7/22/2025 6:07:00 PM until 7/23/2025 6:00:00 PM

ESFGUM This Hydrologic Outlook is for the Guam, Rota, Tinian and Saipan. A tropical disturbance, Joint Typhoon Warning Center's Invest 98W, is centered southeast of Guam near 10.7N 151.1E. This system remains highly disorganized, but is expected to move toward the Marianas over the next day or two as it consolidates. 98W is expected to bring heavy rainfall to the Marianas Thursday evening through Sunday with an expected peak on Friday through Saturday. Models differ on location and strength of 98W as it moves near the Marianas, however, there is strong agreement that heavy rainfall is likely as early as Thursday, continuing through the weekend. There is a potential for Guam and the CNMI to see rainfall amounts of 5 to 10 inches by Sunday, though locally heavier amounts are possible. This rainfall is expected to produce minor flooding across the islands, with flash flooding possible in areas of heavier rainfall, especially over southern Guam. Residents on the Marianas need to closely monitor this developing situation as watches, advisories and warnings could be issued later. If living near streams and rivers, prepare to move items away from stream and river banks. Make sure storm drains nearby are not clogged, especially if living in low-lying areas.