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Somerset Squall

Severe Tropical Cyclone Garry

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Tropical Cyclone 10P has formed, about 300 miles west-northwest of Pago Pago, American Samoa. Intensity is 35kts. Convection is slowly expanding over the LLC, but the majority of the cyclone's convection is in a disjointed band north of the centre. Shear is low, and waters warm, so 10P should strengthen over the coming days. 10P is moving eastwards along the south side of an equatorial ridge, but the track should soon bend to the southeast ahead of a trough.

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10P has been given the name Garry this morning by Fiji Met. Intensity remains at 35kts, but Garry seems poised to strengthen soon. Some moderate shear has affected Garry overnight, but this has now eased and outflow has also become much stronger as an anticyclone is building aloft of Garry. Garry has flaring deep convection over the centre, and improving banding features. Garry is moving eastwards quickly but should slow and turn to the southeast soon as the cyclone's steering influence shifts from a ridge to the north to a ridge to the east. Garry is expected to strengthen over the next 4 days before shear rises on the southeasterly track by day 5, inducing weakening.

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Garry has slowly intensified over the last 36hrs. Sustained winds have reached 50kts. Garry has been fighting moderate shear throughout today which has slowed strengthening. This shear, though not especially damaging to Garry, will continue to cap large intensification gains. Garry is still expected to strengthen modestly over the next 48hrs before sea temps cool along track and shear rises to destructive levels.

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Shear has been stronger than expected and has weakened Garry to 40kts as the cyclone has turned southeast. Convection has been sheared away from the now partially exposed LLC. Shear is not expected to let up over the next day or so, so Garry is going to find it difficult to restrengthen. Shear will rise even further in about 36hrs, and sea temps will cool along track. Garry is expected to begin extratropical transition as a result.

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Garry has unexpectedly strengthened overnight. The severe cyclone has developed a central dense overcast and tightly wrapped banding. Sustained winds have reached 65kts. The intensification has occured as Garry has found a pocket of lower shear and outflow has vastly improved.

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Garry has continued to strengthen. Sustained winds are now 75kts. Garry's eye has been briefly visible on satellite imagery, but is now cloud obscured. Garry should weaken soon as shear rises again later tomorrow.

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Garry has strengthened further to 85kts, a cat 2 hurricane equivalent on the SS scale. Although Garry has strengthened more than anticipated, the cyclone should begin to weaken later today as shear rises over the system. A building ridge to the east should force Garry to turn south soon too, making the cyclone move over cooler water. The cooler water and increased shear will weaken Garry, before initiating extratropical transition.

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Garry is slipping southeastwards out of the tropics and weakening under heavy wind shear. Intensity is down at 55kts. The circulation is broadening and distorting as a result of the windshear, and convection is displaced to the southeast of the LLC. Extratropical transition will begin soon.

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Garry has nearly completed extratropical transition. JTWC have issued their final warning as Garry is expected to be fully extratropical within the next 12hrs.

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