Date and Period of Forecast  In January 2000, the IRI Experimental Forecast Division prepared a Climate Outlook for January-March 2000.  Here we provide a subset of the January Net Assessment Forecast.  The complete forecast, which includes global forecasts for April-June 2000,  can be found at http://iri.columbia.edu/climate/forecast/net_asmt/.
Uncertainties  This Climate Outlook is dependent on the quality of the SST predictions [link to Ocean below]. For the tropical Pacific, these predictions can be expected to provide useful information, but there is some uncertainty concerning the detailed evolution of SSTs.  Spread in global SST predictions is a source of uncertainty in the Outlook provided here. The procedures, models, and data used to derive this Climate Outlook may be somewhat different from those used by National Meteorological Services in particular regions and may differ from the official forecasts issued in those areas.
Regional Influences  The current status of seasonal-to-interannual climate forecasting allows prediction of spatial and temporal averages, and does not fully account for all factors that influence regional and national climate variability. This Outlook is relevant only to seasonal time scales and relatively large areas; local variations should be expected. For further information concerning this and other guidance products, users are strongly advised to contact their National Meteorological Services.
Precipitation Outlook  The Outlook for January-March 2000 can also be found at http://iri.columbia.edu/climate/forecast/net_asmt/.

 Maps are given showing expected precipitation probabilities in tercile classes. The maps indicate probabilities that seasonal precipitation will fall into the wettestthird of the years (top number), the middlethird of years (middle number) or the driestthird of the years (bottom).

An outlook of climatology "C"  (light grey) indicates equal probabilities in each class; i.e., there is no basis for favoring the forecast of any particular category.

Areas marked "D"  (dark grey) experience a pronounced dry season during the forecast period, typically receiving less than 15% of their annual precipitation or less than 5 cm total during this three-month period.

Boundaries between sub-regions should be considered transition zones, and their location considered to be only qualitatively correct.

The following regions of enhanced probabilities of precipitation anomalies are indicated:

P.A) enhanced probabilities of above-normal precipitation over Panama and much of Costa Rica

P.B) greatly enhanced probabilities of above-normal precipitation over much of Colombia

P.C) strongly enhanced probabilities of above-normal precipitation over an area extending from easterm-most Colombia though French Guiana to 50E, north of the Equator

P.D) greatly enhanced probabilities of above-normal precipitation over the northeast region of Brazil

P.E) slightly enhanced probabilities of below-normal precipitation over the east-facing coast of northeast Brazil

P.F) slightly enhanced probabilities of above-normal precipitation over north-central Brazil

P.G) slightly enhanced probabilities of below-normal precipitation over the western portions of Ecuador and northern Peru

P.H) slightly enhanced probabilities of near-normal precipitation over the western part of southern Peru

P.I) slightly enhanced probabilities of below-normal precipitation over Uruguay, northeastern Argentina southern Brazil, and eastern Paraguay

P.J) enhanced probabilities of near-normal to above-normal precipitation over a large region encircling that of P.I, including north-western Argentina, western Paraguay, eastern Bolivia, and a narrow zone through southern Brazil

January-March 2000 Precipitation probabilities

P.A) enhanced probabilities of below-normal precipitation over most of Thailand, the southernmost part of Myanmar, south-western Cambodia, and the south-westernmost part of Vietnam

P.B) slightly enhanced probabilities of below-normal precipitation over the northern half of Sumatra, and western Malaysia

P.C) slightly enhanced probabilities of above-normal precipitation over northern Phillipines, and north central Indonesia

P.D) greatly enhanced probabilities of above-normal precipitation over most of the Philippines (a slightly enhanced risk of extremely wet conditions is indicated)

P.E) greatly enhanced probabilities of below-normal precipitation over the Marshall Islands

P.F) slightly enhanced probabilities of above-normal precipitation over the Solomon Islands, Vanuatu, and New Caledonia

P.G) slightly enhanced probabilities of above-normal precipitation over Fiji

P.H) slightly enhanced probabilities of above-normal precipitation over south-western Australia

P.I) slightly enhanced probabilities of below-normal precipitation central southern Australia

P.J) enhanced probabilities of below-normal precipitation over southern Australia

P.K) enhanced probabilities of above-normal precipitation over eastern Australia

P.L) slightly enhanced probabilities of above-normal precipitation over North Island, New Zealand

P.M) slightly enhanced probabilities of below-normal precipitation over South Island, New Zealand.

Temperature OutlookThe Outlook for January-March 2000 can also be found at  http://iri.columbia.edu/forecast/net_asmt.

The temperature map shows expected probabilities that the seasonal temperatures will fall into the warmest third of the years (top number), the middle third of the years, or the coldest third of the years (bottom number).

A qualitative outlook of climatology "C" (light grey) indicates equal probabilities in each class i.e.; there is no basis for favoring the forecast of any particular category.

Boundaries between sub-regions should be considered transition zones, and their location considered to be only qualitatively correct.

The following regions of enhanced probabilities of temperature anomalies are indicated:

T.A) greatly enhanced probabilities of below-normal temperatures over northern South America from Venezuela to north-western Brazil

T.B) greatly enhanced probabilities of near-normal temperatures over the north coastal region of Brazil

T.C) slightly enhanced probabilities of near-normal to below-normal temperatures in the region of eastern Brazil occupied by the state of Bahia

T.D) enhanced probabilities of near-normal to below-normal temperatures over western South America including Colombia, Ecuador, Peru, north-western Bolivia, and western and central Brazil

T.E) slightly enhanced probabilities of near-normal temperatures over an area including eastern Bolivia, Paraguay, southern Brazil, Uruguay, and northeastern Argentina

T.F) enhanced probabilities of below-normal temperatures over central eastern Brazil, covering much of the states of Minas Gerais and Espirito Santo

T.G) enhanced probabilities of above-normal temperatures over southern Chile

T.H) slightly enhanced probabilities of above-normal temperatures over southern Argentina

January-March 2000 Temperature Probabilities

T.A) slighthly enhanced probabilities of below-normal temperatures over south-eastern China

T.B) greatly enhanced probabilities of above-normal temperatures over Sumatra and western Malaysia

T.C) greatly enhanced probabilities of above-normal temperatures over Java, Borneo, and the Philippines

T.D) enhanced probabilities of above-normal temperatures over eastern Indonesia, New Guinea, Solomon Islands, Vanuatu, New Caledonia, and the northern part of Australia

T.E) enhanced probabilities of above-normal to normal temperatures over central and eastern Australia

T.F) greatly enhanced probabilities of above-normal temperatures over Tasmania

T.G) greatly enhanced probabilities of above-normal temperatures over New Zealand

T.H) enhanced probabilities of below-normal to normal temperatures over Nauru, Kiribati, and Tuvalu

Coupled ocean-atmosphere model predictions of tropical Pacific SST. Particularly heavy weighting has been given to the NOAA /NCEP, Climate Modeling Branch coupled model.

Statistical forecasts of Indian Ocean and Atlantic Ocean sea surface temperature.

The response of Atmospheric global circulation model (GCM) predictions to the present and predicted SST patterns.

Statistical analyses.

Appropriate Regional Climate Outlook Forum consensus guidance.