According to the IMD, a trough extends from South Gujarat to Karnataka at mean sea level. In addition, an upper-air cyclonic circulation persists over the north Bay of Bengal and adjoining southern Bangladesh between 1.5 km and 7.6 km above sea level.
As a result, a low-pressure area is likely to form over the northwest Bay of Bengal around July 3. This weather pattern is expected to trigger light to moderate rainfall with thunderstorms and gusty winds of 40-50 kmph at isolated places across Tamil Nadu, Puducherry and Karaikal today.
Looking ahead:
• July 3: Heavy rainfall is likely at isolated places over the hilly regions of Coimbatore, Nilgiris and Theni districts. North Tamil Nadu, Puducherry and Karaikal may receive moderate rain with thunderstorms and strong winds, while southern Tamil Nadu is likely to experience light to moderate showers.
• July 4: Heavy rain is expected in Coimbatore, Nilgiris and Kanniyakumari districts. Other parts of Tamil Nadu, along with Puducherry and Karaikal, may continue to receive light to moderate rainfall accompanied by thunderstorms.