Media Center
Climate Bulletin for Sri Lanka (Week of 08 December – 15 December 2023)
Highlights
Rainfall Prediction: High probability of heavy rainfall is predicted for Sabaragamuwa province and fairly heavy rainfall is predicted for Uva, Southern, Central provinces during 7 – 13 Dec.
Monitored Rainfall: During the last week, average daily rainfall over Sri Lanka was 10.5 mm and hydro catchment was 14.4 mm. Extreme rainfall (> 150 mm/day) was in Galle. The rainfall of last week was twice as normal.
Monitored and Predicted Wind: From 27 Nov – 3 Dec , up to 5 m/s of north easterly winds were at 850 mb (1.5 km). During 7 – 13 Dec, up to 5 m/s of north easterly 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. From 30 Nov – 6 Dec, maximum daily temperature was recorded in Puttalam & Pottuvil (33.7ºC) and Ratnapura (32.9ºC).
Interpretation
Monitoring
Rainfall: During the last two weeks, there had been very heavy rainfall over the following area: Galle.
Daily Average Rainfall in the Met stations for previous week of (29th November – 6th December) = 10.5 mm
Maximum Daily Rainfall: 116.0 mm & Minimum Daily Rainfall: 0.0 mm.
Wind: North easterly 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, Sabaragamuwa, North Western, Southern and Western provinces of the country driven by the warm SST’s.
Prediction
Rainfall: During the next week (7th December – 13th December), heavy rainfall is predicted for the Sabaragamuwa province and fairly heavy rainfall is predicted for the Uva, Southern, and Central provinces and less rainfall is predicted for rest of the country.
Temperatures: The temperature will remain seasonably near normal for the country during 7th December – 13th December.
Teleconnections: A positive Dipole Mode has set in across the Indian Ocean since 8th of June. MJO shall slightly enhance the rainfall during 6th – 10th December and near normal the rainfall during 11th – 15th December and slightly suppress the rainfall during 16th – 20th December for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the December-January-February, 2024 season shows near normal precipitation.
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 |
