Climate Bulletin For Sri Lanka (5 August 2022)

 

Highlights          

 • Heavy rainfall is predicted for Sabaragamuwa province, Nuwara Eliya & Kandy districts; fairly heavy rainfall in Western and North-western provinces, Galle & Matara districts during 5 - 11 Aug. Landslide warnings have been issued for seven districts for next few days.

 • During the last week, the average daily rainfall over Sri Lanka was 7.5 mm. People had been affected due to floods following heavy rains experienced in the past few days.

 • From 25th- 31st July, up to 10 m/s of westerlies to south-westerlies were experienced over the island. Extremely high speed westerlies are predicted for the coming week

 • Sea surface temperature was above 0.5℃ to the north and East of Sri Lanka. Land surface temperature remained near normal.

Download full report ↓

---

Predictions

Rainfall

7-day prediction: 
IMD GFS Models

From 5^th August – 11^th August: 

Total rainfall by Provinces:

• 50 - 100mm - Sabaragamuwa, Central, Southern, Western, North-western
• < 50mm - Uva, Eastern, North-central, Northern

MJO based OLR predictions:

For the next 15 days: 

MJO shall near-neutral during 3^rd - 12^th August; and slightly enhance the rainfall during 13^th – 17^th August.

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: July 27, 2022 

Equatorial sea surface temperatures (SSTs) are below average across most of the Pacific Ocean in late-July. The tropical Pacific Sea surface temperatures show a classical La Niña pattern. The tropical Pacific atmosphere is consistent with La Niña. A large majority of the models indicate, a La Niña is favored to continue through 2022 with the odds for La Niña decreasing into the Northern Hemisphere late summer (July - September 2022) before increasing through the Northern Hemisphere fall and early winter 2022.

Indian Sea Sate

Sea surface temperature around Sri Lanka was above 0.5℃ to the north and East of Sri Lanka. 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 very heavy rainfall over the following area: Nuwara Eliya

Daily Average Rainfall in the Met stations for previous week of (24^th July - 31^st July) = 7.5 mm

Rmax: 69.5 mm & Rmin: 0.0 mm.

Region	Average rainfall for the Last 8 days
Northern Plains	5.9 mm
Eastern	9.9 mm
Western	5.8 mm
Southern Plains	15.5 mm

The Hydro Catchment Areas recorded 12.0 mm of average rainfall for the last weekRmax: 105.0 mm & Rmin: 0.0 mm. 

Wind:

Westerly to south-westerly prevailed in the sea area and around the island last week. 

Temperature: 

The temperature anomalies were below normal for the north half of the island, driven by the warm SST’s.

Predictions

Rainfall:

During the next week (5^th - 11^th August) heavy rainfall is predicted for Sabaragamuwa province and Nuwara Eliya and Kandy districts and fairly heavy rainfall is expected for Western and North-western provinces and Galle and Matara districts. 

Temperature:

 The temperature remains above normal in the Eastern and Uva provinces during 5^th – 11^th August. 

Teleconnections:

La Niña - La Niña is favored to continue through 2022 with the odds for La Niña decreasing into the Northern Hemisphere late summer (July-September 2022) before increasing through the Northern Hemisphere fall and early winter 2022.

MJO shall near-neutral during 3^rd - 12^th August; and slightly enhance the rainfall during 13^th – 17^th August.

Seasonal Precipitation: 

The precipitation forecast for the August-September-October season shows a higher tendency for below-normal precipitation for the southern half of the country, while the remaining areas are more likely to experience near-normal precipitation.