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Friday, January 20, 2023

Climate Bulletin For Sri Lanka (20 January 2023)

              

Highlights          


 • Fairly heavy rainfall is predicted for the Eastern, Uva, Central, North Central provinces and ≥ 55 mm rainfall is predicted for the Southern, Sabaragamuwa, North Western, and Western provinces during 19th - 25th January.
 • During the last week, maximum daily rainfall over Sri Lanka was 38.0 mm and hydro catchment areas received 37.0 mm.
 • From 10th - 16th Jan, up to 8m/s of north easterly winds were experienced at 850 mb level over the island. During 20th - 26th Jan, north easterly winds are expected for the country.
 • Sea surface temperature around Sri Lanka was near-neutral  for the entire island. Land surface temperature remained near normal. 



Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 
From 19th January – 25th January:
Total rainfall by Provinces:    
  • 95 mm - Eastern
  • 85 mm - Uva
  • 75 mm - Central, North Central
  • 65 mm - Southern, Sabaragamuwa, North Western
  • 55 mm - Western
  • 35 mm - Northern
From 26th January – 1st February:
Total rainfall by Provinces:   
  • 85 mm - Eastern, Central, North Central, North Western
  • 75 mm - Sabaragamuwa, Uva, Western
  • 65 mm - Northern
  • 55 mm - Southern
MJO based OLR predictions:
For the next 15 days: 
MJO shall slightly enhance the rainfall during 19th – 23rd January, moderately enhance the rainfall during 24th January – 2nd February for Sri Lanka.


Ocean State (Text Courtesy IRI)
Pacific Sea Sate: January 17, 2023 
Equatorial sea surface temperatures (SSTs) are below average across most of the Pacific Ocean mid - January. The tropical Pacific atmosphere is consistent with La Niña. A large majority of the models indicate a transition from La Niña to ENSO-neutral anticipate during the February-April 2023 season by Northern Hemisphere spring (March-May 2023), the chance for ENSO-neutral is 82%.

Indian Sea Sate
Sea surface temperature around Sri Lanka was near neutral for the whole country in 11th January, 2023. 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: Colombo

Daily Average Rainfall in the Met stations for previous week of (11th January – 18th January) = 1.6 mm

Rmax: 38.0 mm & Rmin: 0.0 mm.


Region

Average rainfall for the Last 8 days

Northern Plains

0.8 mm

Eastern

1.9 mm

Western

2.0 mm

Southern Plains

0.7 mm


The Hydro Catchment Areas recorded 2.5 mm of average rainfall for the last week

Rmax: 37.0 mm & Rmin: 0.0 mm.

Wind:
North easterly winds prevailed in the sea area and around the island last week.
Temperature: 
The temperature anomalies were below normal for the North Central Province and some parts of the Northern, Eastern, and North Western provinces, driven by the warm SST’s.

Predictions
Rainfall:
During the next week (19th – 25th January), fairly heavy rainfall (≥ 75 mm) is predicted for the Eastern, Uva, Central, North Central provinces, and 55 mm is predicted for the Southern, Sabaragamuwa, North Western, Western provinces and less rainfall is expected for rest of the country.
Temperature:
The temperature will remain below normal for some parts of the Central and Uva provinces during 20th – 26th January.
Teleconnections:
A transition from La Niña to ENSO-neutral is anticipated during the February-April 2023 season by Northern Hemisphere spring (March-May 2023), the chance for ENSO-neutral is 82%.
MJO shall slightly enhance the rainfall during 19th – 23rd January, moderately enhance the rainfall during 24th January – 2nd February for Sri Lanka.

Seasonal Precipitation: 
The precipitation forecast for the February-March-April 2023 season shows a higher tendency of near-normal precipitation for the country.

Friday, January 13, 2023

Climate Bulletin For Sri Lanka (13 January 2023)

             

Highlights          


 • Fairly heavy rainfall is predicted for the Southern province and moderately heavy rainfall is predicted for the rest of the country during 12th - 18th January. The seasonal forecast shows a higher tendency for above-normal precipitation from January - March, 2023.
 • During the last week, maximum daily rainfall over Sri Lanka was 80.0 mm and hydro catchment areas received 53.7 mm.
 • From 3rd - 9th Jan, up to 10m/s of north easterly winds were experienced at 850 mb level over the island. During 13th - 19th Jan, easterly winds are expected for the country.
 • Sea surface temperature around Sri Lanka was near-neutral  for the entire island. Land surface temperature remained near normal. 



Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 
From 12th January – 18th January:
Total rainfall by Provinces:   
  •  55 mm - Southern
  •  45 mm - Sabaragamuwa, Eastern
  •  35 mm - Central, Uva, Western, North Central
  •  ≤ 25 mm - North Western, Northern
From 19th January – 25th January:
Total rainfall by Provinces:   
  • 105 mm - Eastern
  •  95 mm - Central, Uva
  •  85 mm - North Central
  •  75 mm - Sabaragamuwa, Southern, North Western
  •  65 mm - Western
  •  55 mm - Northern
MJO based OLR predictions:
For the next 15 days: 
MJO shall slightly enhance the rainfall during 12th – 16th January, moderately enhance the rainfall during 17th – 21st January, and highly enhance the rainfall during 22nd – 26th January for Sri Lanka.

Ocean State (Text Courtesy IRI)
Pacific Sea Sate: January 9, 2023 
Equatorial sea surface temperatures (SSTs) are below average across most of the Pacific Ocean early - January. The tropical Pacific atmosphere is consistent with La Niña. A large majority of the models indicate La Niña is favored to continue into the winter, with equal chances of La Niña and ENSO-neutral during January-March 2023. In February-April 2023, there is a 71% chance of ENSO-neutral.

