On the high percentage of occurrence of type-B 150-km echoes during the year 2019 and its relationship with mesospheric semi-diurnal tide and stratospheric ozone

•Anomalously high occurrence of 150-km radar echoes over Kototabang during September 2019.•In the years 2017 and 2019, SW2 dominates DW1 due to the larger stratospheric ozone, when compared to other years.•Dominant SW2 along with solar minimum conditions may lead to large echo occurrence through interchange instability.