Climate Bulletin For Sri Lanka (23 August 2024)

  

Highlights   

       

 •  During 21 - 27 Aug, high likelihood of Light Showers (<12.5 mm) is predicted for the whole SL. The middle atmospheric convergence at latitudes around Sri Lanka has the potential to bring rainfall to the SL. According to the medium-range weather forecast, the Eastern Province has a highly tendency of above normal rainfall due to these conditions.

 •    On average, 10 mm was received in SL and rainfall was concentrated in the Western plains (16.2 mm) and hills (11.5 mm) for last 8 days.On average, 9.6 mm was received in the hydro catchments in SL; Kukule Ganga (Kalutara District) received the highest rainfall (125 mm) for last 8 days. Highest daily rainfall was in Mullativu on 20 Aug (151 mm).

 •    From 13 Aug - 19 Aug, winds at 850mb (1.5km) were north- westerly, reaching up to 15 m/s. From 22 Aug - 28 Aug, winds are predicted to be westerly, reaching up to 15 m/s.  

 •    Average land surface temperature was 31.0ºC in the last week with warmer anomalies from seasonal average of 1-3 ºC and cooler anomalies from seasonal average of 1-3 ºC. Eastern plains was warmest followed by Northern and Southern plains. Sea surface temperature around Sri Lanka was 1.0℃ above average of the country.

Download full report ↓

---

Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 

From 21^st August - 27^th August:  
Total rainfall by Provinces

• ≤10 mm - Northern, Southern, Sabaragamuwa, Western, Uva, Central, North Western, North Central, Eastern

From 28^th August - 3^rd September:  

Total rainfall by Provinces

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

MJO based OLR predictions:

For the next 15 days: 

MJO shall slightly enhance the rainfall during 21st – 30th August and near neutral the rainfall during 31st August – 4th September for Sri Lanka.

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: August 21, 2024 

ENSO-neutral conditions are present. Equatorial sea surface temperatures (SSTs) are above average in the western Pacific, near average in the east-central Pacific, and below average in the eastern Pacific Ocean. ENSO-neutral is expected to continue for the next several months, with La Niña favored to emerge during September-November (66% chance) and persist through the Northern Hemisphere winter 2024-25 (74% chance during November-January).

Indian Sea Sate

Sea surface temperature around Sri Lanka was 1.0℃ above average from 30 July to 5 August 2024.

Interpretation

Monitoring

Rainfall: :During the last two weeks, there has been fairly heavy rainfall over the following area: Palugaswewa Estate (Puttlam)

Daily Average Rainfall in the Met stations for the previous week of (15 - 21 Aug) = 6.6 mm
Maximum Daily Rainfall: 96.4 mm & Minimum Daily Rainfall: 0.0 mm.

Region	Average rainfall for 15 - 21 Aug (mm)	Average temperature for 15 - 21 Aug (ºC)
		Maximum	Minimum
Northern plains	8.5	32.3	25.1
Eastern hills	10.2	29.1	24.0
Eastern plains	7.3	32.7	23.1
Western hills	11.5	27.7	23.7
Western plains	16.2	30.1	24.5
Southern plains	9.5	30.9	26.1

Region	Average rainfall for 15 - 21 Aug (mm)	Daily maximum rainfall for 15 - 21 Aug (mm)	Daily minimum rainfall for 15 - 21 Aug (mm)
All SL	10.3	151.1	0.0
Hydro catchment	9.6	125.0	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 Sabaragamuwa province and below normal for some parts of the Eastern province for Sri Lanka driven by the warm SSTs.

                                          

Predictions

Rainfall: During the next week (21 - 27 Aug ), Light Showers (<12.5 mm) is predicted for the whole SL.

Temperatures: The temperature will remain above normal for the Northern and Eastern provinces during 22 August - 28 August.

Teleconnections: MJO shall slightly enhance the rainfall during 21st – 30th August and near neutral the rainfall during 31st August – 4th September for Sri Lanka.

Seasonal Precipitation: The precipitation forecast for the September-October-November, 2024 season shows a 40% or more tendency toward normal precipitation for the country.

Climate Bulletin For Sri Lanka (16 August 2024)

 

Highlights   

       

 • During 15 - 21 Aug, high likelihood of heavy rainfall (100 - 150 mm) is predicted for the Sabaragamuwa, Western, Uva, Central and Southern provinces  fairly heavy rainfall (50 - 100 mm) is predicted for the North Central, North Western and Eastern provinces; moderate rainfall (25-50 mm) is predicted for the Northen province. High likelihood of heavy rainfall (100 - 150 mm) is predicted for the Southwest corner of SL  during 15-21 Aug.

