A fresh low-pressure system over the South Andaman Sea could intensify into a depression by October 31 and move towards Andhra Pradesh.
Bihar faces extremely heavy rainfall exceeding 204.5mm in isolated areas, with red and orange alerts issued.
Heavy to very heavy rainfall is also forecast for parts of West Bengal, Sikkim and eastern Uttar Pradesh.
Delhi-NCR, Haryana, Punjab and Rajasthan could experience thunderstorms, hailstorms and gusty winds reaching 50–60km/h.
Cyclone Arnab continues to weaken over central India, while Uttarakhand faces heavy rainfall and possible snowfall at higher altitudes.
A fresh weather system over the Bay of Bengal could intensify into a depression by October 31, while Bihar faces extremely heavy rainfall and parts of northern India brace for thunderstorms, strong winds and hailstorms, according to the India Meteorological Department (IMD).
In its October 30 forecast, the IMD said several weather systems were affecting the country, including the weakening remnants of Cyclone Arnab over central India and a western disturbance influencing weather across the north.
A low-pressure area over the South Andaman Sea is expected to move west-northwestwards and develop into a depression over the southeast Bay of Bengal and adjoining Andaman and Nicobar Islands around October 31.
The system could intensify further over the following two days as it moves towards the Andhra Pradesh coast.
Although it could strengthen into a deep depression or cyclonic storm, its eventual intensity and track remain uncertain.
Coastal communities, fishermen and shipping operators have been advised to follow official weather updates.
Meanwhile, Cyclone Arnab has weakened considerably after moving inland. Its remnants, currently affecting northern Chhattisgarh and neighbouring areas, are expected to weaken into a well-marked low-pressure area within 24 hours, while continuing to bring rainfall to parts of eastern India.
The IMD has issued orange and red alerts for parts of Bihar, warning of heavy to very heavy rainfall, with isolated areas potentially receiving more than 204.5mm.
The downpours could cause flooding, waterlogging, traffic disruption and damage to crops.
Sub-Himalayan West Bengal, Sikkim and the Andaman and Nicobar Islands are also under orange alerts, with rainfall of 115.6mm to 204.4mm possible in some areas.
Jharkhand is under a yellow alert for heavy rainfall, while eastern Uttar Pradesh faces an orange alert for heavy to very heavy showers.
An active western disturbance over northern Pakistan, combined with an upper-air cyclonic circulation over southern Punjab, is expected to bring unsettled weather across northwestern India.
Delhi-NCR, Haryana and Chandigarh could experience further rainfall and thunderstorms, with hailstorms and winds reaching 50–60km/h possible in some areas.
Punjab, Rajasthan and Jammu and Kashmir may also experience lightning and gusty winds of 40–50km/h.
Uttarakhand is under a yellow alert for isolated heavy rainfall, with snowfall possible at higher altitudes and winds reaching 40–50km/h.
Himachal Pradesh could also experience thunderstorms and lightning.
On October 29, Rajkot in Gujarat recorded 38.2°C, the highest maximum temperature among the country's plains stations.
Una in Himachal Pradesh recorded the lowest minimum temperature among the plains at 11°C.
With several weather systems active simultaneously, the IMD has advised residents in vulnerable areas to monitor updated forecasts and warnings.