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Friday, August 26, 2022

Climate Bulletin For Sri Lanka (26 August 2022)

 


Highlights          

 • Heavy rainfall is predicted for central and sabaragamuwa provinces and less rainfall is expected for the rest of the country during 26th - 31st August.
 • During the last week, the average daily rainfall over Sri Lanka was 1.9 mm and hydro catchment areas have received 6.8 mm on average.
 • From 16th- 22nd August, westerly to south-westerly  of 10m/s winds were experienced at 850 mb level over the island. Up to 10m/s of south-westerlies expected for the next week.
 •  Sea surface temperature around Sri Lanka was above 0.5℃ to the north and south of Sri Lanka. Land surface temperature remained near normal.



Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 
From 25th August – 31st August:
Total rainfall by Provinces: 
  • > 100 mm - Central, Sabaragamuwa
  •    95 mm - Southern, Western, Uva
  •    85 mm - Eastern
  •    75 mm - North-central, North-western, Northern
From 1st September – 7th September:
Total rainfall by Provinces: 
  • 85 mm - Sabaragamuwa, Central
  • 75 mm - Western
  • 65 mm - Southern, Uva, North-western
  • 55 mm - Eastern
  • 45 mm - North-central, Northern
MJO based OLR predictions:
For the next 15 days: 
MJO shall slightly enhance the rainfall during 25th August - 8th September. 


Ocean State (Text Courtesy IRI)
Pacific Sea Sate: August 17, 2022 
Equatorial sea surface temperatures (SSTs) are below average across most of the Pacific Ocean in mid-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 south 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 fairly heavy rainfall over the following area: Nuwara Eliya 
Daily Average Rainfall in the Met stations for previous week of (17th Aug - 24th Aug) = 1.9 mm
Rmax: 29.3 mm & Rmin: 0.0 mm.

Region

Average rainfall for the Last 8 days

Northern Plains

2.4 mm

Eastern

1.3 mm

Western

2.8 mm

Southern Plains

0.0 mm


The Hydro Catchment Areas recorded 6.8 mm of average rainfall for the last week
Rmax: 96.5 mm & Rmin: 0.0 mm. 
Wind:
Westerly to South-westerly winds prevailed in the sea area and around the island last week. 
Temperature: 
The temperature anomalies were above normal for the Sabaragamuwa and Central provinces, driven by the warm SST’s.
Predictions
Rainfall:
During the next week (26th - 31st August) heavy rainfall is predicted for Central and Sabaragamuwa provinces and fairly heavy rainfall is expected for the rest of the country.
Temperature:
The temperature will remain slightly above normal to the East and North of the island during 26th August – 1st September
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 slightly enhance the rainfall during 25th August - 8th September. 

Seasonal Precipitation: 
The precipitation forecast for the September-October-November season shows a higher tendency for below-normal precipitation for the country. 

Friday, August 19, 2022

Climate Bulletin For Sri Lanka (19 August 2022)

    

Highlights          

 • Fairly heavy rainfall is predicted for Central province and less rainfall is expected for the rest of the country during 19th - 23rd August.
 • During the last week, the average daily rainfall over Sri Lanka was 0.4 mm and hydro catchment areas have received 0.9 mm on average.
 • From 8th- 14th August, south-westerlies of 15m/s winds were experienced at 850 mb level over the island. Up to 10m/s of south-westerlies can be expected for the next week.
 •  Sea surface temperature around Sri Lanka was above 0.5℃ to the north of Sri Lanka. Land surface temperature remained near normal.



Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 
From 17th August – 23rd August
Total rainfall by Provinces: 
  • 55 mm - Central
  • 45 mm - Sabaragamuwa
  • 35 mm - North-central, North-western, Western, Eastern, Uva
  • 25 mm - Southern, Northern
From 24th August – 30th August:
Total rainfall by Provinces: 
  • > 100 mm - Sabaragamuwa, Central, Southern, Western
  •    95 mm - Uva, North-western
  •    85 mm - North-central, Eastern
  •    55 mm - Northern 
MJO based OLR predictions:
For the next 15 days: 

MJO shall near-neutral during 17th – 26th August and slightly enhance the rainfall during 27th – 31st August. 


Ocean State (Text Courtesy IRI)
Pacific Sea Sate: August 10, 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 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 fairly heavy rainfall over the following area: Randenigala
Daily Average Rainfall in the Met stations for previous week of (9th Aug - 16th Aug) = 0.4 mm
Rmax: 15.8 mm & Rmin: 0.0 mm

Region

Average rainfall for the Last 8 days

Northern Plains

0.4 mm

Eastern

0.6 mm

Western

0.1 mm

Southern Plains

0.0 mm


The Hydro Catchment Areas recorded 0.9 mm of average rainfall for the last week
Rmax: 55.5 mm & Rmin: 0.0 mm. 
Wind:
South-westerly prevailed in the sea area and around the island last week. 
Temperature: 
The temperature anomalies were above normal for the Sabaragamuwa province, driven by the warm SST’s.
Predictions
Rainfall:
During the next week (19th - 23rd August) fairly heavy rainfall is predicted for Central province and less rainfall is expected for the rest of the country. 
Temperature:
The temperature remains slightly above normal in the Eastern, Northern, North-central and Uva provinces during 19th – 24th 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 17th – 26th August and slightly enhance the rainfall during 27th – 31st August. 

Seasonal Precipitation: 
The precipitation forecast for the September-October-November season shows a higher tendency for below-normal precipitation for the country. 

Friday, August 12, 2022

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.



Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 
From 11th August – 17th 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 18th August – 24th 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 11th – 25th 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 (3rd Aug - 9th 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 (12th - 17th 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 12th – 18th 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 11th – 25th 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.

Friday, August 5, 2022

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.



Predictions

Rainfall

7-day prediction: 
IMD GFS Models
From 5th August – 11th 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 3rd - 12th August; and slightly enhance the rainfall during 13th – 17th 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 (24th July - 31st 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 (5th - 11th 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 5th – 11th 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 3rd - 12th August; and slightly enhance the rainfall during 13th – 17th 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.