Fig.1

Distribution of gale (a) and radar reflectivity higher than 25 dBz (b) over Hebei province on September 21, 2017"

Fig.2

Synoptic situation at 500 hPa (a), 700hPa (b) and 850hPa (c), and composite of sea level pressure field and 10-m wind field (d) at 20:00 on September 21, 2017"

Fig.3

Plot of T-logP in Baoding of Hebei province at 08:00 (a) and 14:00 (b) on September 21, 2017"

Table 1

Comparison of some environmental factors averaged from various strong thunderstorm gales in North China with the thunderstorm gale event analyzed in this study"

Fig.4

Temperature of black body (TBB) products retrieved from FY2F-satellite infrared cloud images at 14:00 (a), 17:00 (b), 20:00 (c) and 22:00(d) on September 21, 2017"

Fig.5

Distribution of reflectivity factor at 1.5°elevation angle (a), radial velocity at 0.5°elevation angle (b), vertical crossing sections of reflectivity factor (c) and radial velocity (d) along the red line in Fig. 5a at 18:30, reflectivity factor at 1.5° elevation angle (e) and radial velocities at 0.5°elevation angle (f) at 19:12 on September 21, 2017, detected by the radar in Shijiazhuang"

Fig.6

Reflectivity factor at 1.5°elevation angle (a) and radial velocity at 0.5°elevation angle (b), vertical crossing sections of radial velocity (c) along the white line in Fig. 6b at 20:00, reflectivity factor at 1.5°elevation angle (d) and radial velocity at 2.4°elevation angle (e) at 20:30, reflectivity factor at 1.5°elevation angle (f) at 22:00 on September 21, 2017, detected by the radar in Shijiazhuang"

Fig.7

The sea level pressure, 10 m wind field, hour-to-hour temperature-change, hour-to-hour pressure-change and reflectivity factor at 1.5° elevation angle detected by the radar in Shijiazhuang at 19:20 (a)、20:30 (b)、22:00 (c) on September 21, 2017"