Media Center
Climate Bulletin for Sri Lanka (Week of 09 Dec – 16 Dec 2022)
Highlights
Rainfall Prediction: Fairly heavy (> 80 mm) rainfall is predicted for the Northern and Eastern provinces and moderately heavy (≥ 45 mm) rainfall is predicted for the rest of the country from 7th – 13th of December.
Monitored Rainfall: During the last week, the average daily rainfall over Sri Lanka was 0.6 mm & hydro catchment areas received 4.5 mm on average and the highest average rainfall (4.3 mm) was received to the Eastern plains of the country.
Monitored Wind: From 28th Nov – 4th Dec, up to 5m/s of north easterly winds were experienced at 850mb level over the island.
Monitored Sea and Land Temperature: Sea surface temperature around Sri Lanka was above normal to the western, eastern, and southern half of the country. Land surface temperature remained near normal.
Interpretation
Monitoring
Rainfall: During the last two weeks, there had been heavy rainfall over Rathnapura and Kalutara.
Daily average rainfall in the Met stations for the previous week of (29th November – 6th December) =5.0 mm
Rainfall max: 73.7 mm & Rainfall min: 0.0 mm.
Wind: Northeasterly winds prevailed in the sea area and around the island last week.
Temperatures: The temperature anomalies were above normal for some parts of the Western, and Sabaragamuwa provinces, driven by the warm SSTs.
Prediction
Rainfall: During the next week (7th Dec – 13th Dec), fairly heavy (> 80 mm) rainfall is predicted for the Northern and Eastern provinces; and moderately heavy (≥ 45 mm) rainfall is expected for the rest of the country.
Temperatures: The temperature will remain below normal for some parts of the Central, Uva, Sabaragamuwa, Northern, and Eastern provinces during 8th – 14th December.
Teleconnections: La Niña is favored to continue through during the Northern Hemisphere winter (December-February) 2022-23, with a transition to ENSO-neutral favored in February-April 2023 (57% chance).
MJO shall slightly increase the rainfall from 7th December – 21st December for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the December-January-February 2023 season shows a higher tendency for near-normal precipitation in 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 |
