December 2019 Climate Forecast Discussion for Jan-Mar through Apr-Jun
The SST forecast shows neutral ENSO conditions (-0.5 to 0.5ºC in the Nino3.4 SST index) for Jan-Mar through Apr-Jun. Near-average SST is forecast for the eastern tropical Pacific, cooling to slightly below average by Apr-Jun; above-average SST is forecast for the central and west-central tropical Pacific for Jan-Mar and Feb-Apr, cooling toward average by Apr-Jun. Most of the extratropical North Atlantic and North Pacific SSTs, as well as the SSTs in the western Indian Ocean and much of the high latitude South Pacific, are predicted to be above-average during the four forecast seasons. Above-average SST is also predicted for much of the north and south tropical Atlantic for all four forecast seasons, most strongly in the first two seasons. Relatively much smaller areas predicted to have below-average SST for most or all of the forecast seasons include the southeast or eastern tropical Pacific, southwest extratropical Indian Ocean, locations just south of Greenland and just south of Australia, and (for Jan-Mar and Feb-Apr) part of the extratropical South Atlantic. A somewhat positive Indian Ocean Dipole is predicted for all four forecast seasons.
An enhanced probability for below-normal precipitation is forecast for southern Africa in most of the four forecast seasons (Jan-Mar through Apr-Jun), for part of southern South America in Feb-Apr through Apr-Jun, and for part of extreme northern South America and west Indonesia in Jan-Mar. Enhanced chances for above-normal precipitation are predicted for Jan-Mar through Mar-May for part of northeast Brazil and part of eastern China, and for Jan-Mar in eastern equatorial Africa and part of western Asia/eastern Europe. A tilt of the odds toward above-normal is also predicted for Jan-Mar and Feb-Apr in parts of north-central and northeastern Asia.
Enhanced probabilities for above-normal temperature are predicted for Greenland, and varying parts of Australia, Asia, Africa, North America, South America and Europe from Jan-Mar through Apr-Jun. Tilts of the odds toward above-normal are strongest for southern Africa for Jan-Mar, south-central North America for Feb-Apr through Apr-Jun, and central or northeast Asia and Greenland for most of the four forecast seasons. The tendency toward above-normal is generally weakest (or absent) in much of tropical Africa, southern Asia, much of Indonesia and fairly substantial portions of South America. An enhanced probability for below-normal temperature is predicted for northern Scandinavia and northern Asia in Feb-Apr, and for northeastern Europe in Mar-May. Enhanced probabilities for near-normal temperature are forecast for all four forecast seasons in parts of northern South America, parts of central, western and/or eastern equatorial Africa, and part of Indonesia. Near-normal is also favored for southeast Asia in Apr-Jun.
The next seasonal climate forecast will be available on January 20th, 2020 (EST)
