ENSO-neutral is favored into the Northern Hemisphere summer 2013
During March 2013, ENSO-neutral continued, with slightly above average
SSTs in the eastern portion of the basin (Fig.
1). Weekly values of all the Niņo indices were between -0.5oC and
+0.5oC during the month (Fig.
2). The oceanic heat content (average temperature in the upper 300m
of the ocean) increased to near-average during the month (Fig.
3) as an area of above-average temperatures at depth moved eastward
into portions of the eastern basin (Fig.
4). The Madden-Julian Oscillation (MJO) again contributed to
increased atmospheric variability over the tropical Pacific. Low-level
winds were near average, and upper-level winds were anomalously westerly
across the equatorial Pacific. Convection was enhanced over the western
equatorial Pacific and suppressed in the central basin (Fig.
5). Collectively, these features indicate the continuation of
ENSO-neutral.
Most models forecast Niņo-3.4 SSTs to remain ENSO-neutral through the
Northern Hemisphere fall (Fig.
6), with dynamical models tending to predict warmer conditions (0oC
to 0.5oC) than the statistical models (-0.5oC to 0oC). There is less
confidence in the forecasts for the last half of the year, partly
because of the so-called "spring barrier," which historically leads to
lower model skill beginning in late spring. Thus, ENSO-neutral is
favored into the Northern Hemisphere summer 2013 (see
CPC/IRI consensus forecast).
This discussion is a consolidated effort of the National Oceanic and
Atmospheric Administration (NOAA), NOAA's National Weather Service, and
their funded institutions. Oceanic and atmospheric conditions are
updated weekly on the Climate Prediction Center web site (El
Niņo/La Niņa Current Conditions and Expert Discussions). Forecasts
for the evolution of El Niņo/La Niņa are updated monthly in the
Forecast Forum section of CPC's Climate Diagnostics Bulletin. The
next ENSO Diagnostics Discussion is scheduled for 9 May 2013. To receive
an e-mail notification when the monthly ENSO Diagnostic Discussions are
released, please send an e-mail message to:
ncep.list.enso-update@noaa.gov.
Climate Prediction Center
National Centers for Environmental Prediction
NOAA/National Weather Service
Camp Springs, MD 20740
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