Media Center
Climate Bulletin for Sri Lanka (Week of 28 Oct – 04 Nov 2022)
Highlights
Rainfall Prediction: Fairly heavy rainfall (≥55 mm) is predicted for the Western, Sabaragamuwa, Southern, North Central and Central provinces; and moderate rainfall (≥35mm) is expected for the rest of the country during 26thOct – 1st Nov
Monitored Rainfalls: The southwest of Sri Lanka experienced very heavy rainfall (<250mm) last week. The average daily rainfall in Sri Lanka was 13.2mm & hydro catchment areas received 24.5mm on average.
Monitored Wind: From 17th-23rd Oct, up to 8m/s of north-westerly winds were experienced at 850mb level over the island. From 27th Oct – 2nd Nov, northeasterlies are expected to the north, and north westerlies are expected to the South of the country.
Monitored Sea and Land Temperature: Sea surface temperature around Sri Lanka was above normal to the North of the country. The 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 the previous week of (18th- 25th October) = 13.2 mm
Rmax: 169.7 mm & Rmin: 0.0 mm.
Wind: North-westerly winds prevailed in the sea area and around the island last week.
Temperatures: The temperature anomalies were below normal for the North Western, and North Central provinces and some parts of the Western and Eastern provinces, driven by the warm SSTs.
Prediction
Rainfall: During the next week (26th October – 1st November) fairly heavy rainfall (85 mm) is predicted for the Western, Sabaragamuwa, and Southern provinces; and below 55 mm of rainfall is expected for the rest of the country.
Temperatures: The temperature will remain above normal for the whole country from 27th October–2nd November.
Teleconnections: La Niña is favored to continue through the Northern Hemisphere winter (December-February) 2022-23, with a 54% chance for ENSO-neutral in February-April 2023.
MJO shall significantly suppress the rainfall during 26th– 30th October and slightly suppress the rainfall from 31st Oct– 9th Nov for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the November-December-January 2023 season shows a higher tendency for above-normal precipitation in the north 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 |