Freezing temperatures over parts of northwest India may thaw a bit ahead of the arrival of a western disturbance but no let-up in fog conditions is seen.
The western disturbance has a ‘steaming engine’ in the front in the form of moisture, which rises and cools against the Himalayan heights to create weather.
This will translate into heavy rain/snowfall in the hills and fog in the plains, a cycle that repeats itself through the winter months in northwest India.
The interregnum will see cold wave set in, when cold Arctic air flows in from the border to fill the space vacated by the east-bound western disturbance.
Northwest India is currently witnessing this phase after the exit of a western disturbance even as the next is expected to call in by Monday.
It has already reached the Afghan-Pak border and is expected move in to Pakistan by tomorrow. It will start sending feelers to northwest India from tomorrow.
The warmth (due to associated lower pressure, rising motion of air and presence of moisture) it carries is expected to grant some relief to the biting cold.
Reasonable strength
The system as of now looks to be of reasonable strength (and commensurately raised capacity to set up weather) but may lose some steam as it enters northwest India.
Rain and snow are for the asking for Jammu and Kashmir, Himachal Pradesh, and Uttarkhand early next week.
It is likely that the plains would see an extension of the dense to very dense fog conditions currently being witnessed and is forecast for the next couple of days.
Visibility will have been reduced to 50 metres or less over parts of Punjab, Haryana, Uttarkhand, Delhi, east Rajasthan, Uttar Pradesh, Bihar and the northeast today.
This very dense fog will move further east to cover most of east and northeast India even as the rear prepares to receive the next western disturbance.
Cold wave and ‘cold day’ (when sun is out due to clouds) conditions have been forecast for some parts of the plains in the northwest over the next couple of days.