Climate Bulletin For Sri Lanka (12 August 2022)

   

Highlights          

 • Moderate rainfall is predicted for Central, North-central and Sabaragamuwa provinces and fairly heavy rainfall is expected for Jaffna districts during 5th - 11th August.

 • During the last week, the average daily rainfall over Sri Lanka was 2.9 mm and hydro catchment areas have received 15 mm on average.

 • From 2nd- 8th August, westerlies of 20 - 30 m/s winds were experienced at 850 mb level over the island. Up to 6 m/s of south-westerlies can be expected for the next 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

14-day prediction: 
NOAA NCEP models: 

From 11^th August – 17^th August:  

Total rainfall by Provinces: 

• 75 mm - Northern
• 35 mm - Central
• 25 mm - North-central, Sabaragamuwa
• 15 mm - Western, Eastern, North-western, Uva, Southern

From 18^th August – 24^th August: 

Total rainfall by Provinces: 

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

MJO based OLR predictions:

For the next 15 days: 

MJO shall near-neutral for Sri Lanka during 11^th – 25^th August.  

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: August 3, 2022 

Equatorial sea surface temperatures (SSTs) are below average across most of the Pacific Ocean in early-August. 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 heavy rainfall over the following area: Nuwara Eliya

Daily Average Rainfall in the Met stations for previous week of (3^rd Aug - 9^th Aug) = 2.9 mm

Rmax: 41.7 mm & Rmin: 0.0 mm.

Region	Average rainfall for the Last 8 days
Northern Plains	0.0 mm
Eastern	0.1 mm
Western	6.7 mm
Southern Plains	0.1 mm

The Hydro Catchment Areas recorded 15.0 mm of average rainfall for the last week.

Rmax: 121.0 mm & Rmin: 0.0 mm. 

Wind:

Westerly prevailed in the sea area and around the island last week. 

Temperature: 

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

Predictions

Rainfall:

During the next week (12^th - 17^th August) moderate rainfall is predicted for Central, North-central and Sabaragamuwa provinces and fairly heavy rainfall is expected for Jaffna districts. 

Temperature:

The temperature remains slightly above normal in the Eastern, Northern, North-central and Uva provinces during 12^th – 18^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 for Sri Lanka during 11^th – 25^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.