Low pressure area forming November 14 expected to intensify into a depression the very next day & undergo rapid intensification
Image: Windy.com_ Two back-to-back low-pressure areas may be forming in the Bay of Bengal, both of which could further intensify into cyclones, according to experts. One of them could also become a severe cyclone.
The first low pressure area is to form on November 14, 2023, induced by an upper air cyclonic circulation over the South Andaman Sea, the India Meteorological Department (IMD) shared. This system may gain strength to become a depression by November 16, IMD officials added.
Another upper air cyclonic circulation has formed over the south-western parts of the Bay of Bengal, the meteorologists observed. This may also induce a low-pressure area, according to Vineet Kumar Singh, a research scientist at the Typhoon Research Centre of Jeju National University in South Korea.
The simultaneous formation of the second low-pressure area could lead to its interaction with the earlier system. Such an interaction is known as the Fujiwhara effect.
When two ocean storms (storms, cyclones, hurricanes or typhoons) have formed in the same region, are spinning in the same direction and pass close enough to each other, “they begin an intense dance around their common centre”, according to the National Weather Service (NWS) of the National Oceanic and Atmospheric Administration, United States.
If one of the storms is a lot stronger and bigger than the other, the smaller one will revolve around the bigger one and “come crashing into its vortex to be absorbed”.
“Two storms closer in strength can gravitate towards each other until they reach a common point and merge, or merely spin each other around for a while before shooting off on their own paths. In rare occasions, the effect is additive when the hurricanes come together, resulting in one larger storm instead of two smaller ones,” according to NWS.
“The second low-pressure area will likely form after the dissipation of the first system so the possibility of them interacting under the Fujiwhara effect is not much,” Singh told Down To Earth.
According to Singh, both the low pressure areas could intensify into cyclones with the earlier system also possibly intensifying into a severe cyclone.
Singh also said that the low pressure area forming today (November 14) would intensify into a depression tomorrow itself and undergo rapid intensification (RI). RI occurs when a tropical cyclone gains wind speeds of 56 kilometres per hour or more in a span of 24 hours. RI generally makes it difficult for weather agencies to predict the track and intensity of tropical cyclones.
Many recent tropical cyclones have undergone RI, which is mainly due to warmer-than-usual sea surface and subsurface temperatures. For instance, cyclone Freddy in February-March 2023 became the first tropical cyclone ever to experience seven phases of rapid intensification over its lifetime.
The cyclone had its genesis near Australia and moved all across the southern Indian Ocean to devastate Madagascar, Malawi and Mozambique. Cyclone Biparjoy in the Arabian Sea in June 2023 also showed RI.
While the threat of the Fujiwhara effect is far off, back-to-back cyclones with RI in tow could create considerable impacts along the Indian coasts.
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
.png)
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.