Media Center
Climate Bulletin for Sri Lanka (Week of 05 May – 12 May 2023)
Highlights
Rainfall Prediction: Heavy rainfall (> 100mm) is predicted for the Sabaragamuwa, and Western provinces and fairly heavy rainfall (75mm – 100mm) is predicted for rest of the country during 3rd – 9th May.
Monitored Rainfall: During the last week, average daily rainfall over Sri Lanka was 13.2 mm and hydro catchment areas received 7.8 mm. Highest average rainfall 16.0mm/day was received to Western plains.
Monitored and Predicted Wind: From 24th – 30th Apr, up to 4 m/s of Easterly winds were experienced at 850mb level (1.5 km). During 5th- 11th May, up to 10 m/s of Westerly winds are expected at 850 mb level (1.5 km).
Monitored Sea and Land Temperature: Sea surface temperature around Sri Lanka was about 1 – 1.5 degree above the seasonal norm. Land surface temperature remained near normal.
Interpretation
Monitoring
Rainfall: During the last two weeks, there had been heavy rainfall over the following areas: Moneragala, Kilinochchi
Daily Average Rainfall in the Met stations for previous week of (26th April – 3rd May) = 13.2 mm
Maximum Daily Rainfall: 87.7 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 near normal for the whole country driven by the warm SST’s.
Prediction
Rainfall : During the next week (3rd May – 9th May), heavy rainfall (> 100 mm) is predicted for the Sabaragamuwa, and Western provinces and fairly heavy rainfall (≥ 75 mm) is predicted for rest of the country.
Temperatures: The temperature will remain above normal for some parts of the Eastern province and below normal for some parts of the Central, Uva, and Sabaragamuwa provinces during 5th May – 11th May.
Teleconnections: ENSO-neutral conditions are expected to continue through the Northern Hemisphere spring, followed by a 62% chance of El Nino developing during May-July 2023.
MJO shall moderately enhance the rainfall during 3rd – 6th May, slightly enhance the rainfall during 7th – 11th May, and slightly suppress the rainfall during 12th – 16th May for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the May-June-July, 2023 season shows near 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 |
Prediction
Rainfall: During the next week (27th April – 3rd May), heavy rainfall (≥ 125 mm) is predicted for the Sabaragamuwa, Western, Southern, and Central provinces and ≥ 105 mm rainfall is predicted for the Uva, North Western, North Central, and Eastern provinces of the country.
Temperatures: The temperature will remain above normal for some parts of the Northern, North Western, North Central, Uva, Eastern, and Southern provinces during 2th April – 4th May.
Teleconnections: ENSO-neutral conditions are expected to continue through the Northern Hemisphere spring, followed by a 62% chance of El Nino developing during May and July 2023.
MJO shall moderately enhance the rainfall from 27th April – 11th May for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the May-June-July, 2023 season shows near-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 |
