Federated States of Micronesia

Yap State: During the 1st Quarter of 2008, the rainfall throughout most of Yap State was below normal with amounts ranging from half to two-thirds of the normal 3-month total. Most locations on Yap Island received approximately 12 to 16 inches of rain with a low of 11.49 inches at Rumung and a high of 15.58 inches at Luweech. No month during the 1st Quarter of 2008 had more than 10 inches of rain at any Yap recording site, and all locations had at least one month with total rainfall below 5 inches. At Ulithi, all three months of the 1st Quarter of 2008 had totals below 5 inches, and the 3-month total of 10.75 inches was 66% of normal. Woleai had been dry for several months, and continued its string of very dry months through January and February 2008. Finally, during March 2008, abundant rains returned to Woleai with 8.50 inches reported. Despite the relative dryness, there were no problems with water supplies reported at Yap Island and its outer atolls.

Yap State Rainfall Summary 1st Quarter 2008

Climate Outlook: During mid-April, the tropical disturbance that later became Typhoon Neoguri in the South China Sea passed through Yap State providing some welcome rainfall. This La Niña pattern of tropical disturbances episodically passing through Yap State and the Republic of Palau should continue through June until the monsoon trough (and subsequent typhoon formation) shifts northward. The tropical cyclone threat at Yap for the remainder of 2008 should be near normal. The greatest risk will occur in May and June, and then again in the late fall. There is roughly a 50% chance that one of these disturbances passing westward through Yap State in May or June will become a tropical storm within the waters of Yap State; a full-fledged typhoon, however, is unlikely. Any tropical storm forming near Yap would bring welcome rains and possibly a day of near-gale force winds to any one of the islands or its territorial waters. There is a secondary risk of a damaging tropical cyclone in Yap State or its northern atolls in the fall of 2008. The level of threat (5 to 10% chance) of a direct strike by a typhoon at Yap Island and at Ulithi, however, is still relatively low, and is roughly one-half to two-thirds that of Guam and the CNMI. The threat is even less to the south at Woleai. While we expect no direct strikes by a typhoon of any island or atoll of Yap State during the rest of the calendar year of 2008, residents should always be prepared for the possibility.

Because of La Niña weather patterns, rainfall should recover from its present dryness within the next few weeks to be slightly above normal throughout Yap State for the remainder of 2008.

Predicted rainfall for Yap State from May 2008 through April 2009 is as follows:

source: UOG-WERI