Study of moisture flux over Uttarakhand State: signature of cloud bursts

Moisture flux and precipitable water content (PWC) analysis are carried out over Himalayan state of Uttarakhand, India during the Indian summer monsoon season for the period 1959–2021 (1959–2001: P1; 2002–2021: P2) to understand their distribution pattern. The intense moisture convergence is seen over the hilly region in the recent past (P2) through the rotational and divergent components of moisture flux analysis. The analysis indicates an increasing trend of PWC with values 1.2, 1.9, 2.0 and 2.5 mm/decade during June to September months respectively. The spatial distribution of rainfall shows a stronger magnitude in the eastern part and relatively weaker magnitude in the western part, during June to August since 2002. Convective available potential energy (CAPE) is increased in the low altitude region in the summer months except July and shows maximum during September (~ 100 J/kg) since 2002. However, the study of vertically integrated moisture flux divergence (VIMFD) shows stronger (weaker) convergence in the windward side (leeward side) in Uttarakhand. These climatological distributions of PWC, CAPE, rainfall, and VIMFD analysis implicate a signature of cloud burst/heavy precipitation region in the recent past in Uttarakhand.