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Friday, June 21, 2024

Climate Bulletin For Sri Lanka (21 June 2024)


Highlights          


 • During 18 - 24 June, high likelihood of fairly heavy rainfall (50 - 100 mm) is predicted for the North Western, Western, Sabaragamuwa provinces; moderate rainfall (25 - 50 mm) is predicted for the Southern, Central provinces and less rainfall is predicted for the rest.
 • On average, 1.2 mm was received in SL and rainfall was concentrated in the Western plains (3.3 mm) and hills (1.8 mm). Daily average rainfall in  this week (1.2 mm) was lower than previous week (2.4 mm). Highest daily rainfall was in Guruluwana (Ratnapura) on 18 June. (95.4 mm).
 • From 9 - 15 June, winds at 850mb (1.5km) north westerly, reaching up to 15 m/s. From 19 - 25 June, winds are predicted to be north westerly, reaching up to 20 m/s.  
 • Average land surface temperature was 32.2ºC in the last week with warmer anomalies from seasonal average of +1ºC - 3ºC. Eastern plain was more warmest followed by Northern and Southern plains. Sea surface temperature around Sri Lanka was 0.25 - 1.5ºC above average.



Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 
From 18th June - 24th June:  
Total rainfall by Provinces
  • 65 mm - North Western
  • 55 mm - Western, Sabaragamuwa 
  • 45 mm - Southern
  • 35 mm - Central
  • ≤ 5 mm - North Central, Northern, Eastern, Uva
From 25th June - 1st July:  
Total rainfall by Provinces
  • 65 mm - North Western, Western, Sabaragamuwa
  • 55 mm - Southern
  • 45 mm - Central
  • 25 mm - North Central
  • 15 mm - Northern, Uva, Eastern
    MJO based OLR predictions:
    For the next 15 days: 
    MJO shall near neutral the rainfall during 18th - 22nd June, slightly enhance the rainfall during 23rd - 27th June, and moderately enhance the rainfall during 28th June - 2nd July for Sri Lanka. 

    Ocean State (Text Courtesy IRI)
    Pacific Sea Sate: June 17, 2024 
    ENSO-neutral conditions are present. Equatorial sea surface temperatures (SSTs) are above average in the west-central Pacific Ocean, near average in the east-central Pacific Ocean, and below-average in the far eastern Pacific Ocean mid-June. La Niña is favored to develop during July-September (65% chance) and persist into the Northern Hemisphere winter 2024-25 (85% chance during November-January). 

    Indian Sea Sate
    Sea surface temperature around Sri Lanka was 0.5above average to the Northern and Eastern half of the country in 28th May - 3rd June 2024.

    Interpretation


    Monitoring
    Rainfall:During the last two weeks, there had been fairly heavy rainfall over the following area:

    Guruluwana (Ratnapura)

    Daily Average Rainfall in the Met stations for previous week of (11th June - 18th June) = 1.2 mm

    Maximum Daily Rainfall: 37.0 mm & Minimum Daily Rainfall: 0.0 mm.


    Region

    Average rainfall for last 8 days (mm)

    Average temperature for last 8 days (ºC)

    Maximum

    Minimum

    Northern plains

                      0.7                 

    33.1

    26.9

    Eastern hills

    0.9

    29.8

    18.4

    Eastern plains

    0.0

    35.0

    25.5

    Western hills

    1.8

    27.8

    20.1

    Western plains

    3.3

    31.6

    26.3

    Southern plains

    0.1

    32.2

    25.9











    Region

    Average rainfall for last 8 days (mm)

    Daily maximum rainfall for last 8 days (mm)

    Daily minimum rainfall for last 8 days (mm)

    All SL

    1.2

    37.0

    0.0

    Hydro catchment

    2.5

    37.5

    0.0






    Wind: North westerly winds prevailed in the sea area and around the island last week.
    Temperatures: The temperature anomalies were above normal for some parts of the Central and Uva provinces and below normal for some parts of the Eastern province driven by the warm SST’s.

                
          
          
            
          
                  

    Predictions
    Rainfall: During the next week (18th June - 24th June), fairly heavy rainfall (50 - 100 mm) is predicted for the North Western, Western, and Sabaragamuwa provinces, moderate rainfall (25 - 50 mm) is predicted for the Southern and Central provinces and less rainfall is predicted for the rest.
    Temperatures: The temperature will remain above normal for the Northern, Eastern, North Central and Uva provinces during 19th June - 25th June.
    Teleconnections: MJO shall near neutral the rainfall during 18th - 22nd June, slightly enhance the rainfall during 23rd - 27th June, and moderately enhance the rainfall during 28th June - 2nd July for Sri Lanka.             
    Seasonal Precipitation: The precipitation forecast for the July-August-September, 2024 season shows a 40 - 50% or more tendency toward above normal precipitation for the country.    

