LPA expected to form in South Bay today

Weather Update

In some bit of relief Chennai & suburbs saw a slight reduction in rains yesterday though the rains did not completely stop. While day time saw mostly dry conditions late in the night closer to midnight hours some moderate to heavy spell of rains did happen across most parts of the city. About 40 kms to the south of Chennai along the coast Mahabalipuram though recorded more than 10 cms of rains. But overall though across Tamil Nadu rains were slightly subdued compared to the past few days.

Partially the effect of UAC merging with the South Bay UAC was the reason for the reduction in rains. While the UAC was persisting off the coast, it created wind convergence to trigger thunderstorms. Once the UAC faded and transferred its energy to the South Bay pulse the coast saw an advent of just Northerlies without the easterlies which resulted in reduction of rains contrary to the model expectations. It is pertinent to note that possibly yesterday’s events happened quicker than the model estimates though we need to see if today’s events confirm that.

This sneaking of Northerlies is possibly reflected in the satellite image as well with coastal areas seeing less convection today compared to the past couple of days while the bulk of convection is seen over the Bay. With the Low Pressure Area expected to form today we will start seeing Easterlies getting streamlined from later today afternoon. This would gradually push the Bay convection towards coastal Tamil Nadu from later today with rains expected to increase in intensity from tonight.

Coastal areas will start seeing increasing rains from tonight as the LPA forms today it will gradually move in a WNW direction and intensify tomorrow bringing more rains as it comes closer to the TN coast. It appears Thursday could be the peak of this spell of rains though it will all depend on how the disturbance intensifies & moves. Any delay in consolidation & movement could push this peak back by a day or two. Irrespective of the movement the coming 3 / 4 days in all probability will see widespread rains over Tamil Nadu with coastal areas coming under heavy rains for at least 2 out of these 3 or 4 days.