Pre-monsoon is at least one-and-a-half months away, but rain, thunderstorms and lightning are already lighting East and North-East India thanks to a cyclonic circulation over north-east Assam, and passing western disturbances with moisture upfront.
It is during pre-monsoon (March-April-May) that severe thunderstorms (nor’westers) originate over East and North-East India, southern Nepal, adjoining Bhutan and Bangladesh. They travel north-west to south-east and sometimes south-west to north-east (generally from west to east), and are destructive in nature from the viewpoint of potential impact on ground.
Destructive nor’westers
Locally known as Kalbaisakhi, nor’westers precipitate heavy showers, lightning, thunder, hailstorms, dust storms, squalls, and even tornadoes. They cause damage to property and crops and even loss of life – even in their hundreds on a single occasion as squally winds and occasional tornadoes that swarm the vulnerable region.
- Also read: Pacific turning ‘neutral’ for now, signals normal monsoon for India: APEC Climate Center
While nor’westers may have to wait until March to announce arrival, India Meteorological Department (IMD) located a weather-causing cyclonic circulation over north-east Assam in the lower levels. It will bring scattered to fairly widespread light to moderate rainfall/snowfall to over Arunachal Pradesh during next five days. Heavy rainfall is likely today (Wednesday).
Thunderstorms, lightning
Isolated to scattered light rainfall is likely over Assam & Meghalaya, Nagaland, Manipur, Mizoram & Tripura and hills of West Bengal and Sikkim during next seven days. Thunderstorms and lightning are likely over Arunachal Pradesh, Assam & Meghalaya, Nagaland, Manipur, Mizoram & Tripura today and tomorrow (Wednesday and Thursday). Gusty winds (speeds of 30-40 km/hr) are likely over Assam & Meghalaya, Nagaland, Manipur, Mizoram & Tripura today (Wednesday).
Western disturbances on way
A western disturbance over Jammu & neighbourhood has send out an offspring cyclonic circulation in advance, which was located over south-west Rajasthan on Wednesday morning. An induced circulation renders a western disturbance active. A follow-up disturbance lies over south-east Iran bracing to cross into Afghanistan and later Pakistan and North-West India.
It may trigger scattered to fairly widespread light to moderate rain/snow, thunderstorms and lightning over Jammu-Kashmir-Ladakh, Himachal Pradesh and Uttarakhand for two days and isolated light rain/snow for three days from Friday.
Rain for plains as well
Heavy rainfall/snowfall is likely at isolated places likely over Jammu-Kashmir-Ladakh and Himachal Pradesh on Thursday. Isolated to scattered light to moderate rainfall, thunderstorms and lightning are over East Rajasthan today (Wednesday); Punjab, Haryana-Chandigarh-Delhi on Wednesday and Thursday; West Uttar Pradesh on Thursday. Gusty winds (speeds of 30-40 km/hr) are likely over West Rajasthan on Wednesday and isolated light rainfall over Central India on Friday and Saturday.
This apart, a trough, that invites fuel in the form of moisture from the Bay of Bengal and generates rain and thunderstorms, runs from Jharkhand to South Odisha. It may trigger isolated to scattered light to moderate rainfall accompanied with thunderstorms and lightning over West Bengal, Jharkhand and Odisha for three days from four days from today (Wednesday).