A new Tropical Cyclone named "FOUR" (locally named "NADA") formed over the southern Bay of Bengal, approximately 520 km east of Sri Lanka, on 29 November. It moved north-west over the Bay of Bengal, towards the south-eastern coasts of India, strengthening.

On 30 November at 0.00 UTC, its centre was located approximately 710 km south-east of the eastern coasts of Tamil Nadu state (India) and had maximum sustained wind speed of 74 km/h (Tropical Storm).

Over the next 24 h, it is forecast to continue moving north-west over the Bay of Bengal, strengthening. It may reach the eastern coasts of Tamil Nadu state (India) over 1-2 December, possibly as a Tropical Storm. Heavy rain and strong winds may affect the northern, eastern and north-Central provinces of Sri Lanka, as well as the south-eastern coastal areas of India.

Heavy rain and strong winds will remain offshore until Thursday and Thursday night as the cyclone approaches the coast.

While Nada is not expected to strengthen rapidly, damaging winds will still be possible along the track of the storm.

Areas that could endure damaging wind gusts include Puducherry, Cuddalore, Chidambaram and Nagapattinam.

Damaging winds will generally be confined to an area close to the track of the cyclone; however, heavy rain and flooding will be possible across a large portion of southern India through the weekend.

Rainfall totals of 75-150 mm (3-6 inches) are possible from Nagapattinam to Chennai which could result in significant flooding and travel delays. Downpours will expand up the coast to Nellore and Ongole where localized flooding is possible.

Heavy rainfall will also heighten the risk of flooding farther inland including locations such as Tiruchirappalli, Salem, Coimbatore and Madurai.

Bengaluru could get some brief downpours; however, the heaviest rainfall is expected to remain to the south of the city.

Nada will weaken dramatically as it crosses India. However, downpours are likely to reach the western coastline late Friday and continue into Saturday. Localized flooding is possible in Kerala and Karnataka.

Heavy rainfall is expected to remain south of Goa though a shower or thunderstorm is possible on Saturday or Sunday.

Most of Sri Lanka will dodge the worst impacts of this cyclone; however, far northern parts of the island will receive heavy rainfall late Wednesday night into Thursday. Localized flooding and mudslides are possible. Nothing more than a brief shower or thunderstorm is expected in Colombo.

Largely dry weather will return to southern India early next week as Nada remains weak and tracks away to the west.

However, a second tropical threat could develop during the first half of next week.

This second cyclone could take a track that could put areas on alert from eastern India through Bangladesh and Myanmar.