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Friday, September 24, 2021

Climate Bulletin For Sri Lanka (24 September 2021)

 

Highlights          

                   

  Heavy rainfall is predicted in Central, Sabaragamuwa, Southern and Western provinces during 24th - 28th Sept. Greater likelihood of dry tendency than normal is predicted for southern Sri Lanka from Oct to Dec.
 •  Heavy rainfall was experienced in Eastern, North Central, Sabaragamuwa and Western provinces with max of 135.2 mm in Trincomalee district on 17th Sept
 •  From 14th - 20th Sept, up to 35 km/h Southwesterlieswere experienced across the island.
 • Sea surface temperature was observed above 0.5℃ to the South and 1.00C to the North of Sri Lanka.



Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 
From 22nd – 28th September
Total rainfall by Provinces
  • 125 mm - Sabaragamuwa, Western
  • 115 mm - Southern
  • 105 mm - Central
  •  95 mm - North Western
  •  85 mm - Uva 
  •  65 mm - East, North Central
  •  55 mm - Northern
From 29th September – 5th  October
Total rainfall by Provinces:
  • 85 mm - Sabaragamuwa, Western
  • 75 mm - Central, Southern
  • 65 mm - North Western
  • 45 mm - Uva
  • 35 mm - Eastern, Northern, North Central
MJO based OLR predictions:
For the next 15 days: 
MJO shall be active, thus giving slightly enhanced rainfall from 24th September – 6th October. 

Ocean State (Text Courtesy IRI)
Pacific Sea Sate: September 15, 2021 
Equatorial SSTs were near-to-below average across most of the equatorial Pacific Ocean and were above average in the western Pacific Ocean in mid-September. A large majority of the model forecasts predict a transition from ENSO-neutral to La Niña is favored in the next couple of months and La Niña to continue through the Northern Hemisphere fall and winter.

Indian Sea Sate
Sea surface temperature was observed above 0.5to the South and 1.00C to the North of Sri Lanka. 


Interpretation


Monitoring
Rainfall: 
During the last two weeks, there had been heavy rainfall over the following Provinces: Eastern, North-Central, Sabaragamuwa and Western.
Wind: 
Southwesterly winds prevailed in the sea area and around the island during last week
Temperature: 
The temperature anomalies were between 10C – 30C in Central and Sabaragamuwa provinces while near-neutral for the rest of the country last week – driven by the warm SST’s.

Predictions
Rainfall:
During the next week (24th - 28th September) heavy rainfall is predicted for Central, Sabaragamuwa, Southern, Western and Central provinces. 
Temperature:
The temperature remains slightly normal for September. During 24th September – 2nd October, the temperature remains high especially in the Eastern, Southern and Uva provinces.
Teleconnections:
La Nina -The SST forecast indicates that ENSO-neutral is present and a transition from ENSO-neutral to La Niña is favored in the next couple of months.
MJO shall be active, thus giving slightly enhanced rainfall from 24th September – 6th October. 
Seasonal Precipitation: 
October to December is the main rainfall season in Sri Lanka. The consensus predictions has switched from neutral to favoring a dry tendency.  A dry tendency can hurt agricultural production and it adds to farmer difficulties due to the fertilizer bans. However, since this is the wet season the impact will not be as severe. 
However, the bigger impact shall be that it shall reduce the generated hydropower in the coming months. This can hurt the economy due to the scarcity in Foreign Exchange within the country due to the Central Bank regulations.

Friday, September 17, 2021

Climate Bulletin For Sri Lanka (17 September 2021)

 

Highlights          

                   

  Heavy rainfall is predicted for Sabaragamuwa, Southern and Western provinces during 17th - 21st Sept. Greater likelihood of dry tendency than normal is predicted in the southern SL from October to December.
 •  Fairly heavy rains were experienced in the Western,  Sabaragamuwa, Southern & North Western provinces with max of 91.7 mm in Ratnapura district on 15th September.
 •  From 7th - 13th September: up to  15 km/h from Southwesterly were experienced over the island.
 •  Sea surface temperature was observed above 0.5℃ to the South and West of Sri Lanka and neutral to the rest.



Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 
From 15th – 21st September
Total rainfall by Provinces
  • 115 mm - Sabaragamuwa
  • 105 mm - Southern, Western
  •  95 mm - Central
  •  85 mm - Uva 
  •  75 mm - North Western 
  •  65 mm - Eastern
  •  45 mm - North Central
  •  35 mm - Northern
From 22nd – 28th September: 
Total rainfall by Provinces:
  • 105 mm - Sabaragamuwa
  •  95 mm - Southern, Western
  •  85 mm - Central
  •  65 mm - North Western, Uva
  •  45 mm - Eastern, North Central
  •  35 mm - Northern
MJO based OLR predictions:
For the next 15 days: 
MJO shall be active, thus giving slightly enhanced rainfall during 17th – 29th September. 

