El Niño conditions have been neutral across the Pacific Ocean during the second quarter of 2017 and will presumably stay so at least to the end of 2017. Figure 5.4 illustrates the behavior of the standard Southern Oscillation Index (SOI) of the Australian Bureau of Meteorology (BOM) from July 2016 to July 2017. Sustained positive values of the SOI above +7 typically indicate La Niña while sustained negative values below −7 typically indicate El Niño. Values between about +7 and −7 generally indicate neutral conditions. During the current season, SOI shows repeated fluctuations between -10.4 and + 8.1 over the monitoring period of this bulletin, which indicates the absence of any sustained negative or positive trend. To be more precise, the SOI increased from -6.3 in April to +0.5 in May, then decreased to -10.4 in June, to increase again to +8.1 in July. The Australian BOM reports that conditions are neutral and there is no El Niño currently from a global point of view. CropWatch will keep on monitoring the condition of El Niño.

Figure 5.4. Monthly SOI-BOM time series for July 2016 to July 2017

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

The sea surface temperatures of all four El Niño regions in the tropical Pacific Ocean were between +0.3°C and -0.3°C in July 2017, resulting in slightly warmer than average condition. The other weak warm anomalies mainly lie in eastern and northern Australia and in the northern Pacific Ocean (see also figure 5.5 from NOAA). The overall slightly warm condition directly confirms the neutral El Niño state in 2017.

Figure 5.5. Sea surface temperature in the tropical Pacific, July, 2017

Source: https://www.climate.gov/news-features/blogs/enso/august-2017-enso-update-extreme-neutral