Ground is getting clear faster for north-east monsoon as predecessor south-west monsoon prepares to exit the country during the next two to four days. Formation of an anticipated monsoon depression has been declared over central Arabian Sea while a low-pressure area has formed over south-east Bay of Bengal, with associated winds likely to drag in north-east monsoon.
Seasonal easterly and north-easterly winds will set in simultaneously over the south peninsula as well as south and adjoining central Bay to trigger north-east monsoon rain initially over south-east peninsula (mainly the Tamil Nadu coast), India Meteorological Department (IMD) announced on Monday.
Extremely heavy rain for TN
Isolated extremely heavy rain is very likely over Tamil Nadu, Puducherry & Karaikal and Rayalaseema on Wednesday. It will be isolated very heavy over Tamil Nadu, Puducherry & Karaikal until Thursday; Kerala & Mahe on Thursday and Friday; Lakshadweep; Coastal Andhra Pradesh & Yanam on Tuesday and Wednesday; Rayalaseema during Tuesday to Thursday; and over coastal and south interior Karnataka on Thursday.
Isolated heavy rain is likely over Kerala & Mahe during the week; over coastal Andhra Pradesh & Yanam and Rayalaseema until Thursday; coastal and south interior Karnataka from Tuesday to Friday; and north interior Karnataka on Thursday and Friday. Over west India, the IMD sees chances for heavy rain for Konkan & Goa on Thursday.
Successful south-west monsoon
An above-normal north-east monsoon has been predicted for the south peninsula this year, on the back of a normal to above normal to excess south-west monsoon during June to September over Tamil Nadu (+18 per cent); Kerala (-13 per cent); Lakshadweep (+27 per cent); south interior Karnataka (+7 per cent); coastal Karnataka (+22 per cent); north interior Karnataka (+4 per cent); Telangana (+29 per cent); and coastal Andhra Pradesh (+33 per cent).
Depression moving away
On Monday morning, the depression over lay central Arabian Sea and posed no threat to the Indian coast as it lay about 800 km south-east of Masirah (Oman); 1,120 km east of Salalah (Oman); and 1,330 km east of Al Ghaidah (Yemen). It is likely to move further towards Oman coast during next two days. A weather-making trough ran down from centre of the depression over to Comorin area across south Kerala while a cyclonic circulation stood guard over Tamil Nadu.
‘Low’ adds new heft
This configuration received added heft as a fresh low-low pressure area over south-east Bay joined in on Monday morning. Given its track and distance from coast, the IMD expects the system to become ‘well-marked’ and move towards north Tamil Nadu, Puducherry and adjoining south Andhra Pradesh coasts during next two days.
The monsoon transition season is replete with chances for further intensification, and the system will be watched closely during this period. The Myanmar Department of Meteorology and Hydrology said in its 10-day outlook that a ‘low’ may form over the Andaman Sea and Bay of Bengal (corresponds to south-east Bay, IMD’s ‘area of interest), and further intensify into a depression.
Depression watch in Bay
The IMD has forecast fairly widespread to widespread to moderate rain for Tamil Nadu, Puducherry & Karaikal; Kerala & Mahe; Lakshadweep; and Karnataka during this week. It will be scattered to fairly widespread to moderate over Coastal Andhra Pradesh & Yanam and Rayalaseema, and isolated to scattered to moderate over Telangana.
Rain outlook extends to west India also with scattered to fairly widespread to moderate rain being over Gujarat State for next two days and isolated to scattered to moderate during subsequent five days; and isolated to scattered to moderate over Konkan & Goa; Madhya Maharashtra; Marathwada; Madhya Pradesh; Vidarbha; and Chhattisgarh during the week.