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.
Update, Friday 23 October: wind speeds given, and a second system
The Department of Meteorology said on Friday that another low-pressure area is likely to form that day over the southeast and adjoining east-central Bay of Bengal, and to intensify further while moving west-northwestwards, NewsFirst reported.
The department also supplied the figure missing from every earlier advisory. Wind speeds in the sea areas off the coast from Kankesanthurai to Pottuvil via Puttalam, Colombo, Galle, Matara and Hambantota could increase to 60–70 km/h.
The Department of Fisheries has told fishing and naval communities not to venture into sea areas above latitude 10° North in the Bay of Bengal — a sharper definition of the restricted zone than the earlier advisory carried.
Separately, the earlier low-pressure area — the one described in this article — is now near Sri Lanka and moving westward away from the island. Thundershowers were expected on Friday in the Western, Sabaragamuwa, Central, Northern and North Western provinces and in the Anuradhapura and Galle districts, with fairly heavy falls of around 75 mm in some parts. The department asked the public to guard against temporary localised strong winds and lightning.
Update, Friday evening: the system has formed, and the Met Department now names the end-state
The prospective system described throughout this article now exists, and the Department of Meteorology has published a dated escalation ladder for it ending in a named storm category.
A new low-pressure area has formed over the Bay of Bengal near the North Andaman Islands, the department said in an advisory reported by the Daily Mirror at 5.43 p.m. Colombo time on Friday. Its forecast course runs in four stages:
| Stage | Timing | Location |
|---|---|---|
| Low-pressure area (now formed) | 23 October | Near the North Andaman Islands |
| Depression | by 24 October | Remains in the same region |
| Deep depression | by 25 October | Moving west-northwestwards |
| Cyclonic storm | by the morning of 26 October | West-central Bay of Bengal |
Two things follow.
First, this closes the question this article has carried open since Thursday. Every earlier advisory described a west-northwestward track without saying where it led. The department has now named the destination: the west-central Bay of Bengal — the stretch of water off the Andhra Pradesh and Odisha coasts, roughly 1,200 km north of Sri Lanka. A system reaching cyclonic-storm strength there is moving away from the island, not towards it. That is the single most important fact for Sri Lankan readers, and it is the first time any filing has supplied it.
Second, the escalation timetable confirms this desk’s own arithmetic. The Thursday advisory gave cyclogenesis probability as nil for 48 hours and high for the 72-to-96-hour window, which this article derived above as running from about 5.00 p.m. on Sunday 25 October to 5.00 p.m. on Monday 26 October. The department’s own forecast now places the cyclonic storm at the morning of 26 October — inside that window. The derivation held.
The deep-sea restriction is restated in its original, wider form: naval and fishing communities are advised not to venture into the area bounded by 10°N–20°N and 80°E–95°E until further notice, and those already operating inside it have again been urged to move to safer locations. This is worth flagging, because Friday morning’s filing had narrowed the zone to “above latitude 10° North” without a southern or eastern bound. The evening advisory restores the full box, so the narrower description should not be relied on.
The department asked fishing and naval communities to remain vigilant and to follow subsequent forecasts and advisories.
The department names the effect on Sri Lanka: more rain in the south-west
A later advisory on Friday evening, reported by Hiru News at 9.06 p.m., restates the same four-stage escalation and then adds the sentence this article has been missing.
The department says that while the system will have no direct impact on Sri Lanka, an increase in rainfall over the south-western part of the island can be expected in the coming days.
That is the first time any filing has paired the “moving away from the island” finding with a named domestic consequence. The two are not in tension: a system tracking west-north-westwards towards the Andhra–Odisha coast draws moisture across the southern Bay, and the island’s south-west quadrant — Colombo, Gampaha, Kalutara, Galle, Kalutara’s interior and the Sabaragamuwa slopes — is where that lands.
It also matters for the warnings already running. The south-west is the catchment feeding the Kalu Ganga and Kelani basins, where spill-gate releases and flood risk are already being tracked, and several of the districts under NBRO landslide warnings sit on the same slopes. More rain there over the coming days acts on ground that is already saturated.
Update, Saturday 24 October: the system has stalled, and the odds have hardened
Three filings on Saturday morning confirm the escalation ladder above is running to timetable, with one change to the system’s behaviour and one to the department’s language.
