Tropical Weather Discussion
Issued by NWS
Issued by NWS
081 AXPQ20 PGUM 310050 TWDPQ Tropical Weather Discussion National Weather Service Tiyan GU 1050 AM ChST Mon Aug 31 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 AND MONSOON DISTURBANCES... A developing monsoon disturbance, Invest 94W, is centered NE of Luzon near 20.8N 133.2E and is currently the subject of a Tropical Cyclone Formation Alert by the Joint Typhoon Warning Center (JTWC). This means that 94W is expected to become a significant tropical cyclone (Tropical Depression) within the next 24 hours. 94W is currently moving slowly NNW. Latest satellite data shows a broad, elongated Low-Level Circulation Center (LLCC) obscured by persistent convection S through W of the center. Scattered to numerous showers and isolated thunderstorms are found up to 230 miles mainly SSE to WNW of the center. Since conditions remain conducive to development, Invest 94W is expected to slowly strengthen as it moves NNW, possibly moving out of the Guam Area of Responsibility (AOR) within the next 24 hours. For more information on Invest 94W and the TCFA, see bulletins issued by JTWC under WMO headers ABPW10 PGTW and WTPN21 PGTW. A weak monsoon disturbance, Invest 95W, is found ESE of Guam, NE of Weno, Chuuk, near 11.4N 154.0E. Invest 95W is currently rated sub- low, meaning development is not expected for the next few days. Latest ASCAT analysis shows a weak circulation with light winds near the center and stronger environmental winds farther S within a monsoon surge across through NE of Pohnpei. Convection is found mainly along the periphery of 95W, to the W through N, beginning around 65 miles from the center, out to 300 miles. Invest 95W looks to slowly move toward the NNW over the next few days, with little development expected until after the middle of the week. ...OTHER WEATHER SYSTEMS... MONSOON TROUGH... The monsoon trough enters the AOR near 13N130E, extending ESE through Invest 94W, crossing the Marianas near Tinian, to Invest 95W. The trough then continues E to NW of Kwajalein near 13N166E, where it turns ESE to beyond the Date Line near 8N. Scattered to numerous showers and scattered thunderstorms are found S of the trough within a band of convergence between 14N and 15N, W of 137E. Another band of scattered to numerous showers and isolated thunderstorms is found W of the Marianas into eastern Yap State within a col area S of the trough. A monsoon surge S of the trough and Invest 95W is generating scattered to numerous showers and isolated thunderstorms from far eastern Yap State, across Chuuk State, including Weno, to just W of Pohnpei. E of Pohnpei, patches of scattered showers are found across Kosrae and the southern Marshall Islands. The trough looks to strengthen over the coming days, with increased convection across the region. SURFACE TROUGHS... A weak surface trough extends E from near 19N165E to end near 19N174E. This trough is generating scattered showers and isolated thunderstorms across and E of Wake Island. This trough will move N over the next few days and be absorbed by a decaying trough, the remnants of the previous monsoon trough, near 25N. $$ Kleeschulte