Blocking Plots

Contents. Two viewers. The first shows composite fields of Northern Hemisphere blocking and propagating anticyclones from the PV-tendency analysis (ERA5). The second shows the latest operational forecast over the Northern Hemisphere at 850, 500 and 250 hPa, updated every 6 h, with 500-hPa cyclone and anticyclone centres tracked over the preceding five days.

• 1 Blocking composite viewer

  Onset, peak and decay composites of blocking and propagating anticyclones (all events, anticyclonic and cyclonic wave-breaking subsets), with PV-tendency terms, vertical motion, diabatic heating and the orthogonal-basis projection. Data: ERA5 composites hosted on Hugging Face.

• 2 Northern Hemisphere forecast viewer

  Latest GFS, ECMWF AIFS-single or ECMWF IFS forecast, 0–240 h, for u, v, T, Z, ω and q at 850, 500 and 250 hPa. Rectangular (0–90°N) or polar-stereographic view; one shaded and one contoured variable at a time; 500-hPa cyclone and anticyclone centres with their five-day tracks. Click a centre for its zonal and meridional displacement.