No. 01-2012 MONTHLY PACIFIC ENSO DISCUSSION FOR MICRONESIA
AND AMERICAN SAMOA
January2012
The Pacific ENSO Applications Climate (PEAC) Centeris now preparingits1st Quarter 2012Pacific ENSO Update Newsletter. Current and past editions of the Pacific ENSO Update can be found at: The Climate Prediction Center (CPC)/International Research Institute for Climate and Society (IRI) stated the following in theJanuary5, 2012ENSO Diagnostic Discussion, which can be found at: ( “La Niña is expected to continue into the Northern spring 2012.” The CPC/IRIindicated that “During December 2011, below average sea surface temperatures (SST) associated with LaNiña continued across the eastern and central equatorial Pacific Ocean”. Furthermore, CPC/IRI observed that “the oceanic heat content (average temperature in the upper 300m of the ocean) anomalies strengthened across the eastern Pacific, reflecting a large area of below-average temperatures in the subsurface.” The atmosphere exhibitedenhanced convection over eastern Indonesia and northern Australia, suppressed convection over the central and western equatorial Pacific, and a strengthened Southern Oscillation Index (SOI). As a result, CPC/IRIconcluded that “Collectively, the ongoing oceanic and atmospheric patterns reflect the continuation of a weak to moderate La Niña.”
With respect to the many national and internationalclimate forecast computer models, a majority indicate that La Niña will peak during the December-February season and will likely continue into the March-May time period before transitioning to an ENSO-neutral status. It is a little too early to accurately predict conditions beyond the boreal summer.
InMicronesia, many locations, such as Yap and the Mariana Islands, will have near-average rainfall. Chuuk, Palau, Pohnpei, and Kosrae will likely have near-average to slightly above average rainfall, while the Marshall Islands will likely have near-average to slightly below average rainfall. Significant tropical cyclone activity should be delayed until the early boreal summer, but will then increase with the onset of monsoon activity. Sea level will be near-average values with a decreased chance of inundation. In American Samoa, rainfall will be near-average to slightly below average and sea levels will be at near-average values as well. There is also a small chance of tropical cyclone activity from January to April 2012, but mostly in the weaker developing stages.
The current ENSO Alert System Status is: La Niña. See the following website: for more information on the NOAA ENSO alert system.
PREPARED BY NOAA’S NATIONAL WEATHER SERVICE
Coordinated with the Climate Prediction Center (CPC), the International Research Institute for Climate and Society (IRI),the Pacific ENSO Applications Center (PEAC) Center, and regional partners.