NWS: Tropical Storm Warning Issued for Northern Mariana Islands of Alamagan, Pagan and Agrihan


Guam  – The National Weather Service MONDAY morning issued a Tropical Storm Warning for the northern CNMI Islands of  Alamagan, Pagan and Agrihan as Tropical Depression 20W approaches

20W is expected to pass across the northernmost CNMI islands Monday night.

There are no watches or warnings out for the southern islands of Guam, Rota or Saipan. 

READ the MONDAY 2 pm Special Weather Statement from the NWS HERE

However, the NWS warns that “the larger scale weather pattern associated with 20W will also affect Saipan, Tinian, Rota and Guam in the coming days. Periods of heavy rainfall are expected with 2 to 5 inches expected through Tuesday night. Southwest winds of 20 to 30 mph will develop by [Monday] tonight and continue at times for the next few days.” 

In addition, the National Weather Service warns that “Marine conditions will become hazardous so that a Small Craft Advisory and a High Surf Advisory may be need by tonight or Tuesday.”

As of  1 pm Monday morning, Tropical Depression 20W was centered near 17.3 degrees north latitude and 145.8 degrees east longitude.

That was:

* 275 miles northeast of  Guam

* 150 miles east-northeast of  Saipan

* 105 miles south of Agrihan

*  55 miles south of Pagan.

*  35 miles south south-west of Alamagan

Tropical Depression 20W is moving west-northwest at 13 mph. It is expected to become a Tropical Storm by Monday afternoon.

The National Weather Service advises residents of the Mariana Islands to remain alert and listen for the latest statements and forecasts from the National Weather Service and from local officials.