NOAA El Niño Advisory: There is a greater than 90% chance that El Niño will continue through Northern Hemisphere winter 2015-16, and around an 80% chance it will last into early spring 2016.
During June, sea surface temperatures (SST) anomalies exceeded +1.0oC across the central and eastern equatorial Pacific Ocean. The largest SST anomaly increases occurred in the Niño-3 and Niño-3.4 regions, while the Niño-4 and Niño-1+2 indices remained more constant through the month. Positive subsurface temperature anomalies weakened due to the eastward shift of an upwelling oceanic Kelvin wave, which reduced above-average temperatures at depth in the central and east-central equatorial Pacific. In many respects, the atmospheric anomalies remained firmly coupled to the oceanic warming. Significant westerly winds were apparent in the western equatorial Pacific and anomalous upper-level easterly winds continued. The traditional and equatorial Southern Oscillation Index (SOI) were both negative, which are consistent with enhanced convection over the central and eastern equatorial Pacific and suppressed convection over Indonesia. Collectively, these atmospheric and oceanic features reflect an ongoing and strengthening El Niño.
Nearly all models predict El Niño to continue into the Northern Hemisphere winter 2015-16, with many multi-model averages predicting a strong event at its peak strength (3-month values of the Niño-3.4 index of +1.5oC or greater). At this time, the forecaster consensus is in favor of a significant El Niño in excess of +1.5oC in the Niño-3.4 region. Overall, there is a greater than 90% chance that El Niño will continue through Northern Hemisphere winter 2015-16, and around an 80% chance it will last into early spring 2016.
Across the contiguous United States, temperature and precipitation impacts associated with El Niño are expected to remain minimal during the Northern Hemisphere summer and increase into the late fall and winter.
Most land masses in the northern hemisphere will experience near average wind conditions for the month. Winds will also be near average in much of the Southern Hemisphere. New Zealand and parts of the Solomon Islands through the Philippines will have stronger than normal winds.
Much of the northern hemisphere should be slightly to moderately above normal. Much of the southern hemisphere should be near normal to slightly below normal.
Cool outbreaks are limited to parts of Australia, New Zealand and the South Pacific and parts of the US Midwest and Caribbean.
Meanwhile in the Pacific Ocean the north Pacific through to the equatorial Pacific will be much warmer than normal as will be the eastern Pacific off of South America and the North Atlantic into Europe. East of the Caribbean will be warmer than normal and along the eastern seaboard of the USA and Canada and northern Europe. The east coast of China and areas of Southeast Asia and areas around the Bay of Bengal will be warmer than normal as will be the Nusa Tengarra region of Indonesia.
Parts of the US Midwest, Rocky Mountains and Sierra Mountains of California and interior parts of Argentina and Brazil near the Andes could have extreme precipitation events as well as the Himalayas, Gulf States and West Africa. Papua New Guinea, Solomon Islands, mainland SE Asia and west central Africa could be unusually dry along with parts of the Amazon Basin, Central America and Caribbean.
The evolution of ENSO can be viewed through sea surface temperature anomaly maps. The Eastern Pacific is warmer than normal as is the Indian Ocean. The central and eastern north Atlantic is also warmer than normal. The ocean surrounding New Zealand is cooler than normal.
The Southwest of the USA and Northeast of Mexico and the South China Sea region and part of the Philippines and central India and large parts of Brazil are all showing positive rainfall anomalies. From Vanuatu northwest through Papua New Guinea and the Indonesian archipelago and also most of Central America and northern South America there is a considerable negative rainfall anomaly as well as in the western part of India.
The warmer than normal areas include much of California and the western States of the USA, Alaska and the Northwest Territories across to Hudson’s Bay in Canada. Also the Maritime Provinces of Canada are likely to be warmer than normal. Central Argentina and western Brazil should be cooler than normal. Peru and south through Chile should be warmer than normal along with most of Central and Western Europe and South Africa and areas around the Red Sea and Persian Gulf and Central Asia. Much of the Eastern Pacific ocean area will be considerably warmer than normal as well as large areas in the central Atlantic and Southeast USA. Much of northern Africa will be warmer than normal while Central Africa will be considerably cooler than normal. Much of Pakistan and north India across the Himalaya into Southern China will be warmer than normal all the way up to Siberia. The Southern Ocean and areas around Greenland will be well below normal along with the central part of the South Atlantic.