Highlights

Rainfall Prediction: Heavy rainfall above 100 mm is expected in Sabaragamuwa, Western and Southern provinces during 3rd – 7th June with the risk of floods and landslides continues for these provinces and adjacent areas.

Monitored Rainfalls: Last week, floods affected twelve thousands with one fatality – O/L exams was scheduled in the peak stormy months with problems in the SW that were not foreseen but should have been.

Monitored  Wind: From 23rd – 29th May, up to 15 m/s of gale-force south-westerly winds were experienced over the island.

Monitored  Temperature: Sea surface temperature was observed to be below average of 0.5°C to the west of the island. Land surface temperature remained near normal.

Interpretation

Monitoring

Rainfall: During the last two weeks, there had been very heavy rainfall over the following area: Galle
Daily Average Rainfall in the Met stations for previous week of (23rd – 30th May) = 7.0 mm

Maximum rainfall: 105.7 mm & minimum rainfall: 0.0 mm.

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

Temperatures: The temperature anomalies were near-normal for the entire island, driven by the warm SST’s

Prediction

Rainfall: During the next week (3rd – 7th June) heavy rainfall (>100 mm) is predicted for the Southern, Western and Sabaragamuwa provinces.

Temperature : The temperature remains slightly above normal in the Eastern province and slightly below normal in the central province during 3rd – 11th June.

Teleconnections:

La Niña – Though La Niña is favored to continue, the odds for La Niña decrease into the late Northern Hemisphere summer (August-October 2022).

MJO shall moderately suppress the rainfall during 3rd- 10th June; and near neutral during 10th – 14th June

Seasonal Precipitation:

The precipitation forecast for the June-July-August season shows below-normal precipitation for the southern province and above-normal precipitation to the north province.

Terminology for Rainfall Ranges