Convection-based assessment of pre-monsoon season instability indices over Chandigarh and Ladakh regions, India

The current study looked at the numerous meteorological variables that influence the occurrence of convective systems in the Indian cities of Chandigarh and Ladakh. The convection-related parameters used in this analysis are the K index (KI), total totals index (TTI), improved KI, improved total totals index, total precipitable water (TPW), humidity index (HI), lifted index (LI), and convective potential energy available (CAPE). The rainfall (RF) linked convective systems that occur in the pre-monsoon season (PREMS) between 1997 and 2020 were studied using ERA5 reanalysis daily datasets. The enhanced KI and TTI indexes plainly suggested that there was a good likelihood of convection in the PREMS. The HI parameter values revealed that severe convective systems were more likely in Ladakh than in Chandigarh. The TPW values are very low over Ladakh region than Chandigarh. Very low CAPE values were observed throughout the season over both the regions. From LI parameter, we have found that Chandigarh region indicated a moderate chance for severe convective system, whereas Ladakh region indicated no chances for the occurrence of any convective system. Large negative values are detected at 400–500 hpa pressure levels, indicating a strong possibility for severe rainfall activity with ascending air motion, according to vertical velocity profiles. The increase in relative humidity values and decrease in dew point depression values indicate the availability of sufficient moisture required for the convection rainfall. The drop in specific humidity values at 500hpa pressure level favors the occurrence of convection rainfall.