Media Center
Climate Bulletin for Sri Lanka (Week of 25 October – 1 November 2024)
Highlights
Rainfall Prediction: During 23 – 29 Oct, high likelihood of Fairly Heavy rainfall (50-100 mm) is predicted for the North Central, North Western, and Western provinces and Moderate rainfall (25-50 mm) is predicted for the Sabaragamuwa, Eastern and Central provinces and Light to Moderate rainfall (12.5- 25 mm) is predicted for the Northern, Uva, and Southern provinces.
Monitored Rainfall: On average, 6 mm/day was received in Sri Lanka, with rainfall concentrated in the Western plains (12.4 mm/day) over the last 8 days. On average, 3.9 mm/day was received in the hydro catchments in SL; Randenigala recorded the highest daily rainfall (42 mm/day) for the last 8 days. Highest daily rainfall occurred in Trincomalee on 20 October (74.3 mm/day).
Monitored and Predicted Wind: From 15 Oct – 21 Oct, winds at 850mb (1.5km) were westerly, reaching up to 15 m/s. From 25 – 31 Oct, winds are predicted to be westerly, reaching up to 6 m/s.
Monitored Sea and Land Temperature: Average land surface temperature was 31.0ºC in the last week with warmer anomalies from seasonal average of -1 +1 ºC. Eastern plains was warmest followed by Northern and Southern plains. Sea surface temperature around Sri Lanka was 1.0℃ above average from 1 – 7 Oct 2024.
Interpretation
Monitoring
Rainfall: During the last two weeks, there has been heavy rainfall over the following area: Kalmunai (Ampara). Average rainfall in the Met stations for the previous week of (16 – 22 Oct) = 6.1 mm/day. Maximum daily rainfall: 74.3 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 near neutral for Sri lanka driven by the warm SSTs anomalies
Prediction
Rainfall: During the next week (23 – 29 October), fairly heavy rainfall (50-100 mm) is predicted for the North Central, North Western, and Western provinces, and moderate rainfall (25-50 mm) is predicted for the Sabaragamuwa, Eastern, and Central provinces. Light to moderate rainfall (12.5-25 mm) is predicted for the Northern, Uva, and Southern provinces.
Temperatures: The temperature will remain normal for the SL during 25 Oct – 31 Oct.
Teleconnections: MJO shall be moderately suppress for the rainfall during 23-27 Oct and highly suppress the rainfall during 28 Oct-1 Nov and moderately suppress the rainfall during 2-6 Nov for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the November-December-January, 2024 season shows a 50% or more tendency toward above-normal precipitation for the 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 |
