Media Center
Climate Bulletin for Sri Lanka (Week of 22 December – 29 December 2023)
Highlights
Rainfall Prediction: High likelihood of fairly heavy rainfall is predicted for Northern, Eastern, North Central, Southern, Sabaragamuwa, Uva, Central provinces during 20 – 26 Dec. Extreme rainfall is predicted during following week.
Monitored Rainfall: During the last week, average daily rainfall over Sri Lanka was 20.9 mm and hydro catchment was 21.9 mm. Extreme rainfall (> 150 mm/day) was in Northern province. The rainfall of last week was twice as normal.
Monitored and Predicted Wind: From 11 – 17 Dec, up to 8 m/s of easterly winds were at 850 mb (1.5 km). During 21 – 27 Dec, up to 8 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. Strong EL Nino patterns sustain.
Interpretation
Monitoring
Rainfall: During the last two weeks, there had been very heavy rainfall over the following area:
Mullaitivu.
Daily Average Rainfall in the Met stations for previous week of (13th December – 20th December) = 20.9 mm
Maximum Daily Rainfall: 153.3 mm & Minimum Daily Rainfall: 0.0 mm.
Wind: 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, and Western provinces of the country driven by the warm SST’s.
Prediction
Rainfall: During the next week (20th December – 26th December), fairly heavy rainfall is predicted for the Northern, Eastern, North Central, Southern, Sabaragamuwa, Uva, Central provinces and less rainfall is predicted for rest of the country.
Temperatures: The temperature will remain seasonably near normal for the country during 21st December – 27th December.
Teleconnections: A positive Dipole Mode has set in across the Indian Ocean since 8th of June. MJO shall near normal the rainfall during 20th – 24th December, slightly enhance the rainfall during 25th – 29th December and near normal the rainfall during 30th December – 3rd January for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the January-February-March, 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 |
