Chennai on Orange Alert as Cyclone Montha Approaches Bay of Bengal

Chennai and the surrounding districts of Tiruvallur and Ranipet are under an orange alert due to the anticipated formation of Cyclone Montha over the Bay of Bengal. The Indian Meteorological Department (IMD) forecasts heavy to very heavy rainfall, ranging from 12 cm to 20 cm within a 24-hour period, starting from October 27, 2023. The intensity of the rainfall in the city will largely depend on the cyclone’s trajectory and proximity to the Tamil Nadu coast.

As per weather models, the cyclone is predicted to track west-northwest before potentially recurving near north Tamil Nadu, heading towards Andhra Pradesh. If the storm slows during the recurving phase, its cloud bands could bring substantial rainfall to Chennai and neighbouring districts. The IMD has noted that the system’s precise path will only be confirmed once the cyclone fully forms, as rain activity is closely tied to the cyclone’s structure and the distribution of its cloud bands.

Cyclone Montha’s Expected Path and Impact

On Saturday evening, the IMD reported that the low-pressure area over the southeast Bay of Bengal had intensified into a depression and is likely to evolve into a cyclonic storm by October 27. Further strengthening is expected, with the storm projected to become a severe cyclonic storm by October 28, crossing the Andhra Pradesh coast between Machilipatnam and Kalingapatnam. Upon formation, this cyclone will be named Montha, which translates to “fragrant flower” or “beautiful flower” in Thai.

Blogger Pradeep John highlighted the uncertainty surrounding the cyclone’s track, stating, “Kancheepuram, Tiruvallur, Chengalpet, and Chennai may experience significant rainfall if the cyclone approaches the north Tamil Nadu coast before recurving. However, there is no consensus yet on the cyclone’s path to Andhra Pradesh, which we expect to clarify by Sunday.”

The potential for heavy rainfall extends beyond Chennai. A yellow alert has also been issued for Villupuram, Chengalpet, Kancheepuram, Vellore, and Puducherry, with expected rainfall between 6 cm and 12 cm on October 27. The following day, a yellow alert will be in effect for the districts of Ranipet and Tiruvallur.

Historical Context and Weather Conditions

Historically, cyclonic storms that have recurved away from Tamil Nadu often resulted in intense rainfall for the city. Notable examples include Cyclone Michaung in 2023 and storms from October 2005, as well as cyclones in November 1985 and November 1976, which each brought between 400 mm and 600 mm of rain over one to two days.

On Sunday, Chennai could anticipate moderate to heavy rainfall accompanied by thunderstorms. Forecasted temperatures are expected to range between 29°C and 24°C. On Saturday, the city experienced varied weather, with some areas enjoying sunshine while others faced showers. By the afternoon, dark clouds blanketed much of the city. As of 19:30, Meenambakkam recorded 24.2 mm of rainfall, NIOT Pallikaranai noted 27.6 mm, while Sathyabama University reported 0.9 mm, and Nungambakkam received only traces.

Chennai residents and officials are advised to remain vigilant as Cyclone Montha approaches, with preparations underway to mitigate potential impacts from the anticipated heavy rainfall.