Media Center
Climate Bulletin for Sri Lanka (Week of 20 May – 27 May 2022)
Highlights
Rainfall Prediction: Heavy rainfall above 100 mm is expected in Sabaragamuwa Western & Southern provinces during 20th to 24th May.
Monitored Rainfalls: During the last week, average daily rainfall over Sri Lanka was 5.6mm and hydro catchment areas have received 24.1mm on average.
Monitored Wind: From 9th- 15th May, up to 15 m/s South-westerlies were experienced over the island.
Monitored Temperature: Sea surface temperature was near-neutral around the island. Land surface temperature remained near normal during the last week.
Interpretation
Monitoring
Rainfall:
During the last two weeks, there had been heavy rainfall over the following area: Kalutara
Daily Average Rainfall in the Met stations for previous week of (10th- 17th May) = 5.6 mm
Wind: South-westerly prevailed in the sea area surrounding the island last week.
Temperatures: The temperature anomalies were near-neutral for the country, driven by the warm SST’s.
Prediction
Rainfall: During the next week (20th- 24th May) heavy rainfall (>100 mm) is predicted for the Southern, Western and Sabaragamuwa provinces.
Temperature : The temperature remains slightly above normal in the Eastern province during 20th – 28th May.
Teleconnections:
La Niña – The SST forecast indicates a continuation of the La Niña event with high probability during May-Jul. And there is some disagreement between the two forecast methods thereafter. MJO shall slightly suppress the rainfall during 20th- 22nd May and moderately enhance the rainfall during 23rd May – 1st June.
Seasonal Precipitation:
The precipitation forecast for the May-June-July season shows below-normal precipitation for the island, but above-normal precipitation for the Northern province.
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 |