Analysis of Hail Events in Rejang Lebong District on March 27, 2023, Utilizing Weather Radar Images

High-impact weather events in the form of hail have affected Rejang Lebong Regency in Bengkulu Province on March 27, 2023. Two areas are affected by hail with a diameter of 1 cm, such as Simpang Nangka Village and Cawang Lama Village, around 17.00 LT–18.00 LT (10.00–1.00 UTC) marked by heavy rain with lightning. Based on the hail incident report, an analysis of the extreme weather phenomenon of hail in Rejang Lebong district was carried out, which focused on the utilization of Bengkulu weather radar data. The results of the study showed the growth of strong convective clouds, such as Cumulonimbus (Cb) clouds detected by radar on March 27, 2023, at 08.00 UTC (15.00 LT) and continued to grow to maturity at 09.30 UTC (16.30 LT) in the Rejang Lebong district area. At the time of the event, a reflectivity value of 65 dBZ was observed. Analysis of the height of the Cb radar cloud around the event location found that the height reached more than 15 km. In addition, a special analysis was conducted in the area of the hail event by utilizing the radar maximum reflectivity value and Quantitative Precipitation Estimation (QPE) from the results of the Z-R relationship equation. In addition, tropical wave analysis shows that the Madden–Julian Oscillation (MJO) is active and is a trigger factor for the growth of massive convective clouds. On the other hand, Equatorial Rossby (ER) waves and Kelvin waves are in an inactive phase in western Indonesia when a hail event occurs.