Stormy weather at the Hong Kong International Airport during the passage of Tropical Cyclone Pakhar
The successive strikes of Hato and Pakhar, which necessitated the issuance of Tropical Cyclone Warning Signal No. 10 and 8 respectively in just under 5 days in August 2017 wreaked havoc to air traffic in Hong Kong. Hato caused the cancellation of over 400 flights. While flight cancellation during Pakhar was less, the impact of Pakhar was nonetheless significant with 70 windshear reports and 18 turbulence reports received from pilots during the period when Tropical Cyclone Warning Signal was in force. When Pakhar was closest to Hong Kong, the occasional hurricane force winds in cross-mountain flow of Lantau resulted in terrain-induced windshear up to microburst strength (Figure 1). The terrain-induced windshear and turbulence were well captured by the TDWR and the WTWS.