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International Research Institute for Climate and Society
C li mate Brief ing
Beginning in late Feb., both oceanic and
atmospheric conditions in the tropical
Pacific met thresholds required for El
Niño, including a warmed sea-surface
temperature, significant weakening
of trade winds and establishment of
above-average cloudiness and rainfall
straddling the international dateline along
the equator. Currently, both ocean and
atmosphere are exhibiting a weak to
moderate El Niño.
A new set of model runs indicates probability for El Niño greater than 90% from
the May-July season in progress through
the July-Sept. season, and at least 80%
through end of 2015 (lower chart on right).
These probabilities are approximately
the same as those of the official ENSO
forecast issued May 14, which used both
models and human judgement.
This month’s key graphic.
Current Official ENSO forecast (issued May 14)
100
Early−May CPC/IRI Consensus Probabilistic ENSO Forecast
90
El Nino
80
Probability (%)
What you need to know.
Neutral
70
La Nina
60
50
Climatological
Probability:
40
El Nino
Neutral
30
La Nina
20
10
0
AMJ
2015
MJJ
JJA
JAS
ASO
SON
Time Period
OND
NDJ
NOAA’s Climate
Prediction Center and
IRI jointly produce this
monthly forecast every second Thursday.
It stands as the official
consensus forecast for
ENSO.
DJF
2016
Updated ENSO forecast (May 21)
100
Mid−May IRI/CPC Plume−Based Probabilistic ENSO Forecast
90
El Nino
80
Probability (%)
MAY
2015
Neutral
70
La Nina
60
50
Climatological
Probability:
40
El Nino
IRI and CPC issue an
updated model-based
ENSO forecast on the
third Thursday of each
month.
Neutral
30
La Nina
20
10
Although a majority of models suggests
further strengthening of El Nino during
summer, we cannot be confident about
forecasts for El Niño’s peak strength due
to continued uncertainty of forecasts
made at this time of year.
Tony’s Take*.
IRI Chief Climate Forecaster Anthony Barnston
gives a video rundown of the climate briefing in
under two minutes. Feel free to embed!
0
MJJ
2015
JJA
JAS
ASO
SON
OND
Time Period
NDJ
DJF
JFM
2016
Additional Resources.
Powerpoint of this month’s briefing:
iri.columbia.edu/~tonyb/fctbriefingMay15.ppt
All of IRI’s Forecasts:
iri.columbia.edu/our-expertise/climate/forecasts/
IRI’s ENSO Map Room:
iridl.ldeo.columbia.edu/maproom/ENSO/
Email [email protected] to sign up for this bulletin
Link: https://vimeo.com/125074930
*Video usually posted by 5 pm on the day
of the briefing.
ENSO questions? Tweet @climatesociety w/ #ENSOQandA
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International Research Institute
for Climate and Society
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