Synopsis: ENSO-neutral conditions have returned and are favored to continue through at least the Northern Hemisphere spring 2017.
La Niña conditions are no longer present, with slightly below-average sea surface temperatures (SSTs) observed across the central equatorial Pacific and above-average SSTs increasing in the eastern Pacific. The latest weekly Niño index values were -0.3°C in the westernmost Niño-4 and Niño-3.4 regions, and +1.5°C in the easternmost Niño-1+2 region. The upper-ocean heat content anomaly increased during January and was slightly positive when averaged across the eastern Pacific, a reflection of above-average temperatures at depth. Atmospheric convection remained suppressed over the central tropical Pacific and enhanced over Indonesia. The low-level easterly winds were slightly enhanced over the western tropical Pacific, and upper-level westerly winds were 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 Northern Hemisphere summer. However, a few dynamical model forecasts, including the NCEP CFSv2, anticipate an onset of El Niño as soon as the Northern Hemisphere spring (March-May 2017). Because of typically high uncertainty in forecasts made at this time of the year for the upcoming spring and summer, and the lingering La Niña-like tropical convection patterns, the forecaster consensus favors ENSO-neutral during the spring with a ~60% chance. Thereafter, there are increasing odds for El Niño toward the second half of 2017 (~50% chance in September-November). In summary, ENSO-neutral conditions have returned and are favored to continue through at least the Northern Hemisphere spring 2017.
Much of the country should be warmer than normal and the northern plains across the Great Lakes considerably so. Only far southern Texas and Florida should be slightly cooler than normal.
Most of Washington, Oregon should be near normal to slightly above normal for precipitation while California and most of Nevada should be near normal in the northern half and moderately drier than normal in the southern half. The northern plans should be slightly wetter than normal while the Southwest through to the Mississippi valley and southern Rockies should be slightly to moderately drier than normal. Much of the Great Lakes region should be near normal and the eastern third of the country should near normal to slightly drier than normal with Florida moderately drier than normal.
The Great Plains should be wetter than normal. The Southwest and across the Gulf states to Florida and up the Mississippi valley should be slightly to moderately drier than normal as well as the Great Lakes region. The eastern seaboard should be near normal to slightly drier than normal.