A couple of weeks back a lot of buzz happened around a rare LPA in Bay of Bengal during the month of March. While going strictly by books what was called as a moderate La Nina episode is in effect behaving like a fairly strong La Nina episode with another LPA now forming over the Equatorial waters of Bay. Though unlike the last time the weather models are fairly consistent on a more Northward track possibly influenced by the genesis point which is slightly to the East compared to the March 1st week LPA the focus on this disturbance among the weather bloggers may not be as active as the March 1st week LPA.
But that does not take anything away from what is going to be a unique event once again. Bay of Bengal is expected to host a cyclone during the month of March after nearly 20 years with only 7 known instances so far of a tropical disturbance strengthening into a Tropical Cyclone at this time of the year. The strong Westerly Wind Burst influenced by the presence of MJO which has taken a fancy to the Indian Ocean has played a constructive role in creating two circulations on either side of the Equator with both expected to become a Cyclonic Storm in the coming few days.
With weather models, including ensembles, consistent on a more Northward track for this Low the impact in terms of rains over Tamil Nadu is going to be negligible. To the contrary we might possibly see an increase in day time temperatures over coastal places like Chennai due to the temporary strengthening of the surface westerlies under the influence of the Northward moving track of the Tropical Disturbance. For the next few days many interior places in Tamil Nadu, particularly around South TN in the districts of Virudhunagar, Madurai & Thoothukudi, may see day time maximum temperatures hover around 40°C for the next few days.
Yesterday saw moderate thunderstorm activity over Kanyakumar district & some parts of Kerala. This is indicative of possibly the end of the hottest period for Kanyakumari district with convective thunderstorms during the afternoon / evening hours now gradually picking up. Today also there is chance of rains for places along the Western Ghats with one or two places likely to see moderate to heavy spell of rains. Unlike Pre Monsoon / Post Monsoon thunderstorms theses activities will be more limited in the spatial scale.