Pohnpei Vol.13, No.4

Pohnpei State: Rainfall was generally below normal throughout all of Pohnpei State during the 3rd Quarter of 2007. On Pohnpei Island , the 2007 3rd Quarter totals were approximately 35 inches at all recording locations around the coastal perimeter of the island. The 36.91 inches at the WSO Kolonia fell short of the normal 50.98 experienced there during this time period. All of the outer atolls Pohnpei State also recorded approximately 35 inches of rain in the 3rd Quarter of 2007. For Nukuoro, Pingelap, and Mwoakilloa, these values were probably below normal (no official normals have been established for these sites), however, at Kapingamarangi, the 3rd Quarter 2007 total of 36.21 inches was well above normal (161%) largely due to a very wet July. Kapingamarangi has been wetter than normal for a long time, and continued to be very wet through its 2007 dry season. The current shift to La Niña conditions may finally force an end to the long period of above normal rainfall at Kapingamarangi, and for this reason it may be prudent for residents of this atoll to begin voluntary conservation measures of drinking water.

Predicted rainfall refers to forecast made in 2nd Quarter 2007 PEAC Newsletter.
* Long term normal is not established for these sites

Climate Outlook: Because of weather patterns associated with La Niña, the risk of a damaging tropical storm or typhoon at any island in Pohnpei State is very unlikely during the remainder of 2007 through the summer of 2008. The very early stages of some developing tropical cyclones may bring some episodes of heavy rain to Pohnpei in the next three months, but these systems should not become tropical storms or typhoons until they are well away from Pohnpei.

Based on the continuation of La Niña conditions for the next few months, rainfall around Pohnpei State should be near normal for the next 3 months, and then becoming wetter than normal in the spring (late March through early June) when the trade-wind trough becomes established in the region. The only exception to the expectation of overall wetter-than-normal rainfall in Pohnpei State will be at Kapingamarangi, where La Niña-related weather patterns may cause conditions to be drier than normal over the next few months.

Forecast rainfall for Pohnpei State from November 2007 through October 2008 is as follows:

Pacific ENSO Update

4th Quarter, 2007 Vol. 13 No. 4