Seasonal Forecasts

Temperature and precipitation outlooks on seasonal (multi-month) timescales.

Forecast

Current seasonal temperature and precipitation outlook maps and discussion. Released on or about the 15th of each month.

Using the forecast maps

Use the controls above each map to choose what it shows. On the seasonal page you can pick the forecast Source, the Type (precipitation or temperature) and the date the forecast was issued. On the subseasonal page you pick the Type, then the year, month and day of issue. The map updates as soon as you change a setting. The box of buttons on the map switches between the forecast periods in that issuance: target seasons on the seasonal map, forecast periods on the subseasonal map. The title changes to match the period you pick. You can zoom with the scroll wheel or the +/– buttons and drag to move around the map. Download PNG saves the period currently shown as an image, with its title and legend.

CCSR/IRI NMME Multi-Model Probability Forecast for Precipitation for
September-October-November Issued August 2019
Probability (%) of Most Likely Category
Below Normal
40
45
50
60
70+
Normal
40+
Above Normal
40
45
50
60
70+
Dry Season (No Forecast) Equal Odds

August 2019 Climate Forecast Discussion

August 2019 Climate Forecast Discussion for Sep-Nov through Dec-Feb

The SST forecast shows neutral ENSO conditions (-0.5 to 0.5ºC in the Nino3.4 SST index) for Sep-Nov through Dec-Feb. Below-average SST is forecast for the eastern tropical Pacific, while above-average SST is forecast for the central and west-central 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 the very high latitudes near the southern tip of South America, for south of Australia and south or southwest of Indonesia for Sep-Nov and Oct-Dec, and for the eastern or 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-average SST is predicted for the north and south tropical Atlantic for all four forecast seasons, except for slightly above-average SST both north and south, farther from the equator.

An enhanced probability for below-normal precipitation is forecast for all four forecast seasons (Sep-Nov through Dec-Feb) for northern and/or northeastern South America and for Indonesia, and for central Chile and much of Australia for Sep-Nov and Oct-Dec. A tilt of the odds toward below-normal remains in western Australia also for Nov-Jan and Dec-Feb, and is forecast for the Philippines and Japan for Sep-Nov, and for southern Africa and central Greenland for Nov-Jan and Dec-Feb. Enhanced chances for above-normal precipitation are forecast for varying parts of northern/northeastern Asia and eastern equatorial Africa for all four forecast seasons, and for part of southeastern South America for Sep-Nov through Nov-Jan. A preference for above-normal is also forecast for part of central Africa for Oct-Dec and Nov-Jan, for parts of northern North America for Nov-Jan, and for extreme northern South America for Dec-Feb.

Enhanced probabilities for above-normal temperature are predicted for Greenland, and varying parts of Australia, Asia, Africa, North America, South America and Europe from Sep-Nov through Dec-Feb. Tilts of the odds toward above-normal are strongest for Sep-Nov through Nov-Jan in Greenland, northeastern Asia, interior South America and northern North America. They are also strong for interior parts of Australia for Oct-Dec and Nov-Jan, for central Asia in Sep-Nov, and for interior North America in Sep-Nov and Oct-Dec. The tendency toward above-normal is weak or absent in central Africa and 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 and western Africa, for central or northern South America, and for parts of Indonesia.

The next seasonal climate forecast will be available on Monday, September 16, 2019

Citation

Kirtman, B., D. Min, J. Infanti, J. Kinter, D. Paolino, Q. Zhang, H. van den Dool, S. Saha, M. Mendez, E. Becker, P. Peng, P. Tripp, J. Huang, D. DeWitt, M. Tippett, A. Barnston, S. Li, A. Rosati, S. Schubert, M. Rienecker, M. Suarez, Z. Li, J. Marshak, Y. Lim, J. Tribbia, K. Pegion, W. Merryfield, B. Denis, and E. Wood, 2014: The North American Multimodel Ensemble: Phase-1 Seasonal-to-Interannual Prediction; Phase-2 toward Developing Intraseasonal Prediction. Bull. Amer. Meteor. Soc., 95, 585–601, doi: 10.1175/BAMS-D-12-00050.1.