Warm Subsurface Kelvin Wave Plows into Cool East Pacific Waters Weakening La Nina

Highlight: Ongoing weak La Nina.

Fig. 1-2: The SSTA across the Nino34 region and 30-day change.

Discussion: The Nino34 SSTA region is currently in a marginal weak La Nina signature (Fig. 1). The daily SSTA for this region is -0.58C. During the past 30 days, the Nino34 SSTA region has warmed by +0.38C (Fig. 2). A marginal weak La Nina remains in-place (Fig. 3). In the subsurface, a strong Kelvin Wave (area of anomalous warm water) is shifting eastward to about 135W. Note that the cool fuel required to sustain La Nina is diminishing (Fig. 4). La Nina remains likely to weaken to neutral phase by April.

Fig. 3: The Nino SSTA regions indicate La Nina is weak.

Fig. 4: NOAA/CPC indicates an east-shifting subsurface warm anomaly known as a Kelvin Wave is slowly eroding away the cool waters needed to sustain La Nina.