Climate Bulletin For Sri Lanka ( 31 March 2023)

    

Highlights          

 • Fairly heavy rainfall is predicted for the Southern province and less rainfall is expected for rest of the country during the 30 th  March - 5th April.

 • During the last week, average daily rainfall over Sri Lanka was 3.0 mm and  hydro catchment areas received 4.7 mm.

 • From 21st - 27th Mar, up to 1 m/s of  North easterly winds were experienced at 850 mb level almost over the island. During 31st Mar - 6th Apr, up to 2 m/s of South easterly winds are expected for the country.

 • Sea surface temperature around Sri Lanka was below normal  for northern half of the island. Land surface temperature remained near normal. 

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Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 

From 30^th March – 5^th April:

Total rainfall by Provinces:    

• 55 mm - Southern 
• 45 mm - Sabaragamuwa, Western
• 35 mm - Eastern
• 25 mm - North Western, Central, North Central, Uva
• 15 mm - Northern

From 6^th April – 12^th April:

Total rainfall by Provinces:   

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

MJO based OLR predictions:

For the next 15 days: 

MJO shall slightly suppress the rainfall during 30^th March – 13^th April for Sri Lanka.

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: March 27, 2023 

Equatorial sea surface temperatures (SSTs) are near average across most of the Pacific Ocean late - March. The tropical Pacific atmosphere is still consistent with a weak La Niña signal. A large majority of the models indicate ENSO-neutral conditions are expected to continue through the Northern Hemisphere spring and early summer 2023.

Indian Sea Sate

Sea surface temperature around Sri Lanka was below - 0.5℃ to the northern half of the country in 1^st February, 2023. 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 heavy rainfall over the following area: Monaragala

          

Daily Average Rainfall in the Met stations for previous week of (22^nd March – 29^th March) = 3.0 mm

Maximum Daily Rainfall: 76.2 mm & Minimum Daily Rainfall: 0.0 mm. 

Region	Average rainfall for the Last 8 days
Northern Plains	1.8 mm
Eastern	0.8 mm
Western	6.9 mm
Southern Plains	0.1 mm

The Hydro Catchment Areas recorded 4.7 mm of average rainfall for the last week

Maximum Daily Rainfall: 69.4 mm & Minimum Daily Rainfall: 0.0 mm.

Wind:

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

Temperature: 

The temperature anomalies were below normal for some parts of the North Central and North Western provinces driven by the warm SST’s.

Predictions

Rainfall:

During the next week (30^th March – 5^th April), fairly heavy rainfall (55 mm) is predicted for the Southern province, and less rainfall is expected for rest of the country.

Temperature:

The temperature will remain above normal for some parts of the Northern, North Western, North Central, and Uva provinces and below normal for some parts of the Central province during 31^st March – 6^th April.

Teleconnections:

ENSO-neutral conditions are expected to continue through the Northern Hemisphere spring and early summer2023.

MJO shall slightly suppress the rainfall during 30^th March – 13^th April for Sri Lanka.

Seasonal Precipitation: 

The precipitation forecast for the April-May-June 2023 season shows a higher tendency of below-normal precipitation for the country except Northern Province.