Highlights

Rainfall Prediction: During 21 – 27 Aug, high likelihood of Light Showers (<12.5 mm) is predicted for the whole SL. The middle atmospheric convergence at latitudes around Sri Lanka has the potential to bring rainfall to the SL. According to the mediumrange weather forecast, mthe Eastern Province has a highly tendency of above normal rainfall due to these conditions.

Monitored Rainfall: On average, 10 mm was received in SL and rainfall was concentrated in the Western plains (16.2 mm) and hills (11.5 mm) for last 8 days. On average, 9.6 mm was received in the hydro catchments in SL; Kukule Ganga (Kalutara District) received the highest rainfall (125 mm) for last 8 days. Highest daily rainfall was in Mullativu on 20 Aug (151 mm).

Monitored and Predicted Wind: From 13 Aug – 19 Aug, winds at 850mb (1.5km) were northwesterly, reaching up to 15 m/s. From 22 Aug – 28 Aug, winds are predicted to be westerly, reaching up to 15 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 1-3 ºC and cooler anomalies from seasonal average of 1-3 ºC. Eastern plains was warmest followed by Northern and Southern plains. Sea surface temperature around Sri Lanka was 1.0℃ above average of the country.

 

Climate Bulletin for Sri Lanka (Week of  23 August –  30 August 2024)

 

Interpretation

Monitoring

Rainfall: During the last two weeks, there has been fairly heavy rainfall over the following area: Palugaswewa Estate ( Puttlam ). Daily Average Rainfall in the Met stations for the previous week of (15 – 21 Aug) = 6.6 mm Maximum Daily Rainfall: 96.4 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 Central and Sabaragamuwa province and below normal for some parts of the Eastern province for Sri Lanka driven by the warm SSTs.

Prediction

Rainfall:During the next week (21 – 27 Aug ), Light Showers (<12.5 mm) is predicted for the whole SL.

Temperatures: The temperature will remain above normal for the Northern and Eastern provinces during 22 August – 28 August.

Teleconnections: MJO shall slightly enhance the rainfall during 21st – 30th August and near neutral the rainfall during 31st August – 4th September for Sri Lanka.

Seasonal Precipitation: The precipitation forecast for the September-October-November, 2024 season shows a 40% or more tendency toward normal precipitation for 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