Highlights

Rainfall Prediction: Up to 55 – 85 mm fairly heavy rainfall is expected for the entire island during 20th – 26th April.

Monitored Rainfalls: During the last week, average daily rainfall over Sri Lanka was 8.5 mm and hydro catchment areas have received up to 6.9 mm on average.

Monitored  Wind: From 11th – 17th April, up to 2 – 6m/s South-westerlies were experienced over the island.

Monitored  Temperature: Sea surface temperature was above 0.5°C to the east of Sri Lanka.

Interpretation

Monitoring

Rainfall: During the last two weeks, there had been heavy rainfall over Ratnapura. Daily Average Rainfall in the Met stations for previous week of (11th- 18th April) = 8.5 mm

Rainfall maximum: 73.5 mm & Rainfall minimum: 0.0 mm.

The Hydro Catchment Areas recorded 6.9 mm of average rainfall for the last week
Rainfall maximum: 68.4 mm & Rainfall minimum: 0 mm.

Wind: South-westerly winds prevailed in the sea area surrounding the island last week.

Temperatures: The temperature anomalies were below normal for the northern half and near-neutral for the rest of the country, driven by the warm SST’s.

Prediction

Rainfall: During the next week (22nd- 26th April) fairly heavy rainfall is predicted for the entire Island.

Temperature :The temperature remains slightly below normal in the central and Uva provinces and slightly above normal in the northern and eastern provinces during 22nd – 30th April.

Teleconnections:

La Nina – The SST forecast indicates that La Niña is favored to continue into the Northern Hemisphere summer (June-August 2022).
MJO shall slightly enhance the rainfall during 20th April – 4th 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