Guam, Northern Mariana Islands Special Weather Statement | Effective 04/09/2026 18:29

Tropical Storm Sinlaku (04W) continues to organize north-northwest of Chuuk. This system will continue to move very slowly in a west to northwest direction for another 24 to 36 hours, before increasing forward speed as it strengthens. The current forecasts have the system strengthening into a typhoon or stronger, and approaching the Marianas. The potential track takes TS Sinlaku into the Marianas, near Guam. However, models continue to show a slight spread where TS Sinlaku's track could shift slightly north or south, though these ranges are narrowing and will continue to narrow over the next 12-24 hours. A breezy, but relatively dry trade-wind pattern is in place over the Marianas, but as Tropical Storm Sinlaku closes in, conditions will deteriorate sometime around late Sunday. The Marianas should make preparations for the potential for Tropical Storm or Typhoon-Force winds, with the most likely time of Tropical Storm-Forced winds around Monday. For the far northern Mariana Islands, breezy and choppy sea conditions are expected late this weekend and inter early next week, with potential for Tropical Storm-Force winds around Tuesday. Locally heavy rainfall is likely with Tropical Storm Sinlaku. Models show the potential 10 to 15 inches near the center of TS Sinlaku, but if any of the islands will see this rainfall will depend on exact track of TS Sinlaku. Ensemble guidance shows broader potential for 5-8 inches across Guam, and 3-5 inches for Rota, Tinian, and Saipan, but higher rainfall totals may shift depending if the track of Tropical Storm Sinlaku shifts southward or northward. of rainfall to develop for Guam early next week