American Samoa:  The 4th quarter of 2006 continued with wet conditions of an above-normal rainfall total of 47.47 inches (137.3% of normal) for Pago Pago International Airport and 63.74 inches (184% of normal) for Aasufou. The most rainfall received for both stations during this quarter was in December, where WSO Pago Pago received 21.63 inches of rainfall (162% of normal) and 27.56 inches of rainfall for Aasufou (206% of normal).

Climate Outlook: American Samoa is now fully into its rainy season, although it has been very wet here for several months. Earlier computer forecasts (as well as the official PEAC forecasts) had indicated that rainfall in American Samoa was likely to remain above normal as the island group entered its rainy season. As ENSO conditions continue with a weak to moderate intensity, American Samoa will continue to experience above-normal rainfall. At the time of this publication (late January), the Pago Pago Weather Service Office wais already experiencing an above-normal rainfall for the month of January due to the establishment of the monsoonal trough that extends southeasterly from Australia reaching as far as the Southern Cooks. The forecast of wet conditions to continue through April 2007 in American Samoa is based on persistance, as well as the slow demise of a weak-to-moderate El Niño.

The threat of a damaging tropical cyclone in any of the islands of American Samoa still high for the remainder of the Hurricane Season (until April 2007) as weak El Nino conditions continue. Thus, it is prudent for American Samoa to stay prepared for any developing low pressure systems. Gale-force winds related to the close passage of a tropical cyclone or the penetration of a very active northwest monsoon into the region should occur at least once through April, and could possibly occur up to three or four times. During January 2007, two cyclones (Zita and Arthur) formed in the South Pacific east of the International Date Line. No reports of damage were received from American Samoa in association with these two cyclones. Normal cyclone activity for an entire rainy season would see one or two named tropical cyclones passing close enough to the south of American Samoa to produce episodes of heavy rainfall and gale-force northwesterly winds.

Predicted rainfall for American Samoa from February 2007 through January 2008 is as follows:

source: UOG-WERI