 • On average, 6.6 mm was received in SL and rainfall was concentrated in the Western hills (9.6 mm) and Northern (7.7 mm) and Eastern  (7 mm) plains for last 8 days. On average, 7.5 mm was received in the hydro catchments in SL; Neboda (Kalutara District) received the highest rainfall (65 mm) for last 8 days. Highest daily rainfall was in Mahailluppallama on 11 Aug (96.4 mm).

 • From 7 Aug - 13 Aug, winds at 850mb (1.5km) were north- westerly, reaching up to 15 m/s. From 16 Aug - 22 Aug, winds are predicted to be westerly  and north-westerly, reaching up to 15 m/s.  

 • Average land surface temperature was 31.0ºC in the last week with warmer anomalies from seasonal average of 1-3 ºC. Northern plains was warmest followed by Eastern, Western and Southern plains. Sea surface temperature around Sri Lanka was normal to the North Eastern and some parts of the Northern side of the country and 1.5℃  above average for the other half of the country.

Download full report ↓

---

Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 

From 15^th August - 21^st August:  
Total rainfall by Provinces

• 135≤ mm - Southern
•  125 mm - Sabaragamuwa, Western
•  105 mm - Uva, Central
•   85 mm - North Western
•   75 mm - North Central, Eastern
•  ≤45 mm - Northern

From 22^nd August - 28^th August:  

Total rainfall by Provinces

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

MJO based OLR predictions:

For the next 15 days: 

MJO shall slightly enhance the rainfall during 15th – 24th August and near neutral the rainfall during 25th August – 29th August for Sri Lanka.

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: August 12, 2024 

ENSO-neutral conditions are present. Equatorial sea surface temperatures (SSTs) are above average in the western Pacific, near average in the east-central Pacific, and below average in the eastern Pacific Ocean. ENSO-neutral is expected to continue for the next several months, with La Niña favored to emerge during September-November (66% chance) and persist through the Northern Hemisphere winter 2024-25 (74% chance during November-January).

Indian Sea Sate

Sea surface temperature around Sri Lanka was normal to the North Eastern and some parts of the Northern side of the country and 1.5℃ above average for the other half of the country from 23 July to 29 July 2024.

Interpretation

Monitoring

Rainfall: :During the last two weeks, there has been fairly heavy rainfall over the following area: Nochchiyagama ( Anuradhapura )

Daily Average Rainfall in the Met stations for the previous week of (8 - 14 Aug) = 6.6 mm

Maximum Daily Rainfall: 96.4 mm & Minimum Daily Rainfall: 0.0 mm.

Region	Average rainfall for 8 - 14 Aug (mm)	Average temperature for 8 - 14 Aug (ºC)
		Maximum	Minimum
Northern plains	7.7	33.7	25.5
Eastern hills	2.8	29.4	19.1
Eastern plains	7.1	33.6	24.9
Western hills	9.6	28.5	19.8
Western plains	4.4	31.6	25.9
Southern plains	1.5	31.4	25.9

Region	Average rainfall for 8 - 14 Aug (mm)	Daily maximum rainfall for 8 - 14 Aug (mm)	Daily minimum rainfall for 8 - 14 Aug (mm)
All SL	6.6	96.4	0.0
Hydro catchment	7.5	65.0	0.0

Wind: North Westerly and 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 Western, Central and Sabaragamuwa province and below normal for some parts of the Eastern province for Sri Lanka driven by the warm SSTs.

                                          

Predictions

Rainfall: During the next week (15 - 21 Aug ), heavy rainfall (100 - 150 mm) is predicted for the Sabaragamuwa, Western, Uva, Central and Southern provinces and fairly heavy rainfall (50 – 100 mm) is predicted for the North Central, North Western and Eastern provinces and moderate rainfall (25-50 mm) is predicted for the Northern province.

Temperatures: The temperature will remain above normal for the Northern, Eastern and North Central provinces during 16 August - 22 August.

Teleconnections: MJO shall slightly enhance the rainfall during 15th – 24th August and near neutral the rainfall during 25th August – 29th August for Sri Lanka.

