American Samoa:  American Samoa finished the heart of its 2008-09 rainy season with slightly below average rainfall totals, with 79% of normal rainfall at Pago Pago International Airport (28.95 inches total) and 68% of normal at Aasufou (36.14 inches total). February was particularly dry, with both sites recording only 60% of normal rainfall for the month. The 2008-09 hurricane season in the American Samoa region passed without incident, as persistent easterly wind anomalies associated with La Niña kept tropical cyclones away from American Samoa and prevented the Australian Northwest Monsoon from making any major incursions across the region.

American Samoa Rainfall Summary 1st Quarter 2009

Climate Outlook: Computer forecasts and a consensus of outlooks from several regional meteorological centers show a pattern of wetter than normal conditions to the south and west of American Samoa, and drier than normal conditions to the north and east. Thus, American Samoa sits right along the axis between anticipated wetter-than-normal conditions and drier-thannormal conditions. The PEAC Center anticipates that the rainfall in American Samoa will be near normal for the next three months, and remain near normal until the next rainy season. The next rainy season of 2009-10 should be wetter than the one just finished given the relaxation of La Niña and the progression to ENSO-neutral conditions.

The tropical cyclone season of the Southern Hemisphere for 2008-09 is coming to a close. It is unlikely that any tropical cyclone will impact the islands of American Samoa or its coastal waters in the next three months. Beginning in late November 2009, the next cyclone season of 2009-10 may be more active than the one just completed, which was very quiet.

Forecast rainfall for American Samoa from April 2009 through March 2010 is as follows:

Forecast rainfall quantities represent BEST ESTIMATES given the probabalistic forecast for each particular season and station.

source: UOG-WERI