Highlights

Rainfall Prediction: Heavy (> 100 mm) rainfall is predicted for the Eastern province and fairly heavy (≥ 55 mm) rainfall is predicted for the rest of the country during 30thNov – 6th Dec.

Monitored Rainfall: During the last week, the average daily rainfall over Sri Lanka was 0.6 mm & hydro catchment areas received 4.5 mm on average and the highest average rainfall (4.3 mm) was received to the Eastern plains of the country.

Monitored Wind: From 21st – 27th Nov, up to 6m/s of westerly winds were experienced at 850mb level over the island. Wind Direction has changed from arriving from the South-West to arriving from North East.

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

Interpretation

Monitoring

Rainfall: During the last two weeks, there had been very heavy rainfall over Wellawaya.                                                                                                                                                          Daily Average Rainfall in the Met stations for the previous week of (22nd November – 29th November) =0.6 mm
Rainfall max: 13.3 mm & Rainfall min: 0.0 mm.

Wind: Westerly winds prevailed in the sea area and around the island last week.

Temperatures:  The temperature anomalies were below normal for some parts of the North Central, and North Western provinces, driven by the warm SSTs.

Prediction

Rainfall: During the next week (30th Nov – 6th Dec), heavy (>100 mm) rainfall is predicted for the Eastern province; and fairly heavy (≥ 55 mm) rainfall is expected for the rest of the country.

Temperatures: The temperature will remain below normal for some parts of the Central, Uva, and Sabaragamuwa provinces from 1st – 7th December.

Teleconnections: La Niña is favored to continue through during the Northern Hemisphere winter (December-February) 2022-23, with a transition to ENSO-neutral, favored in February-April 2023 (57% chance).
MJO shall near neutral the rainfall from 30th Nov – 4th Dec, slightly increase the rainfall during 5th–9th December, and moderately increase the rainfall during 10th – 14th December for Sri Lanka.

Seasonal Precipitation: The precipitation forecast for the December-January-February 2023 season shows a higher tendency for near-normal precipitation to the country.

Terminology for Rainfall Ranges