Incoming weather systems approaching North and North-West India as well as the South Peninsula from mutually converse directions over next few days will bring heavy rainfall, thunderstorms, damaging winds and lightning to rain-deficient regions to the extreme north and south of the country, even as the transition from winter to spring happens after a fortnight.
North-West India has run up a rain deficit of -73 per cent in the new year as February prepares to sign off. The South Peninsula lags not far behind with -64 per cent, while the deficit is worse at -89 per cent over Central India. East and North-East India alone offers some comfort with -22 per cent., with the region expecting more rain and thunderstorms this week.
Western disturbance on its way
North-West India sets great store by an incoming western disturbance spotted on Tuesday morning, quite some distance away over west Iran. It has to navigate Afghanistan and Pakistan, before finally knocking the doors of North-West India. The India Meteorological Department (IMD) has hinted at the potential of its sustaining a heavy moisture feed from the Arabian Sea.
Thus, westerly winds associated with the disturbance will whip up incremental moisture from the Arabian Sea and blow it into the heights of the Himalayas, where it will be wrung out in the form of deep clouds and widespread snowfall/ rainfall along the hills.
Rainfall, thunderstorms
The IMD has forecast fairly widespread to widespread light to moderate rainfall/ snowfall, thunderstorms and lightning over Jammu-Kashmir-Ladakh and Himachal Pradesh till Friday; and over Uttarakhand from tomorrow (Wednesday) to Friday.
Heavy rainfall/ snowfall is likely over Jammu-Kashmir-Ladakh during these four days; over Himachal Pradesh for three days; and Uttarakhand on two days, with very heavy rainfall/ snowfall likely over Jammu-Kashmir-Ladakh-Himachal Pradesh on Thursday.
Plains, too, may benefit
Some of this activity will filter into the plains, with IMD predicting isolated to scattered light to moderate rainfall likely over Punjab, Haryana and Chandigarh from Wednesday to Saturday (March 1); West Uttar Pradesh and Rajasthan for three days from Thursday to Saturday; and over East Uttar Pradesh for two days on Friday and Saturday. Thunderstorms and lightning may roll out over Punjab and Haryana for three days from Wednesday to Friday; and over north Rajasthan on Thursday and Friday.
In the East and North-East, a cyclonic circulation over Assam continues to feed on oodles of moisture from the neighbouring Bay of Bengal. This, too, gets lifted up against the heights of the eastern Himalayas, and may trigger scattered light to moderate rainfall, thunderstorms and lightning over Arunachal Pradesh, Assam, Meghalaya, and Nagaland, Manipur, Mizoram and Tripura today.
Active easterly wave
In the south, an active easterly wave traversing the southern parts of the Bay is expected to cause fairly widespread to widespread light to moderate rainfall, thunderstorms and lightning over the Andaman & Nicobar Islands today and tomorrow (Tuesday and Wednesday). Heavy rainfall is likely at isolated places over the islands on both these days.
Easterly waves propagate along a straight line eyeing mainly Sri Lanka, parts of Tamil Nadu and Kerala during this time of the year. Scattered to fairly widespread light to moderate rainfall, thunderstorms and lightning are likely over Tamil Nadu, Puducherry and Karaikal, as well as Kerala and Mahe for three days from Thursday to Saturday, with isolated heavy rainfall on Friday and Saturday.