## 6 Conclusions  
A novel study is conducted in this paper to compare the vertical winds and EDRs retrieved from the weather radars for an intense squall line over southern China with  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Flight** & **Time** & **Circraft Altitude** & **EDR from** & **EDR Derived from** & **Vertical Velocity** & **Vertical Velocity** \\
**No.** & **Period** & **Aircraft Altitude** & **Aircraft Data** & **Width Data** & **from** & **Radar-Based Wind** \\  & & & **(m\({}^{20}\)s\({}^{-1}\))** & **(m\({}^{20}\)s\({}^{-1}\))** & **Aircraft Data** & **Retrieval** \\ \hline \multirow{4}{*}{A} & 06-54 to & \multirow{4}{*}{\begin{tabular}{} \end{tabular} } & About 0.6 at around & & & \\  & 06:56 UTC. & & 06:56 UTC when the & & & \\  & 06:56 UTC. & about 0.06 km to & aircraft was at a height & About 0.6 to 0.7 at 1 km height. & & \\  & 06:56 UTC. & 1.3 km. & of about & & & \\  & & 1.1 km. & & & & \\ \hline \multirow{4}{*}{B} & 06-56 to & \multirow{4}{*}{\begin{tabular}{} \end{tabular} } & Between 0.6 to 0.7 at & & & \\  & 06:57 UTC & & 06:57 UTC when & Between 0.6 to 0.7 & \(-12.0\) to & \\  & 06:57 UTC & about 0.27 km to & around 0.09 km. & & & \\  & & & & & & \\  & & & & & & \\  & & & & & & \\  & & & & & & \\  & & & & & & \\  & & & & & & \\ \hline \multirow{4}{*}{B} & 07:00 to & \multirow{4}{*}{\
\begin{tabular}{} \end{tabular} } & \multirow{4}{*}{
\begin{tabular}{} \end{tabular} } & Max. about 1.0 between & & & \\  & 07:26 to & 07:27 UTC & 07:26 and & 07:27 UTC when the aircraft was at a height of about & 1 km height and & 1 km height. & & \\  & 07:27 UTC. & about 1.4 km. & & & & \\  & & & & & & \\  & & & &  
the point measurements from six aircraft. In general, the EDR maps based on radars are consistent with the aircraft data and they are verified, at least for this case, to be useful for timely alerting of severe turbulence for aviation applications. Some discrepancies in the vertical velocities are observed, and they may be related to the limited spatial and temporal resolutions of the weather radars particularly the sampling time of radar data can significantly affect the accuracy of retrieved vertical velocity as mentioned by [PERSON] and [PERSON] [19]. To the knowledge of the authors, such comparisons using actual commercial flight data are very limited in the literature, and the results in this paper could be useful for reference for the development of turbulence alerts for aircraft.  
HKO is going to expand the network of ground-based X-band PAWR in Hong Kong, based on the success of a previous trial [15]. This network would provide data nearer the ground, so that more radar data near the sea surface would be available for retrieval of low-altitude winds. Moreover, the volume scan would be performed every 1 to 1.5 min, with a higher spatial resolution at the same time. All these may help reduce the discrepancies between the radar-derived products and the aircraft's point measurements. Future observations and comparison studies would be reported in the literature later.  
Conceptualization, P.-w.C. and Y.-w.C.; methodology, P.-w.C. and Y.-w.C.; software, Y.-w.C. and P.C.; validation, Y.-w.C. and M.-l.C.; formal analysis, P.-w.C. and Y.-w.C.; investigation, Y.-w.C. and P.C.; resources, Y.-w.C. and P.C.; data curation, M.-l.C.; writing--original draft preparation, P.-w.C. and Y.-w.C.; writing--review and editing, P.C. and M.-l.C.; visualization, Y.-w.C. and M.-l.C.; supervision, P.-w.C.; project administration, P.-w.C. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The datasets presented in this article are not readily available because the study involves proprietary aircraft data.  
The authors declare no conflict of interest.