dry, subsiding air is diminishing convection and raising surface pressure. In summary, this means Ken isn't expected to strengthen and intensity remains at 35kts. What a difference 12 hours has made for Ken, the environment certainly has deteriorated rapidly!

As shear is getting stronger, and waters cooler, Ken is likely to begin extratropical transistion beyond 12 hours time, and complete the change at around 36 hours.

[Cookie]

you're right mate some change in conditions

[Somerset Squall]

Ken has made use of the last stretch of warm waters before the sharp decline, and has strengthened to 45kts. Shear has been moderate, but not strong enough to prohibit intensification. Banding features are still quite good, and there is some solid convection over the centre. Extratropical transition will begin soon as shear increases and waters cool, but for now, Ken is looking the best he has done do far.

EDIT: Ken may be entering a period of rapid intensification! An eye is emerging on latest satellite imagery.

Edited March 18, 2009 by Somerset Squall

[Cookie]

I don't think it lasted long

[Somerset Squall]

Indeed Cookie, what a fickle cyclone Ken is! I think it probably reached about 55kts briefly but the eye like feature is rapidly dissapearing, and your image shows dry air penetrating the core of Ken thus weakening the storm. Convection ocerall is becoming more shallow, perhaps the first signs of extratropical transition.

[kold weather]

Convection is shallow at the moment but the actual structure isn't too bad still, I suspect there won't be much change before Ken becomes extra tropical and the convection becoming more shallow is a sign of heat content really lowering and given its current track SE I don't think ET transition is all that far away, indeed that may be why the structure has improved recently as Baroclinic forces start to impact Ken.

[Cookie]