Reanalysis study demonstrates that subpolar North Atlantic cooling fostered an Omega block during the 2026 European heatwave, suggesting ocean-atmosphere drivers of summer extremes.
Key Points
Investigate the synoptic, dynamical, and climatic mechanisms driving the severe early-summer heatwave across Western and Central Europe in June 2026.
Analyzed atmospheric and surface variables using ERA5 reanalysis data during the late June 2026 event.
Evaluated 500 hPa geopotential height, 850 hPa temperature, polar jet stream dynamics, Rossby wave breaking, and the dynamical tropopause alongside sea surface temperature anomalies and soil moisture.
A persistent Omega block drove intense atmospheric subsidence, warm air advection, and solar heating over Western Europe, reinforced by dry soils and heightened sensible heat fluxes.
A prominent cold sea surface temperature anomaly in the subpolar North Atlantic preceded the blocking onset, weakening the meridional temperature gradient and reducing lower-tropospheric baroclinicity along the jet stream.