Is Cyclonic Storm Brewing In Bay? GFS & ECMWF Models Indicate Movement Towards Odisha

Bhubaneswar: A cyclonic circulation has formed over the south Andaman Sea and its neighbourhood and it is likely to intensify into a low pressure over southeast and adjoining eastcentral Bay of Bengal around October 20, the India Meteorological Department (IMD) informed on Monday.

While the system is likely to become more marked after moving west­northwestwards towards west-central and adjoining southwest Bay of Bengal during the subsequent 48 hours, there is no possibility of cyclogenesis (depression) during the next 120 hours, the IMD said in its Tropical Weather Outlook for North Indian Ocean.

Major weather models have indicated the formation of a cyclone over the Bay of Bengal and movement towards south Odisha-north Andhra Pradesh this month. However, there is variation among them with respect to the track of the system.

According to IMD’s Cyclone Warning Division, the models are indicating development of cyclonic circulation over Andaman Sea during October 16-18. However, NCUM group is indicating its intensification into a low around October 18, while the GFS group and ECMWF are indicating formation of a low around October 20. Similarly, the NCUM group is indicating depression around October 21 and GFS and ECMWF around October 23.

Most of the models are indicating intensification of the system into a cyclonic storm. There is variation among the models with respect to track of the system with NCUM group indicating nearly westwards movement towards North Tamil Nadu. The GFS and ECMWF are indicating nearly north-northwestwards movement towards North Andhra Pradesh-South Odisha.

1. IMD-GFS: Another cyclonic circulation is likely to emerge into the Andaman Sea on October 22, develop into a low-pressure area over North Andaman Sea the following day and a cyclonic storm over westcentral and adjoining northwest Bay of Bengal on October 24. The system is likely to intensify into a severe cyclonic storm over central parts of North Bay of Bengal on October 25 and become less marked the following day.

2. IMD-GEFS: The extended circulation over central and adjoining south Bay of Bay is likely to concentrate into a low over southwest Bay of Bengal on Octoebr 21, westcentral & adjoining southwest Bay of Bengal on October 22 before becoming well marked over the same region on October 23 and depression over central parts of Bay of Bengal the following day.

3. NCMRWFNEPS: A cyclonic circulation is likely to form over central parts of the Bay of Bengal on October 17. It is likely to move west-northwestwards and lie as a low over westcentral and adjoining southwest Bay of Bengal on October 18, well-marker low pressure over southwest & adjoining west-central Bay of Bengal on October 19 and depression over the same region the following day, deep depression over southwest & adjoining westcentral Bay of Bengal on October 21. It is likely to intensify into a severe cyclonic storm over Chennai on October 22 and depression over north interior Karnataka on October 23, a depression over coastal Karnataka on October 24, well-marker low pressure over the same region on October 25 and less marked thereafter.

4. ECMWF: This model indicates a nearly north-northwestwards movement of a cyclonic storm towards north Andhra Pradesh-south Odisha on October 25. The cyclonic circulation is likely to form over central Andaman Sea on October 16 and over eastcentral Bay of Bengal on October 17-18 and westcentral bay of Bengal on October 19, westcentral & adjoining southwest Bay of Bengal on October 20. The system is likely to intensify into a low pressure over south and adjoining central Bay of Bengal on October 21 and well-marked low pressure/depression over westcentral BoB on October 22 and depression over westcentral & adjoining southwest Bay of Bengal on October 23, deep depression over westcentral BoB on Octoebr 24 and cyclonic storm over North Andhra Pradesh and adjoining South Odisha on October 25 and well-marked low over North Odisha on October 26.

5. NCEP-GFS: A fresh cyclonic circulation is likely to form over North Andaman Sea and adjoining eastcentral BoB on October 17. It is likely to move nearly westwards and lie over southeast Bay of Bengal on October 18 and develop into a low over eastcentral Bay of Bengal on October 19, a depression over eastcentral Bay of Bengal on Octiober 20, deep depression over westcentral Bay of Bengal on October 21, cyclonic storm over westcentral Bay of Bengal on October 22, severe cyclonic storm over westcentral Bay of Bengal on October 23, crossing North Andhra Pradesh-South Odisha coast as a very severe cyclonic circulation on October on 24.

The report inferred that a fresh cyclonic circulation is likely to form over central and adjoining North Andaman Sea around Octoebr 17-18. It is likely to move west-northwestwards, become a low around octoebr 19/20 over eastcentral and adjoining southeast BoB and concentrate into a depression over westcentral & adjoining southwest Bay of Bengal around October 22. Further intensification needs to be monitored, it added.

It further said that the environmental conditions like Sea Surface Temperature and ocean thermal energy are favourable over south and central Bay of Bengal for formation of low-pressure area/ depression. The La Nina conditions supported with negative IOD conditions will support the movement of remnant circulations from South China Sea to Andaman Sea with possible further intensification. However, MJO being in phase 6 with an amplitude of more than 1, will not be supportive for amplification of convection and hence the system.

AccuWeather lead international forecaster Jason Nicholl also tweeted about the possibility of a cyclonic storm impacting eastern India between Andhra Pradesh and West Bengal next week.