January 2023 Climate Forecast Discussion

Jan 2023 Climate Forecast Discussion for Feb-Apr through May-Jul 2023

Note: The IRI seasonal forecasts of precipitation and temperature issued this month are based on an objective calibration procedure that combines the NCEP-CFSv2, CanSIPS-IC3, COLA-RSMAS-CCSM4, and GFDL-SPEAR, and NASA-GEOSS2S models. The climatological base period for normal is 1991-2020.

In December 2022, the equatorial sea surface temperatures (SSTs) in the central-eastern tropical Pacific Ocean remained cooler than normal, exhibiting persistent La Niña conditions (NINO3.4 index value in December 2022 was -0.84C). According to the early-January CPC ENSO Forecast, La Niña is likely to continue into the Northern Hemisphere spring (67% chance during Mar-May 2023), with ENSO-neutral becoming the most likely category in subsequent seasons. The prolonged La Niña SST pattern in the tropical Pacific does impact the associated seasonal climate forecast, described below. No strong SST anomalies are present in the tropical Indian and Atlantic Oceans in both observations and the forecast.

In Feb-Apr and Mar-May 2023, moderately enhanced probabilities of below-normal precipitation are forecast for northwest Mexico and the southwestern US, while during the same period, slightly enhanced probabilities of above-normal precipitation are forecast over northwest and northeast US, northern South America, southern Africa, parts of Arabian Peninsula, and Pakistan. Strongly enhanced probabilities of above-normal precipitation are forecast over the Philippines. In Feb-Mar 2023 and onwards, weakly enhanced probabilities of above-normal precipitation are forecast over the African Sahel region.

For temperature, moderately to strongly increased probabilities of above-normal temperatures are forecast over many land areas, becoming particularly widespread from Feb-Mar onwards; these areas include the Maritime Continent, Asia, the Middle East, large parts of the African continent (northern parts), much of southern and southeastern US, eastern Canada, and southern South America. Moderately enhanced probabilities of below-normal temperatures are forecasted over western Canada, northern South America, parts of Madagascar, southern India and SE Asia, during Feb-Apr and Mar-May, disappearing during Apr-Jun, and May-Jul 2023 (except for Madagascar).