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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
August-September-October Issued July 2017
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

July 2017 Climate Forecast Discussion

July 2017 Climate Forecast Discussion for Aug-Oct through Nov-Jan

The SST forecast shows warmish but neutral ENSO conditions for Aug-Oct, remaining approximately steady through the fourth forecast season of Nov-Jan. The subtropical North Pacific SST is predicted to be well above average during all four forecast seasons. A somewhat positive Indian Ocean Dipole is predicted to continue throughout the four forecast seasons, weakening slightly by the fourth period. The tropical Atlantic maintains slightly above average SST during all four seasons.

Slightly enhanced probabilities for below-normal precipitation are predicted in parts of northern and eastern South America during Aug-Oct and Sep-Nov, shifting to just northern South America for Oct-Dec and Nov-Jan. An enhanced likelihood for below-normal is predicted for parts of Australia from Aug-Oct to Oct-Dec, with most widespread coverage during Sep-Nov. A below normal tendency is also predicted for southern and western Indonesia from Aug-Oct to Oct-Dec, and for northern central Africa for Sep-Nov and Oct-Dec. A tilt of the odds toward above normal is forecast for part of eastern Africa for Oct-Dec and Nov-Jan, parts of eastern Europe for Sep-Nov and Oct-Dec, portions of northern Asia from Sep-Nov to Nov-Jan, and parts of western or southwestern Asia for all four forecast periods.

A tendency toward above-normal temperature is predicted in varying portions of Africa, Australia, South America, southern or central Asia, eastern Europe, North America and Greenland during a majority of the four forecast seasons. Probabilities for above-normal are strongest in northeastern Asia and Greenland during all four forecast seasons, extending into northern North America from Sep-Nov through Nov-Jan. A tendency toward below-normal temperature is forecast in very small areas of north-central Asia during Nov-Jan.

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.