Pre-monsoon thunderstorms are likely to get better organised over most parts of the country in another week (from mid-April) with particularly heavier rain leading to an above normal wet session indicated from April 23, according to an assessment of the India Meteorological Department (IMD).
Ahead of this, North-East India will suddenly see activity build up during the ongoing week (April 9 to 15) with the seasonal Nor’westers (or the Kalbaishakhi) getting into top gear. Nor’westers occur increasingly frequently from March till the South-West monsoon established over North-East India later in June.
Monsoon forecast expected
The South-West monsoon is less than two months away from striking the South-West coast (Kerala) in June, a keenly awaited long-term forecast for which, giving an indication about its performance during the four-month season ending in September, will be made available by the IMD any time from now.
Private forecaster Skymet Weather said that between April and the first half of June, dust storms are unleashed over the north-western parts of the country. Associated wind speeds may reach 80-90 km/hr occasionally during the month of May, leading to widespread damage to life and property.
Pre-monsoon activities are expected to commence over parts of Vidarbha and adjoining Chhattisgarh today (Friday). Between Saturday and Thursday next, parts of Vidarbha, Marathawada, Madhya Pradesh, Chhattisgarh, Odisha and Rajasthan may witness thunderstorms, patchy rain and thundershowers. These will keep the rising temperatures under check, though occasional heat waves may develop.
Impending western disturbances
Two western disturbances may affect the hills of North-West India, respectively from tomorrow (Saturday) night and Monday night. They will spark scattered rain/snow, thunderstorms and over the hills of North-West India from Sunday to Wednesday before heading East and touching off activity over East India and North-East India.
The country as a whole has logged in a rainfall deficit of 44 per cent during the pre-monsoon season so far (from March 1-April 8) with only Kerala, Lakshadweep and Sikkim receiving an excess and Maharashtra, Madhya Pradesh and Meghalaya recording normal rainfall, IMD statistics reveal.
The rest of the states in South Peninsula and most in Central India and North-West India are in ‘large deficit’ (60 per cent or more). They would have to wait after April 15, and better still, after April 23, for the Bay of Bengal to get active again and blow in helpful easterly winds to bring in their usual quota.
Better showers expected
On Friday, a cyclonic circulation lay parked over East Uttar Pradesh and adjoining Bihar from which a trough (line representing a narrow corridor of lower pressure) ran down to East Vidarbha across East Madhya Pradesh and Chhattisgarh, which may shift south-westwards during the next 3-4 days.
This will attract moisture incursion from the Bay of Bengal and trigger thunderstorms with lightning, hail and squall (wind speeds reaching 50-60 km/hr) over the plains of West Bengal; Assam and Meghalaya; and the hills of West Bengal and Sikkim today (Friday), an IMD outlook said.
Thunderstorms, lightning, hail and gusty winds (30-40 km/hr) are also likely over Odisha; with lightning and gusty winds (40-50 km/hr) over Nagaland, Manipur, Mizoram and Tripura; and with lightning and gusty winds (30-40 km/hr) over South-East Uttar Pradesh, Jharkhand and Arunachal Pradesh.
Volatile weather pattern
Other areas likely falling under volatile weather on Friday are Bihar, Vidarbha, Chhattisgarh, Madhya Maharashtra, Marathwada, Coastal Andhra Pradesh, Yanam, Tamil Nadu, Puducherry, Karaikal, Kerala, Mahe and Lakshadweep. Heavy rainfall has been forecast at isolated places over Arunachal Pradesh.
Outlook for next 3-4 days said isolated to scattered rainfall with thunderstorm, lightning and gusty winds (30-40 km/hr) are likely over Odisha, West Bengal, Sikkim and Jharkhand during next 3-4 days. Isolated thunder squall (50-60 km/hr) with hail may lash plains of West Bengal and Odisha until Sunday.
Thunderstorms, lightning warned
Isolated rainfall with thunderstorm, lightning and gusty winds is likely over Madhya Maharashtra, Marathawada, Vidarbha and Chhattisgarh during next five days with maximum activity over Maharashtra on Sunday and Monday and isolated hailstorm over Vidarbha and Chhattisgarh on Saturday and Sunday.
Fairly widespread to widespread rainfall with thunderstorm, lightning and gusty winds (30-40 km/hr) are likely over Arunachal Pradesh, Assam, Meghalaya and Nagaland, Manipur, Mizoram and Tripura till Monday. Thunder squalls may line up over Assam, Meghalaya and Nagaland, Manipur, Mizoram and Tripura today while isolated heavy rainfall may lash Arunachal Pradesh today and tomorrow.