Application Research of Wind Profile Radar in Land Gale Forecast of Typhoon in Fujian Province

This study employed wind profile radar data from inland stations in Fujian to analyze changes in characteristic quantities near the time of extreme winds for typhoons that made landfall or affected Fujian during 2012-2019, using 265 station-hours of extreme wind samples. A retrospective analysis of Typhoon Mekkhala (2020) was conducted as validation. A low-level strong wind belt (LLSW) was present within 3 h prior to and at the time of over 95% of extreme wind station-hours, with maximum wind speeds below 2 km ( V max ) ranging from 8 to 36 m/s in over 95% of observations and predominant directions of NE, SE, and NW. During the 3 h preceding event onset, V max and low-level wind intensity index I progressively increased while the LLSW base H 12 descended, peaking at onset. As extreme wind approached, 500–850 hPa vertical wind shear remained relatively small. Mann-Whitney U tests confirmed that V max , LLSW base, low-level wind intensity index, and vertical wind shear differed significantly between pre-gale and non-gale samples ( p <0.001). Subsequent ROC analysis revealed that parameters related to LLSW had the highest discriminative power (AUC: 0.883–0.923). Using median thresholds for 1 h lead time ( V max : 20.4 m/s; H 12 : 0.79 km; I : 30×10 -3 s -1 ; vertical wind shear: 2.1×10 -3 s -1 ), V max achieved the highest POD (50.2%) with a low FAR (3.0%), while index I showed the highest AUC (0.923) but a lower POD (43.4%). These quantified thresholds and process insights derived from wind profiler data can provide objective guidance for short-term forecasting of inland typhoon gales in operational settings.