Thunderstorms likely in Nellore, Tirupati on October 21; heavy rain forecast on October 2

The India Meteorological Department (IMD) on Wednesday (October 21, 2026) issued an orange alert for Sri Potti Sriramulu Nellore and Tirupati districts, where moderate thunderstorms with lightning, gusty winds of 40 to 50 kmph and moderate rain were “very likely” at one or two places. The alert, issued by the IMD’s Visakhapatnam centre at 10.20 a.m. and valid for the next few hours, named the Rapur, Gudur and Mopuru areas. It advised people to take shelter in safe places and not under trees. The IMD’s nowcast puts moderate rain at 5 to 15 mm an hour.

A yellow alert issued at 10 a.m. covers Chittoor, Annamayya and YSR Kadapa districts, with light thunderstorms, winds of 30 to 40 kmph and light rain likely at one or two places.

The IMD is tracking two systems. An upper-air cyclonic circulation over the southwest Bay of Bengal and the adjoining Tamil Nadu coast, extending up to 5.8 km above mean sea level, is likely to give rise to a low-pressure area over the same region within 24 hours of the October 20 bulletin. A trough runs from it to north coastal Andhra Pradesh. A second circulation over the Gulf of Thailand and neighbourhood is likely to emerge into the north Andaman Sea on Wednesday morning and move west-northwestwards. Under its influence, a low-pressure area is likely to form over the southeast and adjoining east-central Bay around October 23, and it is likely to move northwestwards and intensify further.

In its bulletin of October 20, the Meteorological Centre in Amaravati forecast light to moderate rain or thundershowers at a few places in Rayalaseema and at one or two places in coastal Andhra Pradesh and Yanam on Wednesday. Rain is likely to be scattered in Chittoor, Annamayya, Tirupati and Sri Sathya Sai districts. Heavy rain is forecast at isolated places in Nellore and Tirupati on Thursday. For Amaravati and its surroundings, the IMD expects a generally cloudy sky with one or two spells of rain or thundershowers over the next 48 hours, with the maximum and minimum temperatures around 35 and 26 degrees Celsius.

Thunderstorms with lightning are likely at isolated places in most coastal districts and Yanam, and across Rayalaseema, until the morning of October 23, and in Rayalaseema until the morning of October 24. Strong surface winds of 30 to 40 kmph, gusting to 50 kmph, are likely at isolated places in all three regions until the morning of October 24. The three northern coastal districts of Srikakulam, Parvathipuram Manyam and Vizianagaram are forecast to turn dry from Thursday. Visakhapatnam is expected to see isolated light rain until the morning of October 25 and dry weather after that. Isolated rain is likely to continue in the southern coastal districts and parts of Rayalaseema until the morning of October 27.

The IMD described the northeast monsoon as weak over the region. From October 1 to 20, Andhra Pradesh received 43.9 mm of rain against a normal of 107.7 mm, a deficit of 59%. The shortfall was 70% in coastal Andhra Pradesh and Yanam and 41% in Rayalaseema. Kurnool recorded the steepest district deficit at 99%, followed by Alluri Sitharama Raju and Parvathipuram Manyam at 91% each. Visakhapatnam district was 74% below normal. Annamayya and Chittoor were 17% and 19% above normal, and Tirupati 1% below.

The Regional Specialised Meteorological Centre in New Delhi assigned nil probability of a depression forming until the morning of October 25, a low probability for the following 24 hours and a moderate probability for the 24 hours after that, ending on the morning of October 27. It noted that the Madden Julian Oscillation, in Phase 3, favoured convective activity over the Bay. The IMD has forecast heavy to very heavy rain over Tamil Nadu, Puducherry and Karaikal until October 26.