Blocking high
From Glossary of Meteorology
blocking high[edit | edit source]
(Or blocking anticyclone.) Any high (or anticyclone) that remains nearly stationary or moves slowly compared to the west-to-east motion "upstream" from its location, so that it effectively "blocks" the movement of migratory cyclones across its latitudes.
A blocking high may comprise a smaller-scale effect than that associated with large-scale blocking.