Climate Bulletin For Sri Lanka (26 January 2024)

                     

Highlights          

 • High likelihood of very heavy rainfall (> 100 mm) is predicted for Eastern province,  fairly heavy rainfall (50 - 100 mm) is predicted for Uva province and less rainfall (≤ 45 mm) is predicted for the rest during  24 - 30 Jan.

 • Rainfall on 18 & 19 Jan reached peak (164 mm & 64 mm) at Mullaitivu. During the last week, average daily rainfall was 6.1 mm and hydro catchment was 2.8 mm.

 • Winds at 850mb (1.5 km) were north easterly from 15 - 21 Jan reaching up to 5 m/s. Winds at 850mb (1.5 km) are predicted north easterly from 25 - 31 Jan reaching up to 6 m/s.

 • Sea surface temperature around Sri Lanka was 0.5 - 1.5ºC above normal. Strong El Nino and positive indian ocean dipole patterns sustained. Maximum daily temperature was  in Ratnapura (35.0ºC), Ratmalana (33.9ºC) and Katunayake (33.9ºC).

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Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 

From 24^th January - 30^th January:   

Total rainfall by Provinces

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

MJO based OLR predictions:

For the next 15 days: 

MJO shall moderately suppress the rainfall during 24^th January - 7^th February for Sri Lanka.

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: January 22, 2024 

El Nino Mode has set in according to NOAA since 8^th of June, 2023. Equatorial sea surface temperatures (SSTs) are above average across the central and eastern Pacific Ocean mid-January. El Niño is expected to continue for the next several seasons, with a transition to ENSO-neutral favored during April-June 2024 (73% chance).

Indian Sea Sate

Sea surface temperature around Sri Lanka was 0.5℃ above normal to the country in 2^nd - 8^th January 2024. A positive Dipole Mode has set in across the Indian Ocean since 8^th of June.

Interpretation

Monitoring

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

Daily Average Rainfall in the Met stations for previous week of (17^th January - 24^th January) = 6.1 mm

Maximum Daily Rainfall: 164.3 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	6.7	30.0	23.5
Eastern hills	0.9	25.7	17.4
Eastern plains	6.2	30.3	23.5
Western hills	5.3	28.6	18.0
Western plains	9.3	32.0	24.2
Southern plains	0.4	31.6	23.7

Region	Average rainfall for last 8 days (mm)	Daily maximum rainfall for last 8 days (mm)	Daily minimum rainfall for last 8 days (mm)
Hydro catchment	2.8	46.4	0.0

Wind: North easterly 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 province of the country driven by the warm SST’s.

Predictions

Rainfall: During the next week (24^th January - 30^th January), heavy rainfall is predicted for the Eastern province, fairly heavy rainfall is predicted for the Uva province, and less rainfall is predicted for rest of the country.

Temperatures: The temperature will remain above normal for some parts of the Western province during 25^th January - 31^st January.

Teleconnections: A positive Dipole Mode has set in across the Indian Ocean since 8^th of June.

MJO shall moderately suppress the rainfall during 24^th January - 7^th February for Sri Lanka.

Seasonal Precipitation: The precipitation forecast for the February-March-April, 2024 season shows near normal precipitation.                                                            

Climate Bulletin For Sri Lanka (19 January 2024)

                    

Highlights          

 • High likelihood of  moderate rainfall (25 - 50 mm) is predicted for Sabaragamuwa province and less rainfall (≤ 20 mm) is predicted for rest of the country during    19 - 25 Jan.

 • During the last week, average daily rainfall over Sri Lanka was 4.6 mm and hydro catchment was 2.1 mm. Maximum average daily rainfall was 39 mm on 8 Jan and 35 mm on 10 Jan.

 • From 8 - 14 Jan, up to 8 m/s of north easterly winds were at 850 mb (1.5 km). During 18 - 24 Jan, up to 5 m/s of  north easterly winds are expected at 850 mb (1.5 km). 

 • Sea surface temperature around Sri Lanka was 0.25 - 1.0ºC above normal. Strong EL Nino and positive indian ocean dipole patterns sustained. Maximum daily temperature was  in Ratnapura (34.6ºC) and Ratmalana (33.7ºC).

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Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 

From 19^th January - 25^th January:  

Total rainfall by Provinces

•  20 - 40 mm -  Sabaragamuwa
•  10 - 20 mm - Uva, Southern, Eastern, Western
• ≤ 10 mm - Central, North Central, Northern, North Western

MJO based OLR predictions:

For the next 15 days: 

MJO shall slightly suppress the rainfall during 17^th - 21^st January and significantly suppress the rainfall during 22^nd - 31^st January for Sri Lanka.

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: January 15, 2024 

El Nino Mode has set in according to NOAA since 8^th of June, 2023. Equatorial sea surface temperatures (SSTs) are above average across the central and eastern Pacific Ocean mid-January. El Niño is expected to continue for the next several seasons, with a transition to ENSO-neutral favored during April-June 2024 (73% chance).

Indian Sea Sate

Sea surface temperature around Sri Lanka was 0.5℃ above normal to the country in 26^th December - 1^st January 2024. A positive Dipole Mode has set in across the Indian Ocean since 8^th of June.

Interpretation

Monitoring

Rainfall: : During the last two weeks, there had been very heavy rainfall over the following areas: Pannalgama, Lahugala, Vakaneri Wewa.

Daily Average Rainfall in the Met stations for previous week of (10^th January - 17^th January) = 4.6 mm

Maximum Daily Rainfall: 172.1 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	2.5	29.9	23.2
Eastern hills	6.3	23.8	16.0
Eastern plains	9.2	29.5	23.0
Western hills	1.6	27.0	16.8
Western plains	0.7	31.1	23.1
Southern plains	5.7	30.2	22.8

Region	Average rainfall for last 8 days (mm)	Daily maximum rainfall for last 8 days (mm)	Daily minimum rainfall for last 8 days (mm)
Hydro catchment	2.1	53.9	0.0

Wind: North easterly 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, Sabaragamuwa, and Northern provinces of the country driven by the warm SST’s.

Predictions

Rainfall: During the next week (19^th January - 25^th January), moderate rainfall is predicted for the Sabaragamuwa province and less rainfall is predicted for rest of the country.

Temperatures: The temperature will remain seasonably near normal for the country during 18^th January - 24^th January.

Teleconnections: A positive Dipole Mode has set in across the Indian Ocean since 8^th of June.

MJO shall slightly suppress the rainfall during 17^th - 21^st January and significantly suppress the rainfall during 22^nd - 31^st January for Sri Lanka.

Seasonal Precipitation: The precipitation forecast for the February-March-April, 2024 season shows near normal precipitation.