CYCLONE YAAS TO DECORATE BOB

Post the landfall of the Extremely severe cyclonic storm Tauktae over Gujarat, the westerly winds have strengthened over entire southern peninsula which helped in the onset of the great Indian monsoon over the Andaman and Nicobar islands a couple of days back.

An Upper air circulation which was extending till 5kms ASL developed into a low pressure area over east central BOB. Due to the wind convergence associated with the UAC, NTN and SAP including Chennai saw very good thunderstorms that provided the much needed moderate to rather heavy rains after a long wait which indeed was a respite from the highly humid weather. Once the LPA forms, the westerlies become streamlined which reduces the instability in the atmosphere and the convergence zone will shift closer to the center of the system thereby reducing the rains over Tamilnadu and SAP.

The reason behind the highly clouded, conducive BOB to host a strong cyclone early next week is the east moving master of planetary waves, the MJO. It helped in the timely onset of SWM into the islands and also now helping the formation of a cyclonic storm in the basin. The LPA is at a very conducive environment currently for its development into a cyclone. With very high Sea surface temperatures over North bay, even a CAT 3 cyclone should give us no surprise.

Subtropical deep layered ridge to the NE of the system will guide it in a NNW direction towards North-bay. Models and ensemble members are swinging from Odisha to eastern Bangladesh regarding the landfall of the system. Nevertheless, the entire coastline from Paradip to Chittagong should be on high alert for a potential cyclone landfall. As the system develops and starts its journey, we will get a clear picture on the landfall prospect. If the ridge extends east, the system would move in a more North or NNE direction heading to Bangladesh. Else if the ridge extends west, Odisha and west Bengal might end up bearing the brunt of the cyclonic storm.

As the cyclone moves north, dry WNW winds from Rayalaseema will notch up the heat quotient over entire NTN and Coastal AP from 24th May. Coastal areas which were having a relatively cooler summer so far will start to face the real heat as the sea breeze struggles to enter the coastline. All in all another interesting week of Cyclone tracking awaits us!