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.

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Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 

From 12^th June - 18^th 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 19^th June - 25^th 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 12^th June - 26^th 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 0.5℃ above normal to the Northern and Eastern half of the country in 21^st - 27^th 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 (5^th June - 12^th 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 (12^th June - 18^th 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 13^th June - 19^th June.

Teleconnections: MJO shall significantly suppress the rainfall during 12^th June - 26^th 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.                               

Climate Bulletin For Sri Lanka (7 June 2024)

Highlights          

 • During  5-11  June, there is a high likelihood of moderate rainfall (25 - 50 mm) predicted for Puttalam town and light rainfall for the Puttalam district and adjacent areas, with no rainfall predicted for the rest.

 • During 29 May - 5 June, on average, 8.4 mm was received in SL, rainfall was concentrated in the western hills (28 mm) and plains (11 mm). 31 May, 1 and 2 June: extreme rainfall (62.5mm,282mm,154mm) was recorded in Ratnapura, and floods ensued. The highest daily rainfall (436 mm) was in Eheliyagoda on June 1.

 • From 28 May- 3 June, strong winds at 850mb (1.5 km) north westerly, reaching up to 15m/s. From 6-12 June, winds are predicted to be westerly, reaching up to 15m/s.

 • Average maximum land surface temperature was 31.7ºC in last week. Sea Surface Temperature around Sri Lanka was 0- 0.25ºC above normal to the north east and, the south west is cooler. Both the EL Nino and Indian ocean dipole patterns transitioned to neutral last week. 

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Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 

From 5^th June - 11^th June:  

Total rainfall by Provinces

• 45 mm - North Western
• 25 mm - Western
• 15 mm - North Central, Sabaragamuwa, Central,  Northern 
• ≤5 mm - Southern,  Eastern,  Uva

From 12^th June - 18^th June:  

Total rainfall by Provinces

• 75 mm - North Western
• 65 mm - Western
• 55 mm - Sabaragamuwa 
• 45 mm - Central, Southern  
• 35 mm - North Central
• ≤25 mm - Eastern,  Northern, Uva

MJO based OLR predictions:

For the next 15 days: 

MJO shall slightly suppress the rainfall during 5^th June – 19^th June. 

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: June 3, 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 ranging from 1.0℃ below normal to 1.0℃ above normal for the country in 14^th - 20^th May 2024.  

Interpretation

Monitoring

Rainfall: :During the last two weeks, there had been very heavy rainfall over the following area: Ehellyagoda. 

Daily Average Rainfall in the Met stations for previous week of (29^th May - 6^th June) = 8.4 mm 

Maximum Daily Rainfall: 281.9mm & 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	3.3	33.0	26.5
Eastern hills	4.3	28.9	20.0
Eastern plains	4.1	34.2	26.0
Western hills	28.6	27.3	20.6
Western plains	11.2	30.8	26.4
Southern plains	4.3	32.4	25.7

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	8.4	281.9	0.0
Hydro catchment	16.4	264.0	0.0

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

Temperatures: The temperature anomalies were neutral for the Sri Lanka except some part of the Uva province driven by the warm SST’s.                                                       

Predictions

Rainfall: During the next week (5^th June - 11^th June), moderate rainfall (25 - 50 mm) is predicted for the Western, and North Western, provinces and light to moderate rainfall (12.5 - 25 mm) is predicted for the North Central, Sabaragamuwa, Central, Northern Provinces and light shower is predicted for the rest.

Temperatures: The temperature will remain above normal for some parts of the Northern, Eastern, North central and Uva provinces during 6^th June 12^th June.

Teleconnections: MJO shall slightly suppress the rainfall during 5th June – 19th June.            

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.