Media Center
Climate Bulletin for Sri Lanka (Week of 20 – 27 September 2024)
Highlights
Rainfall Prediction: Light to Moderate rainfall (12.5 – 25 mm) is predicted for the North Western, Southern and Western province and Light Showers (12.5 mm) is predicted for the Northern, Eastern, North Central, Sabaragamuwa, Central, and Uva provinces.
Monitored Rainfall: On average, 1 mm/day was received in SL and rainfall was concentrated in the Western plains (2.5 mm/day) and hills (2.6 mm/day) for last 8 days. On average, 2.5 mm/day was received in the hydro catchments in SL; Kukule Ganga received the highest daily rainfall (42mm/day) for last 8 days. Highest daily rainfall was in Ratnapura on 11 Sep (26.3 mm/day).
Monitored and Predicted Wind: From 10 Sep – 16 Sep, winds at 850mb (1.5km) were north westerly – westerly, reaching up to 15 m/s. From 19 Sep – 25 Sep, winds are predicted to be north west – westerly, reaching up to 15 m/s.
Monitored Sea and Land Temperature: Average land surface temperature was 31.5ºC in the last week with warmer anomalies from seasonal average of 1-3 ºC. Eastern plains was warmest followed by Northern, Southern and Western plains. Sea surface temperature around Sri Lanka was 1.0℃ above average from 27 Aug – 2 Sep 2024.
Interpretation
Monitoring
Rainfall: During the last two weeks, there has been fairly heavy rainfall over the following area: Negombo(Gampaha). Average Rainfall in the Met stations for the previous week of (11 – 18 Sep) = 1.1 mm/day Maximum Daily Rainfall: 26.3 mm & Minimum Daily Rainfall: 0.0 mm.
Wind: North West – Westerly winds prevailed in the sea area and around the island last week.
Temperatures: The temperature anomalies were above normal for Eastern and Uva provinces and some parts of the Western, Southern, Sabaragamuwa and Central provinces for Sri Lanka driven by the warm SST anomalies.
Prediction
Rainfall: During the next week (18 Sep – 24 Sep ), Light to Moderate rainfall (12.5 – 25 mm) is predicted for the North Western, Southern and Western province and Light Showers (12.5 mm) is predicted for the Northern, Eastern, North Central, Sabaragamuwa, Central, and Uva provinces.
Temperatures: The temperature will remain above normal for the Northern, Eastern, Southern, North Central and Uva provinces during 19 – 25 September.
Teleconnections: MJO shall slightly suppress the rainfall during 18 – 22 Sep and near neutral the rainfall during 23 Sep – 2 Oct for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the October-November-December, 2024 season shows a 40% or more tendency toward above-normal precipitation for the Eastern part of 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 |