The Department of Meteorology has rated the probability of a cyclone forming in the Bay of Bengal as “high” for the 72-to-96-hour window — a period that begins on Saturday — and has closed a wide block of deep sea to Sri Lankan fishing and naval vessels until further notice.
The advisory was issued at 5.00 p.m. on Thursday by the department’s Natural Hazards Early Warning Centre, the Daily Mirror reported. It says a system is likely to form over the Southeast and adjoining East-central Bay of Bengal, then move west-northwestwards and intensify further.
Naval and fishing communities have been told not to venture into the sea area bounded by 10°N–20°N and 80°E–95°E. Vessels already operating inside that box have been urged to move to safe locations.
The probability rises rather than fades
The most unusual feature of the advisory is the shape of its own forecast. The department’s assessment of the probability of cyclogenesis — the formation of a depression — runs in one direction only:
| Window | Probability |
|---|---|
| Next 24 hours | Nil |
| 24–48 hours | Nil |
| 48–72 hours | Moderate |
| 72–96 hours | High |
Most hazard advisories describe a risk that is present now and expected to decay. This one describes a risk that is absent now and expected to arrive, and it names the arrival window rather than leaving it open.
Measured from the 5.00 p.m. Thursday issue time, the 72-to-96-hour window runs from about 5.00 p.m. on Sunday 25 October to 5.00 p.m. on Monday 26 October, with the moderate band covering Saturday evening into Sunday.
A second filing points independently at the same stretch of the calendar. The Disaster Management Centre said on Thursday night that the Met Department has forecast that the prevailing rainy conditions could intensify further until 25 October, the Daily Mirror reported at 9.12 p.m. Two separate advisories, issued four hours apart and describing different things — a rainfall trend and a cyclone probability — converge on the same date.
This is a different system from the one that flooded the island
This advisory resolves an apparent contradiction this desk flagged on Thursday, when the department’s morning filing placed a low-pressure area to the island’s north-west and moving away, while an evening filing cited a risk from a low-pressure area in the Bay of Bengal, on the opposite side.
The 5.00 p.m. advisory makes clear these are not the same feature. It describes a system that is likely to form — it does not yet exist — in the southeastern Bay of Bengal. The low that drove this week’s flooding had already crossed the island and moved west. The Bay of Bengal system is a prospective, separate development, which is why the cyclogenesis probability for the next 48 hours is nil even as heavy rain continues to fall.
That also closes the open question this desk recorded on Thursday, when no filing gave the expected track of the Bay of Bengal system. The track is now stated: west-northwestwards.
On the ground, the rain is already biting
The warnings are not purely anticipatory.
Colombo flooded on Thursday afternoon. Police said a number of roads were inundated, NewsFirst reported at 1.49 p.m. The affected points named are Armour Street–Barber Junction in the Grandpass Police Division, the vicinity of the Jethawana Temple, a section of Sangharaja Mawatha, and roads in the Maligawatte Cemetery area, which carry traffic in and out of the city. Motorists were advised to plan journeys carefully and use alternative routes.
Flood warnings are active along the Deduru Oya. The Irrigation Department warned low-lying areas in nine divisional secretariat divisions — Wariyapola, Nikaweratiya, Mahawa, Kobeigane, Bingiriya, Pallama, Chilaw, Arachchikattuwa and Rasnayakapura — with the reservoir’s sluice gates open and water being released at 16,500 cubic feet per second, NewsFirst reported at 12.19 p.m. That is the same release rate recorded when the gates were opened.
Travel advice for the hill country
The Disaster Management Centre’s Director (Awareness) Pradeep Kodippili said people planning to travel to affected areas should check weather and road conditions before setting out.
“We are receiving frequent inquiries from people who have planned excursions to the central hill country. Given the prevailing heavy rains, it is important to remain alert and be mindful of the situation.”
He asked travellers to check road conditions by calling the Disaster Management Centre hotline on 117 before setting off, and to pay close attention to forecasts when travelling through mountainous areas vulnerable to landslides.
Heavy rainfall was affecting the Central Province, Kurunegala District, Western Province and areas in and around Ratnapura, the centre said.
A narrower landslide list than the NBRO’s
The Disaster Management Centre named landslide warnings for six districts: Badulla, Kandy, Kegalle, Kurunegala, Nuwara Eliya and Ratnapura, citing the risk of earth slips and rockfalls to motorists.
The National Building Research Organisation’s 24-hour warning, issued earlier the same evening, covered nine districts — the same six plus Colombo, Kalutara and Monaragala.
The two lists are not contradictory so much as differently scoped: the centre’s advisory is addressed to people travelling into the hill country, and Colombo and Kalutara are origins rather than destinations for that traffic. But readers in Colombo, Kalutara and Monaragala should treat the broader list as the one that covers them, since the NBRO is the issuing authority for landslide warnings.
Update, Friday morning: the departing system is still raining on the island
The Met Department’s Friday forecast confirms the separation set out above, and it is the first filing to state the departing low’s direction in the department’s own words.
The low-pressure area that had been near Sri Lanka is moving away from the island, westwards, the department said in a statement reported by Hiru News at 6.35 a.m. on Friday. Its effects are nonetheless expected to persist across the island through Friday.
Showers or thunderstorms may occur at times in the Western, Sabaragamuwa, Central, Northern and North-Western provinces and in the Anuradhapura and Galle districts. In the rest of the island, rain is expected after 1.00 p.m. Some places may receive falls above 75mm, and misty conditions are possible in parts of the Central and Uva provinces in the pre-dawn hours.
Two points follow for readers of the advisory above.
First, the 75mm threshold is the same one that has driven this week’s flooding and landslide warnings, so Friday is not a recovery day. Second, and more importantly, this forecast is about the departing system, not the prospective one. A reader seeing “low-pressure area moves westward” could reasonably take it as the cyclone risk receding. It is not: the Thursday evening advisory described a system that does not yet exist, forming in the southeastern Bay of Bengal, with cyclogenesis probability rated nil for the first 48 hours and high for the 72-to-96-hour window beginning Sunday evening. Friday’s forecast neither revises nor mentions that assessment.
The deep-sea restriction between 10°N–20°N and 80°E–95°E has not been reported as lifted.
Still unavailable: the department’s own site, meteo.gov.lk, returned no response again on Friday, and island.lk — which reproduces the Met release verbatim and is this desk’s usual route to the English text — had not yet posted Friday’s forecast at the time of writing, carrying only Thursday’s. The wording above is therefore translated from Hiru’s Sinhala rather than taken from the department’s English release, and the department’s English phrasing for the post-1.00 p.m. timing could not be checked against it.
Not reported
No filing states where the prospective system is expected to make landfall, or whether it is expected to approach Sri Lanka at all — the west-northwestward track from the southeastern Bay of Bengal would carry it toward the Indian coast rather than the island, but none of the advisories says so. None gives expected wind speeds, and none says when the deep-sea restriction will be reviewed or lifted. The department’s own site, meteo.gov.lk, remains unreachable from this desk.
Sources: Fishing, naval communities warned of developing low-pressure system in Bay of Bengal — Daily Mirror, October 22, Public urged to reconsider planned excursions due to heavy rains, landslide warnings — Daily Mirror, October 22, Heavy rains lash several provinces — NewsFirst, October 22, Heavy rains flood Colombo roads — NewsFirst, October 22.