Federated States of Micronesia

Yap State:  Rainfall throughout Yap State during the first half of 2006 was slightly drier than normal at all reporting locations. On Yap Island, the 2nd Quarter rainfall totals at most stations was between 20 to 25 inches, with the WSO among the drier readings. For the whole first half of 2006, the total rainfall at most Yap Island stations was between 35 and 40 inches. On the outer islands of Yap State conditions were also slightly drier than normal for most months of the first half of 2006, and drier than normal for the 6-month total. In all of Yap State, the highest 2nd Quarter rainfall total, and the highest total for the first half of 2006, occurred at Woleai with 26.67 inches and 56.10, inches respectively. Woleai, at its more southern location, is normally wetter than Yap Island and Ulithi.

During the morning of the first day of July 2006, Tropical Storm Ewiniar (TC04W) passed approximately 40 miles to the southwest of Yap. Gale-force winds rose suddenly in the mid-morning, and persisted for a few hours. The peak wind at the WSO was 40 knots (1-minute sustained) with a gust to 53 knots. The minimum SLP was 995 mb. The 24-hour rainfall during the storm was 2.33 inches at the WSO. This relatively weak tropical storm caused a surprising amount of damage on Yap Island from sea inundation. The highest waves during the storm came at high tide, and there was substantial inundation that flooded coastal roads and damaged some homes. Actual sea heights were approximately half of those generated by Typhoon Sudal. A boat at mooring broke loose and damaged the official tide gage in Colonia.

Climate Outlook:

Nearly all of the western North Pacific tropical cyclones for the first half of 2006 affected Yap in their early stages of development. For the rest of 2006 the tropical cyclone threat for Yap should be near normal, with the greatest threat occurring in the months of September through December. In the latter half of 2006, approximately 2 or 3 tropical cyclones should pass close enough to Yap (and/or its outer islands) to cause gales. The threat of a direct strike by a typhoon at Yap Island and at Ulithi is roughly one-half to two-thirds that of Guam and the CNMI. The threat is even less at Woleai. While we expect no direct strikes by a typhoon of any island or atoll of Yap State during 2006, residents should always be prepared for the possibility.

Predicted rainfall for Yap State from July 2006 through Jun 2007 is as follows: