FXPQ50 PGUM 160805 AFDGUM Area Forecast Discussion National Weather Service Tiyan GU 605 PM ChST Thu Apr 16 2026 .Marianas Synopsis... Typhoon Sinlaku is seen to the north of Tinian and Saipan, over the northern CNMI. Mostly cloudy to cloudy skies with isolated showers are seen across Guam and Rota, with cloudy skies and numerous showers over Tinian and Saipan waters. Tanapag buoy shows seas between 25 and 28 feet while altimetry shows seas of 19 to 28 feet over the Marianas, with highest seas for the northern waters of Tinian and Saipan. && .Discussion... Typhoon Sinlaku continues to move away from the Marianas, passing through the northern CNMI west of Alamagan, Pagan and Agrihan. Tropical storm conditions are beginning to wind down, with the Tropical Storm Warning and Typhoon Watch for Guam cancelled earlier today. Rota will likely see improved conditions later this evening. the latest forecast shows Tinian and Saipan moving out of tropical storm conditions around 3 am. As the Typhoon Warnings clear, strong gusty winds look to continue for the next couple of days. Guam and Rota will see a dry pattern develop, with POPs (Probability of Precipitation) falling into the 10 to 20 percent range through the middle of next week. Tinian and Saipan will see scattered showers through Friday afternoon, then the dry pattern will move in. Nice and quiet weather for the first half of next week, allowing clean up from Sinlaku to proceed. && .Marine... Although Sinlaku is moving out of the area and tropical storm/typhoon conditions continue to improve, large swell producing seas in excess of 15 feet will continue into the weekend, producing hazardous seas across the region. A Hazardous Seas Warning and Small Craft Advisory were issued for Guam waters earlier today and will likely be issued for Rota, Tinian and Saipan as the Typhoon Warnings are cancelled. Seas and winds will remain above 10 feet well into the weekend. The seas will maintain dangerous surf conditions into the weekend, along with coastal flooding through at least Saturday. Marine conditions look to fall below Small Craft Advisory levels late in the weekend for Guam and early next week for the CNMI. && .Hydrology... Heavy rainfall potential has subsided and all flood products have expired. && .Tropical Systems... At 500 PM ChST, 0700 UTC, the center of Typhoon Sinlaku was located near 17.8N, 144.6E, or 80 miles west of Alamagan and around 200 miles north-northwest of Tinian and Saipan. Sinlaku was slow to move away from Tinian and Saipan for much of the morning, but visible satellite imagery trends this afternoon show that the center of Sinlaku's eye is now moving north-northeast as it passes to the west of Alamagan, beginning to pick up forward speed moving at roughly 7 to 9 mph. TY Sinlaku remains a powerful Category 3 storm with maximum sustained winds of around 115 mph within the eyewall. Sinlaku is forecast to continue weakening through the next few days, making a turn toward the northeast Friday morning as it passes Pagan and Agrihan to the west, then to the north of Agrihan Friday afternoon. Tinian and Saipan are expected to remain within the tropical storm force wind field until at least midnight tonight, with sustained winds gradually subsiding below 39 mph through the early morning hours of Friday. The latest forecast shows typhoon winds around 75 mph developing for Pagan and Agrihan late tonight before departing Agrihan late Friday morning. Tropical storm conditions are expected across the northern CNMI until late Friday night. For more information, please refer to bulletins from the Joint Typhoon Warning Center (JTWC) under WMO header WTPN31 PGTW and from the National Weather Service under WMO header WTPQ31 PGUM and WTPQ81 PGUM. && .Eastern Micronesia... An unsettled pattern has set up from the RMI to central eastern Micronesia. This is due to the remains of a fragment of the Inter-Tropical Convergence Zone (ITCZ) interacting with a trade-wind trough traversing the ITCZ. As Sinlaku moves further away, this will allow for the ITCZ fragment to move westward over the coming days and bring showers to Kosrae and lingering in RMI. These showers may move into Pohnpei around Friday night and Monday. Altimetry shows combined seas of 6 to 7 feet near Pohnpei and 4 to 6 near Majuro. There are two mixed swells in the region at Pohnpei and Kosrae and one at Majuro. The first is a mix of west and northeast swells and the other is a mix of east and northeast swells. Winds are expected to light to moderate through the middle of next week. && .Western Micronesia... A dry pattern has set up in the wake of Typhoon Sinlaku. Through the middle of next week, isolated showers with a few periods of scattered showers can be expected with one caveat, around Monday showers around Chuuk may build to around 50 percent chance as the showers from Pohnpei may move through the region. The main concerns for the region are in the marine regions around Yap and Koror. Swells produced by Sinlaku are keeping the seas and surf elevated. At Koror, surf is expected to be 7 to 10 feet along north facing reefs, while at Yap, surf is expected to be 10 to 14 feet especially during high tide times with the new moon cycle adding to the surf heights. Seas near Yap will also be elevated to above 10 feet and hazardous to small craft operations. Seas and surf are expected to crest over the evening and early morning hours, then begin to fall as early as Friday. Chuuk on the other hand has fallen to just below 9 foot surf along west and north facing reefs and is expected to continue to fall for the next several days. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...Coastal Flood Warning until 5 PM ChST this afternoon for GUZ001. High Rip Current Risk through Saturday afternoon for GUZ001. High Surf Warning until 5 PM ChST Friday for GUZ001. Wind Advisory until 5 AM ChST Friday for GUZ001. Coastal Flood Advisory until 5 PM ChST Saturday for GUZ001. High Surf Advisory from 5 PM Friday to 5 PM ChST Saturday for GUZ001. MP...Coastal Flood Warning until 5 PM ChST this afternoon for MPZ001. High Rip Current Risk through Saturday afternoon for MPZ001>003. High Surf Warning until 5 PM ChST Friday for MPZ001>003. Coastal Flood Advisory until 5 PM ChST Saturday for MPZ001. High Surf Advisory from 5 PM Friday to 5 PM ChST Saturday for MPZ001>003. Typhoon Warning for MPZ001>003. Coastal Flood Warning until noon ChST Friday for MPZ002-003. Coastal Flood Advisory from noon Friday to 5 PM ChST Saturday for MPZ002-003. Marianas Waters...Typhoon Warning for PMZ152>154. Small Craft Advisory until 5 PM ChST Saturday for PMZ151. Hazardous Seas Warning until 5 PM ChST Friday for PMZ151. && $$ Marianas: Kleeschulte East/West Micronesia: Bowsher Tropical: DeCou