September 2019 Climate Forecast Discussion
September 2019 Climate Forecast Discussion for Oct-Dec through Jan-Mar
The SST forecast shows slightly warmish, but neutral ENSO conditions (-0.5 to 0.5ºC in the Nino3.4 SST index) for Oct-Dec through Jan-Mar. Slightly below-average SST is forecast for the eastern tropical Pacific, while above-average SST is forecast for the central and much of the western tropical Pacific for all four forecast seasons. Most of the extratropical North Atlantic and North Pacific SSTs, as well as the SSTs in the western Indian Ocean and parts of the middle and/or high latitude south Pacific, are predicted to be above-average during the four forecast seasons. Small areas of below-average SST are predicted for southeast of the southern tip of South America, for just southwest of Indonesia in Oct-Dec and Nov-Jan, for southeast of southern Africa, for south of Greenland, and for the eastern/southeastern tropical Pacific for all four seasons. A positive Indian Ocean Dipole is predicted for all four forecast seasons, most strongly for the earlier seasons, and near to slightly above average SST is predicted for the north and south tropical Atlantic for all four forecast seasons.
An enhanced probability for below-normal precipitation is forecast for all four forecast seasons (Oct-Dec through Jan-Mar) for a major part of northern and/or northeastern South America, and for Oct-Dec through Dec-Feb (most strongly for Oct-Dec) in parts of Australia and most of Indonesia. A tilt of the odds toward below-normal is also forecast for southern Africa from Nov-Jan through Jan-Mar and for parts of Greenland for Nov-Jan and Dec-Feb. Enhanced chances for above-normal precipitation are forecast for part of southeastern South America, east equatorial Africa and parts of northern Asia from Oct-Dec through Dec-Feb. A preference for above-normal is also predicted for part of Central America and part of the Caribbean, and for southern or central Asia, for Oct-Dec and Nov-Jan; for part of eastern Europe/northwestern Asia for Dec-Feb and Jan-Mar, part of eastern China in Nov-Jan and Dec-Feb, and part of the southern U.S. in Nov-Jan.
Enhanced probabilities for above-normal temperature are predicted for Greenland, and varying parts of Australia, Asia, Africa, North America, South America and northeast Europe from Oct-Dec through Jan-Mar. Tilts of the odds toward above-normal are strongest for Oct-Dec in Greenland, northeastern Asia, and northern and part of central North America. The tendency toward above-normal is weak or absent in central Africa, much of Europe and most of Indonesia during all four seasons. Weakly enhanced probabilities for below-normal temperature are forecast for east-central Asia from Oct-Dec to Dec-Feb and for small pockets in central North America for Dec-Feb. An enhanced likelihood for near-normal temperature is predicted for all four forecast seasons for parts of central, western or east equatorial Africa, for central or northern South America, and for parts of Indonesia.
The next seasonal climate forecast will be available on Tuesday, October 15, 2019