Expected Depression in Bay of Bengal to bring in rains for Coastal TN

Yesterday saw the Delta districts get fairly widespread rains with Kollidam in Thanjavur district getting about 6 cms rains till 1:30 AM, while Chidambaram in Cuddalore district got about 5 cms during the same time.  Other places like Muthupettai, Orathanadu & Adiramapattinam also got some moderate rains during the day. Karaikal in neighbouring Pondicherry UT got 3 cm rains till 11:30 PM in the night.

Northeast Monsoon Udpate : The Well Marked Low now lying about 200 kms East of the Sri Lankan Coast is expected to become a Depression within the next 12 – 24 hours.  It appears as things stand this disturbance could possibly peak as Depression in Bay of Bengal while lying slightly off the coast of Sri Lanka.

There is some divergence in the model runs on both the possible track of the system & potential timelines as well with some models expecting NW movement and the evolving depression in Bay of Bengal to brush along the Eastern Coast of Sri Lanka on its way to Tamil Nadu coast.  Some other models expect the depression in Bay of Bengal to continue its W/NW track and move subsequently in a NW direction after making landfall over Sri Lanka.  This would mean possible interaction with the Central Sri Lankan Highlands which could seriously impact the intensity of the system thereby reducing the impact of the disturbance when it eventually tracks its way to Tamil Nadu.


A third possibility which the models have not put out yet is a possible complete W/NW track for the system in which case the impact of this disturbance over Tamil Nadu could be lesser than what is estimated.   Considering the divergence in the model estimates and the system’s movement suggesting a possible alternative not yet picked up by models it would be prudent to take one day at a time.


Like yesterday we could see Delta districts getting good rains today as well particularly around Nagapattinam / Karaikal region.  South Tamil Nadu could see spells of heavy rains around Kanyakumari, Tirunelveli & Thootukudi districts. Along with it parts of Kerala & Western Tamil Nadu along the foothills of Western Ghats could see spells of heavy rains. North Coastal Tamil Nadu could see rains start in the morning and possibly by afternoon could see spells of heavy rains between Chennai & Puducherry stretch.   Depending on the movement of this disturbance the rainfall patterns could alter slightly with intensity picking up or dropping off.

Chennai Weather Update: Cloudy skies with possible early morning showers at a few places.  Rains to pick up as the day progresses with heavy spells expected from about 11 in the morning.  On and off spells of rains could be seen for Chennai the whole of today and till early morning tomorrow with few heavy spells in between under the influence of the outerbands of the Depression in Bay of Bengal.