Pacific ENSO Update

3rd Quarter, 2007 Vol. 13 No. 3

FSM Flag Federated States of Micronesia

Kosrae State: Total rainfall during the first half of 2007 was slightly drier than normal at all Kosrae rain gage sites, ranging from 75% of normal at Utwa to 85% of normal at the airport. Although the 92.74 inches of rainfall at the airport during the first six months of 2007 was one of the highest readings for all of Micronesia, it was slightly below normal (85%) for this location, which has the wettest annual average rainfall of any official observing site in the region.

Kosrae Rainfall Summary 2nd Quarter 2007

Station  
Apr.
May
June
2nd Qtr
Predicted (2nd Qtr)
1st Half 2007
Kosrae Airport (SAWRS) Rainfall (Inches)
20.35
16.94
14.56
51.85
56.62
92.74
% of Normal
94%
90%
77%
87%
95%
85%
Utwa* Rainfall (Inches)
14.14
20.40
11.81
46.35
56.62
81.33
% of WSO
N/A
N/A
N/A
78%
95%
75%
Nautilus* Rainfall (Inches)
18.39
13.96
13.20
45.55
56.62
86.93
% of WSO
N/A
N/A
N/A
77%
95%
80%
Predicted rainfall refers to forecast made in 1st Quarter 2007 PEAC Newsletter.
* Long term normal is not established for these sites
** Estimated

Climate Outlook: Easterly trade winds should continue to dominate the flow in eastern Micronesia (Pohnpei and eastward), resulting in average to slightly below average rainfall for Kosrae State. Within this anticipated weather pattern, the rainfall at Kosrae for the rest of 2007 should be near normal (approximately 15-18 inches per month), or slightly below normal. Islands from Pohnpei eastward into the RMI primarily experience tropical storms and typhoons during El Niño years; therefore, no tropical cyclone activity is expected to affect Kosrae State during the remaining months of 2007 or during the first half of 2008.

Forecast rainfall for Kosrae State from August 2007 through July 2008 is as follows:


Inclusive Period
% of Long-Term Average Rainfall /
Forecast Rainfall (inches)

Aug - Oct 2007
(Heart of Next Rainy Season)

95%
(47.40 inches)

Nov 2007 - Jan 2008
(Onset of Next Dry Season)

100%

Feb - April 2008
(Heart of Next Dry Season)

100%

May - July 2008
(Onset of Next Rainy Season)

100%
Forecast rainfall quantities represent BEST ESTIMATES given the probabalistic forecast for each particular season and station.

source: UOG-WERI