Climate Outlook: Normally, the rainy season in the RMI slowly builds from April through June, and then extends through the final quarter of the year. Unfortunately, during the past three months, which was the heart of the normal RMI rainy season, many islands experienced persistent dryness. Computer models now indicate near average to below average rainfall over the final two months of the year. This is consistent with the expectation that ENSO-neutral conditions will dominate the climate pattern instead of El Niño conditions that were previously anticipated.
There are two factors that should influence rainfall in the first half of 2013. The first is the establishment of the trade wind convergence over the southern half of the RMI, which should provide increased rainfall across the southern islands. In addition, Majuro and Kwajalein are two of several locations in eastern Micronesia with a robust drying trend of rainfall during the post-WWII period of record. The forecasts below indicate a relaxation of the very dry conditions experienced over the last two to three months but with consideration of the long-term drying trend . Significant tropical cyclone activity is not expected in the RMI until at least the end of the forecast period.
Forecast rainfall for the Republic of the Marshall Islands from October 2012 through September 2013 is as follows: |
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Republic of the Marshall Islands: Nearly all of the rainfall reports from the atolls of the RMI indicated rather persistent dry conditions during the 3rd Quarter of 2012. Some atolls were very dry with 3-month totals below 50% of average. WSO Majuro had a 3-month total of 25.16 inches or only 69%. The rainfall during both July and September 2012 at WSO Majuro was below 10 inches. This level of dryness is insufficient to replenish the water supply in the municipal reservoir at the Majuro International Airport. During the October PEAC conference call, it was reported that the water level in the reservoir was below half its 33-million-gallon capacity, and that it had not filled above 20 million gallons from July through September. This kind of situation typically triggers some level of rationing. Quarterly rainfall was particularly low in the southern atoll of Mili (36%) and in the northern atolls of Wotje (45%) and Utirik (45%).