Heavy rain forecast for coastal Andhra Pradesh and Rayalaseema from September 19, says IMD

The India Meteorological Department (IMD) has forecast heavy rain at isolated places in Andhra Pradesh from September 19, under the influence of a low-pressure system expected to form over the north Andaman Sea around that date.

In a bulletin issued on Wednesday, the IMD said an upper-air cyclonic circulation lay over north Thailand and extended up to 7.6 km above mean sea level. It was likely to emerge over the north Andaman Sea around September 18. Under its influence, a low-pressure area was likely to form over the same region by the evening of September 19.

"Thereafter, it is likely to intensify gradually and move west-northwestwards towards south Odisha-north Andhra Pradesh coasts," the bulletin said.

This may bring heavy rain, accompanied by thunderstorms and strong winds, at isolated places in Coastal Andhra Pradesh and Rayalaseema next week.

On Wednesday, a few places in coastal Andhra Pradesh received light to moderate rainfall. Rowthulapudi in Kakinada district received 68.6 mm, followed by Marripalem in Anakapalli district at 54 mm, D. Polavaram in Kakinada district at 48.5 mm, Konapapapeta in Kakinada district at 46.8 mm, Akkireddypalem in Visakhapatnam district at 45.5 mm, Anakapalli at 44.5 mm, and Payakaraopeta in Visakhapatnam district at 43.7 mm.

The districts that recorded the heaviest falls on Wednesday — Kakinada, Anakapalli and Visakhapatnam — are among the areas that the IMD expects to be affected if the system moves towards the north Andhra coast as forecast.

Low-pressure systems forming over the Bay of Bengal and the Andaman Sea are a regular feature of September and October, a period when the southwest monsoon begins to withdraw from the country. Such systems often pull moisture-laden winds towards the eastern coast, producing spells of rain over coastal Andhra Pradesh, Rayalaseema and adjoining parts of Odisha. Not every system intensifies into a depression or a cyclone, and the IMD tracks each one and updates its forecasts as the system develops.

The term "isolated places", as used in the bulletin, refers in IMD terminology to rainfall over a relatively small portion of a region rather than across the whole district or state. Forecasts of this kind are therefore best read as an indication of where rain is most likely, rather than a guarantee that every locality in the named area will receive heavy showers.

The IMD issues colour-coded warnings — green, yellow, orange and red — for districts and regions as a system approaches, with orange and red indicating a higher degree of alert. These warnings are shared with State disaster management authorities, which in turn issue local advisories.

Residents in the affected districts are advised to follow updates from the IMD and the State disaster management authority. Standard precautions during spells of heavy rain include avoiding travel through flooded roads and low-lying areas, staying away from water bodies, trees and unstable structures during thunderstorms and strong winds, and checking official advisories before venturing out. Fishermen along the Andhra Pradesh coast are advised to track the IMD's sea-area warnings, which are issued separately for coastal waters.

The IMD is expected to issue further bulletins as the low-pressure area forms and its path becomes clearer over the next few days.