The low pressure is now lying over South Central Bay of Bengal and adjoining equatorial areas of the Indian Ocean.
The upper air circulation from this system extends up to mid tropospheric levels. The system is likely to move in an East South-easterly direction.
The system has already given good rain over Andaman and Nicobar Islands with Nancowy observing 140 mm of rain in just a span of 24 hours.
February 15 onward, the system will result in isolated rainfall activity over parts of South Tamil Nadu as well as South Kerala.
Both spread and intensity of rain will increase over Kerala and Tamil Nadu on February 16. Light to moderate rain will be observed over the region.
The capital city of Tamil Nadu, Chennai will also receive light rain during this period.
Gradually, South Interior and Coastal Karnataka will also start receiving rain.
Updated on February 13, 2016: Low pressure area brings heavy rainfall in Andaman and Nicobar
The low pressure is now lying over South Central Bay of Bengal and adjoining equatorial areas of the Indian Ocean.
During last 24 hours, isolated heavy rainfall has occurred over Andaman and Nicobar Islands. Nancowry recorded a whopping 140 mm of rain.
Southern parts of Andaman and Nicobar Islands could witness moderate rain at few places and heavy at one or two places over the next 24 hours.
The weather system will keep moving westwards and reach close to the coast of Tamil Nadu by February 15. It will bring some rainfall till the 17th. First the coastal areas of Tamil Nadu will receive some rains, followed by the interiors and then South Interior Karnataka and Kerala.
Updated on February 12, 2016: Low pressure area to bring rain in Tamil Nadu early next week
Tamil Nadu has not received any rainfall so far in the month of February. Generally, rainfall is minimal in the state and most parts of Peninsular India this month. Northeast Monsoon has retreated and pre-Monsoon season is yet to set in.
The monthly average rainfall in Chennai and Vellore (northern parts of Tamil Nadu) are 2 mm and 4mm, respectively. The southern parts receive more rains with monthly average being 16 mm in Nagapattinam and 15 mm in Kanyakumari. This is because any weather system which forms in the Bay of Bengal track westwards and affects South Coastal Tamil Nadu.
At the moment, maximums are settling in the lower-thirties and minimums in the lower-twenties.
We can see a low pressure area over South Bay of Bengal. It is the first system after the withdrawal of Northeast Monsoon. Initially, it formed as cyclonic circulation over Southeast Bay of Bengal and promised to organize into a well-marked low. The cloud configuration at present suggests that it will remain as a low pressure area.
Nevertheless, it will move westwards by February 15 and bring some rainfall till the 17th. First the coastal areas of Tamil Nadu will receive rainfall, followed by the interiors and then South Interior Karnataka and Kerala.
Updated on February 10, 2016: Rain likely in Tamil Nadu, low pressure area forms
A low-pressure area has developed over Southeast Bay of Bengal and adjoining Andaman Sea. The freshly formed system is supported by a cyclonic circulation extending up to 15000 feet.
According to Skymet Weather, a cyclonic circulation has been prevailing over South Andaman Sea for the last three days, which has intensified into a low-pressure area on Tuesday evening.
The system will bring good showers over Andaman and Nicobar Islands during the next 24 hours, shifting ahead thereafter. The low-pressure area will be moving from eastwards to westwards at a very slow pace.
We expect this system to intensify into a well-marked low-pressure area during the next 48 hours but is not likely to strengthen further. As per Skymet, usually weather systems forming during this season do not intensify into very strong systems.
Meanwhile, as this weather system moves closer to the Indian coast, it will start giving rain over Tamil Nadu by February 15 that will continue till February 16. Intensity of rain will be more over southern parts of the state. Coastal parts of TN could also receive occasional spell of rain during the period.
Image credit: thesun.co.uk