The low-pressure area near the North Andaman Islands is remaining stationary in that same region, the Department of Meteorology said, and is very likely to develop into a depression by today, 24 October, Hiru News reported at 6.25 a.m. The Daily Mirror carried the same forecast at 8.25 a.m., and NewsFirst at 7.28 a.m.
The stall is new. Friday evening’s advisory had the system moving west-northwestwards from the outset. Saturday’s has it holding position off the North Andamans while deepening, and only then tracking west-northwest — a deep depression by 25 October and a cyclonic storm near the west-central Bay of Bengal by the morning of 26 October. The destination and the dates are unchanged from Friday; what has changed is that the first leg of the journey has not started.
The probability has hardened. Thursday’s advisory rated cyclogenesis “high” for the 72-to-96-hour window. Hiru’s Saturday rendering of the department’s wording is ඉතා ඉහළ සම්භාවිතාවක් — a very high probability — for the cyclonic-storm stage on the 26th. A system that is intensifying while stationary is consolidating rather than shearing apart, which is consistent with the firmer language.
For Sri Lanka the assessment is unchanged: no direct impact, but changes in wind patterns bringing increased rainfall to the island’s south-western quarter.
What Saturday’s forecast asks of readers
Showers or thundershowers are expected at times in the Western, Sabaragamuwa, Northern and North Western provinces, with rain elsewhere on the island after 1.00 p.m. Misty conditions are possible in parts of the Central and Uva provinces in the pre-dawn hours.
Wind speeds in sea areas off the coast from Kankesanthurai to Pottuvil via Puttalam, Colombo, Galle, Matara and Hambantota could reach 60–70 km/h — the same figure first given on Friday, now restated a third time. The Department of Fisheries has again advised fishing and naval communities not to venture into Bay of Bengal sea areas north of latitude 10°N.
Landslide early warnings issued for divisional secretariat divisions in Kegalle, Ratnapura, Badulla, Colombo, Kalutara, Kandy, Kurunegala, Monaragala and Nuwara Eliya districts remain in effect. That is the nine-district list — the broader of the two scopes this article compared above — and Saturday’s filing confirms it has not been narrowed.
Update, Saturday evening: a red warning, and the sea box narrows
The Department of Meteorology has issued a red warning for strong winds and rough seas, the Daily Mirror reported at 5.35 p.m. Hiru News carried the same advisory at 8.11 p.m., describing the affected waters as having been declared high-risk zones for fishing and naval craft.
The restricted sea area has changed shape, and this is the detail to carry forward. The box is now bounded by 10°N–20°N and 85°E–95°E. Every earlier advisory in this article gave the western bound as 80°E. Both Saturday-evening filings independently give 85°E, so the five-degree narrowing is the department’s own revision and not a transcription error in one newsroom. The restriction runs until further notice, and vessels already inside the zone have again been told to move to safer locations.
The escalation ladder itself is unchanged from Saturday morning: the low near the North Andaman Islands is very likely to deepen into a depression on 24 October, a deep depression by 25 October, and a cyclonic storm over the west-central Bay of Bengal by the morning of 26 October. Hiru again renders the probability of the cyclonic stage as ඉතා ඉහළ — very high. The assessment for Sri Lanka is still no direct impact.
Rainfall figures, for the first time
Saturday morning’s filings described more rain in the south-west without quantifying it. The evening advisory puts numbers on it:
- Saturday night: falls of around 75 mm at some places in the Western, Sabaragamuwa and Uva provinces and in the Galle, Matara, Nuwara Eliya, Kandy, Ampara and Batticaloa districts.
- Sunday 25 October: falls above 100 mm at some places in the Western, Sabaragamuwa, Northern, North Western, Southern and Central provinces.
Those totals land on catchments already under strain, where spill-gate releases and flood risk are being tracked.
One caveat on the landslide warnings. Hiru’s evening filing lists continuing landslide risk for Kegalle, Nuwara Eliya and Ratnapura only — three districts, against the nine-district list confirmed earlier on Saturday. It is not clear from the filing whether the warning has been narrowed or whether Hiru has summarised the highest-risk districts. Readers in the other six districts should treat the nine-district warning as still in force until the NBRO says otherwise.
Update, Sunday 25 October (latest): the storm has a name — Arnab — and a landfall window
The two questions this article has carried as unreported since Thursday have both now been answered. The system has been named, and a landfall point has been given.
