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Tropical Storm Warning
ActiveTinian; Saipan
Status
In Progress
Started about 1 hour ago
Ends
Issued
Severity
Severe
Urgency
Immediate
Certainty
Likely
Details
...TYPHOON WARNING NOW IN EFFECT FOR AGRIHAN AND PAGAN IN THE CNMI...
...TROPICAL STORM CHOI-WAN NEARLY STATIONARY AS IT CONTINUES WEST- NORTHWEST AWAY FROM ANATAHAN...
.NEW INFORMATION... A Typhoon Warning is now in effect for Agrihan and Pagan in the CNMI.
.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 Typhoon Warning is now in effect for Agrihan and Pagan in the CNMI.
A Tropical Storm Warning remains in effect for Tinian, Saipan, and Alamagan in the CNMI.
A Typhoon Watch remains in effect for Alamagan in the CNMI.
A Typhoon Warning means that typhoon conditions, including winds of 74 mph or more are expected, with tropical storm force winds beginning within 24 hours. A Tropical Storm Warning means that tropical storm conditions, including winds of 39 to 73 mph, are expected within 24 hours. A Typhoon Watch means that typhoon conditions are possible 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 8 PM ChST, the center of Tropical Storm Choi-wan (26W) was located near latitude 17.1N, longitude 144.7E. This was about 80 miles northwest of Alamagan, 100 miles southwest of Pagan, 130 miles south-southwest of Agrihan, and 250 miles north of Guam. Storm motion was west-northwest, 300 degrees, at 2 mph. Storm intensity was 70 mph.
.SITUATION OVERVIEW... Tropical Storm Choi-wan is very slowly pivoting to the north as it moves away from Anatahan, and is expected to continue to intensify through tonight and Saturday as it turns north-northeast toward Agrihan and Pagan, likely becoming a typhoon later tonight. The latest forecast shows Choi-wan as a Category 1 typhoon as it passes just west of Pagan and moves near or over Agrihan, sometime Saturday afternoon, and a Typhoon Warning has been issued for Agrihan and Pagan. During this time, the wind field will continue to expand slightly, exposing Tinian and Saipan to tropical storm conditions a little longer, possibly into late Saturday night. While showers have tapered a little earlier in the day, the intense rainbands that pummeled Guam and Rota earlier this morning are now being pulled toward Tinian and Saipan, with additional heavy showers and thunderstorms expected tonight.
Instructions
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. 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 tonight as Choi-wan slowly pivots north- northeast toward the northern CNMI and strengthens, potentially becoming a typhoon later tonight to the west of Alamagan. Tropical storm force winds of 39 to 50 mph look to continue through Sunday. Winds are expected to increase to strong tropical storm-force of 58 to 65 mph for Alamagan and Pagan late tonight, then sometime Saturday morning for Agrihan. Typhoon force winds greater than 74 mph are expected for Pagan and Agrihan during time of closest passage on Saturday in the late morning to early afternoon for Pagan, and Saturday afternoon to evening for Agrihan. Typhoon conditions remain possible for Alamagan, but are not expected at this time.
.COASTAL INUNDATION AND SURF INFORMATION... Hazardous surf of 8 to 12 feet along east 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.
Data from the National Weather Service
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