The National Building Research Organisation (NBRO) has issued landslide early warnings for six districts, escalating a morning rainfall advisory into an active hazard warning within hours.

The warnings cover Galle, Kalutara, Kandy, Kegalle, Nuwara Eliya and Ratnapura, and remain in force until 7.00 a.m. on Monday (21), Daily Mirror reported at 9.21 a.m.

The 100mm threshold was already crossed before the warning

The Department of Meteorology said heavy rainfall exceeding 100 mm is possible in parts of the Western and Sabaragamuwa provinces and the Kandy and Nuwara Eliya districts, according to NewsFirst and Hiru News, which carried the forecast in near-identical terms.

That figure is not only a forecast. Kegalle District recorded 103.5 mm — the island’s highest — in the 24 hours ending at 6.00 a.m. on Sunday, Daily Mirror reported separately at 7.46 a.m. Kegalle is one of the six districts placed under a landslide warning three and a half hours later. Neither outlet connects the two filings, but the sequence indicates the warning follows rain that has already fallen, rather than rain that is merely expected.

Daily Mirror attributes the conditions to the active Southwest Monsoon. That differs from the driver cited earlier in the week, when the rainfall increase in the south-west was tied to a low-pressure area near the Andaman Islands. No outlet addresses the change in attribution.

The rest of Sunday’s forecast

Showers may occur at times in the Western, Sabaragamuwa, North Western and Northern provinces and in the Galle, Matara, Kandy and Nuwara Eliya districts. Showers or thundershowers are likely at several places in the Uva Province and the Batticaloa and Ampara districts after 2.00 p.m.

Winds of 30 to 40 km/h are expected at times over the western slopes of the central hills, the North Central and North Western provinces, and the Trincomalee, Hambantota and Matale districts. The department advised the public to take precautions against temporary strong winds and lightning during thundershowers.

Daily Mirror’s version of the advisory also places Galle and Matara inside the heavy-fall zone, where NewsFirst and Hiru list those two districts only under the lighter “showers at times” category. The two-outlet version is reflected above.

A flood risk on the same rain

Separately, the Department of Irrigation warned of a risk of minor flooding in low-lying areas along the Mahaweli River in the Pasbage Korale Divisional Secretariat Division of Kandy, attributing it directly to the heavy rainfall, Hiru News reported. Residents living close to the river were urged to remain highly vigilant.

Kandy therefore carries both an active landslide warning and a flood advisory on Sunday. Kalutara and Ratnapura, two of the other warned districts, sit in the Kalu basin, where river levels were already reported rising earlier in the week.

Not reported

No outlet gives rainfall totals for districts other than Kegalle, names specific at-risk towns or slopes within the six districts, or reports whether any evacuations, road closures or school closures have been ordered. It is not stated how many households sit inside the warning zones, whether any landslides, injuries or deaths have already occurred, or whether the NBRO warning is expected to be extended or upgraded beyond Monday morning.

The Irrigation Department does not say how many people live in the affected Mahaweli low-lying areas, nor whether other river basins are under watch.

Sources