August 2017 Climate Forecast Discussion

Aug 2017 Climate Forecast Discussion for Sep-Nov through Dec-Feb

The SST forecast shows neutral to very slightly coolish ENSO conditions for Sep-Nov, remaining approximately steady through the fourth forecast season of Dec-Feb. The subtropical North Pacific SST and the SST in some other extratropical regions are predicted to be above average during all four forecast seasons. A slightly positive Indian Ocean Dipole is predicted to continue throughout the four forecast seasons. The tropical Atlantic maintains near-average equatorial SST to slightly above average off-equator SST during all four seasons.

Slightly enhanced probabilities for below-normal precipitation are predicted in part of northern South America during Sep-Nov and Oct-Dec, while below-normal is predicted for Nov-Jan and Dec-Feb in parts of southern North America. An enhanced likelihood for below-normal is also predicted for tropical southern Africa for Sep-Nov. A tilt of the odds toward above normal precipitation is forecast for parts of Indonesia for Sep-Nov and Oct-Dec, for northern South America for Dec-Feb, for parts of Europe from Oct-Dec to Dec-Feb, and for parts of northern or northeastern Asia for all four periods.

A tendency toward above-normal temperature is predicted in varying portions of North America, Asia, Australia, and Greenland during most of the four forecast seasons, with weaker warm tendencies in South America, eastern Europe and Africa. Probabilities for above-normal are strongest from Sep-Nov through Nov-Jan in northeastern Asia, northern North America and Greenland. A tendency toward below-normal temperature is forecast in portions of north-central Asia for Dec-Feb.