Tropical Cyclone Hina

[Somerset Squall]

Tropical Cyclone 16S has developed from invest 94S, and is currently located several hundred miles to the east-southeast of Diego Garcia. 16S is a very well organised system with good central convection and prounounced banding features. Shear is low, waters are warm and the system has dual outflow channels which has helped the quick strengthening to TC status. These conditions will allow 16S to intensify over the next day or so, perhaps rapidly. The storm is expected to remain out to sea with a general southwestward motion expected as a subtropical steering ridge continues to develop to the east. JTWC expect this system to be a 65kt, cat 1 storm in 48hrs time.

[Cookie]

thanks for the update mate

some more images

[Somerset Squall]

Nice graphic there Cookie, shows the strong rotation and the quick consolidation of the system well.

[Cookie]

glad it worked my pc is playing up tonight, really ain't sure what is and isn't loading.

[Somerset Squall]

16S has now been named as Tropical Cyclone Hina, and intensity has increased to 40kts. Hina will continue to intensify as conditions remain favourable. A southwestward motion is forecast but Hina may eventually turn westwards as the subtropical ridge may re-orientate itself to the south of the cyclone. The timing of this and whether it occurs is important for the long term outlook for Hina, if she continues to move southwards too far then the system will meet cooler waters in a couple days time, if it manages to curve westwards the cyclone will remain over the warmer waters and will get the oppurtunity to become an intense system (providing shear doesn't increase).

[Somerset Squall]

Hina has continued to intensify overnight, and is now a 50kt storm. Through the next 24 hours, Hina is forecast to strengthen as shear remains low, waters warm and the system continues to make good use of the dual outflow channels. However, both JTWC and MeteoFrance are in agreement of arrested development thereafter, and perhaps instead some weakening, as it seems likely that shear may now increase as the storm heads southwestwards. JTWC are forecasting a peak of 60kts and then weakening to 45kts at 48hrs as the shear sets in. It's touch and go whether Hina will make cat 1 status now on the SS scale. JTWC are keen to keep tracking Hina southwestwards wheras MeteoFrance turn Hina west-southwestwards in a few days time. Both scenarios are credible, it just depends where the subtropical steering ridge finally wants to settle.

[Cookie]

thanks for the updates mate

[Somerset Squall]

Latest satellite imagery shows that Hina has developed a small central dense overcast feature in the last few hours, and this is a sign of a very well organised system- once the CDO feature is in place then usually an eye can begin forming. Intensity has increased to 55kts. Hina has baout another 18hrs before shear is progged to increase, so Hina may make cat 1 status. Sea temps will remain warm so the amount of weakening and future intensity of Hina will be governed by the shear.

[Cookie]

this from earlier

----- Current Analysis -----

Date : 22 FEB 2009 Time : 130000 UTC

Lat : 16:37:33 S Lon : 78:16:26 E

CI# /Pressure/ Vmax

3.7 / 983.1mb/ 59.0kt

[Somerset Squall]

Hina continues to strengthen. Deep convection continues to cover the LLC and there are hints of an eye trying to develop. Pressure has fallen to 974mb. Intensity has been increased to 65kts, making Hina a cat 1 in the SS scale.

Edited February 23, 2009 by Somerset Squall

[Cookie]

Am I right in saying this dosen't look like it will affect land?

[Cookie]

Hina continues to strengthen. Deep convection continues to cover the LLC and there are hints of an eye trying to develop. Pressure has fallen to 974mb. Intensity has been increased to 65kts, making Hina a cat 1 in the SS scale.

did it officially reach cat 1?

new images

Edited February 23, 2009 by cookie

[Cookie]

doesn't look like it will get to cat 1 at the moment.

the forecasted track shows Hinna heading towards colder waters.

[Somerset Squall]

did it officially reach cat 1?

Yes, intensity peaked at 65kts in the early hours, but only briefly. So Hina briefly reached cat 1 status, but it wasn't reported by JTWC as it occured between two advisories. Latest JTWC advisory said Hina weakened to 60kts, which implies it was stronger before the last advisory.

But indeed, Hina is weakening now. Strong shear has set in over the system and intensity is now 55kts. Strong poleward outflow and warm sea temps will prevent rapid weakening for now but as you rightly say Cookie, Hina is heading for colder waters which may finish it off in around 48hrs.

[Cookie]

thanks for clearing that up mate. as you can see by latest images shes not what she was.

[Somerset Squall]

Hina is drifting weatwards and rapidly dissipating. The LLC is now entirely exposed and there is very little convection associated with the system. Intensity has been reduced to 30kts and JTWC have isssued their final warning on the system.