Seasonal Precipitation: The precipitation forecast for the September-October-November, 2024 season shows a 40% or more tendency toward normal precipitation for the country.

Climate Bulletin For Sri Lanka (9 August 2024)

  

Highlights   

       

 • During 7 - 13 Aug, high likelihood of fairly heavy rainfall (50 - 100 mm) is predicted for the Sabaragamuwa, Western, North Western, and Southern provinces and moderate rainfall (25 - 50 mm) is predicted for the Uva, North Central, Central, Northern and Eastern provinces. 

 • On average, 2.4 mm was received in SL and rainfall was concentrated in the   Eastern hills (6 mm) for last 8 days. On average, 3 mm was received in the hydro catchments in SL; Kukule Ganga (Kalutara District) received the highest rainfall (55 mm) for last 8 days. Highest daily rainfall was in Bandarawela on 5 Aug (35.6 mm).

 • From 24 Jul - 4 Aug, winds at 850mb (1.5km) were  westerly and north- westerly, reaching up to 15 m/s. From 8 Aug - 14 Aug, winds are predicted to be north-westerly, reaching up to 3 m/s

 • Average land surface temperature was 31.5ºC in the last week with warmer anomalies from seasonal average of 1-3 ºC. Eastern plains was warmest followed by Northern and Southern plains. Sea surface temperature around Sri Lanka was normal to the Eastern , North Eastern and some parts of the Northern side of the country and 1.0℃ above average for the other half of the country 

Download full report ↓

---

Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 

From 7^th August - 13^th August:  
Total rainfall by Provinces

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

From 14^th August - 20^th August:  

Total rainfall by Provinces

• 135≤ mm - Southern
• 115 mm - Western
• 105 mm - Sabaragamuwa
•  95 mm - Central, Uva
•  75 mm - North Western, North Central, Eastern
• ≤55 mm - Northern

MJO based OLR predictions:

For the next 15 days: 

MJO shall be moderately suppress for the rainfall during 31 July-14 August for Sri Lanka.

     

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: July 29, 2024 

ENSO-neutral conditions are present. Equatorial sea surface temperatures (SSTs) are above average in the western and west-central Pacific, near average in the east-central Pacific, and below average in the eastern Pacific Ocean. ENSO-neutral is expected to continue for the next several months, with La Niña favored to develop during August-October (70% chance) and persist into the Northern Hemisphere winter 2024-25 (79% chance during November-January).

Indian Sea Sate

MJO shall near neutral the rainfall during 7 – 16 August and slightly enhance the rainfall during 17 – 21 August for Sri Lanka.

Interpretation

Monitoring

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

Huruluwawa (Anuradhapura District)

Daily Average Rainfall in the Met stations for the previous week of (1 - 8 Aug) = 2.4 mm

Maximum Daily Rainfall: 35.6 mm & Minimum Daily Rainfall: 0.0 mm.

Region	Average rainfall for 1 - 8 Aug (mm)	Average temperature for 1 - 8 Aug (ºC)
		Maximum	Minimum
Northern plains	1.6	34.4	25.8
Eastern hills	6.1	29.6	18.8
Eastern plains	2.8	34.9	25.1
Western hills	2.7	27.9	20.1
Western plains	2.1	31.3	26.5
Southern plains	0.0	31.7	24.7

Region	Average rainfall for 1 - 8 Aug (mm)	Daily maximum rainfall for 1 - 8 Aug (mm)	Daily minimum rainfall for 1 - 8 Aug (mm)
All SL	2.4	35.6	0.0
Hydro catchment	2.9	55.0	0.0

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

Temperatures: The temperature anomalies were above normal for Eastern, Uva and some parts of the Sabaragamuwa province for Sri Lanka driven by the warm SSTs.

                                                    

Predictions

Rainfall: During the next week (7 August - 13 August), fairly heavy rainfall (50 - 100 mm) is predicted for the Sabaragamuwa, Western, North Western, and Southern provinces and moderate rainfall (25 - 50 mm) is predicted for the Uva, North Central, Central, Northern and Eastern provinces.

Temperatures: The temperature will remain above normal for the Northern, Eastern and North Central provinces during 8 August - 14 August.

Teleconnections: MJO shall near neutral the rainfall during 7 – 16 August and slightly enhance the rainfall during 17 – 21 August for Sri Lanka.

Seasonal Precipitation: The precipitation forecast for the August-September-October, 2024 season shows a 40% or more tendency toward normal precipitation for the country.