severe · immediate · likely
Tropical Storm Warning
Tinian; Saipan
Issued Oct 2, 2:54 PM GMT+10 by NWS Tiyan GU · in effect until Oct 2, 9:00 PM GMT+10
What to do
Stay indoors during heavy rain and tropical storm-force wind conditions associated with Tropical Storm Choi-wan (26W). Heed the advice of your local emergency managers and officials, and continue to monitor forecasts by the National Weather Service office in Tiyan, Guam. Remain in sturdy shelter until the all- clear is given. Preparations for Tropical Storm Choi-wan should be complete, or rapidly rushed to completion. Take small loose object indoors. Remain in suitable shelter, such as a cave or sturdy concrete structure. Shelter in place until the all- clear is given. .WIND INFORMATION... North to northeast winds of 25 to 35 mph will turn toward the southeast and increase today as Choi-wan pivots north across the northern CNMI and strengthens, potentially becoming a typhoon later today to the west of Alamagan and Pagan. Tropical storm force winds of 39 to 50 mph look to continue through Sunday. Depending on the track and intensity, winds may increase to strong tropical storm- force of 58 to 65 mph early Saturday morning. Typhoon force winds greater than 74 mph look to remain possible during closest passage. .COASTAL INUNDATION AND SURF INFORMATION... Hazardous surf of 8 to 12 feet along east-facing and south facing reefs are expected to continue, to then spread along north and west- facing reefs as the center moves north-northeast parallel to the northern CNMI tonight through Saturday night, increasing by several feet during this time. As Choi-wan continues to strengthen, surf will continue to increase, likely becoming dangerous by early next week. Significant coastal erosion and some coastal inundation is expected during Choi- wan's passage. .OTHER STORM EFFECTS... Periods of rain, widespread heavy showers and scattered thunderstorms are expected through tonight, which is expected to produce rainfall totals of 8 to 14 inches by early Monday morning, with up to 20 inches of rainfall possible near the center of the system.
Official text
Tropical Storm Warning issued October 2 at 2:54PM ChST by NWS Tiyan GU
...TROPICAL STORM CHOI-WAN SLOWLY MOVING WEST-NORTHWEST AND INCHING CLOSER TO ALAMAGAN... .NEW INFORMATION... None. .AREAS AFFECTED... This local statement provides information and recommended actions for people on Saipan, Tinian, Agrihan, Pagan and Alamagan in the Commonwealth of the Northern Marianas. .WATCHES/WARNINGS... A Tropical Storm Warning remains in effect for Saipan, Tinian and their adjacent coastal waters, as well as Alamagan, Pagan, and Agrihan in the CNMI. A Typhoon Watch remains in effect for Alamagan, Pagan, and Agrihan in the CNMI. A Typhoon Watch means that typhoon conditions, including winds of 74 mph or more, are possible within 48 hours. A Tropical Storm Warning means that tropical storm conditions are expected within 24 hours. A Flood Watch remains in effect for Tinian and Saipan. Please listen closely for any Flash Flood Warnings that might be in effect 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 Storm Choi-wan (26W) was located near latitude 17.2N and longitude 144.7E. This was about 260 miles north of Guam. Choi-wan is moving west-northwest at 5 mph, slowing down before pivoting toward the north-northeast with little change in forward speed through Saturday as it moves up the Far Northern Marianas. Maximum sustained winds have increased to 65 mph. Choi-wan is forecast to intensify through tonight, possibly becoming a typhoon later today. Tropical storm force winds continue to extend outward from the center up to 125 miles, however, the wind field is expected to expand farther south over the next few hours. .SITUATION OVERVIEW... Tropical Storm Choi-wan continues to move away from Anatahan and is inching closer to Alamagan, pivoting slowly to the north-northeast through Saturday. During this time, the wind field will continue to expand, exposing Tinian and Saipan in Tropical Storm condition a little longer, now through Saturday. While showers have tapered a little earlier in the day, rainbands that pummeled Guam and Rota earlier this morning are now being pulled toward Tinian and Saipan, with more intense showers and thunderstorms expected tonight.