Special Weather Statement - Moderate | Effective 05/23/2026 00:25

A tropical disturbance, known as JTWC's Invest 99W, is currently centered near 8N145E west of Satawal. This system remains disorganized with little change in organization since yesterday. The chance of this system developing into a significant tropical cyclone is rated as sub-low by Joint Typhoon Warning Center (JTWC). Current estimations has the system passing near Fais and Ulithi before moving northward into the Philippine Sea. This system is expected to bring numerous to widespread showers with possible heavy downpours, gusty winds and choppy seas. In addition, high uncertainty remains regarding rainfall amounts, but model trends indicate 3 to 5 inches over the next 72 hours. Yap Proper and Palau may also experience this disturbance as models are not in alignment on when the northward turn is anticipated to happen. As Invest 99W lifts northward next week, a monsoon tail will develop on the south side. Westerly to southwesterly winds of 20 to 30 kts will be possible along with seas hazardous to small craft. At this time guidance shows this region as a narrow band displaced from both Yap's and Palau's coastal waters, with seas remaining below 10 feet through Wednesday. As the system shifts further away, the monsoon tail may transition into an inflow tail with southerly flow. This could bring seas near hazardous conditions to Yap's coastal waters late next week. Residents and mariners should monitor the latest forecasts for the region at weather.gov/gum/PublicForecasts and any information shared by WSO Yap and WSO Chuuk for the local regions. For more information on Invest 99W, see bulletins issued by JTWC under WMO header ABPW10 PGTW and WTPN21 PGTW.