    Friday, June 14, 2024

    Climate Bulletin For Sri Lanka (14 June 2024)


    Highlights          


     • High likelihood of moderate rainfall (25 - 50 mm) is predicted for the North Western, Western, Central, and Sabaragamuwa provinces and less rainfall is predicted for the rest during 12 - 18 June.
     • On average 2.4 mm was received in SL and rainfall was concentrated in the western plains (6.2 mm) and hills (4.2 mm). Daily average rainfall in  this week (2.4 mm) was lower than previous week (8.4 mm). Highest daily rainfall was in Kirindiwela on 8 June and Moraliya Oya on 9 June (80 mm).
     • From 29 May - 4 June, winds at 850mb (1.5km) north westerly, reaching up to 10 m/s. From 13 - 19 June, winds are predicted to be north westerly to south westerly, reaching up to 15 m/s.  
     • Average land surface temperature was 31.5ºC in the last week with warmer anomalies from seasonal average of   +1ºC to +3ºC. Sea surface temperature around Sri Lanka was 0.25 - 1.0ºC above normal.



    Predictions

    Rainfall

    14-day prediction: 
    NOAA NCEP models: 
    From 12th June - 18th June: 
    Total rainfall by Provinces
    • 45 mm - North Western 
    • 35 mm - Western 
    • 25 mm - Central, Sabaragamuwa
    • 15 mm - Southern
    • ≤ 5 mm - Northern, Eastern, Uva, North Central
    From 19th June - 25th June:  
    Total rainfall by Provinces
    • 85 mm - North Western
    • 65 mm - Western, Sabaragamuwa
    • 55 mm - Southern, Central
    • 35 mm - North Central
    • ≤ 25 mm - Northern, Uva, Eastern 
      MJO based OLR predictions:
      For the next 15 days: 
      MJO shall significantly suppress the rainfall during 12th June - 26th June for Sri Lanka

      Ocean State (Text Courtesy IRI)
      Pacific Sea Sate: June 10, 2024 
      El Niño is transitioning toward ENSO-neutral. Equatorial sea surface temperatures (SSTs) are above average in the western and central Pacific Ocean, and below-average SSTs are emerging in east central and eastern Pacific Ocean. La Niña may develop in June-August 2024 (49% chance) or July-September (69% chance).

      Indian Sea Sate
      Sea surface temperature around Sri Lanka was 0.5above normal to the Northern and Eastern half of the country in 21st - 27th May 2024. 

      Interpretation


      Monitoring
      Rainfall:During the last two weeks, there had been fairly heavy rainfall over the following areas:

      Kirindiwela (Gampaha), Moraliya Oya (Kegalle)

      Daily Average Rainfall in the Met stations for previous week of (5th June - 12th June) = 2.4 mm

      Maximum Daily Rainfall: 49.1 mm & Minimum Daily Rainfall: 0.0 mm.

      Region

      Average rainfall for last 8 days (mm)

      Average temperature for last 8 days (ºC)

      Maximum

      Minimum

      Northern plains

                        0.5                 

      32.3

      26.6

      Eastern hills

      0.4

      28.6

      19.7

      Eastern plains

      0.5

      34.0

      26.0

      Western hills

      4.2

      27.7

      20.7

      Western plains

      6.2

      31.4

      26.0

      Southern plains

      3.5

      31.3

      25.9











      Region

      Average rainfall for last 8 days (mm)

      Daily maximum rainfall for last 8 days (mm)

      Daily minimum rainfall for last 8 days (mm)

      All SL

      2.4

      49.1

      0.0

      Hydro catchment

      3.1

      40.0

      0.0






      Wind: North westerly winds prevailed in the sea area and around the island last week.

      Temperatures: The temperature anomalies were above normal for some parts of the Central and Uva provinces and below normal for some parts of the Eastern province driven by the warm SST’s.

                  
            
            
              
            
                    

      Predictions
      Rainfall: During the next week (12th June - 18th June), moderate rainfall (25 - 50 mm) is predicted for the North Western, Western, Central, and Sabaragamuwa provinces and less rainfall is predicted for the rest.
      Temperatures: The temperature will remain above normal for the Northern, Eastern, North Central and Uva provinces during 13th June - 19th June.
      Teleconnections: MJO shall significantly suppress the rainfall during 12th June - 26th June for Sri Lanka.             
      Seasonal Precipitation: The precipitation forecast for the June-July-August, 2024 season shows a 50% or more tendency toward above normal precipitation for the country.