Pacific ENSO Update

4th Quarter, 2007 Vol. 13 No. 4

PEAC'S TROPICAL CYCLONE OUTLOOK

The PEAC outlook for tropical cyclones in the western North Pacific basin made during early 2007 called for below-normal activity in every category (e.g., number of typhoons and number of intense typhoons). Through mid-October 2007, this has held true, with one exception: there have been four super typhoons (those typhoons with peak intensities of 130 kt 1-minute sustained wind or higher). This is the normal annual number of such high-intensity typhoons. The PEAC forecast also called for typhoon activity to be displaced to the west because of La Niña. This has been the case throughout the year. No typhoons have made a direct strike anywhere in Micronesia during 2007.

The PEAC TC outlook for the rest of 2007 is for activity to recover to near normal (for the time of year) in the western half of Micronesia (Palau, Yap, Guam and the CNMI), and remain below normal in the eastern half of Micronesia (all island groups from Chuuk eastward). The coming cyclone season in the South Pacific should be near normal for areas west of the International Date Line, and near or below normal to the east of the Date Line. Thus, the risk of a damaging cyclone in American Samoa should be less than normal.