Media Center
Climate Bulletin for Sri Lanka (Week of 23 Dec – 30 Dec 2022)
Highlights
Rainfall Prediction: Due to the low-pressure area over the southwest Bay of Bengal, fairly heavy rainfall is predicted for the Eastern, Sabaragamuwa,and Western provinces during 22nd- 28th December.
The seasonal forecast shows a higher tendency for above-normal precipitation in the country for January – March, 2023.
Monitored Rainfall: During the last week, the maximum daily rainfall over Sri Lanka was 106.6 mm & hydro catchment areas received 83.0mm on maximum, and the highest average rainfall (10.1 mm) was received to the Eastern plains of the country.
Monitored Wind: From 13th – 19th Dec, up to 8m/s of northeasterly winds were experienced at 850mb level over the island.
Monitored Sea and Land Temperature: Sea surface temperature around Sri Lanka was above normal in the Western, Eastern, and Southern half of the country. The land surface temperature remained near normal.
Interpretation
Monitoring
Rainfall: During the last two weeks, there had been very heavy rainfall over Trincomalee.
Daily Average Rainfall in the Met stations for previous week of (13thDecember – 20th December) =7.7 mm
Rainfall max: 106.6 mm & Rainfall min: 0.0 mm.
Temperatures: The temperature anomalies were below normal for some parts of the North Western, North Central, and Central provinces, driven by the warm SST’s.
Wind: North easterly winds prevailed in the sea area and around the island last week.
Prediction
Rainfall: During the next week (22nd Dec – 28thDec), fairly heavy rainfall is predicted for the Eastern, Western, and Sabaragamuwa provinces; and ≥ 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, and Sabaragamuwa provinces during 23rd – 29th December.
Teleconnections: La Niña is favored to continue into the winter, with equal chances of La Niña and ENSO-neutral during January-March 2023.
MJO shall near neutral the rainfall during 22nd December – 26th December, and moderately suppress the rainfall during 27th December – 5th January for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the December-January-February 2023 season shows a higher tendency for near-normal precipitation to 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 |
