Current ENSO Information
ENSO Update
19 June 2003
Summary
Overall ENSO conditions are currently near-neutral, even though ocean
temperatures in the eastern and central equatorial Pacific are below average.
Indicators are mixed as to whether further cooling will lead to the development
of La Niña conditions over the next few months, although this possibility
remains above historical odds. Forecasts made this time of year have
lowered skill. Based on the behavior of past La Niña event
onsets, recent observations, and model forecasts, there is an estimated
likelihood of 45% that La Niña will develop in the coming few months,
with continued near-neutral conditions the other likely scenario.
General Discussion
The recent cooling of the central and eastern equatorial Pacific eased
by late May but ocean temperatures remain below average as of mid-June.
Recent behavior of sea surface temperatures has been similar to that seen
in the early stages of past La Niña events, although oceanic and
atmospheric indicators over the past month have stalled in their trend
in this direction. Overall, near-neutral conditions currently exist
in the equatorial Pacific.
The skill of forecast models is still relatively low at this time of
year. A large set of dynamical and statistical models are currently divided
between those showing near to slightly below average sea surface temperatures,
and some indicating the development of La Niña conditions.
Only a small number of models indicate warming in the east-central equatorial
Pacific (Note
1). Based on past events and current observations of the ocean
surface and subsurface, the chances for La Niña are believed to
be greater than those of an average year. However, chances for neutral
conditions currently appear slightly more likely.
In summary, current observations and model forecasts suggest that ocean
conditions will likely remain near to slightly below average, with an estimated
45% probability of attaining La Niña status during the coming few
months. If La Niña conditions do develop in the next few months,
they would likely persist through the remainder of the calendar year and
into the beginning of the next year.
Note 1 - Only models that produce a
new ENSO forecast every month are included in the above statement.
Top of Page
|
