Highlights

Rainfall Prediction: Heavy rainfall (≥135mm) is predicted for the Sabaragamuwa, Western, Northern, Southern, and Central provinces during 2nd-8th Nov. During 9th- 15th Nov heavy rainfall (≥115mm) is expected for Eastern, North Central, North Western, and Uva provinces.

Monitored Rainfall: During the last week, the average daily rainfall in Sri Lanka was 10.8mm & hydro catchment areas received 11.37 mm on average.

Monitored Wind: From 24th-30th Oct, up to 4m/s of north-westerly winds were experienced at 850mb level over the island. During 3rd- 9thNov, north easterly winds are expected to the north and northerly winds are expected to south of the country.

Monitored Sea and Land Temperature: Sea surface temperature around Sri Lanka was above normal to the whole country. Land surface temperature remained near normal.

Climate Bulletin for Sri Lanka (Week of 04 Nov – 11 Nov 2022)

Interpretation

Monitoring

Rainfall: During the last two weeks, there had been very heavy rainfall over the following area: Kegalle

Daily Average Rainfall in the Met stations for the previous week of (25th October – 1st November) =10.8 mm

Rmax: 117.6 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 Central province and some parts of the North western and Eastern provinces, driven by the warm SSTs.

Prediction

Rainfall: During the next week (2nd – 8th November), above 135 mm rainfall is predicted for the Western, Sabaragamuwa, Northern, Southern and Central provinces; and heavy (≥ 115mm) rainfall is expected for the rest of the country.

Temperatures: The temperature will remain above normal for the whole country during 3rd– 9th November.

Teleconnections: La Niña is favored to continue through during the Northern Hemisphere winter (December-February) 2022-23, with a 54% chance for ENSO-neutral in February-April 2023.
MJO shall slightly suppress the rainfall from 2nd– 6th November and slightly increase the rainfall from 7th – 16th November 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 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