Tropical depression forms

A tropical depression with sustained winds of 30 miles per hour and moving west at 6mph has formed near the Northern Islands, according to the National Weather Service in Tiyan, Guam, yesterday.

The bad weather has resulted in the issuance of multiple advisories, warning motorists against flash floods and mariners to expect rough seas.

The tropical depression is also expected to produce large monsoonal and wind waves that will create hazardous surf of 12 to 14 feet along west, south and southeast facing reefs.

The public is being warned to stay away from reefs and shorelines, and inter-island travel by boat should be avoided through Wednesday night.

As of 12:30pm yesterday, Tropical Depression 11W was about 125 miles west of Alamagan, 130 miles west-southwest of Pagan, and 150 miles southwest of Agrihan. It is expected to move in a northwest to north-northwest direction and pass west of the northern CNMI over the next couple of days.

Mariners are especially vulnerable from the rough seas, with NWS warning of heavy showers and strong gusts over the waters of Rota.

At 1:15 pm yesterday, NWS reported that doppler radar indicated a line of heavy showers moving northeast at 30 knots and located about 32nm west of the Ritidian Buoy in Guam. These showers are capable of producing wind gusts of around 30 knots.

Tropical Depression 11W is not expected to affect the northern CNMI directly but will enhance the ongoing monsoon surge. Expect south-southwest to south-southeast winds of 30 to 40 mph with gusts of 50 to 55 mph. Scattered to numerous showers and isolated thunderstorms will also continue through today, Wednesday evening, with 2 to 4 inches of rain possible.

Acting governor Arnold I. Palacios is advising residents on Alamagan, Pagan, and Agrihan to monitor the situation closely and maintain necessary precautionary measures for possible gusty winds and heavy rain and to also stay informed on the latest statements or advisories.

Mariners and the public are also advised to expect gusty winds of around 30 knots accompanying the monsoon. Higher waves will result in poor visibility over the water and occasional lightning strikes are also possible. NWS said boaters should seek safe harbor immediately until the rough water passes.

To this end, NWS issued small craft advisory in effect through Friday night. The small craft advisory means that wind speeds of 22 to 33 knots and seas 10 feet or higher are expected to produce wave conditions hazardous to small craft.

NWS also issued an urban and small stream flood advisory yesterday due to the monsoon brought about by Tropical Depression 11W.

The advisory noted that moderate to brief heavy rain was expected yesterday and likely would produce 1 to 2 inches of rainfall, resulting in street flooding and brief flooding of streams and low-lying areas.

Motorists were advised to turn around to avoid drowning when encountering flooded road as most flood deaths occur in vehicles.

The advisory also said that excessive runoff from heavy rainfall will cause flooding of small creeks and streams, urban areas, and streets as well as other low-lying spots.

Future weather advisories will be available through media sources and NOAA weather radio broadcast on 162.5 megahertz, or call CNMI EOC State Warning Point at 237-8000 or 664-8000, and for the Northern Islands to contact EOC State Warning Point at high frequency single side band radio on frequency 5.205.0.