The canonical correlation analysis (CCA) forecast of
SST in the central Pacific (Barnett et al. 1988, Science, 241,
192‑196; Barnston and Ropelewski
1992, J. Climate, 5, 1316‑1345), is shown in Figs. F1 and F2. This forecast is produced routinely by the
Prediction Branch of the Climate Prediction Center. The
predictions from the National Centers for Environmental Prediction (NCEP)
Coupled Forecast System Model (CFS03) are presented in Figs. F3 and
F4a, F4b. Predictions from the
Markov model (Xue, et al. 2000: J. Climate, 13,
849‑871) are shown in Figs. F5 and F6. Predictions from the latest version of the
LDEO model (Chen et al. 2000: Geophys. Res.
Let., 27, 2585‑2587) are shown in Figs. F7
and F8. Predictions using linear inverse modeling (Penland and Magorian 1993: J.
Climate, 6, 1067‑1076) are shown in Figs. F9 and F10. Predictions from the Scripps / Max Planck
Institute (MPI) hybrid coupled model (Barnett et al. 1993: J. Climate, 6,
1545‑1566) are shown in Fig. F11.
Predictions from the ENSO‑CLIPER statistical model (Knaff and Landsea 1997, Wea. Forecasting, 12, 633‑652)
are shown in Fig. F12. Niño 3.4
predictions are summarized in Fig. F13, provided by the Forecasting and
Prediction Research Group of the IRI.
The CPC and the contributors to the Forecast Forum caution
potential users of this predictive information that they can expect only modest
ENSO Alert System Status: Not Active
favored into the Northern Hemisphere fall 2013.
persisted during July 2013, as reflected by near-average sea surface
temperatures (SSTs) across the central and east-central equatorial Pacific, and
below-average SSTs in the eastern Pacific (Fig. T18).
Consistent with this pattern, the monthly Niño-4 and Niño-3.4 indices
were between -0.5° and 0°C, while
Niño-3 and Niño-1+2 indices were cooler than -0.5°C (Table T2). The oceanic
heat content (average temperature in the upper 300m of the ocean) anomalies
continued to be slightly above average during July, due to the persistence of
above-average sub-surface temperatures in most of the eastern half of the
Pacific (Fig. T17). The low-level winds remained near average
across the equatorial Pacific, while weak upper-level westerly anomalies
persisted in the western Pacific (Figs. T20 and T21). Convection
continued to be enhanced over Indonesia and suppressed in the central part of
the basin (Fig. T25). Collectively, these atmospheric and oceanic
conditions reflect ENSO-neutral.
Most model forecasts
continue to predict ENSO-neutral (Niño-3.4 index between -0.5°C and 0.5°C) into
the Northern Hemisphere spring 2014 (Figs. F1-F13). The statistical model
forecasts remain cooler in the Niño-3.4 region relative to the dynamical model
forecasts. Similar to last month, the
forecast consensus favors ENSO-neutral (60% chance or greater) through October
– December 2013.
Weekly updates of oceanic
and atmospheric conditions are available on the Climate Prediction Center homepage
Niño/La Niña Current Conditions and Expert Discussions).