The Department of Meteorology issued a severe lightning advisory at 11.00 a.m. on Thursday covering five provinces and six districts, valid until 1.00 a.m. on Friday — and by early afternoon several roads in Colombo were under water.
The advisory covers the North-central, Eastern, Central, Sabaragamuwa and Uva provinces and the Kilinochchi, Mullaitivu, Vavuniya, Gampaha, Colombo and Kurunegala districts, the Daily Mirror reported at 11.36 a.m. Thundershowers with severe lightning are likely at several places in those areas, and temporary, localised strong winds may occur during them.
The sequence extended into a fourth day, but the warning area shrank
When Wednesday’s advisory was issued it covered all nine provinces and expired at 1.00 a.m. on Thursday. This desk noted at the time that the expiry was the point at which the spell would either break or extend into a fourth day. It has extended — but not at Wednesday’s extent.
Four provinces have come out of the lightning warning: Western, Southern, North-western and Northern. What replaces the Northern Province is three of its districts named individually — Kilinochchi, Mullaitivu and Vavuniya — while Jaffna and Mannar are not listed.
The Western and North-western provinces are handled the same way. Kurunegala is named but not Puttalam, the other North-western district. And in the Western Province — the detail that matters for Colombo — the province as a whole is not in the lightning warning, yet Colombo and Gampaha are, leaving Kalutara the only one of the three Western districts outside it. The capital is therefore covered by the advisory even though its province is not.
Only the Southern Province is out altogether, with none of Galle, Matara or Hambantota named.
By 2 p.m. the forecast had become an event
Several Colombo roads flooded after heavy rainfall, the Daily Mirror reported at 2.06 p.m., with motorists in the city and other affected areas advised to take care over flooded roads and reduced visibility. The department repeated the same lightning warning area list in that filing, confirming the two reports describe one advisory.
Its rainfall guidance at that point:
- Heavy rainfall continuing in most parts of the Western and Southern provinces
- Showers or thundershowers above 75 mm at some places in Sabaragamuwa, Central and North-central provinces and in the Trincomalee and Kurunegala districts
The public was urged to take precautions against lightning strikes and temporary strong winds.
The stated cause of the rain has changed
This is the part no filing draws attention to. Through 11 October, 13 October and 14 October, the department attributed the cloud and rainfall to a low-level atmospheric disturbance in the Bay of Bengal near Sri Lanka — the same phrase, repeated daily.
Thursday’s attribution is different. The department says heavy rainfall is expected to continue over the Western and Southern provinces “due to changes in the prevailing wind pattern.” The Bay of Bengal disturbance is not mentioned.
That is consistent with the geography of the two lists. The heaviest rain has moved to the south-west — Western and Southern — while the lightning risk sits inland and to the east and north. On Wednesday the heavy-rain provinces were Western, Sabaragamuwa, Southern, Central and North-western, with a 100 mm floor; Thursday’s heavy-rain statement is confined to Western and Southern, with the 75 mm band applying elsewhere. No filing states that the driver has changed, and neither report gives a new figure for expected rainfall in the Western Province, so this is recorded here as a change in the department’s own stated reason rather than as a confirmed shift in the weather system.
Context
The spell has already produced consequences outside Colombo. The Navy deployed 171 relief teams on Wednesday as Deduru Oya’s spill gates opened, and roads went under water in Colombo once already on 12 October, when landslide early warnings covered seven districts. The Prime Minister ordered Colombo’s canals cleared within two weeks on 13 October.
Thursday’s flooding also coincided with the Gnanasara campaign’s march arriving in Colombo, giving the afternoon’s traffic disruption in the capital two live causes.
Not reported
Neither filing gives an advisory colour grade, says what the department expects after the 1.00 a.m. Friday expiry, or reports how much rain has actually fallen. Neither gives the number of roads affected, names them, or reports any casualty, displacement or damage figure.
Neither says whether the National Building Research Organisation’s landslide early warnings have been extended or lifted since 12 October, or whether any district flood warning is in force.
Both sources are the Daily Mirror, so this report rests on a single newsroom. The Island, which reproduces the department’s 5.30 a.m. daily forecast in full and supplied the morning half of Wednesday’s account, had no retrievable 15 October forecast at the time of writing; Ada Derana remains blocked.
