Highlights

Rainfall Prediction: Moderate rainfall is predicted for the Western province, and less rain is expected for the rest of the country from 9th-13th September.

Monitored Rainfalls: During the last week, the average daily rainfall in Sri Lanka was 12.7mm, and hydro catchment areas received 80.9 mm on average.

Monitored Wind: From 29th August-4th September,up to 10m/s of South-westerlies were experienced at 850 mb level over the island. South-westerly winds are expected next
week.

Monitored Sea and Land Temperature:  Sea surface temperature around Sri Lanka was above 0.5°C to the North of Sri Lanka. The land surface temperature remained near normal.

Interpretation

Monitoring

Rainfall: During the last two weeks, there had been heavy rainfall over Ratnapura. Daily Average Rainfall in the Met stations for the previous week of (30th Aug – 6th Sep) =12.7mm

Rainfall maximum: 247.1 mm & Rainfall minimum: 0.0 mm.

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

Temperatures:  The temperature anomalies were below for the northern half of the island and were even lower in the North Central region of the island, driven by the warm SSTs.

Prediction

Rainfall: During the next week (9th- 13th September) moderate rainfall is predicted for the Western province, and less rain is expected for the rest of the country.

Temperatures: The temperature will remain slightly above normal for the Northern, North Central, Uva, and Eastern provinces during 8th September – 14th September.

Teleconnections: La Niña is expected to continue, with chances for La Niña gradually decreasing from 86% in the coming season to 60% during December-February 2022-23.
MJO shall be near neutral during 7th September – 16th September and slightly suppress rainfall from 17th September – 21st September.

Seasonal Precipitation: The precipitation forecast for the September-October-November season shows a higher tendency for below-normal precipitation for the country.

Terminology for Rainfall Ranges