The Bay of Bengal system has become a severe cyclonic storm named “Arnab” and is expected to track across the Andhra Pradesh and Yanam coast of India, Hiru News reported on Sunday.
The landfall window is 28 October, between Bapatla and Visakhapatnam. That is the first coastal crossing point any filing in this article has given. Both towns are on the Andhra Pradesh coast, roughly 400 km apart, which makes this a broad window rather than a fixed point.
For Sri Lanka, the assessment is unchanged in kind but now explicitly indirect. The filing states that rain and wind will increase over the island’s south-west and Northern provinces as an indirect effect of the storm. The deep-sea restriction stands: the Department of Meteorology continues to advise against fishing and naval activity in the deep-sea areas of the Bay of Bengal.
A caution on whether the threshold has actually been crossed
Readers should treat the tense carefully. Hiru’s filing is written as though the cyclone already exists. The Department of Meteorology’s own staged forecast, recorded in the section below and unretracted, put the cyclonic storm stage at the morning of 26 October and the severe stage at the morning of 27 October — tomorrow and the day after.
So the name is now fixed and published, but whether the system had reached cyclonic-storm strength at the time of writing is not settled by this filing. This desk has recorded the same newsroom running a stage ahead of the department’s own text on this system once already, on Sunday morning. The safe reading is that Arnab is the name assigned to this system, and that the strengthening is still on the department’s published timetable.
A further caution on the landfall window. Indian outlets reporting the India Meteorological Department on 24 October gave a narrower crossing — near or south of Kakinada, which sits inside Hiru’s Bapatla–Visakhapatnam window — and noted that forecast models disagreed, one putting it between Machilipatnam and Kakinada and another near Srikakulam. None of those outlets is a verified newsroom for this desk’s purposes, so they are described here and not cited. The point for readers is that the crossing point is genuinely uncertain within a few hundred kilometres, and the window should not be read as a forecast of a specific town.
Update, Sunday 25 October (earlier): the depression has formed, and a new rung is added to the ladder
The system now exists as a depression, and for the first time a filing gives its actual position.
The low-pressure area that had been sitting near the North Andaman Islands has developed into a depression, the Department of Meteorology said in an advisory reported by Hiru News at 6.32 a.m. on Sunday.
As at 11.30 p.m. on Saturday 24 October, it was centred near latitude 15.5°N, longitude 91.0°E. That is the first set of coordinates any filing in this article has carried, and it settles the question of whether the stall reported on Saturday had broken: the North Andaman Islands sit near 13.3°N, 92.9°E, so the centre has moved roughly 300 km north-westwards from where it was holding position — this desk’s own estimate from the two positions, not a departmental figure.
The forecast now runs a day longer, and one category higher
| Stage | Timing | Location |
|---|---|---|
| Depression (now formed) | by 24 October | Moved to 15.5°N, 91.0°E |
| Deep depression | today, 25 October — high probability | Across the east-central and adjoining south-east Bay of Bengal |
| Cyclonic storm | by the morning of 26 October | Moving west-northwestwards |
| Severe cyclonic storm | by the morning of 27 October | West-central Bay of Bengal |
Two changes from every earlier version of this table.
First, the ladder has been extended. Each previous advisory in this article ended at “cyclonic storm by the morning of 26 October”. Sunday’s adds a further rung — a severe cyclonic storm — and a further day. The department has not previously named that category for this system.
Second, the destination has moved down the table. The west-central Bay of Bengal was the location attached to the cyclonic stage on the 26th in Friday’s and Saturday’s filings. It is now attached to the severe stage on the 27th. The endpoint is unchanged; the system is forecast to reach it a day later and stronger.
The assessment for Sri Lanka is unchanged and remains the central point for readers here: no direct impact. The department repeats that the wind flow running across the island towards the system is what brings the rain, and that an increase is expected over the island’s south-west in the coming days.
Today’s rainfall warning, and a changed district list
Showers or thundershowers are expected at times in the Northern, Western, Sabaragamuwa, Southern, North Western and Central provinces and in the Anuradhapura district, with falls above 100 mm at some places. In the Uva province and the Ampara and Batticaloa districts, showers or thundershowers may develop after 1.00 p.m.
