The sub-cyclonic system or “deep depression” that inundated Telangana and Andhra Pradesh is likely to peter out in a day, but will regain in strength again once it crosses the Maharashtra coast on October 16, according to a weather update from the India Meteorological Department (IMD).
October and November are cyclone months with several storms originating in the Bay of Bengal. Most that gain enough energy to become full-fledged cyclones eventually dissipate once they make landfall in a day or so into what are called ‘well-marked lows’. However, it’s rare for a storm that never became a cyclone to manage a crossing across India’s east and west coasts. Moisture from the sea imparts energy to tropical storms and can make them stronger.
“There was a similar situation in 2009,” said Mrutyunjay Mohapatra, Director General, IMD, “But this happens because active monsoon conditions are still prevailing and they give energy to depressions.”
Though the monsoon has officially ended, monsoon-like conditions continue to prevail into October and a full withdrawal was unlikely at least until October 26, he added.
Only storms that whip up wind speeds greater than 62 kmph are classified as cyclones and the current disturbance is hovering over north Karnataka and Maharashtra with wind speeds of 30-40 kmph.
Cyclones Gaja (2018) and Vardah (2016) were both storms that originated in the Bay of Bengal and crossed over all the way into the Arabian sea.
Dr. Mohapatra said that while weather models did indicate the current depression would become a “deep depression” (a notch below a cyclone) and it would happen off the Maharashtra coast, but would not bring cyclonic winds in either Maharasthra or Gujarat, though there would be heavy rains in these States.
“Extremely heavy rains at isolated places would occur over Konkan and Goa, and heavy rains [will occur] in parts of Mahrashtra and south Gujarat beginning Wednesday evening. On the 16th, wind speeds are likely to increase from 40 kmph from Thursday morning and go up to 55 kmph by the evening of Thursday. The seas would be extremely rough and fisherfolk ought not to be venturing out, according to the IMD’s Wednesday bulletin.