A new low-pressure area has formed over the south Andaman Sea and adjoining region, with the system expected to move towards the southeast Bay of Bengal by October 31 before shifting north towards the Andhra Pradesh coast. West Bengal currently has no coastal warning, while heavy to extremely heavy rain is forecast in parts of north Bengal on Friday.
The Alipore weather office said the remnants of Cyclone Arnab, which had weakened over Chhattisgarh and Odisha, have moved north-westwards and lost further strength. The system has become a well-marked low-pressure area and is expected to weaken into an ordinary low-pressure area over northern Chhattisgarh within the next 24 hours.
The newer system over the south Andaman Sea is being monitored for gradual movement and intensification. It is expected to reach the southeast Bay of Bengal by October 31 and then move northwards over the following two days towards the Andhra Pradesh coast. Its influence may bring rain and thunderstorms to Odisha and Andhra Pradesh.
For Kolkata and the districts of south Bengal, the forecast indicates intermittent light rain for several days from Friday through next Thursday. The weather office has not forecast heavy rain in the region and has not issued a separate warning for the southern districts as a whole. It has also said that the immediate impact of the low-pressure area and cyclone over the sea has passed, with no warning currently issued for fishermen.
However, thunderstorms and gusty winds are possible on Friday in Purba Bardhaman, Paschim Bardhaman, Birbhum, Murshidabad and Nadia. Wind speeds in these districts may reach 30 to 40 kilometres per hour. The forecast means that local authorities and residents in these areas may need to account for short-duration weather disruptions even though there is no broader heavy-rain alert for south Bengal.
North Bengal is expected to see the more severe weather. Darjeeling and Jalpaiguri may receive extremely heavy rain of 7 to 20 centimetres on Friday, accompanied by gusty winds. Kalimpong and Alipurduar may receive heavy rain measuring 7 to 11 centimetres. A yellow warning for thunderstorms and scattered rain has been issued for Cooch Behar, North Dinajpur, South Dinajpur and Malda. Rain and thunderstorms may continue in north Bengal until Saturday.
Daytime temperatures in the northern districts are expected to fall by 3 to 4 degrees Celsius over the next 24 hours, before rising gradually by another 2 to 3 degrees over the following two days. South Bengal is not expected to see a fall in temperature; daytime readings there may rise by 2 to 3 degrees over the next 48 hours, while night temperatures are likely to remain unchanged.
Kolkata recorded a minimum temperature of 25.2 degrees Celsius on Friday morning, 2.6 degrees above normal. The city’s maximum temperature on Thursday was 28.2 degrees Celsius, 2.7 degrees below normal. The Alipore weather office is continuing to monitor the new low-pressure area as it moves across the Bay of Bengal towards the Andhra coast.