Strong winds of 40–50 kmph are expected at times over the western slopes of the central hills, the Northern, North Central and North Western provinces and the Trincomalee and Hambantota districts. The public has been asked to take precautions against damage from localised strong winds and lightning.
This is the day Saturday evening’s advisory singled out, and both the 100 mm threshold and the province list have held. Saturday evening gave the above-100 mm list as the Western, Sabaragamuwa, Northern, North Western, Southern and Central provinces; Sunday’s filing keeps all six and adds the Anuradhapura district. The only change in the heaviest band is an addition, not a substitution.
Correction. An earlier version of this section said Sunday’s filing had dropped Central province as a whole, replacing it with the Kandy and Nuwara Eliya districts only, and advised readers elsewhere in the Central province — principally Matale — that they had been moved out of the heaviest band. That was wrong, and the advice should not have been given. It followed Hiru’s rendering of the advisory. The Daily Mirror, filing at 2.52 p.m., and NewsFirst both quote the department as naming Central province in full. Two outlets against one, and the whole of the Central province remains inside the above-100 mm band.
A separate lightning advisory covers the districts outside that band. The department has warned of severe lightning with thundershowers in the Uva province and the Ampara and Batticaloa districts during the evening or night, with temporary strong winds possible where the thundershowers develop, Hiru reported at 2.18 p.m.
A caution on the headline
Hiru’s own headline on this filing reads that the depression “intensifies into a cyclone”. Its text does not say that. The body says the system has become a depression and is expected to reach cyclonic-storm strength on 26 October — tomorrow, not today. No filing reports a cyclone in existence at the time of writing.
Two later filings settle the point. The Daily Mirror at 2.52 p.m. and NewsFirst both quote the department directly: the system was still a depression when it was last located at 8.30 a.m. on Sunday, is “very likely to intensify further into a deep depression” during the day, and is expected to become a cyclonic storm by the morning of 26 October. Ada Derana’s headline on the same advisory likewise reads that the depression intensifies — not that a cyclone has formed.
This article’s own headline has been corrected accordingly. An earlier version read “Bay of Bengal storm named Cyclone Arnab”, which asserted as fact the very thing the body of this report was flagging as unsupported. The storm has not formed and the name is not confirmed.
Update, Sunday evening: the track is stated as “towards India”, and the severe stage is corroborated
The last filing of Sunday is the clearest of the sequence, and it closes two gaps.
The low-pressure area over the Bay of Bengal near the North Andaman Islands has now intensified into a depression, NewsFirst reported at 7.21 p.m. — the first filing in this article’s sequence to give the location at which the depression actually formed, rather than the sea area in which it was expected to.
On the department’s assessment as NewsFirst reports it, the system is expected to move across the east-central Bay of Bengal and the adjoining southeastern region during Sunday, potentially intensifying into a deep depression; to develop into a cyclone on Monday; and to intensify further into a severe cyclonic storm over the west-central Bay of Bengal by the morning of 27 October, as it moves towards India.
Two things follow.
First, the severe-cyclonic-storm rung is no longer single-sourced. The section above noted that Sunday’s filing added that category for the first time and that “the department has not previously named that category for this system.” NewsFirst’s independent account of the same advisory carries the same rung, the same location and the same date, which settles it as the department’s own forecast rather than one outlet’s rendering.
Second, the destination is now stated in plain words. Every earlier advisory in this article gave a direction — west-northwestwards — and a sea area. This filing names the landmass: the system is moving towards India. That is consistent with, but more explicit than, the “west-central Bay of Bengal” endpoint, and it is consistent with the Andhra Pradesh landfall that Hiru alone has reported. It is not confirmation of Hiru’s specific landfall point or of the name Arnab, neither of which NewsFirst mentions.
The assessment for Sri Lanka is unchanged and is stated directly: the system is not expected to have a direct impact on Sri Lanka. An increase in rainfall is nonetheless expected in the south-western parts of the country, as the wind flows drawn towards the system pass across the island — the same mechanism described in the earlier advisories, now with the affected quarter of the island named.
Status at the time of this update. No Sri Lankan newsroom had filed since Sunday evening — Colombo newsrooms are closed overnight — so at this point the report could not say whether the cyclone had formed or been named. Readers in the south-west should expect increased rainfall regardless of the system’s final category, and the deep-sea restriction between 10°N–20°N and 80°E–95°E has still not been reported as lifted. The section above, written on Monday morning from the India Meteorological Department’s own bulletin, supersedes this paragraph on the system’s status.
