Study on the Precursor Signal Capturing of Unfavorable Weather: Months/Years in Advance to Ultra-Early Forecast for Hourly Transient Weather Changes during the Beijing Winter Olympics

Figure 7

(a) Directed transport of pollution meteorological conditions index (PLAM_⟶obj) to Beijing at 00:00 on February 27, 2021, (b) surface weather map of Beijing–Tianjin–Hebei region at 06:00 on February 27, 2021, (c) directed transport of pollution meteorological conditions index (PLAM_⟶obj) to Beijing at 00:00 on February 11, 2021, and (d) directed transport of pollution meteorological conditions index (PLAM_⟶obj) to Beijing at 00:00 on February 12, 2021.