Indian Sea Sate
Sea surface temperature around Sri Lanka was near neutral for the whole country in 4th January, 2023. 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 areas: Galle, Kalutara

Daily Average Rainfall in the Met stations for previous week of (4th January – 11th January) = 4.3 mm

Rmax: 80.0 mm & Rmin: 0.0 mm.


Region

Average rainfall for the Last 8 days

Northern Plains

6.0 mm

Eastern

4.0 mm

Western

3.9 mm

Southern Plains

0.4 mm


The Hydro Catchment Areas recorded 5.3 mm of average rainfall for the last week
Rmax: 53.7 mm & Rmin: 0.0 mm.
Wind:
North easterly winds prevailed in the sea area and around the island last week.
Temperature: 
The temperature anomalies were below normal for some parts of the Central, North Western, and North Central provinces, driven by the warm SST’s.

Predictions
Rainfall:
During the next week (12th – 18th January), fairly heavy rainfall (≥ 55 mm) is predicted for the Southern province; and moderately heavy rainfall is expected for the Sabaragamuwa, Eastern, Central, Uva, Western, North Central and less rainfall is expected for rest of the country.
Temperature:
The temperature will remain below normal for some parts of the Central, Uva, and Sabaragamuwa provinces during 13th – 19th January.
Teleconnections:
La Niña is favored to continue into the winter, with equal chances of La Niña and ENSO-neutral during January-March 2023.
MJO shall slightly enhance the rainfall during 12th – 16th January, moderately enhance the rainfall during 17th – 21st January, and highly enhance the rainfall during 22nd – 26th January for Sri Lanka.

Seasonal Precipitation: 
The precipitation forecast for the January-February-March 2023 season shows a higher tendency of above-normal precipitation for the country.

Friday, January 6, 2023

Climate Bulletin For Sri Lanka (6 January 2023)

            

Highlights          


 • Fairly heavy rainfall is predicted for the Eastern, North Central, Central, Sabaragamuwa, North Western, Western, and Uva provinces during 5th - 11th January. The seasonal forecast shows a higher tendency for above-normal precipitation from January - March, 2023.
 • During the last week, maximum daily rainfall over Sri Lanka was 30.6 mm and hydro catchment areas received 0.0 mm.
 • From 27th Dec - 2nd Jan, up to 8m/s of north easterly winds were experienced at 850 mb level over the island. During 6th - 12th Jan, north easterly winds are expected for the country.
 • Sea surface temperature around Sri Lanka was near-neutral  for the entire island. Land surface temperature remained near normal. 



Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 
From 5th January – 11th January:
Total rainfall by Provinces:   
  • 65 mm - Eastern, Central, North Central
  • 55 mm - Sabaragamuwa, North Western, Western, Uva
  • 45 mm - Northern, Southern
From 12th January – 18th January:
Total rainfall by Provinces:   
  • 75 mm - Eastern, North Central
  • 65 mm - Central, Uva
  • 55 mm - Western, Sabaragamuwa, North Western, Northern
  • 45 mm - Southern
MJO based OLR predictions:
For the next 15 days: 
MJO shall slightly suppress the rainfall during 5th – 9th January, slightly enhance the rainfall during 10th – 14th January, and moderately enhance the rainfall during 15th – 19th January for Sri Lanka.

Ocean State (Text Courtesy IRI)
Pacific Sea Sate: January 3, 2023 
Equatorial sea surface temperatures (SSTs) are below average across most of the Pacific Ocean early - January. The tropical Pacific atmosphere is consistent with La Niña. A large majority of the models indicate La Niña is favored to continue into the winter, with equal chances of La Niña and ENSO-neutral during January-March 2023. In February-April 2023, there is a 71% chance of ENSO-neutral.

Indian Sea Sate
Sea surface temperature around Sri Lanka was near neutral for the whole country in 28th December, 2022. 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: Galle

Daily Average Rainfall in the Met stations for previous week of (29st December – 4th January) = 0.3 mm

Rmax: 30.6 mm & Rmin: 0.0 mm.


Region

Average rainfall for the Last 8 days

Northern Plains

0.1 mm

Eastern

0.1 mm

Western

0.6 mm

Southern Plains

0.3 mm


The Hydro Catchment Areas recorded 0.0 mm of average rainfall for the last week

Rmax: 0.0 mm & Rmin: 0.0 mm.

Wind:
North easterly winds prevailed in the sea area and around the island last week.
Temperature: 
The temperature anomalies were above normal for some parts of the Northern, and Sabaragamuwa provinces, driven by the warm SST’s.

Predictions
Rainfall:
During the next week (5th – 11th January), fairly heavy rainfall (≥ 55 mm) is predicted for the Eastern, North Central, Central, Sabaragamuwa, North Western, Western, and Uva provinces; and moderately heavy rainfall is expected for the rest of the country.
Temperature:
The temperature will remain below normal for some parts of the Central, and Uva provinces during 6th – 12th January.
Teleconnections:
La Niña is favored to continue into the winter, with equal chances of La Niña and ENSO-neutral during January-March 2023.
MJO shall slightly suppress the rainfall during 5th – 9th January, slightly enhance the rainfall during 10th – 14th January, and moderately enhance the rainfall during 15th – 19th January for Sri Lanka.

Seasonal Precipitation: 
The precipitation forecast for the January-February-March 2023 season shows a higher tendency of above-normal precipitation for the country.