No Cyclones in October in 2020 : Reasons
October to December period is among the favorable months for the development of cyclones in the Bay of Bengal and the Arabian Sea. In year 2020, however, October passed without any occurrence of cyclonic storm.
What happens normally in October month near the Indian coast?
- Normally, five cyclones are formed in the Bay of Bengal and the Arabian Sea, together known as the North Indian Ocean.
- Cyclones in the North Indian Ocean are bi-modal in nature, that is, they occur during two seasons:
- April to June (pre-monsoon)
- October to December (post-monsoon).
- May and November remain the most conducive for the development of cyclones.
Why were there no cyclones in the year 2020?
- Normally, Ocean disturbances enter the Bay of Bengal from the South China sea and head towards the Indian coast.
- This year, however, there was no system that intensified to form a cyclone.
- Another reason is the weak La Nina conditions along the equatorial Pacific Ocean.
- There was also the influence of Madden Julian Oscillation (MJO).
- MJO is kind of an eastward-moving cyclic weather event along the tropics that influences rainfall, winds, sea surface temperatures, and cloud cover. They have a 30 to 60-day cycle.
- Also, in November, the vertical wind shear created due to significant wind speed differences observed between higher and lower atmospheric levels prevented the low-pressure systems and depression from strengthening into a cyclone.