WTPQ81 PGUM 240448 HLSPQ1 URGENT - IMMEDIATE BROADCAST REQUESTED Tropical Depression 12W Local Statement National Weather Service Tiyan GU 248 PM ChST Thu Jul 24 2025 ...A SLOWLY-INTENSIFYING TD 12W NOW WEST OF ROTA MOVING NORTHWEST... ...TD 12W COULD BECOME A TROPICAL STORM FRIDAY WEST OF ANATAHAN... .NEW INFORMATION... None. .AREAS AFFECTED... This local statement provides important information and recommended actions for people in the Commonwealth of the Northern Mariana Islands. .WATCHES/WARNINGS... A Tropical storm watch continues for Rota, Tinian, Saipan, Agrihan, Pagan, and Alamagan. Tropical storm conditions are possible Friday morning for Rota, Tinian and Saipan, depending on how quickly 12W intensifies once it has passed to the northwest of the islands. All persons in the watch areas should continue preparations for low- end tropical storm conditions as indicated by your local forecast and additional details, found below, for your island. A Flood Watch remains in effect for Rota, Tinian and Saipan. Please listen closely for any Flood Warnings that might be issued for your area. Please check the latest public and marine forecasts for detailed information about additional hazards. .STORM INFORMATION... At 1 PM ChST...the center of Tropical Depression 12W was located near latitude 14.1N...longitude 143.6E. This was about 90 miles west-northwest of Guam and 110 miles west of Rota. Storm motion was northwest, 320 degrees, at 9 mph. Storm intensity has increased to 35 mph. .SITUATION OVERVIEW... Tropical Depression 12W has made a slight turn toward the northwest and is moving at 9 mph. Currently west of Rota, it will continue to move along a northerly course to keep west of the Marianas island chain. The bulk of rainfall and strong winds remains in the eastern and southern periphery and will persist over the islands for several days, despite TD 12W having made its closest point of approach (CPA) to Rota and soon for Tinian and Saipan. Again, worsening conditions including strong winds, gusts, and heavy rains will be felt after CPA. Showers, occasionally heavy, and increasing south to southwest winds and strong gusts will spread over the southern CNMI islands today and onward to the far northern islands Friday and Saturday. A Tropical Storm Watch is in effect based on the potential for 12W to intensify to a tropical storm Friday as it heads northward, staying west of the CNMI. .PRECAUTIONARY/PREPAREDNESS ACTIONS... For those under a watch, continue preparations for your home or business according to your typhoon disaster plan. Listen for possible warnings and be ready to evacuate if necessary if your location is vulnerable to tropical storm conditions. Heed the advice of local officials and comply with any orders that are issued. For interests at ports, docks, and marinas, it is recommended that you perform the prescribed preparations according to your emergency operations plan for tropical cyclones. If you live on a boat, safely secure your craft and make plans to leave it for adequate land-based shelter. Listen for possible warnings. Regarding the coastal waters under a watch, small craft should return to port or seek safe harbor. Closely monitor NOAA weather radio or other local news outlets for official storm information. Listen for possible changes to the forecast. For additional precautionary and preparedness information, please refer to the detailed recommendations relative to your location as further described by your local emergency management office. && .NEXT UPDATE... The next local statement will be issued by the National Weather Service in Tiyan around 9 PM...or sooner if conditions warrant. MPZ001>003-241300- /O.CON.PGUM.TR.A.4012.000000T0000Z-000000T0000Z/ Rota-Tinian-Saipan- 248 PM ChST Thu Jul 24 2025 ...TROPICAL STORM WATCH REMAINS IN EFFECT... .PRECAUTIONARY/PREPAREDNESS ACTIONS... Preparations should be made as soon as possible before conditions deteriorate and should be focused on the potential for tropical storm force winds of 39 mph or greater. Keep informed while listening for possible warnings. Secure loose outdoor objects which can be blown around. Strongly consider evacuating if you live in a metal roof or container home, and do so if ordered by local officials. && .WIND INFORMATION... As Tropical Depression 12W continues to intensify, the threat for sustained tropical storm force winds will increase. Current forecast track and intensity guidance suggests tropical storm winds of 39 mph and greater could briefly develop near the islands and over the western coastal waters Friday even while 12W moves farther away. This, and the prolonged strong wind event post-12W, will be due to the strong southwest monsoon following behind 12W. Moving forward starting tonight, south winds will continue to increase, becoming increasingly gusty, then will shift to southwest Friday through Saturday, approaching tropical storm force with winds reaching 35 mph with gusts to around 45 mph. Due to the ensuing southwest monsoon in the wake of 12W, winds will be slow to subside, possibly not until sometime Saturday. .COASTAL INUNDATION AND SURF INFORMATION... Surf will rise along east and south facing reefs today, approaching hazardous levels of 9 to 12 ft. 12W continues northward west of the islands, larger surf will focus along south and west facing reefs, reaching hazardous levels of 10 to 14 ft. Surf could increase another couple of feet, depending on 12W's motion and the overall wind field. Hazardous surf will maintain a high risk of rip currents, so folks should stay out of the waters. Based on current wind and surf projections, coastal inundation could reach up to around 1 ft, focused more around times of high tide. Elevated surf will continue through the weekend before eventually subsiding. .OTHER STORM EFFECTS... A Flood Watch is in effect for all 3 islands. Heavy rains will spread northward today and tonight and will continue,, even as 12W later moves away from the islands, due to the onset of a very wet southwest monsoon flow. Currently, 8 to 12 inches of rain is possible through Saturday night, and periods of very heavy rainfall may result in localized flooding. Additionally, the the risk of mudslides could increase with a prolonged multi-day heavy rain pattern. ...AGRIHAN...PAGAN AND ALAMAGAN... ...TROPICAL STORM WATCH REMAINS IN EFFECT... .PRECAUTIONARY/PREPAREDNESS ACTIONS... Residents should keep aware of the latest trends regarding TD 12W. The latest track depicts a passage to the west of the islands with tropical storm conditions possible by midday Friday. Preparations should focus on securing loose items with anticipation for southerly tropical storm winds of at least 39 mph. && .WIND INFORMATION... The latest forecast track shows TD 12W moving generally northward to the west of the islands Friday through Sunday. This will cause southeast winds to shift to south and increase tonight and Friday, becoming increasingly gusty as more widespread showers arrive Friday. Latest forecast projections show south tropical storm winds of 35 to 40 mph arriving midday Friday and gradually shifting to southwest Saturday, before diminishing sometime Sunday. Even then, a strong southwest monsoon pattern will prolong windy conditions through Sunday night. .COASTAL INUNDATION AND SURF INFORMATION... Surf will initially rise along south facing reefs Friday, then spread to west facing reefs Saturday, exceeding hazardous levels of 9 ft. Surf along these windward shores could approach dangerous levels of 15 ft Saturday and Sunday and remain at hazardous levels of 10 to 14 ft into early next week due to the persistent monsoon flow. Rip currents during this time will be strong and life threatening. Stay out of the water. Minor wind and wave-driven coastal inundation of 1 to 2 feet will be possible along windward shores, especially around times of high tide as surf reaches peak heights Saturday and Sunday. .OTHER STORM EFFECTS... Scattered showers will persist through tonight but will increase beginning around midday Friday, becoming locally heavy Saturday and Sunday as 12W passes to the west. Rainfall amounts of 8 to 12 inches are possible between Friday and Monday. Even after 12W begins to move away Sunday and Monday, a wet monsoon pattern will prolong showers across the islands. $$ W. Aydlett