NWS Tiyan GUTR.W 4026October 1, 2026
Tropical Storm Warning: Tinian and Saipan, MP
The National Weather Service office in Tiyan issued a tropical storm warning for Tinian and Saipan in Northern Mariana Islands, which was in force until 3:00 p.m. local time on October 1.
ExpiredWarning
Issued9:10 a.m. UTC+10, October 1, 2026
In force9:10 a.m. UTC+10, October 1, 2026
Expired3:00 p.m. UTC+10, October 1, 2026
In force for 5.8 hours; it has expired. The agency may have replaced it with a new notice.
The notice
- Issued by
- National Weather Service, Tiyan GU
- Area
- Tinian and Saipan
- State
- Northern Mariana Islands
- Level
- Warning
- Issued
- 9:10 a.m. UTC+10, October 1, 2026
- Expires
- 3:00 p.m. UTC+10, October 1, 2026
- CAP severity, certainty, urgency
- Severe, Likely, Immediate
- VTEC event
- PGUM TR.W 4026
- Official source
- National Weather Service: the notice at its source
Source: National Weather Service: the notice at its source. AreaZine rebuilds this page from the agency's record; the agency's page is the one to act on. A U.S. Government work, in the public domain.
The notice as issued
...NEWLY NAMED TROPICAL STORM CHOI-WAN CONTINUES MOVING WEST- NORTHWEST TOWARDS THE FAR NORTHERN MARIANAS... .NEW INFORMATION... Tropical Storm 26W is now named Choi-wan. A Tropical Storm Warning is now in effect for Tinian and Saipan and their adjacent waters in the CNMI. .AREAS AFFECTED... This local statement provides important information and recommended actions for people in Guam and the Northern Marianas. .WATCHES/WARNINGS... A Tropical Storm Warning is now in effect for Tinian and Saipan in the CNMI. A Tropical Storm Warning remains in effect for Alamagan and Pagan in the CNMI. A Typhoon Watch remains in effect for Alamagan and Pagan in the CNMI. A Tropical Storm Watch remains in effect for Agrihan in the CNMI. A Tropical Storm Watch means that tropical storm conditions, including winds of 39 to 73 mph, are possible within 48 hours. 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 Flash 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. All persons in the Watch areas should review their preparedness plan and begin to take actions to prepare for conditions as indicated by your local forecast and additional details, below, for your island. .STORM INFORMATION... At 7 AM ChST, the center of Tropical Storm Choi-wan (26W) was located near latitude 16.3N, longitude 149.5E. This was about 370 miles east-northeast of Guam. Storm motion was west-northwest, 285 degrees, at 9 mph. Storm intensity was 40 mph. .SITUATION OVERVIEW... Tropical Storm Choi-wan (26W) has increased in forward speed once again, with a slight expansion in the tropical storm-force wind field expected to the west and southwest, keeping Tinian and Saipan well within said wind field. As such, the Tropical Storm Watch was upgraded to Tropical Storm Warning for Tinian, Saipan and their adjacent waters. Timing of further intensification and storm trek remains largely unchanged. Choi-wan will continue west through tonight, making a turn to the northwest Friday morning as it begins to approach Alamagan from the south and intensify into a typhoon, turning sharply northward, to then move north-northeastward late Friday night. This forecasted passage over Alamagan and Pagan is still expected to prolong the duration of damaging winds across the northern islands, likely leading to a lengthy period of time of damaging to destructive tropical storm conditions beginning this evening and continuing into Sunday afternoon. As Choi-wan is forecast to strengthen to a typhoon Friday morning as it approaches Alamagan, this would bring Alamagan and later Pagan, directly within the typhoon force winds Friday night through early Saturday morning. So, a Typhoon Watch and Tropical Storm Warning remain in effect for Alamagan and Pagan. It is too early to provide exact wind and surge forecast values for specific locations. A general concern should be for the possibility of at least damaging winds likely somewhere within the Northern Marianas.
What the agency told people 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 continues to monitor forecasts by the National Weather Service office in Tiyan, Guam. Remain in sturdy shelter until the all-clear is given. ...WIND INFORMATION... Breezy northwesterlies today will quickly increase toward the late afternoon, with tropical storm force winds of 35 to 45 mph with gusts to 60 mph expected beginning tonight, lasting through at least Saturday as Tropical Storm Choi-Wan (26W) stalls slightly on approach to the Far Northern Marianas. This is expected to expose Tinian and Saipan to a longer period of potentially TS conditions. At this time, strong tropical storm-force winds look to remain north of Saipan and Tinian as said winds are expected to remain closely packed near the center of the system. ...COASTAL INUNDATION AND SURF INFORMATION... Surf will initially build to 8 to 11 feet along north-facing reefs by tonight, then quickly spread to west-facing reefs as the center of Choi-wan crosses the far northern CNMI and exposes a western fetch by early Friday morning. Surf will continue to increase along all reefs as Choi-wan continues to strengthen. Coastal inundation of 1 to 2 feet, as well as significant coastal erosion, will be possible along all reefs. ...OTHER STORM EFFECTS... Periods of rain, widespread heavy showers and scattered thunderstorms could produce rainfall totals of 5 to 8 inches by early Monday morning, with locally heavier amounts possible. So, a Flash Flood Watch is still expected to be in effect beginning late this evening, lasting through at least Sunday night. Additionally, a monsoon surge south of TS Choi-wan will maintain wet conditions across Saipan and Tinian into next week. Take small loose object indoors. Identify suitable shelter. Stock up a few days worth of food and water. If no concrete shelter is available, look for a cave or something similar. Take action to protect food crops or other possessions as appropriate. .WIND INFORMATION... Northerly winds of 10 to 15 mph will turn toward the northwest, then southwest and increase through Friday as 26W moves into the northern CNMI and strengthens, potentially becoming a typhoon Friday morning as it approaches Alamagan from the south. Tropical storm force winds of 39 to 50 mph may begin by Friday morning. 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 just east of Agrihan at this time. .COASTAL INUNDATION AND SURF INFORMATION... Surf will initially build to 8 to 11 feet along east-facing reefs through Friday morning, then spread along north and west-facing reefs as the center moves north-northeast through the northern CNMI Friday night through Saturday night, increasing by several feet during this time. As Choi-wan continues to strengthen, surf will continue to increase, likely becoming hazardous during the weekend and then 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 could 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. Take small loose object indoors. Identify suitable shelter. Stock up a few days worth of food and water. If no concrete shelter is available, look for a cave or something similar. Take action to protect food crops or other possessions as appropriate. .WIND INFORMATION... Northerly winds of 10 to 15 mph will turn toward the northwest, then southwest and increase through Friday as 26W moves into the northern CNMI and strengthens, potentially becoming a typhoon Friday morning as it approaches Alamagan from the south. Tropical storm force winds of 39 to 50 mph are expected to begin by early Friday morning. 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 may begin Friday evening as Choi-wan nears Alamagan. .COASTAL INUNDATION AND SURF INFORMATION... Surf will initially build to 8 to 11 feet along east-facing reefs through Friday morning, then spread along north and west-facing reefs as the center moves north-northeast through the northern CNMI Friday night through Saturday night, increasing by several feet during this time. As Choi-wan continues to strengthen, surf will continue to increase, likely becoming hazardous during the weekend and then 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 could produce rainfall totals of 10 to 16 inches by early Monday morning, with up to 20 inches of rainfall possible near the center of the system.
Source: National Weather Service: the notice at its source. The text is the agency's, unedited. A U.S. Government work, in the public domain.