DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
11 April 2019
ENSO Alert System Status: El Niño Advisory
Synopsis: A weak El Nino is likely to continue through the Northern Hemisphere summer 2019 (65% chance) and possibly fall (50-55% chance).
El Niño continued during March 2019, as above-average sea surface temperatures (SSTs) persisted across the equatorial Pacific Ocean [Fig. 1]. The latest weekly values of the Niño3 and Niño4 indices were +0.8°C, while the Niño3.4 value was +0.9°C [Fig. 2]. The anomalous upper-ocean heat content (averaged across 180°-100°W) decreased during March but remained well above average [Fig. 3], as the above-average temperatures at depth peaked in early March in association with a downwelling equatorial oceanic Kelvin wave [Fig. 4]. Enhanced equatorial convection was observed near the Date Line and in the western Pacific, while suppressed convection prevailed over western Indonesia [Fig. 5]. Low-level wind anomalies were westerly in the western Pacific Ocean during March. Meanwhile, upper-level winds were mostly near average. The equatorial and traditional Southern Oscillation Index values were negative. Overall, these features are consistent with a weak El Niño.
The majority of models in the IRI/CPC plume predict a Niño 3.4 index of +0.5°C or greater through the remainder of 2019 [Fig. 6]. Most forecasters expect SST anomalies in the Niño 3.4 region to remain between +0.5°C and +1.0°C for at least the next several seasons, indicating a weak El Niño. However, because forecasts made during spring tend to be less accurate, the predicted chance that El Niño will persist through fall is currently 50-55%. In summary, a weak El Niño is likely to continue through the Northern Hemisphere summer 2019 (65% chance) and possibly fall (50-55% chance; click CPC/IRI consensus forecast for the chance of each outcome for each 3-month period).
https://www.cpc.ncep.noaa.gov/products/ ... disc.shtml