Tropical Storm Warning issued October 1 at 9:10AM ChST by NWS Tiyan

...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.