Tropical Weather Discussion
Issued by NWS
Issued by NWS
955 AXPQ20 PGUM 120104 TWDPQ Tropical Weather Discussion National Weather Service Tiyan GU 1104 AM ChST Sun Apr 12 2026 Tropical Weather Discussion for the Western North Pacific between the Equator and 25N from 130E to 180. The following information is based on recent satellite imagery/data, weather observations, radar, and meteorological analysis. ...SPECIAL FEATURES... TROPICAL CYCLONES... Typhoon Sinlaku (04W) is currently centered roughly 145 miles north- northwest of Weno, Chuuk, near 9.3N 151.5E, or about 520 miles southeast of the Marianas. Sinlaku was nearly stationary overnight, with the center now moving slightly north-northeast at around 5 mph. The storm track is expected to shift back to the north, and then northwest as it approaches the Marianas through the next 24 to 48 hours, increasing in forward speed. Maximum sustained winds have increased to 110 mph, and Sinlaku is expected to continue intensifying through late Monday night as it nears the Marianas. Widespread heavy showers and isolated thunderstorms are seen 200 miles outward from the center, with outer bands of numerous to widespread showers between 200 to 400 miles from the center. Scattered thunderstorms are seen within these outer rainbands east to east-southeast of the center. The latest track from the Joint Typhoon Warning Center (JTWC) still brings TY Sinlaku toward the Marianas, but has shifted more toward the north with the center potentially passing near Rota as a Category 3 or 4 typhoon. For more information please refer to bulletins from the Joint Typhoon Warning Center under WMO header WTPN31 PGTW and from the National Weather Service under WMO header WTPQ31 PGUM. ...OTHER WEATHER SYSTEMS... NEAR-EQUATORIAL TROUGH... The Near-Equatorial Trough (NET) extends east into the region near 8N130E, passing over the Republic of Palau and south of Yap Proper, into TY Sinlaku. Patchy scattered showers and cloud cover are seen along the NET axis, mainly north of Koror and south of Yap, extending eastward into the heavy outer rainbands of Sinlaku. The NET looks to drift slightly north through the next day or so, becoming more indistinct as TS Sinlaku dominates the wind field across the region, in addition to the strong trade-wind surge north of Sinlaku and the westerly wind burst to the south. TRADE-WIND TROUGHS... A trade-wind trough is seen just east of the Marshall Islands, extending northeast from around 6N173E to the Date Line near 11N. Numerous showers and isolated thunderstorms are seen within the trough near the Date Line. This trough looks to diminish over the next day or so with very slight movement west toward Majuro. OTHER SYSTEMS... A Westerly Wind Burst (WWB) is located south of TY Sinlaku to south of the Equator, with overnight scatterometry showing fresh to strong northwest to west winds, about 20 to 30 kt from 140E to 155E. As TY Sinlaku gradually shifts toward the Marianas, this area of westerlies will shift west, creating choppy seas hazardous to small craft across much of Yap State including Yap Proper into midweek, and potentially into the Republic of Palau around midweek. OTHER FEATURES CAUSING GALE FORCE WINDS OR HAZARDOUS SEAS... A significant trade-wind surge exists to the north of TY Sinlaku, with overnight scatterometry depicting an area of strong to gale force winds around 25 to 35 knots, from roughly 147E to 158E, and north of Sinlaku to around 18N. Fresh to strong winds are seen from around 145E to 165E, and north of Sinlaku to around 21N. The regional pressure gradient is being enhanced by a strong mid-latitude high pressure center far to the northeast, and an intensifying TY Sinlaku north-northwest of Weno. Patchy scattered showers are seen within the trade-wind surge, north to northwest of the Marshall Islands, where the east to east-northeast trade winds are converging with the southeasterlies feeding into Sinlaku. As this high pressure continues to move east, the surge will weaken east toward the Date Line. However, another area of high pressure is moving east off of Japan and is expected to re-enhance the trade winds north of 10N over the next few days as it interacts with the northwest-moving Sinlaku. $$ DeCou