Monsoon advances into parts of South Arabian Sea, Maldives, Comorin

The southwest monsoon has advanced to parts of the southern Arabian Sea, the Maldives and the Comorin regions as well as some other parts of the south and east-central Bay of Bengal.

The Indian Meteorological Department (IMD) said in an update that conditions are favorable for further progress in other parts of these regions as well as over the northeastern Bay of Bengal over the next two days.

On Thursday, the monsoon entered an area along an arc extending from the west of the Maldives and cutting through its central atolls eastward (far to the southwest of the Lakshadweep islands) and some distance south of Sri Lanka. (where he was supposed to arrive by 22 May) and onwards through the southwest, east-central and north-eastern Bay of Bengal.

Low pressure area soon

A developing cyclone’s circulation over the southeastern Arabian Sea (off Kerala) next Monday (5 June) is expected to herald the onset of the monsoon over Kerala at a later date.

IMD expects this circulation to deepen as a low-pressure area, which would anchor the incoming monsoon flows, and set up what is likely seen as strong starting conditions along the coast of Kerala.

circling over the bay

On Thursday, another cyclonic circulation occurred on the other side of the peninsula over the central eastern Bay of Bengal off Myanmar.

Although this circulation may not get much momentum in the Gulf over the next few days, inflows from the Arabian Sea will create a “low” habitat here just as its predecessor in the Arabian Sea is gaining strength.

perfect wallpaper

The simultaneous flows over the Arabian Sea and the Gulf provided the perfect backdrop for the monsoon boom over mainland India. But the “lower” Arabian Sea course needs careful monitoring.

There are contradictory opinions, with some models taking it away from India and into disfavor of the monsoons. Others point to a more structured path along the west coast.

Outlook for the first week

IMD said it expects less than normal rain during the first week of June (1-7) for west coast, eastern and northeastern India and normal to above normal for northwest and central India (thanks to western disturbances).

Its extended weather forecast valid till June 7 has thus ruled out the full onset of the monsoon over Kerala during this period.

Heavy rains in Kerala

The five-day outlook forecast light to moderate to fairly widespread rain, thunderstorms, lightning, gusty winds over Kerala, Lakshadweep, coastal Karnataka and southern interior and isolated scattered rain over Tamil Nadu and Andhra Pradesh until Monday.

Heavy rain is likely over Kerala, while it will be isolated over coastal Tamil Nadu and Karnataka on Thursday.

Wind pattern to settle

The forecast wind pattern in effect until Tuesday does not indicate the onset of the monsoon until Tuesday (6 June). The wind should be westerly to southwesterly along the coast of Kerala to mark the start.

The fermenting ‘bottom’ in the Arabian Sea will be a ‘vortex’ for the monsoon flows to loop around, and its strength from Wednesday (June 7) is likely to lead to an onset in subsequent days.

The normal date for onset is June 1 with a standard deviation of seven days, but IMD’s long-range forecasts expect that this year to be pushed back to June 4, by a margin of ±4 days.

Satellite imagery on Thursday afternoon (June 1, the usual day of onset) showed intense convection (cloud building) over the coast of Karnataka, Goa, and off the coast of Kerala.