A large and disorganized tropical disturbance is located east- northeast of the Marianas and is producing isolated to numerous, locally heavy showers and isolated thunderstorms. This system is expected to move through or just north of the Marianas over the next two days. A col has developed over the Marianas between this disturbance and another system to the northwest. This will keep winds fairly light through Wednesday. The unstable airmass and high precipitable water values may allow for heavy showers to develop and stall over the islands, creating a potential flooding risk. However, high uncertainty remains in where the highest rainfall amounts will occur and there may be breaks between instances of heavy rainfall.
By Thursday, a monsoonal tail may develop and push north into the Marianas, bringing more locally heavy showers and isolated thunderstorms, with the highest chances remaining over Guam and Rota. Sustained winds of 15 to 25 mph will be possible with gusts of 30 mph.