July 2018 Climate Forecast Discussion
July 2018 Climate Forecast Discussion for Aug-Oct through Nov-Jan2019
The SST forecast shows weak El Nino conditions developing for the initial Aug-Oct season, intensifying to moderate strength (>1.0C in the Nino3.4 region) by Oct-Dec and Nov-Jan. Much of the subtropical and extratropical North Atlantic and North Pacific SST, as well as the SST in much of the mid-latitude Southern Hemisphere, are predicted to be above-average during all four forecast seasons. Exceptions are noted in the very high latitudes north of North America and south of South America, where below-average SST is predicted for all four forecast seasons. A positive Indian Ocean Dipole is predicted for all four forecast seasons. Slightly above-average SST is predicted for the tropical Atlantic for all four seasons, especially in the south tropical Atlantic.
Strongly enhanced probabilities for below-normal precipitation are predicted for Central America, the Caribbean islands, Indonesia and eastern Australia for Aug-Oct, and for Indonesia, the Caribbean and eastern Australia for Sep-Nov. A tilt of the odds toward below-normal is also forecast for Indonesia, much of Australia, central Africa, northern South America and the Caribbean for Oct-Dec, and for Australia, Indonesia and northern South America for Nov-Jan. Enhanced chances for above-normal precipitation are forecast for part of the African Sahel and Gulf of Guinea for Aug-Oct, for eastern equatorial Africa for Aug-Oct through Nov-Jan, and for the southern U.S. and/or Mexico, central-southwest Asia and part of northern Asia for Oct-Dec and Nov-Jan.
Enhanced probabilities for above-normal temperature are predicted for varying parts of Greenland, Asia, Europe, northern or southern Africa, Australia, North America and South America from Aug-Oct through Nov-Jan. The tilt of the odds toward above-normal averages weakest in Australia and South America in Aug-Oct, North America in Oct-Dec, and Africa in all four forecast seasons. Enhanced probabilities for below-normal temperature are relatively scant, but do appear in part of central North America in Oct-Dec and Nov-Jan. An enhanced likelihood for near-normal temperature is predicted for a small part of northeastern South America and central and northwestern Africa mainly for Aug-Oct and Sep-Nov, and for Africa’s Guinea coast and south-central Africa for Nov-Jan.