Conflicting signals in February regarding ENSO as sharp negative phase southern oscillation index (-SOI) reveals the El Nino climate for the 2023-24 episode is peaking while the subsurface equatorial Pacific Ocean is cooling rapidly as ocean warming to sustain El Nino is fading fast. The outlook maintains a rapid decline in El Nino intensity during the next 2-4 months with neutral ENSO likely by MAY/JUN followed by further Pacific cooling causing La Nina to form by JUL/AUG. La Nina may last into 2026.

The surge of MJO convection past the Dateline in the tropical Pacific helped to motivate a Pacific “atmospheric river” storm track bringing “bomb cyclones” to California. Speculated is the latent heat release from this MJO episode may have traveled upward and poleward in the atmosphere to trigger a 3rd stratospheric warming event in the polar region. Of course, the consequence of stratospheric warming is generation of arctic air at ground level.