Media Center
Climate Bulletin for Sri Lanka (Week of 07 July – 14 July 2023)
Highlights
Rainfall Prediction: Fairly heavy rainfall is predicted for the Sabaragamuwa, Western, Southern, Central provinces and less rainfall is predicted for the rest of the country during 6 – 12 July.
Monitored Rainfall: During the last week, average daily rainfall over Sri Lanka was 4.8 mm and hydro catchment areas received 22.8 mm. Highest average rainfall of 12.0mm/day received in Western region.
Monitored and Predicted Wind: From 27 Jun – 3 Jul, up to 15 m/s of northwest-westerly winds were at 850mb (1.5 km). During 7 – 13 July, up to 15 m/s of northwest-westerly winds are expected at 850 mb (1.5 km).
Monitored Sea and Land Temperature: •Sea surface temperature around Sri Lanka was 0.25 – 1.5°C above normal. Average maximum land temperature ranged from 29 -32°C and minimum ranged from 24 -25°C with a drop in the hills.
Interpretation
Monitoring
Rainfall: During the last two weeks, there had been very heavy rainfall over Nuwara Eliya
Daily Average Rainfall in the Met stations for previous week of (28th June – 5th July) = 4.8 mm
Maximum Daily Rainfall: 93.2 mm & Minimum Daily Rainfall: 0.0 mm.
Wind: Northwest-westerly winds prevailed in the sea area and around the island last week.
Temperatures: The temperature anomalies were near normal for the country driven by the warm SST’s.
Prediction
Rainfall: During the next week (6th July – 12th July), fairly heavy rainfall (≥ 55 mm) is predicted for the Sabaragamuwa, Western, Southern, and Central provinces and less rainfall is predicted for the rest of the country.
Temperatures: The temperature will remain above normal for some parts of the Northern, Eastern, Uva, North Central, and Southern provinces and below normal for some parts of the Central province during 7th July – 13th July.
Teleconnections: A positive Dipole Mode has set in across the Indian Ocean.
MJO shall slightly enhance the rainfall during 6th- 20th July for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the July-August-September, 2023 season shows above normal precipitation for the country.
Terminology for Rainfall Ranges
| Rainfall (During 24 hours of the period) | |
| Light Showers | Less than 12.5 mm |
| Light to Moderate | Between 12.5 mm and 25 mm |
| Moderate | Between 25 mm and 50 mm |
| Fairly Heavy | Between 50 mm and 100 mm |
| Heavy | Between 100 mm and 150 mm |
| Very Heavy | More than 150 mm |
