Pacific ENSO Update

4th Quarter, 2008 Vol. 14 No. 4

Palau Flag Republic of the Marshall Islands: The rainfall throughout most of the atolls of the Republic of the Marshall Islands was below normal during the 3rd Quarter of 2008. The 3-month total of 26.36 inches at Majuro WSO, in the central RMI, was 71% of its normal rainfall. In the northern RMI, Kwajalein was dry with 85% of it normal 3-month total; Jaluit was even drier, having only received 45% of its normal 3- month total. Because we are now in the wetter months of the year, the municipal water supply on Majuro (a rainwater catchment system that collects water from the airport’s runway) should remain at or above adequate levels.

Republic of the Marshall Islands Rainfall Summary 3rd Quarter 2008

Station   July August Sept. 3rd Qtr
Predicted
RMI Central Atolls (6°N - 8°N)
Majuro WSO
Rainfall (inches)
10.11
8.40
7.85
26.36
34.50
% of Normal
78%
73%
63%
71%
95%
Laura*
Rainfall (inches)
8.74
N/A
11.12
N/A
34.50
% of Normal
70%
N/A
93%
N/A
95%
Arno*
Rainfall (inches)
N/A
N/A
N/A
N/A
34.50
% of Normal
N/A
N/A
N/A
N/A
95%
Alinglaplap*
Rainfall (inches)
7.35
N/A
N/A
29.85
34.50
% of Normal
59%
N/A
N/A
70%
95%
RMI Southern Atolls (South of 6 °N)
Jaluit*
Rainfall (inches)
6.34
6.54
13.09
25.97
36.32
% of Normal
51%
55%
109%
70%
95%
RMI Northern Atolls (North of 8°N)
Kwajalein
Rainfall (inches)
11.62
6.83
9.20
27.65
30.86
% of Normal
111%
68%
78%
85%
95%
Wotje*
Rainfall (inches)
1.94
5.52
6.19
13.65
30.86
% of Normal
20%
56%
55%
45%
95%
Predictions made in 2nd Quarter 2008 Pacifc ENSO Update newsletter.
* Long term normal is not established for these sites
** Estimated

Climate Outlook: The rainy season in the RMI extends through December. Therefore, even with slightly below normal rainfall, there should be enough precipitation to ensure adequate water supplies through the end of the year. With the onset of the dry season in January, below normal rainfall could result in some water stress, especially in the northern atolls. However, no extreme dryness is anticipated at this time. Given the underlying climate pattern, it is reasonable to expect that near normal to slightly below normal rainfall will continue for the next three to six months. Based on a persistence of the Micronesia-wide low-level easterly wind anomalies, the RMI has a very low risk of a typhoon during the foreseeable future.

Forecast rainfall for the RMI from October 2008 through September 2009 is as follows:

Inclusive Period
% of Long-Term Average Rainfall /
Forecast Rainfall (inches)
S. of 6° N
6° N to 8° N
N. of 8° N 
October - December 2008
(Start of Dry Season)
95%
(36.14 inches)
90%
(34.23 inches)
90%
(27.13 inches)
January - March 2009
(Dry Season)
95%
85%
80%
April - June 2009
(Onset of Rains)
110%
90%
90%
July - September 2009
(Onset of Rains)

100%
100%
90%
Forecast rainfall quantities represent BEST ESTIMATES given the probabalistic forecast for each particular season and station.

source: UOG-WERI