Stratospheric warming leading to evolution of a large arctic air mass remains in the forecast for Eurasia. Latest indications are the air mass releases southeastward into China in the 1-15-day period rather than cross-polar into North America. Consequently, the U.S. gas population weight HDD forecast is revised milder for the second half of February.

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.

Strengthening drought was observed during NOV/DEC/JAN 2023-24 in Central Brazil, Northwest Africa, the Middle East, and Central Indonesia. El Nino 2023-24 has shifted past the mature stage. The outlook is for rapid deceleration to neutral ENSO during MAR/APR/MAY 2024. Drought concern is highest across Central Brazil to Chile, the Middle East, and South Africa. A climate pattern change to a wetter scenario is projected for Southeast Asia and Indonesia.