October 2017 Climate Forecast Discussion

October 2017 Climate Forecast Discussion for Nov-Jan through Feb-Apr

The SST forecast shows weak La Nina conditions for Nov-Jan through Jan-Mar, weakening to neutral by Feb-Apr. Most of the subtropical North Pacific SST and the SST in many of the other extratropical regions is predicted to be above average during all four forecast seasons. A slightly positive Indian Ocean Dipole is predicted for Nov-Jan, weakening for the later seasons. Slightly above-average north tropical Atlantic SST is predicted for Nov-Jan, weakening thereafter.

Enhanced probabilities for below-normal precipitation are predicted for Mexico and the southeastern and/or extreme southern U.S., as well as in part of southeastern South America, from Nov-Jan through Feb-Apr. A tilt of the odds toward below-normal is also forecast for part of southwestern Asia, and for part of east coastal Asia, mainly for Nov-Jan and Feb-Apr in both cases. Enhanced chances for above-normal precipitation are forecast for northern South America and for most of Indonesia and the Philippines from Nov-Jan through Feb-Apr. A tilt toward above-normal is also predicted for northern Asia, mainly for Nov-Jan but also for Dec-Feb.

Strongly enhanced probabilities for above-normal temperature are predicted for most of North America, Asia, northeastern Europe and Greenland for Nov-Jan, continuing more weakly and in more scattered areas from Dec-Feb to Feb-Apr. A tendency toward below-normal temperature is forecast in varying portions of mid-latitude North America, central Asia and eastern Europe from Dec-Feb to Feb-Apr.