Update, Monday 26 October: the Indian forecaster’s own bulletin settles the landfall point — but not the name
This desk has now read the primary document. The India Meteorological Department is the Regional Specialised Meteorological Centre for the north Indian Ocean — the body that actually classifies and names storms in this basin — and its National Bulletin No. 7, issued at 2.30 a.m. IST on Monday, resolves most of what this article has been carrying as unreported. Three things follow from it.
First, the landfall window is confirmed, and Hiru was right. The bulletin states that the system is very likely to “cross Andhra Pradesh & Yanam coasts between Bapatla and Visakhapatnam” by the forenoon of 28 October. That is word for word the window Hiru published and that this article has, until now, treated as resting on a single outlet. Hiru was reading the Indian bulletin. The caution recorded above was reasonable at the time but is now discharged: the crossing point and date are the Indian forecaster’s own.
Second, the system is still a depression, and this article’s warning about tense was correct. At 11.30 p.m. IST on Sunday the system was a deep depression, not a cyclone — centred near 15.3°N, 89.7°E, moving west-northwest at 15 kmph, carrying winds of 55–65 kmph gusting to 75, and about 990 km east of Bapatla. Hiru’s filing was written as though the cyclone already existed. It did not. The strengthening was, as this report said, still on the published timetable.
Third, the Indian bulletin forecasts a stronger storm than any Sri Lankan filing has reported. Where the Department of Meteorology’s ladder stopped at severe cyclonic storm, the IMD takes it one rung higher, to very severe cyclonic storm, and gives the landfall intensity that no filing in this article had supplied:
| Date / time (IST) | Category | Sustained wind (kmph) |
|---|---|---|
| 25 Oct, 11.30 p.m. | Deep depression | 55–65, gusting 75 |
| 26 Oct, 5.30 a.m. | Cyclonic storm | 65–75, gusting 85 |
| 26 Oct, 11.30 p.m. | Severe cyclonic storm | 100–110, gusting 120 |
| 27 Oct, 11.30 a.m. | Very severe cyclonic storm | 115–125, gusting 140 |
| 28 Oct, 11.30 a.m. | Severe cyclonic storm (landfall) | 95–105, gusting 115 |
| 30 Oct, 11.30 a.m. | Well-marked low | 25–35, gusting 45 |
The bulletin also warns of a storm surge of 1.0 to 1.5 m above astronomical tide at Kakinada and Yanam at landfall, and of phenomenal sea conditions over the west-central Bay of Bengal on the morning of 28 October.
But the storm is still not named. The word Arnab does not appear in the bulletin, and it does not appear anywhere on the IMD’s site. The bulletin’s own subject line calls the system a “Deep Depression over Eastcentral and adjoining Southeast Bay of Bengal”. A name is assigned when a system reaches cyclonic-storm strength, which on the IMD’s own table was forecast for 5.30 a.m. IST on Monday — about half an hour before this update was written, and not yet confirmed by a bulletin. So the name remains the one claim in this article that no primary source supports.
For Sri Lanka, the Indian bulletin is silent, which is itself informative. Its rainfall and wind warnings run to a dozen Indian states and the Andaman Islands; Sri Lanka appears nowhere in them. That is consistent with the Department of Meteorology’s assessment of no direct impact. Its fishermen warning does, however, cover the west-central and adjoining north-west and south-west Bay of Bengal from 26 to 28 October — waters that overlap the deep-sea box Sri Lankan vessels have been told to avoid.
The IMD is not among this desk’s verified newsrooms, so it is cited here as a primary document and does not count towards this article’s credibility rating.
Update, Monday midday: the storm is named, and the name was Arnab all along
The cyclone has formed and it is called Arnab. The India Meteorological Department’s National Bulletin No. 8, issued at 5.30 a.m. IST on Monday, is headed: “Deep Depression intensified into Cyclonic Storm ‘Arnab’ [Pronunciation: Ornab] over Eastcentral and adjoining Westcentral Bay of Bengal”. It carries a red message cyclone warning for the Andhra Pradesh and adjoining south Odisha coasts.
