Media Center
Climate Bulletin for Sri Lanka (Week of 13 May – 20 May 2022)
Highlights
Rainfall Prediction: NCEP GFS prediction for 11th onwards, the heaviest rainfall in Ratnapura, Galle &Kalutara districts is hazardous. Heavy rainfall above100mm is expected in Sabaragamuwa Western, Southern & Central provinces.
Monitored Rainfalls: During the last week, average daily rainfall over Sri Lanka was 4.4mm and hydro catchment areas have received 9.4mm on average
Monitored Wind: From 2nd – 8th May, up to 10 m/s westerlies and South-westerlies were experienced over the Island.
Monitored Temperature: Sea surface temperature was above 0.5℃ to the north and east of Sri Lanka. 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: Ratnapura.
Daily Average Rainfall in the Met stations for previous week of (2nd- 9th May) = 4.4 mm
Rmax: 105 mm & Rmin: 0.0 mm.
The Hydro Catchment Areas recorded 9.4 mm of average rainfall for the last week
Rmax: 98 mm & Rmin: 0 mm.
Wind: Westerly and South-westerly prevailed in the sea area surrounding the island last week.
Temperatures: The temperature anomalies were above normal for the Western, Sabaragamuwa and North-western provinces and neutral for the rest of the country, driven by the warm SST’s.
Prediction
Rainfall: During the next week (13th- 17th May) heavy rainfall (>100 mm) is predicted for the Western, Sabaragamuwa, Southern, and Central provinces. NCEP GFS prediction for 11th onwards, the heaviest rainfall expected in Ratnapura, Galle & Kalutara districts is hazardous
Temperature : The temperature remains slightly below normal in the Central, Uva & Sabaragamuwa provinces and above normal in the Eastern province during 6th- 14th May.
Teleconnections:
La Nina – The SST forecast indicates that La Niña is favored to continue into the Northern Hemisphere summer (June-August 2022). MJO shall neutral during 13th – 15th May, shall moderately suppress the rainfall during 16th – 20th May and severely suppress during 21st – 25th May.
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 |