Media Center
Climate Bulletin for Sri Lanka (Week of 4 August – 11 August 2023)
Highlights
Rainfall Prediction: Moderately rainfall (25 mm) is predicted for the Sabaragamuwa provinces and less rainfall is predicted for the rest of the country during 3 – 9 Aug. Fairly heavy rainfall (55mm) is predicted for the Southern and Sabaragamuwa provinces during 10 – 16 Aug.
Monitored Rainfall: During the last week, average daily rainfall over Sri Lanka was 0.1 mm and hydro catchment areas received 0.2 mm.
Monitored and Predicted Wind: From 25 – 31 Jul, up to 15 m/s of north westerly winds were at 850 mb (1.5 km). During 4 – 10 Aug, up to 10 m/s of northwest-westerly winds are expected at 850 mb (1.5 km).
Monitored Sea and Land Temperature: Sea surface temperature around Sri Lanka was 0.25 – 1.5oC above normal. Average maximum land temperature ranged from 31 – 33oC and minimum ranged from 24 – 25oC with a drop in the hills.
Interpretation
Monitoring
Rainfall: During the last two weeks, there had been light showers over the following areas: Bandarawela, Galle.
Daily Average Rainfall in the Met stations for previous week of (26th July – 2nd August) = 0.1 mm
Maximum Daily Rainfall: 14.3 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, Sabaragamuwa, Southern, Central, and Eastern provinces of the country driven by the warm SST’s.
Prediction
Rainfall: During the next week (3rd August – 9th August), moderately rainfall (25 mm) is predicted for the Sabaragamuwa province, and less rainfall is predicted for the rest of the country.
Temperatures: The temperature will remain above normal for some parts of the Eastern, Uva, Northern, North Central, Southern, and Central provinces during 4th August – 10th August.
Teleconnections: A positive Dipole Mode has set in across the Indian Ocean since 8th of June. MJO shall near neutral the rainfall during 3rd – 17th August for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the August-September-October 2023 season shows above normal precipitation for the country.
Terminology for Rainfall Ranges
| Rainfall (During 24 hours of the period) | |
| 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 |
