Analysis of the Causes and Wind Field Structure of a Dry Microburst in a Weak Weather Background

Abstract

Dry microbursts in weak weather backgrounds, due to their small scale and general lack of precipitation, are often difficult to observe using weather radar. On the night of 26 April 2023, a dry microburst occurred at the Yinchuan Airport. Based on conventional meteorological observations, Automated Weather Observing System (AWOS) data, and the Doppler Wind Lidar data, an analysis was conducted on the causes and wind field structure of this microburst. It was found that (1) the sounding data indicated a DCAPE value of 880 J·kg−1, which is important for forecasting the potential for dry microburst events; (2) the foehn from the Helan Mountains contributed to the occurrence of microburst weather at the Yinchuan Airport; (3) the Doppler Wind Lidar wind data showed distinct characteristics of the wind field during this microburst event, including a symmetric horizontal wind field structure, significant vertical downdraft velocities (reaching −5.76 m·s−1), and low-level wind shear over the airport runway and its vicinity; and (4) effective monitoring of such microburst weather events with the Doppler Wind Lidar wind measurements is crucial for ensuring aviation safety.

Keywords

• the Doppler Wind Lidar
• dry microburst
• foehn
• wind shear