Ocean State (Text Courtesy IRI)
Pacific Sea Sate: September 8, 2021 
Equatorial SSTs were below average in parts of the eastern Pacific Ocean and near average across the rest of the Pacific Ocean in early-September and most key atmospheric variables were ENSO –Neutral condition. A large majority of the model forecasts predict ENSO-neutral likely to continue through the Northern Hemisphere summer.

Indian Sea Sate
Sea surface temperature was observed above 0.5to the South and West of Sri Lanka and neutral to the rest.

Interpretation


Monitoring
Rainfall: 
During the last two weeks, there had been fairly heavy rainfall over the following Provinces: Sabaragamuwa, Western, North-Western and Southern.
Wind: 
Southwesterly winds prevailed in the sea area and around the island during last week. 
Temperature: 
The temperature anomalies were near-neutral for the whole country last week – driven by the warm SST’s.

Predictions
Rainfall:
During the next week (17th – 21st September) heavy rainfall is predicted for Sabaragamuwa, Southern and Western provinces. 
Temperature:
The temperature remains slightly normal for September. During 17th – 25th September, the temperature remains high especially in the Eastern, Northern, North Central and Uva provinces.
Teleconnections:
La Nina -The SST forecast indicates that the La Niña event has transitioned to ENSO-neutral and will likely remain so through the boreal summer. 
MJO shall be active, thus giving slightly enhanced rainfall during 17th – 29th September. 
Seasonal Precipitation: 
October to December is the main rainfall season in Sri Lanka. The consensus has switched from neutral to having a dry tendency.  If so, it can hurt agriculture adding to fertilizer bans and hydro-power generation, given $ scarcity.


Friday, September 10, 2021

Climate Bulletin For Sri Lanka (10 September 2021)


Highlights          

                   

 •  Fairly heavy rainfall is predicted for Sabaragamuwa, Southern and Western provinces during 10th - 14th September
 •  Fairly heavy rains were experienced in the Central, Sabaragamuwa & Southern provinces with max of 94.5 mm in Matara district on 4th September
 •  From 31st Aug- 6th Sept: up to  15 km/h from Southwesterly were experienced over the island
 •  Sea surface temperature was observed above 0.5℃ to the West of Sri Lanka and neutral to the East.




Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 
From 8th – 14th September
Total rainfall by Provinces
  • 65 mm - Sabaragamuwa
  • 55 mm - Western, Southern
  • 45 mm - Central
  • 35 mm - Uva
  • 25 mm - Eastern, North Western
  • 15 mm - Northern 
From 15th – 21st September: 
Total rainfall by Provinces:
  • 75 mm - Sabaragamuwa 
  • 65 mm - Central, Western
  • 55 mm - Southern
  • 45 mm - Uva
  • 25 mm - Eastern, North Western
  • 15 mm - Northern, North Central
MJO based OLR predictions:
For the next 15 days: 
MJO shall be active, thus giving slightly enhanced rainfall during 10th – 22nd September. 

Ocean State (Text Courtesy IRI)
Pacific Sea Sate: September 1, 2021 
Equatorial SSTs were below average in parts of the eastern Pacific Ocean and near average across the rest of the Pacific Ocean in early-September and most key atmospheric variables were ENSO –Neutral condition. A large majority of the model forecasts predict ENSO-neutral likely to continue through the Northern Hemisphere summer.

Indian Sea Sate
Sea surface temperature was observed above 0.5to the West of Sri Lanka and neutral to the East.

Friday, September 3, 2021

Climate Bulletin For Sri Lanka (3 September 2021)


Highlights          

                   

  • Fairly heavy rainfall is predicted for Central, Northern, Sabaragamuwa and Western provinces and Galle and Matara districts during 3rd - 7th September.
  • Fairly heavy rains were experienced in the Southern, Central, Sabaragamuwa & Western provinces with max of 86 mm in Matara district on 1st September.
  • From 24th- 30th August: up to  15 m/s from Southwesterly were experienced over the island.
  • Sea surface temperature was observed above 0.5℃ to the West of Sri Lanka and neutral to the East.




Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 
From 1st – 7st September
Total rainfall by Provinces
  • 65 mm - Sabaragamuwa, Western
  • 55 mm - Central, Northern, Southern
  • 45 mm - Uva
  • 35 mm - Eastern
  • 25 mm - North Central, North Western
From 8th – 14th September: 
Total rainfall by Provinces:
  • 45 mm - Sabaragamuwa
  • 35 mm - Central, Western, Southern
  • 25 mm - Uva, Northern
  • 15 mm - Eastern 
MJO based OLR predictions:
For the next 15 days: 
MJO shall be active thus, slightly enhanced rainfall during 3rd – 15th September. 

Ocean State (Text Courtesy IRI)
Pacific Sea Sate: August 25, 2021 
Equatorial SSTs were below average in parts of the eastern Pacific Ocean and near average across the rest of the Pacific Ocean in late-August and most key atmospheric variables were ENSO –Neutral condition. A large majority of the model forecasts predict ENSO-neutral likely to continue through the Northern Hemisphere summer.

Indian Sea Sate
Sea surface temperature was observed above 0.5to the West of Sri Lanka and neutral to the East.