Climate Bulletin For Sri Lanka (31 December 2021)

 

Highlights          

                   

 • Heavy rainfall is predicted for Eastern province from 1st Jan – 4th Jan. Greater likelihood of wet tendency is predicted for Sri Lanka from Jan - Mar.

 • Dry conditions with below average rainfall was observed in the entire island last week except for fairly heavy rainfall in the Southern province with max of 94.5 mm in Matara district on 22nd Dec.

 •  From 21st Dec - 28th Dec, up to 45 km/h Northeasterlies were experienced across the island.

 • Sea surface temperatures were neutral around the entire island.

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Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 

From 1^st – 4^th  January:  

Total rainfall by Provinces

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

From 5^th – 11^th  January: 

Total rainfall by Provinces:

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

MJO based OLR predictions:

For the next 15 days: 

MJO shall be active during 1^st – 12^th January giving significantly suppressed rainfall from 1^st – 2^nd January and sightly suppressed rainfall from 3^rd – 12^th January for the entire island.

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: December 22, 2021 

Equatorial sea surface temperatures (SSTs) are below average across the central and east-central Pacific Ocean in the mid-December. The tropical Pacific atmosphere is consistent with La Niña conditions. A large majority of the model forecasts indicates very high probabilities of La Niña during the Northern Hemisphere winter, weakening gradually, and likely to dissipate in Mar-May 2022. 

Indian Sea Sate

Sea surface temperatures were neutral around the entire island.

Interpretation

Monitoring

Rainfall: 

During the last two weeks, there had been fairly heavy rainfall over the following provinces: Southern. 

Wind: 

Northeasterly winds prevailed in the sea area and around the island last week. 

Temperature: 

The temperature anomalies were 1⁰C - 3⁰C above neutral for some parts of Central, Sabaragamuwa and Western provinces last week, driven by the warm SST’s.

Predictions

Rainfall:

During the next week (1^st– 4^th January) heavy rainfall is predicted for Eastern province.

Temperature:

The temperature remains normal during 1^st January – 8^th January for the entire island.

Teleconnections:

La Niña - The SST forecast indicates that La Niña is favored to continue through the Northern Hemisphere winter.

MJO shall be active during 1^st – 12^th January giving significantly suppressed rainfall from 1^st – 2^nd January and sightly suppressed rainfall from 3^rd – 12^th January for the entire island.

Seasonal Precipitation: 

The precipitation forecast for the Jan-Mar season show enhanced probabilities of above-normal precipitation over Sri Lanka.