The India Met Department has said in its outlook that the monsoon on the retreat will continue to bring moderate to heavy rain for the south peninsula until October 4.
But the US-based models expect the rains to linger until October 10, especially along coastal Karnataka, Kerala and over adjoining south Tamil Nadu.
PACIFIC STORM
They also maintain the watch for the North-East monsoon (winter monsoon) to arrive over peninsular India on time. The normal onset window is October 15 to 20.
The Global Forecast Model of the US National Centres for Environmental Prediction predicts formation of a storm in the northwest Pacific/South China Sea to signal the arrival of the season.
The storm may send in a remnant system into the Bay of Bengal, which may develop into a low-pressure area and further into a depression, if not a cyclone.
Initially, this was shown tracking towards Odisha, but the US model has shifted the landfall point further south i.e. north coastal Andhra Pradesh.
SHOWERS PERSIST
According to this model, the ongoing showers over the peninsula would morph into the northeast monsoon, although the India Met Department may not quite agree.
Meanwhile, the monsoon on the retreat caused moderate to heavy rain over northeast India and south interior Karnataka and Kerala in the south until Saturday morning.
The causative upper air cyclonic circulation continued to persist over the Comorin-Lakshadweep area, while passing western disturbances kept parts of Jammu and Kashmir wet.
With a couple of days to go before the southwest monsoon ends, the overall rain deficit for the country as a whole clocked in at 12 per cent by last night.
This is close to what the India Met Department had projected in its updated outlook for the second-half of the four-month season.