June 2021 Climate Forecast Discussion
June 2021 Climate Forecast Discussion for Jul-Sep through Oct-Dec
The sea surface temperature (SST) forecast indicates that the tropical Pacific is currently ENSO-neutral and will likely remain so through the boreal summer. This small collection of models suggests a re-emergence of cool SST anomalies near the end of 2021 that are just cool enough to meet the La Niña condition threshold of -0.5 C below average; however, they are not forecast to persist long enough to constitute a second La Niña event. Nonetheless, this La Niña-like SST pattern in the latter seasons of the forecast does impact the associated seasonal climate forecast. The SST forecasts over the upcoming seasons are primarily for normal conditions in the tropical Indian and Atlantic Oceans; however, there is some indication of warmer than normal SSTs in the equatorial Atlantic, and additionally some warming over the western equatorial Indian ocean is predicted with the re-emergence of La Niña.
Precipitation forecasts show enhanced probabilities of above-normal precipitation over the Maritime Continent and much of eastern Australia for all forecasted seasons. Enhanced probabilities of below-normal precipitation are forecast over northwestern United States, parts of Central America, and much of southern South America for the Jul-Sep season. Forecasts suggest enhanced likelihood for below-normal precipitation developing by Sep-Nov over parts of the Middle East and the equatorial coast of West Africa, and the confidence in the below-normal forecasts increases over Chile, southern Argentina, southern Brazil and Uruguay. For Oct-Dec, below-normal precipitation remains likely over much of the Middle East and SW Asia, and develops over Texas and Mexico.
All forecasted seasons show an increased likelihood for above-normal temperatures for the high latitudes of the Northern Hemisphere. In Jul-Sep enhanced probabilities of above-normal temperatures are also forecast for the northern tier of the United States. By Sep-Nov, the warm forecasts for the high-latitudes become even more confident, as the season of Artic sea ice minimum arrives. Also, in Sep-Nov, a likelihood for above-normal temperatures appears over the Great Plains of the US and over western China. For Oct-Dec, a localized high probability for above-normal temperatures appears over Texas; the high-latitude forecasts favoring above-normal temperatures expands into eastern Canada and much of northern Asia.
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