Pacific ENSO Update

2nd Quarter, 2005 Vol. 11 No. 2

FSM Flag Federated States of Micronesia

Yap State:  The rainfall at most recording locations in Yap Island was below normal, mostly a result of a very dry February. 1st Quarter totals were near normal at the southern Woleai Atoll (101% of normal) and slightly less than normal on Yap Island (78% of normal) and at Ulithi (78% of normal).

Yap State Rainfall Summary 1st Quarter 2005
Station   Jan. Feb. Mar. Total
Yap WSO Rainfall (inches) 6.94 2.04 5.97 14.95
% of Normal 95% 34% 100% 78%
Dugor* Rainfall (inches) 6.80 2.00 6.94 15.74
Gilman* Rainfall (inches) 8.14 1.29 3.12 12.55
Luweech* Rainfall (inches) 7.30 2.01 6.04 15.35
Maap* Rainfall (inches) 4.58 1.37 5.33 11.28
North Fanif* Rainfall (inches) 4.29 1.42 4.31 10.02
Tamil* Rainfall (inches) 7.99 1.42 4.48 13.39
Ulithi Rainfall (inches) 12.68 1.92 4.81 19.41
% of Normal 204% 38% 95% 78%
Woleai Rainfall (inches) 17.75 2.16 6.93 26.84
% of Normal 166% 29% 83% 101%
* Long term normal is not established for these sites

Climate Outlook:

The tropical cyclone threat at Yap during 2005 should be near normal. So far this year, two tropical cyclones — Roke and Sonca — passed north of Yap without incident. During an average year approximately two to three tropical cyclones pass close enough to Yap (and/or its outer islands) to cause gales, but a direct strike by a typhoon at any Yap location does not occur. 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 further south at Woleai. While we expect no direct strikes by a typhoon of any island or atoll of Yap State during 2005, residents should always be prepared for the possibility.

Predicted rainfall for Yap State from Jun 2005 through May 2006 is as follows:

Inclusive Period
% of Long-Term Average
Yap and Ulithi
Woleai
Jun – Jul 2005 (Onset of Rainy Season)
90%
100%
Aug – Oct 2005 (Heart of Rainy Season)
100%
110%
Nov – Dec 2005 (Onset of next Dry Season)
95%
100%
Jan 2006 – May 2006 (Next Dry Season)
90% 90%
source: UOG-WERI