Tropical Storm No. 27 (Choi-wan) has formed over the open waters of the Northwest Pacific north of the Mariana Islands, with forecasters projecting rapid intensification into a powerful typhoon as it slows down and recurves northward toward the Ogasawara archipelago over the coming days.
CURRENT STATUS
Based on the latest JMA observations on October 1, 2026 04:05 UTC
- Location: 16.4°N, 147.5°E — approximately 230 km east-northeast of Saipan, Northern Mariana Islands
- Classification: Tropical Storm (TS)
- Movement: West at 14 kt (25 km/h)
- Central pressure: 998 hPa
- Maximum sustained winds: 35 kt (65 km/h)
- Maximum gusts: 50 kt (93 km/h)
- ≥30-kt wind area: 330 km (180 NM)
Weathernews Global Composite Satellite Imagery valid September 30, 2026 05:30 UTC to October 1, 2026 05:30 UTC
FORECAST TRACK SUMMARY
Tropical Storm No. 27 (Choi-wan) tracks north of the Mariana Islands and is forecast to strengthen into a powerful typhoon while recurving slowly northward across the Philippine Sea corridors and the Ogasawara waters from 2 to 6 October.
INTENSITY FORECAST
Tropical Storm No. 27 (Choi-wan) is forecast to undergo substantial intensification over favorable oceanic conditions. The system is expected to strengthen into a Severe Tropical Storm (STS) by 03:00 UTC on 2 October, packing sustained winds of 50 kt (93 km/h) with gusts up to 70 kt (130 km/h) and a central pressure deepening to 990 hPa.
By 00:00 UTC on 3 October, Tropical Storm Choi-wan is projected to reach Typhoon (TY) intensity as central barometric pressure drops to 970 hPa, with sustained winds increasing to 65 kt (120 km/h) and gusts to 95 kt (175 km/h). Peak intensity is forecast between 4 and 5 October, with central pressure plummeting to 950 hPa and maximum sustained winds reaching 80 kt (150 km/h) with gusts up to 115 kt (215 km/h). By 6 October, the typhoon is forecast to maintain sustained winds of 75 kt (140 km/h) with a central pressure of 960 hPa.
IMPACTS & THREATS
Developing over the Mariana Basin and steering toward the southern maritime approaches of Japan, Tropical Storm No. 27 (Choi-wan) presents expanding wind hazards across major Western Pacific shipping corridors over the next several days.
Strong Winds: Gale-force to storm-force winds will rapidly intensify along the storm's path. Tropical Storm No. 27 (Choi-wan) currently sustains winds of 35 kt (65 km/h) near its center, with a 30-kt gale-force wind field extending 330 km (180 NM). A storm warning area (winds ≥50 kt) is forecast to establish by 00:00 UTC on 3 October across a 230 km (125 NM) radius, widening considerably to 350 km (190 NM) on 4 October and reaching up to 520 km (280 NM) by 6 October as the typhoon matures. Core sustained winds will reach 65 to 80 kt (120 to 150 km/h) during this period.
Violent Gusts: Severe and destructive gusts pose escalating risks to vessels and offshore installations. Maximum gusts near the center are currently 50 kt (93 km/h). Gust speeds are forecast to increase to 70 kt (130 km/h) by 2 October, escalating to 95 kt (175 km/h) on 3 October and peaking at 115 kt (215 km/h) between 4 and 5 October. Peak gusts of 105 kt (195 km/h) are projected to persist through 6 October.
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Note on the storm's name: "Choi-wan" is drawn from the Western North Pacific and South China Sea tropical cyclone name list, contributed by Hong Kong, and means "colorful cloud" in Cantonese. The WMO and the ESCAP/WMO Typhoon Committee adopt these names sequentially to make tracking specific storms straightforward and to quickly communicate warnings. To learn more about how storms are named, please visit the World Meteorological Organization (WMO) website.
