The rarely severe weather over north-west India has also thrown up the rarest of weather-setting systems over the past 24 hours. The low-pressure area embedded into an intense but trendsetting western disturbance has overnight intensified into a depression.
MOISTURE INCURSION
The India Meteorological Department (IMD) said in its bulletin that the system is called a ‘western depression.’ It has already triggered widespread rain, snow and even hailstorm across the hills and plains. The system was located over west Rajasthan but IMD observed a trend in moisture incursion from peninsular seas. This could mean that the system is moving faster to east than earlier thought and preparing to exit the region and away. In fact, the IMD said that the system might move away east-north-eastwards during the next 24 hours (Wednesday).
EASTERLY WAVE
Global models hinted that the system might ‘yank in’ an away-going easterly wave to position across south peninsula. Easterly waves travel from east to west over south Bay of Bengal and are oriented mostly south towards Sri Lanka during this time of the year. But the ‘westerly’ influence on this wave is expected to bring some rain to parts of Kerala and adjoining south interior Karnataka. The western disturbance is enormous in size, with its reach spanning the Arabian Sea, central India and the Bay of Bengal.
OCEAN MOISTURE
It features anticlockwise (cyclonic) winds getting intense nearer to the ‘western depression.’ Ocean moisture and cold and dry continental winds blowing across the North-west border had combined to spark the severe weather. The IMD cited initial reports suggesting occurrence of hailstorm over Haryana, Uttar Pradesh, Rajasthan and Himachal Pradesh during the 24 hours ending on Tuesday morning.
Forecasts said that moderate rain/snow is likely over Jammu Kashmir, Himachal Pradesh and Uttarakhand on Wednesday and decrease thereafter. Light to moderate rain or showers are likely over Haryana and Delhi on Wednesday and over Uttar Pradesh during next two days. Isolated thundershowers are forecast over Punjab and Rajasthan on Wednesday and over North Madhya Pradesh and Bihar during next two days.