Climate Bulletin For Sri Lanka (6 January 2023)

            

Highlights          

 • Fairly heavy rainfall is predicted for the Eastern, North Central, Central, Sabaragamuwa, North Western, Western, and Uva provinces during 5th - 11th January. The seasonal forecast shows a higher tendency for above-normal precipitation from January - March, 2023.

 • During the last week, maximum daily rainfall over Sri Lanka was 30.6 mm and hydro catchment areas received 0.0 mm.

 • From 27th Dec - 2nd Jan, up to 8m/s of north easterly winds were experienced at 850 mb level over the island. During 6th - 12th Jan, north easterly winds are expected for the country.

 • Sea surface temperature around Sri Lanka was near-neutral  for the entire island. Land surface temperature remained near normal. 

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Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 

From 5^th January – 11^th January:

Total rainfall by Provinces:   

• 65 mm - Eastern, Central, North Central
• 55 mm - Sabaragamuwa, North Western, Western, Uva
• 45 mm - Northern, Southern

From 12^th January – 18^th January:

Total rainfall by Provinces:   

• 75 mm - Eastern, North Central
• 65 mm - Central, Uva
• 55 mm - Western, Sabaragamuwa, North Western, Northern
• 45 mm - Southern

MJO based OLR predictions:

For the next 15 days: 

MJO shall slightly suppress the rainfall during 5^th – 9^th January, slightly enhance the rainfall during 10^th – 14^th January, and moderately enhance the rainfall during 15^th – 19^th January for Sri Lanka.

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: January 3, 2023 

Equatorial sea surface temperatures (SSTs) are below average across most of the Pacific Ocean early - January. The tropical Pacific atmosphere is consistent with La Niña. A large majority of the models indicate La Niña is favored to continue into the winter, with equal chances of La Niña and ENSO-neutral during January-March 2023. In February-April 2023, there is a 71% chance of ENSO-neutral.

Indian Sea Sate

Sea surface temperature around Sri Lanka was near neutral for the whole country in 28^th December, 2022. Across the Indian Ocean, a classical negative Indian Ocean Dipole prevails as is typical during a La Niña.

 

Interpretation

Monitoring

Rainfall: 

During the last two weeks, there had been fairly heavy rainfall over the following area: Galle

Daily Average Rainfall in the Met stations for previous week of (29^st December – 4^th January) = 0.3 mm

Rmax: 30.6 mm & Rmin: 0.0 mm.

Region	Average rainfall for the Last 8 days
Northern Plains	0.1 mm
Eastern	0.1 mm
Western	0.6 mm
Southern Plains	0.3 mm

The Hydro Catchment Areas recorded 0.0 mm of average rainfall for the last week

Rmax: 0.0 mm & Rmin: 0.0 mm.

Wind:

North easterly winds prevailed in the sea area and around the island last week.

Temperature: 

The temperature anomalies were above normal for some parts of the Northern, and Sabaragamuwa provinces, driven by the warm SST’s.

Predictions

Rainfall:

During the next week (5^th – 11^th January), fairly heavy rainfall (≥ 55 mm) is predicted for the Eastern, North Central, Central, Sabaragamuwa, North Western, Western, and Uva provinces; and moderately heavy rainfall is expected for the rest of the country.

Temperature:

The temperature will remain below normal for some parts of the Central, and Uva provinces during 6^th – 12^th January.

Teleconnections:

La Niña is favored to continue into the winter, with equal chances of La Niña and ENSO-neutral during January-March 2023.

MJO shall slightly suppress the rainfall during 5^th – 9^th January, slightly enhance the rainfall during 10^th – 14^th January, and moderately enhance the rainfall during 15^th – 19^th January for Sri Lanka.

Seasonal Precipitation: 

The precipitation forecast for the January-February-March 2023 season shows a higher tendency of above-normal precipitation for the country.