Amaravati: The very severe cyclonic storm Nivar weakened into a well-marked, low-pressure area by Friday morning, over south coastal Andhra Pradesh and adjoining west central Bay of Bengal.
"The associated cyclonic circulation now extends up to 4.5 km above the mean sea level," a Met official said, adding that it was very likely to move nearly northwards and weaken into the low-pressure area during the next 12 hours.
The Met department warned that the Bay of Bengal will be rough along and off the south AP coast during the next 12 hours. Fishermen have been warned against venturing into the sea.
Earlier, the depression over south coastal Andhra and neighbourhood moved north- northwestwards to weaken into low-pressure area and lay centred over south coastal Andhra and adjoining part of Bay of Bengal by 5.30 am.
The deep depression over south Rayalaseema and vicinity moved north and northwards with a speed of 8 km per hour during the six hours prior to 6 am on Friday and weakened into the depression.
By 11.30 pm on Thursday, it lay centred over south coastal Andhra and neighbourhood near latitude 14 degrees north and longitude 79.5 degrees east.
It was 35 km north of Tirupati and 70 km south - southeast of Nellore.
The Met department forecast light to moderate rain or thundershowers at many places in coastal Andhra Pradesh, Yanam and Rayalaseema from 6 am on Friday till 8.30 am on Saturday.
A 'yellow' warning has been issued for Chittoor, Kadapa, Kurnool, Prakasam and Nellore districts as their parts are very likely to receive heavy rain.
Winds reaching speeds of 45 - 55 kmph till 12 pm blowing along and off southern AP are expected to improve thereafter on Friday.
Squally winds of speeds between 50 - 60 kmph and gusting up to 70 kmph prevailing over Chittoor, Kadapa and Nellore districts are expected to gradually decrease thereafter from 12 pm on Friday.
The incessant rain falling around 9 pm on Wednesday in several villages near Bhimavaram in West Godavari district stopped around 1 pm on Friday, with another hiatus of an hour in between around 9 am in Seesali, Kalla, Kallakuru, Doddanapudi, Chinnapulleru and other villages.
Though the sun pierced through the clouds briefly a few times at these places, rain again started by 3 pm on Friday.
(With IANS Inputs)