Rains Converge Over Kolkata Again, 2nd Time In January

Rains appear to be heading for the capital city Kolkata anytime soon. The city of Hooghly river is likely to witness the 2^nd wet spell of this month commencing this week and roll over to the next one, for 2 more days.

Earlier, Kolkata received good showers between 11^th and 15^thJan, recording 45mm rainfall, bulk of it on 11^thJan. Airport observatory at Dum Dum recorded 43mm on 11-12 Jan, surpassing its monthly normal of 10.4mm.  The other regional observatory at Alipore  received only scattered showers.

City of Kolkata is not known for any heavy rains during January.  Weak weather systems, as remnant of western disturbance of North India, do stray over Gangetic West Bengal and cause sporadic showers.  Since Jan 2011, it is only twice that the city was lashed with decent showers. It measured deluge of 94.4mm in Jan 2012, followed by drench of 42.5mm in 2020.  On rest of the occasions, the rainfall was either totally missing or remained extremely light.

Meteorological conditions are building up for a wet spell between 23^rd and 25^thJan.  As a precursor, a western disturbance over hills and cyclonic circulation over the plains of North India is arriving on 21^stJan. Fairly widespread rain and thundershower will lash north India between 21^st and 23^rdJan. This weather system will move eastward, reaching eastern parts with a lag of 48hr. A trough is getting established along Indo Gangetic plains, marking convergence zone between easterly and westerly winds. This development is getting fueled by the anticyclone in the North Bay of Bengal. Moist winds from head Bay will rush over Gangetic West Bengal to cast rain spell.

Moderate rain and thundershower are quite likely over the capital city between 23^rd and 25^thJan.  Light rain may even commence, a day prior on 22^ndJan. Showers will be relatively strong on 23^rdJan and may even spill over, the next day also. The weather conditions will improve significantly on the 25^thJan and become pleasant enough for the Republic Day celebration on 26^thJan. However, thick fog may descend over the city and suburbs on 25^th and 26^thJan, in the morning hours.