Highlights

Rainfall Prediction: During 11 Sep – 17 Sep, high likelihood of Light to Moderate rainfall (12.5 – 15 mm/week) is predicted for the North Western province and Light Showers (≤12.5 mm/week) is predicted for the Northern, Eastern, North Central, Southern, Sabaragamuwa, Western, Central, and Uva provinces of SL.

Monitored Rainfall: On average, 2.7 mm/day was received in SL and rainfall was concentrated in the Western plains (7.9 mm/day) and hills (6 mm/day) for last 8 days. On average, 7.2 mm/day was received in the hydro catchments in SL; Kukule Ganga received the highest daily rainfall (42 mm/day) for last 8 days. Highest daily rainfall was in Ratnapura on 9 Sep (44.2 mm/day).

Monitored and Predicted Wind: From 3 Sep – 9 Sep, winds at 850mb (1.5km) were north westerly, reaching up to 15 m/s. From 12 Sep – 18 Sep, winds are predicted to be north 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 0.5°C above average for the Western side of the country and 1°C above average for the other half\ of the country from 20 – 26 Aug 2024.

 

Climate Bulletin for Sri Lanka (Week of  13 –  20 September 2024)

 

Interpretation

Monitoring

Rainfall:During the last two weeks, there has been heavy rainfall over the following area: Ilubuluwa Estate(Rathnapura). Average Rainfall in the Met stations for the previous week of (5 – 11 Sep) = 2.7 mm/day Maximum Daily Rainfall: 44.2 mm & Minimum Daily Rainfall: 0.0 mm.

Wind: North Westerly winds prevailed in the sea area and around the island last week.

Temperatures: The temperature anomalies were above normal for some parts of the Uva province for Sri Lanka driven by the warm SST anomalies.

Prediction

Rainfall: During the next week (11 Sep – 17 Sep ), Light to Moderate rainfall (12.5 – 15 mm) is predicted for the North Western province and Light Showers (12.5 mm) is predicted for the Northern, Eastern, North Central, Southern, Sabaragamuwa, Western, Central, and Uva provinces.

Temperatures: The temperature will remain above normal for the Northern, Eastern, Southern, North Central and Uva provinces during 13 – 19 September.

Teleconnections: MJO shall near neutral the rainfall during 12-26 September for Sri Lanka

Seasonal Precipitation: The precipitation forecast for the September-October-November, 2024 season shows a 45% or more tendency toward above-normal precipitation for the Eastern part of the country

Terminology for Rainfall Ranges

 Rainfall
Light ShowersLess than 12.5 mm
Light to ModerateBetween 12.5 mm and 25 mm
ModerateBetween 25 mm and 50 mm
Fairly HeavyBetween 50 mm and 100 mm
HeavyBetween 100 mm and 150 mm
Very HeavyMore than 150 mm