An incoming western disturbance is progressing on its onward journey through Iran and next into Afghanistan and Pakistan before entering West India or North-West India, even as its southern flanks on Wednesday morning appeared to dip as far down as Ras al-Khaimah and Abu Dhabi in the UAE, signalling its size and intensity.
It will likely throw up a rare low-pressure area ahead of it over West Rajasthan and adjoining areas of Pakistan by tomorrow (Thursday), the India Meteorological Department (IMD) said on Wednesday morning. Normally, active western disturbances set up lower-intensity cyclonic circulations in advance, which start impacting weather both over the hills and plains of North-West India. More developed weather systems such as full-fledged low-pressure areas are hard to come by.
Follow-up system soon
Meanwhile, a fresh western disturbance may affect North-West India from Sunday (March 2). Under its influence, scattered to fairly widespread light/moderate rainfall/snowfall is likely over Jammu-Kashmir-Ladakh and Himachal Pradesh on Sunday and Monday, while Uttarakhand will experience isolated light/moderate rainfall/snowfall. The sudden increase in western disturbance activity is believed to be in response to a massive polar vortex that swung through the US, setting off a record cold blast there last week.
Thunderclouds have swarmed the Andaman & Nicobar Islands on Wednesday morning as a weather-setting easterly wave moves across the southern Bay of Bengal eyeing the Sri Lanka and southern Tamil Nadu coasts.
| Photo Credit: www.meteologix.com/in
Easterly wave in South
Towards the South, a counterpart easterly wave approaching Sri Lanka and South Tamil Nadu coasts will trigger fairly widespread to widespread light/moderate rainfall, thunderstorms, and lightning, making its first impact over the Andaman & Nicobar Islands today (Wednesday). Scattered to fairly widespread light/moderate rainfall, thunderstorms, and lightning are expected over Tamil Nadu, Puducherry & Karaikal, and Kerala & Mahe for three days starting tomorrow (Thursday).
Heavy rain for Tamil Nadu
Isolated heavy rainfall is forecast for Tamil Nadu, Puducherry & Karaikal for three days from Thursday, and over Kerala & Mahe on Friday and Saturday. Western disturbances in North-West, East, and North-East India and easterly waves moving across the southern parts of the Bay of Bengal in the opposite direction are weather systems that bring rain and thunderstorms to respective regions during an otherwise quiet period in winter and even into spring. The 2024-25 winter draws to a close in the next two weeks.
High moisture feed
Meanwhile, it remains to be seen how long the ensuing low-pressure area over Rajasthan will last, but the IMD said it will lead to a high moisture feed incrementally from the adjoining North Arabian Sea. Associated westerly to south-westerly winds will cause moisture to ride up to the heights of the Himalayan ranges, where it will condense to form clouds, rainfall, and snow.
The IMD sees the possibility of fairly widespread to widespread light to moderate rainfall/snowfall, thunderstorms, and lightning over Jammu-Kashmir-Ladakh, Uttarakhand, and Himachal Pradesh for three days from Wednesday. Heavy rainfall/snowfall is likely at isolated places over Jammu-Kashmir-Ladakh, Himachal Pradesh, and Uttarakhand on Thursday and Friday. Isolated very heavy rainfall/snowfall is likely over Jammu-Kashmir-Ladakh today and tomorrow, and over Himachal Pradesh on Thursday.
Rain for plains also
Across adjoining plains, isolated to scattered light to moderate rainfall is expected over Punjab, Haryana, Chandigarh, and West Rajasthan for four days; over West Uttar Pradesh on Thursday and Friday; East Uttar Pradesh on Friday and Saturday; East Rajasthan for three days from Thursday, and gusty winds over Punjab & Haryana on Thursday and Friday. Thunderstorms and lightning may hit Punjab and Haryana for three days from Wednesday; West Uttar Pradesh for three days from Thursday; and East Uttar Pradesh and Rajasthan on Friday. Isolated hailstorms are likely in Punjab and Haryana on Thursday.
