western pacific Typhoon Choi-wan

[Somerset Squall]

The 23rd tropical cyclone of the Western Pacific season has formed in the far east of the basin, just south of Wake Island. Choi-wan has winds of 35kts. Choi-wan is a large, sprawling storm with a large expanse of storm force winds. The storm is currently heading westwards along the south side of a ridge to the north. Choi-wan will continue westwards then turn to the northwest then north as it reaches the western extent of the ridge. Shear is low, and waters warm, which suggests Choi-wan will continue to intensify at at least a steady pace over the next few days. JTWC expect a peak of 85kts before weakening eventually begins on day 5 due to increasing shear and cooler waters in the higher latitudes.

[Somerset Squall]

Choi-wan is very slowly intensifying, with winds now at 50kts according to JTWC. The storm remains very broad, with the majority of the convection to the southwest and northeast of the LLCC, and not over the LLCC itself. Whilst Choi-wan has this structure, it will find it difficult to strengthen. JTWC still expect Choi-wan to become a typhoon in about 24hrs before it recurves northeast into stronger shear and cooler waters.

[Somerset Squall]

Choi-wan's structure has vastly improved this morning with convection now persisting over the LLCC, with the circulation of Choi-wan also having become much better defined aswell (ie much less broad). Winds are up to 60kts. Choi-wan is heading generally westwards but should soon turn to the north as it reaches the western extent of the steering ridge to the north. Further intensification is likely, with JTWC forecasting a cat 2 peak with 85kt winds before weakening over cooler water and higher shear.

[Somerset Squall]

Choi-wan became a typhoon late yesterday and has since strengthened to 70kts. The typhoon could strengthen a little more over the next 12hrs before shear increases and waters cool along track, initiating extratropical transition. Chan-hom is likely to become quite an intense extratropical cyclone over the North Pacific.

[Somerset Squall]

Choi-Wan peaked at 70kts and has now become extratropical whilst racing northward east of Japan.