Media Center
Climate Bulletin for Sri Lanka (Week of 31 May – 7 June 2024)
Highlights
Rainfall Prediction: High likelihood of fairly heavy rainfall (50 – 100 mm) is predicted for the Western, Southern, Sabaragamuwa, North Western, Central provinces and moderate rainfall (25 – 50 mm) is predicted for the rest during 29 May – 4 June.
Monitored Rainfall: On average 8.6 mm was received in SL, rainfall was concentrated on the western hills (22mm) and plains (17 mm) during 22 – 29 May. Depression 99B intensified as a severe cyclonic storm (‘Remal’) and made landfall over the Bangala/West Bengal border regions on 26 May.
Monitored and Predicted Wind: Strong winds at 850mb (1.5 km) westerly from 21 – 27 May reaching up to 30m/s due to the cyclonic storm. Winds at 850mb are predicted north westerly to south westerly from 30 May – 5 June reaching up to 10m/s.
Monitored Sea and Land Temperature: Average land surface temperature was 30.8°C in the last week with cooler anomalies from seasonal average of -1°C to -3°C. The temperature has dropped slightly. Sea surface temperature around Sri Lanka was 0.25 – 1.5°C above normal.
Interpretation
Monitoring
Rainfall: During the last two weeks, there had been very heavy rainfall over the following area:
Keragala (Ratnapura)
Daily Average Rainfall in the Met stations for previous week of (22nd May – 29th May) = 8.6 mm
Maximum Daily Rainfall: 48.5 mm & Minimum Daily Rainfall: 0.0 mm.
Wind: Westerly winds prevailed in the sea area and around the island last week.
Temperatures: The temperature anomalies were below normal for the Northern, North Central, North Western provinces and some parts of the Eastern, Western, and Central provinces driven by the warm SST’s.
Prediction
Rainfall: During the next week (29th May – 4th June), fairly heavy rainfall (50 – 100 mm) is predicted for the Western, Southern, Sabaragamuwa, North Western, and Central provinces and moderate rainfall (25 – 50 mm) is predicted for the rest.
Temperatures: The temperature will remain above normal for some parts of the Northern, Eastern, and North Central provinces during 30th May – 5th June.
Teleconnections: MJO shall slightly enhance the rainfall during 29th May – 2nd June, and near neutral the rainfall during 3rd June – 12th June for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the June-July-August, 2024 season shows a 50% or more tendency toward above normal precipitation for the country.
Terminology for Rainfall Ranges
| Rainfall | |
| Light Showers | Less than 12.5 mm |
| Light to Moderate | Between 12.5 mm and 25 mm |
| Moderate | Between 25 mm and 50 mm |
| Fairly Heavy | Between 50 mm and 100 mm |
| Heavy | Between 100 mm and 150 mm |
| Very Heavy | More than 150 mm |