That closes the one claim this article has carried since Saturday without primary support. Hiru was right about the name, as it was right about the landfall window. The scepticism recorded in the section above was appropriate while the system was still a deep depression — a name is only assigned at cyclonic-storm strength — but it is now discharged. Sri Lanka’s own Department of Meteorology is also using the name, according to Hiru, so the name is confirmed from both the regional authority and the national one.
The IMD’s own satellite fix bulletin for 0300 UTC (8.30 a.m. IST) places the centre at 15.5°N, 88.8°E, moving north-northwestwards over the previous 12 hours, with a curved band pattern yielding a Dvorak intensity of T2.5 — consistent with cyclonic-storm strength and with the published timetable.
One caution on category, and it is Hiru’s headline rather than Hiru’s reporting
Hiru’s headline says the system has intensified into a severe cyclonic storm. Its own body text does not say that. The body says the deep depression has intensified into cyclonic storm Arnab, and that by about 11.30 tonight, over the west-central Bay of Bengal, it is likely to intensify further into a severe cyclonic storm.
The body is exactly right, and matches the IMD on both points — the forecast table published in the section above puts severe cyclonic storm at 11.30 p.m. IST on 26 October. The headline has collapsed tonight’s forecast into this morning’s fact. Readers meeting this story through a headline should take the category from the text beneath it.
What this means for Sri Lanka today
The assessment of no direct impact is unchanged. But the rain the system is drawing across the island is now producing warnings on the ground.
Rainfall above 100 mm is forecast in the Western, Sabaragamuwa, North Western, Central and Southern provinces and the Anuradhapura district, the Department of Meteorology said in a heavy-rainfall advisory, NewsFirst reported at 7.29 a.m. (That filing still describes the system as a deep depression — it was written from the local advisory about two hours before the IMD’s upgrade reached Colombo newsrooms.)
A minor flood warning is now in force for the Kalu Ganga basin. The Irrigation Department warned that sustained rainfall over the basin’s catchment could produce minor flooding in low-lying areas within 24 hours, Hiru reported at 11.41 a.m. The warning was issued at 11.30 a.m. on Monday and runs to 11.30 a.m. on Tuesday, naming:
- Ratnapura district: Pelmadulla, Nivitigala, Ratnapura, Kuruwita, Ayagama and Elapatha
- Kalutara district: Ingiriya, Horana, Dodangoda, Millaniya, Bulathsinhala, Madurawala and Palindanuwara
The Irrigation Department and the Disaster Management Centre asked residents of those areas, and drivers passing through them, to take precautions.
Hiru’s report also carries red advisories for several sea areas, with waves of 3 to 4 metres possible and the public advised against going to sea.
Still not reported
No filing says when Sri Lanka’s deep-sea restriction between 10°N–20°N and 80°E–95°E will be reviewed or lifted — it has now stood since Thursday. The department’s own site, meteo.gov.lk, remains unreachable from this desk. No filing gives river gauge heights for the Kalu Ganga, or says whether any evacuations have been ordered in the named divisions.
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, Thundershowers expected in several areas as new low-pressure system forms in Bay of Bengal — NewsFirst, October 23, Fishermen warned over possible cyclone in Bay of Bengal — Daily Mirror, October 23, Low-pressure system in Bay of Bengal likely to develop into depression today — NewsFirst, October 24, Rainfall to increase as Bay of Bengal system intensifies — Daily Mirror, October 24, Naval, fishing communities cautioned not to venture into deep sea — Daily Mirror, October 24, Heavy rainfall exceeding 100 mm forecast in several areas — Daily Mirror, October 25, Bay of Bengal depression set to intensify further today — NewsFirst, October 25, Lightning warning for Uva, Ampara and Batticaloa — Hiru News, October 25, Bay of Bengal cyclone system expected to move towards India by Tuesday (27); no direct impact on Sri Lanka — NewsFirst, October 25, National Bulletin No. 7 (BOB/08/2026), issued 0230 IST — India Meteorological Department / RSMC New Delhi, October 26, Deep depression formed in Bay of Bengal; rainfall above 100 mm forecast across several areas — NewsFirst, October 26, Arnab intensifies in the Bay of Bengal; red advisories for several sea areas — Hiru News, October 26, Minor flood warning for low-lying areas of the Kalu Ganga basin — Hiru News, October 26, National Bulletin No. 8, issued 0530 IST — India Meteorological Department / RSMC New Delhi, October 26.
