Synopsis: ENSO-neutral conditions are favored to continue through at least the Northern Hemisphere spring 2017, with increasing chances for El Niño development by late summer and fall.
ENSO-neutral conditions continued during March, with near-average sea surface temperatures (SSTs) across the central equatorial Pacific and above-average SSTs in the eastern Pacific. The latest weekly Niño index values were near zero in the Niño-4 and Niño-3.4 regions, and +0.8 and +0.9°C farther east in the Niño-3 and Niño-1+2 regions, respectively. The upper-ocean heat content anomaly, averaged across the central and eastern Pacific, decreased to near zero during March, a reflection of above-average temperatures at depth in the east offset by below-average temperatures in the central Pacific. Atmospheric convection remained suppressed over the central tropical Pacific and enhanced over the Maritime Continent. The low-level easterly winds were enhanced over the central and western tropical Pacific, and weaker than average over the eastern Pacific. Also, upper-level westerly winds were anomalously easterly over the western and far eastern Pacific, while the Southern Oscillation Index was near average. Overall, the ocean and atmosphere system is consistent with ENSO-neutral conditions.
Most models predict the continuation of ENSO-neutral (3-month average Niño-3.4 index between -0.5°C and 0.5°C) through the late Northern Hemisphere spring (April-June). However, at least one-half of the dynamical model forecasts, including the NCEP CFSv2, anticipate an onset of El Niño as soon as the April-June season. Because of typically lower skill in forecasts made at this time of the year, and the lingering La Niña-like tropical convection and wind patterns over the western half of the Pacific basin, the forecaster consensus favors ENSO-neutral during April-June with a 60-65% chance. Thereafter, there are increasing odds for El Niño toward the second half of 2017 (~50% chance from approximately August-December). In summary, ENSO-neutral conditions are favored to continue through at least the late Northern Hemisphere spring 2017, with increasing chances for El Niño development by late summer and fall.
North and South America are near normal. Australia and New Zealand are near normal. Asia and Africa are near normal however winds are greater than normal in the northern Indian Ocean and Southern India Ocean and also in the central and western Pacific.
Much of the northern half of the northern hemisphere should be above normal while the mid-latitudes and tropics should be slightly below normal and the southern latitudes should be below normal.
Much of North, Central and South America are forecast as usually low while similar conditions prevail in much of Southern Africa and Eastern and northern Russia and the Korean Peninsula and Japan and eastern Australia and New Zealand. Only the eastern seas board of China is expected to have unusually high temperature outbreaks.
Most land areas are forecast to have usually high or usually low extreme forecast events. Parts of the Amazon Basin could experience extremely low rainfall events as well as parts of the Congo Basin and Southern Thailand and Peninsular Malaysia. Unusually wet events are possible in eastern Mexico and southern Texas and eastern and mid-central China as well as parts of southern West African countries.
Warmer than normal conditions prevail in the western North Atlantic and near normal conditions elsewhere. In the South Atlantic near normal conditions prevail.
The Northern Pacific is near normal with cooler to near normal waters in the eastern tropical Pacific. The far northern Pacific should be cooler than normal as well as the Arctic sea north of North America while the Arctic Sea north of Russia should be considerably warmer than normal. The South Pacific is warmer than normal off the South American coast and also in the western South Pacific The sea around New Zealand is warmer than normal.
The Indian Ocean is near normal in the north and cooler than normal for a larger area south of the equator off of the coast of Western Australia. A very cold pool of water remains of the west coast of Alaska.
North and South America near normal with slightly wetter conditions in northern and northeast South America and drier than normal in eastern Brazil.
Southeast Asia looks drier than normal for much of insular SE Asia. But wetter than normal conditions prevail in eastern PNG and the Solomon Islands. In the Central to western Pacific it should be wetter than normal north of the equator and drier than normal to the south of the equator.
Much of Africa should be near normal except for parts of the Southern West Africa from Nigeria to the west that should be wetter than normal. The Middle East and western central Asia should be near normal. Europe should be near normal.
Much of North America, the Caribbean, and Central America should be warmer than normal. The Northwest of Canada that should be warmer than normal along with northern South America and Argentina.
New Zealand should be slightly warmer than normal. Most of Australia should be near normal except for the Eastern Seaboard that should be warmer than normal. All the Asian continent should be slightly to moderately warmer than normal.
The Congo Basin should be cooler than normal and Southern Africa near normal and the Sahel should be warmer than normal while south of the Sahel in West Africa should be cooler than normal. The Middle East and Iran and Afghanistan should be warmer than normal. The Arctic should be considerably warmer than normal in eastern Canada and cooler than normal elsewhere. Most of Europe should be near normal except Northern Europe could be moderately cooler than normal.