Highlights

Rainfall Prediction: During the next week (30th September – 4th October) fairly heavy rainfall is predicted for the Sabaragamuwa, Southern, and Western provinces, and less rainfall is expected for the rest of the country.

Monitored Rainfalls: During the last week, the average daily rainfall over Sri Lanka was 1.1mm and hydro catchment areas received 2.1 mm on average.

Monitored Wind: From 19th-25th Sept, up to 10m/s of north-westerly to westerly winds were experienced at 850 mb level over the island. 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 and South of the country. Land surface temperature remained near normal.

Interpretation

Monitoring

Rainfall: During the last two weeks, there had been heavy rainfall over Polonnaruwa.

Daily Average Rainfall in the Met stations for the previous week of (21st Sep – 27th Sep) = 1.1 mm

Rainfall maximum: 21.1 mm & Rainfall minimum: 0.0 mm.

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

Temperatures:  The temperature anomalies were below for the northern province, driven by the warm SSTs.

Prediction

Rainfall: During the next week (30th September – 4th October) fairly heavy rainfall is predicted for the Sabaragamuwa, Southern and Western provinces, and less rainfall is expected for the rest of the country.

Temperatures: The temperature will remain above normal for the Uva and Eastern provinces from 1st October – 9th October.

Teleconnections: La Niña is favored to continue through Northern Hemisphere winter 2022-23, with a 91% chance in September-November, decreasing to a 54% chance in January-March 2023.
MJO shall be near neutral from 28th September – 12th October for Sri Lanka.

Seasonal Precipitation: The precipitation forecast for the October-November-December 2022 season shows a higher tendency for below-normal precipitation to the southern half of the country.

Terminology for Rainfall Ranges