May 2020 Climate Forecast Discussion for Jun-Aug through Sep-Nov
The SST forecast shows neutral ENSO conditions in the east-central tropical Pacific Ocean for Jun-Aug, with a cooling tendency during those months as well as later on, and thus reaching a borderline La Nina level by Sep-Nov. Through the forecast periods, the eastern one-third of the tropical Pacific is forecast to develop a stronger negative anomaly than the central Pacific. Most of the extratropical North Atlantic and North Pacific SSTs, as well as the SSTs in parts of the Indian Ocean and some portions of the subtropical and extratropical South Atlantic and Pacific, are predicted to be above-average during the four forecast seasons. A tendency for a negative Indian Ocean dipole is predicted for Jul-Sep through Sep-Nov. Relatively smaller areas that are predicted to have below-average SST for most or all of the forecast seasons include the east-central and eastern tropical Pacific, and various small areas in the extratropical Southern Hemisphere.
An enhanced probability for below-normal precipitation is forecast in the Philippines, part of southern Africa and part of central South America for Jun-Aug, the extreme northwestern U.S. in Jun-Aug and Jul-Sep, and part of the Gulf of Guinea of Africa for Jul-Sep. Below-normal is also favored in part of northern South America for Aug-Oct and Sep-Nov, part of Scandinavia for Sep-Nov, and for all four forecast seasons in part of northwestern North America, part of Chile, and mainly western Argentina. Enhanced chances for above-normal precipitation are predicted in much of the African Sahel, part of eastern equatorial Africa and the northeastern tip of Brazil for Jun-Aug and Jul-Sep, and for Pakistan and parts of China for Jun-Aug through Aug-Oct. A tilt of the odds toward above-normal is also forecast in extreme north-central and northeastern Asia for Sep-Nov, the Philippines for Aug-Oct and Sep-Nov, and for all four forecast seasons in the Indonesian archipelago, much of Australia, and India.
Enhanced probabilities for above-normal temperature are predicted for Greenland, and varying parts of Australia, Asia, Africa, North America, South America and Europe from Jun-Aug through Sep-Nov. Tilts of the odds toward above-normal are strongest in parts of North America and Turkey for Jun-Aug, extreme northern North America for Sep-Nov, and for all forecast seasons in parts of Greenland and part of either central or northeastern Asia. The tendency toward above-normal is generally weakest or absent for most or all forecast seasons in tropical Africa, the southern half of Australia, and parts of southern Asia. An enhanced probability for below-normal temperature is predicted for part of the western Greater Horn of Africa for Jun-Aug through Aug-Oct, southeastern Australia in Sep-Nov, and parts northern Asia for Aug-Oct and Sep-Nov. Enhanced probabilities for near-normal temperature are forecast for all four forecast seasons in parts of northeastern South America and part of mainly central Africa.
