El-NINO UPDATE - Lake Gregory Weather

EASTERN PACIFIC TROPICAL STORMS

HURRICANE LALA

ENSO: Recent Evolution, Current Status and Predictions

El Niño conditions are strengthening across the tropical Pacific, with sea surface temperature (SST) anomalies in the Niño 3.4 region showing a steady upward trend. The observed SST anomaly averaged +0.98 °C during April–June 2026 and increased to +1.55 °C in June 2026. The latest weekly Niño 3.4 index, centered on July 15, 2026, climbed further to +2.1 °C. Together, these Pacific Ocean SST observations indicate that El Niño conditions continue to intensify, suggesting the event is evolving toward a very strong El Niño.

EL NIÑO/SOUTHERN OSCILLATION (ENSO)DIAGNOSTIC DISCUSSION

ENSO Alert System Status: El Niño Advisory-August 13, 2026

Synopsis: El Niño is strengthening, with a greater than 90% chance of a very strong event during the Northern Hemisphere fall and winter 2026-27.

El Niño strengthened over the past month, with sea surface temperature anomalies exceeding +2.0°C in the eastern equatorial Pacific [Fig. 1]. The July Niño index values were +1.4°C in Niño-3.4, +1.7°C in Niño-3, and +2.9°C in Niño-1+2 [Fig. 2]. The equatorial subsurface temperature index (average from 180°-100°W) increased during July [Fig. 3], reflecting a deeper-than-average thermocline [Fig. 4]. Subsurface temperature anomalies were significant, reaching +10.0°C at depth. Low-level westerly wind anomalies and upper-level easterly wind anomalies extended from the western to east-central equatorial Pacific. Convection and rainfall were enhanced from the central to eastern Pacific and were suppressed over Indonesia [Fig. 5]. The traditional and equatorial Southern Oscillation indices were significantly negative, with values near 2 standard deviations during July. Collectively, the coupled ocean-atmosphere system reflected a strengthening El Niño.

The CPC Official ENSO outlook, which synthesizes multiple models from North America and abroad, indicates El Niño will continue to strengthen through the end of the year [Figs. 6-7-8]. During the October-December 2026 season, there is a 69% chance of a historic event that would exceed the strength of previous El Niño events dating back to 1950 (+2.5°C or more for a 3-month RONI value). With an event of this magnitude, the chances of experiencing impacts consistent with El Niño are larger, but they are not guaranteed (see CPC outlooks for probabilities of seasonal anomalies). In summary, El Niño is strengthening, with a greater than 90% chance of a very strong event during the Northern Hemisphere fall and winter 2026-27.

Official NOAA Relative Oceanic Niño Index (RONI) Outlook Issued August 2026
The values show the forecasted range of Relative Oceanic Niño Index (RONI) values for 9 upcoming, overlapping 3-month seasons (each letter represents a month, F = February). The color shading shows the forecast ranges, with the darkest color shading indicating that there is a 50% chance that the forecasted RONI values will remain between the RONI values displayed. There is a 90% chance that forecasted RONI values will remain between the upper and lower edges of the lightest color shading. The middle color shade provides the RONI forecast range with a 70% chance. Alternatively, the table provides RONI values corresponding to the various percentiles displayed in the image.