Moderate la nina conditions continue in the tropical pacific ocean. Sea surface temperatures (ssts) in the equatorial pacific ocean are below average from around 160e to the south american coast, with ssts between 1 and 2 degrees c below normal in some areas. This very large area of anomalously cool ssts has significant impact on the large scale atmospheric circulation throughout the tropical pacific region, which, in turn, is expected to considerably influence the mean atmospheric circulation patterns over north america.
The temperature outlook for march, april, and may 2011 reflects typical spring la nina condition and favors below average temperatures from washington and oregon eastward across the northern rockies to the western great lakes region. The chances for above average mean temperatures are enhanced from the interior southwest and southern rockies to the central gulf coast states.
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