An incoming western disturbance spotted over east Iran and west Afghanistan on Wednesday will bring to bear clouds and moisture as it negotiates the international border and enters India to put a lid, though briefly, on prevailing hot conditions in parts of North-West India, Central India and adjoining East India.
India Meteorological Department (IMD) identified the heat-struck areas on Wednesday as pockets of the Jammu Division, Himachal Pradesh, Punjab, Haryana, Delhi, Uttar Pradesh, Rajasthan, Madhya Pradesh, Vidarbha, Chhattisgarh, and Jharkhand.
Moisture, cloud cover
The heat is likely to abate due to the approaching western disturbance, associated change in wind direction and ensuing cloudiness over the region, the IMD said in its afternoon update.
Rain, thunderstorms, lightning and gusty winds are forecast over the hills of North-West India and adjoining plains on Wednesday and Thursday peaking tomorrow (Thursday). Similar weather may pan out over Central India on both days and over East India until Friday. The ongoing heavy rain spell is likely to continue over Assam-Meghalaya during the next five days.
Cyclonic circulations and troughs capable of heralding unstable weather (thunderstorms, lightning, high winds and showers) are present elsewhere over land either sustaining the seasonal thundery and wet weather over some parts of South Peninsula and East-North-East India or smothering the heat elsewhere.
Circulations and troughs
A cyclonic circulation hangs over Coastal South Tamil Nadu and has cut open a trough (narrow corridor of lower pressure where opposite winds meet) to Rayalaseema across Interior Tamil Nadu. Isolated to scattered rainfall, thunderstorms, lightning and gusty winds over Kerala, Mahe, Tamil Nadu, Puducherry, Karaikal, Karnataka, coastal Andhra Pradesh and Telangana during next five days.
In the East, a circulation persists over east Uttar Pradesh and a trough runs down to central Bangladesh, while another extends from plains of West Bengal to south Chhattisgarh across interior Odisha.
Flare-up over North-East
Strong seasonal south-westerly winds from the Bay of Bengal blowing into the North-East will bring fairly widespread rainfall over Arunachal Pradesh, Assam, Meghalaya, Nagaland, Manipur, Mizoram, Tripura and hills of West Bengal and Sikkim punctuated by thunderstorms, lightning and gusty winds for next five days.
Isolated heavy rainfall is likely over Assam and Meghalaya until Sunday and over Arunachal Pradesh on Friday. Isolated to scattered rainfall with thunderstorms, lightning, gusty winds are forecast over Bihar, Jharkhand, Gangetic West Bengal and Odisha during the next three days.