Pacific ENSO Update

4th Quarter, 2008 Vol. 14 No. 4

FSM Flag Federated States of Micronesia

Chuuk State:  Chuuk State was relatively dry throughout most of the 3rd Quarter of 2008. Very dry conditions in July and August were followed by a wet September, a pattern also seen nearly everywhere else in Micronesia. The 3-month total rainfall ranged from about 25 to 30 inches throughout Chuuk State. Polowat’s 3-month total of only 7.38 inches (17%) looks suspiciously low, but is somewhat in-line with low values of rainfall at Woleai (Yap State) where the 3-month total was reported to be 17.78 inches (44%). No problems were reported from within Chuuk State with respect to the dry conditions in July and August.

Chuuk State Rainfall Summary 3rd Quarter 2008

Station   July August Sept. 3rd Qtr Predicted
Chuuk Lagoon
Chuuk WSO
Rainfall (inches)
7.46
3.27
13.85
24.58
39.08
% of Normal
62%
22%
120%
64%
110%
Piis Panew*
Rainfall (inches)
3.81
4.67
10.24
18.72
39.08
% of Normal
31%
37%
89%
49%
110%
Southern Mortlocks
Lukunoch*
Rainfall (inches)

11.54

5.14
10.63
27.31
39.08
% of Normal
95%
41%
93%
71%
110%
Ettal*
Rainfall (inches)
7.01
8.67
10.22
25.90
39.08
% of Normal
58%
69%
89%
68%
110%
Ta*
Rainfall (inches)
8.99
8.93
15.34
33.60
39.08
% of Normal
74$
71%
134%
87%
110%
Namoluk*
Rainfall (inches)
8.56
5.77
10.64
24.97
39.08
% of Normal
71%
46%
93%
65%
110%
Northern Atolls
Fananu*
Rainfall (inches)
3.77
5.15
9.06
17.98
39.08
% of Normal
31%
41%
79%
47%
110%
Onoun*
Rainfall (inches)
9.07
5.14
14.56
28.77
39.08
% of Normal
75%
41%
127%
75%
110%
Northern Mortlocks
Losap*
Rainfall (inches)
14.19
4.29
12.32
30.80
39.08
% of Normal
117%
34%
107%
81%
110%
Nama*
Rainfall (inches)
11.74
4.65
9.67
26.06
39.08
% of Normal
97%
37%
84%
68%
110%
Western Atolls
Polowat
Rainfall (inches)
2.72
2.12
2.54
7.38
36.19
% of Normal
22%
17%
22%
19%
100%
Predictions made in 2nd Quarter 2008 Pacifc ENSO Update newsletter.
* Long term normal is not established for these sites (% normal based on WSO).

Climate Outlook: Based on a continuation of the pattern of anomalous low-level easterly wind, the risk of a tropical storm or typhoon is very unlikely anywhere in Chuuk State through the remainder of 2008 through the first half of 2009. In addition, this same easterly wind pattern should be accompanied by near normal rainfall for the foreseeable future.

Forecast rainfall for Chuuk State from October 2008 through September 2009 is as follows:

Inclusive Period
% of Long-Term Average Rainfall /
Forecast Rainfall (inches)
Chuuk Lagoon, and Northern Mortlocks
Polowat
Northern Atolls

Southern
Mortlocks

October - December 2008
100%
(35.55 inches)
90%
(32.00 inches)
100%
(35.55 inches)
100%
(35.55 inches)
January - March 2009
100%
90%
100%
110%
April - June 2009
110%
100%
100%
120%
July - September 2009
100%
100%
100%
100%
Forecast rainfall quantities represent BEST ESTIMATES given the probabalistic forecast for each particular season and station.

source: UOG-WERI