Media Center
Climate Bulletin for Sri Lanka (Week of 09 – 16 June 2023)
Highlights
Rainfall Prediction: Heavy rainfall is predicted for the Sabaragamuwa, Southern and Western provinces, and fairly heavy rainfall is predicted for the Central and Uva provinces of the
the country during 8 – 14 June.
Monitored Rainfall: During the last week, the average daily rainfall over Sri Lanka was 3.0 mm and hydro catchment areas received 6.7 mm. Highest average rainfall of 8.1 mm/day was received by the Western plains.
Monitored and Predicted Wind: From 30 May – 5 June, up to 8 m/s of westerly winds were at 850 mb (1.5 km). During 9 – 15 June, up to 15 m/s of northwesterly winds are expected at 850 mb (1.5 km).
Monitored Sea and Land Temperature: The sea surface temperature around Sri Lanka was 0.5 – 1.5°C above normal. The average maximum land temperature ranged from 32-33°C and the minimum ranged from 24 – 25°C with a drop in the hills.
Interpretation
Monitoring
Rainfall: During the last two weeks, there had been very heavy rainfall over Ratnapura, Galle
Daily Average Rainfall in the Met stations for the previous week of (31st May – 7th June) = 3.0 mm
Maximum Daily Rainfall: 183.2 mm & Minimum Daily Rainfall: 0.0 mm.
Wind: Westerly 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, Sabaragamuwa, Central, North Western, Uva, and Southern provinces and near normal for the rest of
the country driven by the warm SSTs.
Cyclone: The cyclonic storm ‘Biparjoy’ originated as a low-pressure area over the east-central Arabian Sea and moved north-northeastwards. Then it intensified into a ‘very severe cyclonic storm (VSCS) on 7th June and lay centered at 14.8 N, 66.4 E on 9th June, maintaining a 6 kmph wind speed.
Prediction
Rainfall: During the next week (8th June – 14thJune), heavy rainfall (≥ 115 mm) is predicted for the Sabaragamuwa, Southern, and Western provinces, and fairly heavy rainfall (≥ 75 mm) is predicted for the Central and Uva provinces and less rainfall is predicted for rest of the country.
Temperatures: The temperature will remain above normal for some parts of the Eastern, Northern, Uva, and Southern provinces from 9th June – 15th June.
Teleconnections: A large majority of the models indicate an El Niño to continue into the winter.
MJO shall slightly enhance the rainfall from 8th – 22nd June for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the June-July-August, 2023 season shows above-normal precipitation for 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 |
