Satellite pictures this morning show entire Jammu & Kashmir and adjoining Himachal Pradesh being cut off from the rest of the country by a cloud cover extending from Afghanistan and Pakistan.
This indicated the grip that an incoming western disturbance located to over Iran and Afghanistan yesterday, having shifted bearing closer in over Afghanistan and Pakistan this morning.
Rains and thundersqualls
The cloud cover in broken bands North-East to Tajikistan and Kyrgyzstan and South-South-East into interior India over Punjab, Uttarakhand and West Uttar Pradesh.
India Met Department (IMD) said the western disturbance would bring about fairly widespread to widespread precipitation, isolated thundersqualls and hailstorms over the hills of the region. Isolated thunderstorms with squalls and gusty winds have been forecast for adjoining plains in Haryana, Chandigarh, North Rajasthan, and North-West Uttar Pradesh for today.
Fairly widespread rain or thunder showers are likely for North-East and adjoining East India today and tomorrow as the western disturbance moves in further, though weakening in the process.
Rough in east
Strong winds and with moderately rough sea conditions have been forecast for Bengal and Odisha coast until tomorrow given the presence of a trough and a cyclonic circulation in the neighbourhood.
The East-to-West oriented trough runs down from East Bihar to South Assam across the hills of Bengal, which invites moisture-laden winds to blow in from the North Bay of Bengal.
The cyclonic circulation over Chhattisgarh and adjoining Odisha lends further strength to this moisture transport over heated-up land, setting up ripe conditions for violent thunderstorms and squalls.
In the South, the principal weather makers include a ‘wind discontinuity’ running down from North Interior Karnataka to South Tamil Nadu across South Interior Karnataka.
‘Unstable’ south
A wind discontinuity represents an area where winds change direction abruptly, setting the platform for 'unstable' atmospheric conditions, which in turn trigger thunderstorms/thundershowers. Additionally in the South, a trough lies over Equatorial India Ocean and adjoining Male, generating a cloud cover all around, especially along the Kerala coast this morning.
The IMD has forecast thunderstorms accompanied by gusty winds today over Telangana, Tamil Nadu and Kerala while heavy rain is likely over South Interior Karnataka and North Interior Tamil Nadu.
As for tomorrow, thunderstorms accompanied by gusty winds are forecast for Kerala while heavy rain is likely at isolated places in the state. Heavy rain might spread out to other states in next couple of days.