Media Center
Climate Bulletin for Sri Lanka (Week of 16 Sep – 23 Sep 2022)
Highlights
Rainfall Prediction: During the next week (16th- 20th September) moderate rainfall is predicted for the Western and Sabaragamuwa provinces, and less rainfall is expected for the rest of the country.
Monitored Rainfalls: During the last week, the average daily rainfall over Sri Lanka was 0.5mm and hydro catchment areas received 1.6 mm on average.
Monitored Wind: From 5th – 11th September, up to 15m/s of south-westerlies were experienced at 850mb level over the island. South-westerly winds are expected next week.
Monitored Sea and Land Temperature: Sea surface temperature around Sri Lanka was above 0.5°C to the North and below 0.5°C to the West. Land surface temperature remained near normal.
Interpretation
Monitoring
Rainfall: During the last two weeks, there had been fairly heavy rainfall over Colombo. Daily average rainfall in the Met stations for the previous week of (6th-13th Sep)=0.5mm
Rainfall maximum : 16.2 mm & Rainfall minimum : 0.0 mm.
Wind: South-westerly winds prevailed in the sea area and around the island last week.
Temperatures: The temperature anomalies were below for the northern half of the island and were even lower in provinces like Uva and Sabaragamuwa, driven by the warm SSTs.
Prediction
Rainfall: During the next week (16th- 20th September) moderate rainfall is predicted for the Western and Sabaragamuwa provinces, and less rainfall is expected for the rest of the country.
Temperatures: The temperature will remain above average for the Northern, North-central, Uva, and Eastern provinces from 16th September – 22nd September.
Teleconnections: La Niña is favored to continue through Northern Hemisphere winter 2022-23, with a 91% chance in September-November, decreasing to a 54% chance in January-March 2023. MJO shall be near neutral for Sri Lanka during 14th September – 28th September.
Seasonal Precipitation: The precipitation forecast for the October-November-December 2022 season shows a higher tendency for below-normal precipitation in the southern half of the country.
Terminology for Rainfall Ranges
| Rainfall (During 24 hours of 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 |
