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Somerset Squall

Tropical Cyclone 04 A

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The fourth tropical cyclone of the 2012 North Indian cyclone season has formed around 400 miles east of Somalia. Sustained winds are currently 40kts. The cyclone had deep centralised convection overnight and tight banding. This convection has become slightly displaced this morning as shear has risen a little. This shear will prevent significant intensification, but 04A is likely to strengthen a little more as it heads towards the Somalian coast. This westward track is expected due to strong ridging to the north.


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240300z position near 8.3n 53.8e.

Tropical cyclone (tc) 04a, located approximately 280 nm southeast of

cape guardafui, Somalia, had tracked westward at 17 knots over the

past six hours. Animated enhanced infrared satellite imagery shows

the system has maintained organization and deep convective bands

around a well-defined low level circulation center. The initial

position is based on the above animation and on the 232244z trmm

microwave pass. The initial intensity is based on the high end of

Dvorak estimates from pgtw and knes. The cyclone continues to exhibit

good outflow on the poleward side which is countering the

negative effects of moderate (15-20 knot) easterly vertical wind

shear (vws), as evident on animated water vapor satellite imagery.

With little change in the upper level environment along the forecast

track, tc 04a is expected to maintain its current intensity until it

makes landfall along the northeast coast of Somalia after tau 24. The

tc will dissipate over land by tau 36 due to increased vws and land

interaction. The available numerical forecast track guidance is in

fair agreement with the exception of the WBAR, which depicts a

west-northwestward track that is inconsistent with the forecast

steering flow. The remaining models show flaring after landfall, an

indication of significant weakening of the cyclone. The forecast

track has been adjusted slightly equatorward to offset WBAR. Maximum

significant wave height at 240000z is 16 feet. Next warnings at

240900z, 241500z, 242100z and 250300z.//



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04A has maintained strength since I last posted. Moderate shear has kept the system from intensifying. The LLC is somewhat exposed this morning, east of the banded convection. 04A should make landfall on Somalia just in a little more than 12hrs, but most of the weather action is spreading inland now ahead of the lagging LLC. Dissipation will occur quickly over land.

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