Highlights
• Fairly heavy rainfall (55 mm) is predicted for the Eastern province, and less rainfall is expected for rest of the country during the 16th – 22nd March.
• During the last week, average daily rainfall over Sri Lanka was 3.3 mm and hydro catchment areas received 5.5 mm. Highest average rainfall 5.4 mm/day was received to Western plains.
• From 7th - 13th Mar, up to 6 m/s of north easterly winds were experienced at 850 mb level over the island. During 17th - 23rd of March 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.
Predictions
Rainfall
14-day prediction:NOAA NCEP models:
From 16th March – 22nd March:
Total rainfall by Provinces:
- 55 mm - Eastern
- 45 mm - Western, Southern, Sabaragamuwa
- 35 mm - North Western, Uva
- 25 mm - Central, North Central, Northern
From 23rd March – 29th March:
Total rainfall by Provinces:
- 45 mm - Southern
- 35 mm - Western, Sabaragamuwa, Eastern
- 25 mm - Central, Uva
- 15 mm - North Western, North Central
- ≤ 5 mm - Northern
MJO based OLR predictions:
For the next 15 days:
MJO shall slightly enhance the rainfall during 16th March – 20th March, and moderately enhance the rainfall during 21st March – 30th March for Sri Lanka.
Ocean State (Text Courtesy IRI)
Pacific Sea Sate: March 13, 2023
Equatorial sea surface temperatures (SSTs) are near average across most of the Pacific Ocean mid - 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 1st 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 moderately rainfall over the following area: Galle
Daily Average Rainfall in the Met stations for previous week of (8th March – 15th March) = 3.3 mm
Maximum Rainfall: 63.6 mm & Minimum Rainfall: 0.0 mm.
Region | Average rainfall for the Last 8 days |
Northern Plains | 0.4 mm |
Eastern | 4.6 mm |
Western | 5.4 mm |
Southern Plains | 0.5 mm |
The Hydro Catchment Areas recorded 5.5 mm of average rainfall for the last week
Maximum Rainfall: 57.0 mm & Minimum 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 Northern Province and normal for rest of the country driven by the warm SST’s.
Predictions
Rainfall:
During the next week (16th March – 22nd March), fairly heavy rainfall (55 mm) is predicted for the Eastern 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 17th March – 23rd March.
Teleconnections:
ENSO-neutral conditions are expected to continue through the Northern Hemisphere spring and early summer2023.
MJO shall moderately enhance the rainfall during 16th March – 20th March, and significantly enhance the rainfall during 21st March – 30th March 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.
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