* WHAT...West winds 15 to 25 kt and seas 8 to 13 feet expected. Gusts to 35 kt possible. * WHERE...Guam Coastal Waters. * WHEN...From 6 AM Sunday to 6 AM ChST Friday. * IMPACTS...Conditions will be hazardous to small craft. * ADDITIONAL DETAILS....The Gale Watch has been upgraded to a Small Craft Advisory. A monsoon pattern, south to southwest of distant Typhoon Dolphin will build over the Marianas over the coming days. Strong westerlies will develop starting Sunday morning across southern Guam coastal waters, generating choppy seas hazardous to small craft, which will then spread northward across the CNMI through early next week. Winds will peak early next week, with a possibility of frequent gale-force gusts Monday through Tuesday, which would necessitate a Gale Warning at that time. In addition to the stronger winds and wind waves, distant Typhoon Dolphin is generating a long-period easterly swell that is beginning to move through the Marianas, which will gradually shift north early next week, then northwest. Meanwhile, the developing monsoon pattern will lead to increasing southwesterly swell over the coming days. These increasing swells and wind waves will build combined seas to exceed 10 feet across the coastal waters, maintaining hazardous sea conditions for much of the coming week. Inexperienced mariners, especially those operating smaller vessels, should avoid boating in hazardous conditions.