EI Niño conditions have strengthened across the Pacific Ocean during the first quarter of 2017 with an increasing probability (around 50% chance) that the phenomenont may develop in the coming months. The sea surface temperatures in the tropical Pacific Ocean have warmed since the start of 2017, especially in the west coastal regions of Peru with a 6°C above normal temperature, according to the Peruvian Government Multisectoral Committee on the El Niño Phenomenon (ENFEN). The average sea surface temperature anomalies are shown in the NOAA image in figure 5.6. As only the sea waters in the coastal areas of Peru and Ecuador heated up significantly and not the entire Pacific Ocean, scientists are reporting a "Coastal Niño." As a result, severe rains have been ongoing since December 2016 in Peru and neighboring countries (see also section 5.2), which have intensified in the past few weeks, causing landslides, floods, flash floods, and mud flows.

Figure 5.6. Average sea surface temperature (SST) anomalies (°C), April 2017 

Note: Anomalies are computed with respect to the monthly means for the 1981 to 2010 period.

Source: NOAA, https://www.climate.gov/maps-data/data-snapshots/data-source-sst-anomaly-enso-monitoring-region

Figure 5.7 Behavior of the standard Southern Oscillation Index (SOI) of the Australian Bureau of Meteorology (BOM), April 2016 to April 2017

Source: http://www.bom.gov.au/climate/current/soi2.shtml.

In the current season, the Southern Oscillation Index (SOI) has decreased from +1.3 in January to -2.2 in February, after which it rose to 5.1 in March and then again decreased to -6.3 in April (figure 5.7). The Australian BOM reports an El Niño watch, and CropWatch will continue paying attention to the risk of a renewed El Niño in 2017.