Media Center
Climate Bulletin for Sri Lanka (Week of 23 Sep – 30 Sep 2022)
Highlights
Rainfall Prediction: During the following week (23rd- 27th September) moderate rainfall is predicted for the Sabaragamuwa and Western province, and less rain is expected for the rest of the country.
Monitored Rainfalls: During the last week, the average daily rainfall over Sri Lanka was 0.4 mm and hydro catchment areas received 0.1 mm on average.
Monitored Wind: From 12th- 18th September, up to 8m/s of south-westerly 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 the country. Land surface temperature remained near normal.
Interpretation
Monitoring
Rainfall: During the last two weeks, there had been light to moderate rainfall over Galle.Daily Average Rainfall in the Met stations for the previous week of (13th Sep – 20th Sep) = 0.4 mm.
Rainfall maximum: 19.4 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 province, driven by the warm SSTs.
Prediction
Rainfall: During the following week (23rd- 27th September) moderate rainfall is predicted for the Sabaragamuwa and Western provinces and less rain is expected for the rest of the country.
Temperatures: The temperature will remain above normal for the Northern, North-central, Uva, and Eastern provinces from 23rd September – 29th September.
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 21st September – 25th September and start to heavily enhance rainfall from 26th September onwards for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the October-November-December 2022 season shows a higher tendency for below-normal precipitation in the southern half of the country.
Terminology for Rainfall Ranges
| Rainfall (During 24 hours of the period) | |
| Light Showers | Less than 12.5 mm |
| Light to Moderate | Between 12.5 mm and 25 mm |
| Moderate | Between 25 mm and 50 mm |
| Fairly Heavy | Between 50 mm and 100 mm |
| Heavy | Between 100 mm and 150 mm |
| Very Heavy | More than 150 mm |
