Highlights

Rainfall Prediction: During 18 – 24 June, high likelihood of fairly heavy rainfall (50 – 100 mm) is predicted for the NorthWestern,Western,Sabaragamuwa provinces; moderate rainfall (25 – 50 mm) is predicted for the Southern, Central provinces and lessrainfall is predicted for the rest.

Monitored Rainfall: On average, 1.2 mm was received in SL and rainfall was concentrated in the Western plains (3.3 mm) and hills (1.8 mm).Daily average rainfall in this week(1.2 mm) was lower than previous week (2.4 mm). Highest daily rainfall was in Guruluwana (Ratnapura) on 18th June. (95.4 mm).

Monitored and Predicted Wind: From 9 – 15 June, winds at 850mb (1.5km) north westerly, reaching up to 15 m/s. From 19 – 25 June, winds are predicted to be north westerly, reaching up to 20 m/s.

Monitored Sea and Land Temperature: Average land surface temperature was 32.20 °C in the last week with warmer anomalies from seasonal average of +10 °C – 30 °C. Eastern plain was more warmest followed by Northern and Southern plains. Sea surface temperature around Sri Lanka was 0.25 – 1.50 °C above average.

 

Climate Bulletin for Sri Lanka (Week of  21 June – 28 June 2024)

 

Interpretation

Monitoring

Rainfall: During the last two weeks, there had been fairly heavy rainfall over the following area: Guruluwana (Ratnapura) Daily Average Rainfall in the Met stations for previous week of (11th June – 18th June) = 1.2 mm

Wind: North westerly winds prevailed in the sea area and around the island last week.

Temperatures: The temperature anomalies were above normal for some parts of the Central and Uva provinces and below normal for some parts of the Eastern province driven by the warm SST’s.

Prediction

Rainfall: During the next week (18th June – 24th June), fairly heavy rainfall (50 – 100 mm) is predicted for the North Western, Western, and Sabaragamuwa provinces, moderate rainfall (25 – 50 mm) is predicted for the Southern and Central provinces and less rainfall is predicted for the rest.

Temperatures: The temperature will remain above normal for the Northern, Eastern, North Central and Uva provinces during 19th June – 25th June.

Teleconnections: MJO shall near neutral the rainfall during 18th – 22nd June, slightly enhance the rainfall during 23rd – 27th June, and moderately enhance the rainfall during 28th June – 2nd July for Sri Lanka.

Seasonal Precipitation: The precipitation forecast for the July-August-September, 2024 season shows a 40 – 50% or more tendency toward above normal precipitation for the country.

Terminology for Rainfall Ranges

 Rainfall
Light ShowersLess than 12.5 mm
Light to ModerateBetween 12.5 mm and 25 mm
ModerateBetween 25 mm and 50 mm
Fairly HeavyBetween 50 mm and 100 mm
HeavyBetween 100 mm and 150 mm
Very HeavyMore than 150 mm