Climate Bulletin For Sri Lanka (26 November 2021)

 

Highlights          

                   

 • Heavy rainfall is predicted for Central, Northern, North Central, North Western, Sabaragamuwa, Southern and  Western provinces from 27th Nov - 1st Dec.

 • Very heavy rainfall was experienced in Sabaragamuwa province with max of 219.0 mm in Ratnapura district on 24th Nov.

 • From 17th Nov - 23rd Nov, up to 40 km/h Northerlies and Northeasterlies were experienced across the island.

 •  Sea surface temperatures were neutral for the entire island.

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Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 

From 25^th November – 1^st  December:  

Total rainfall by Provinces

• >135 mm - Central, Northern, North Central, North Western, Sabaragamuwa, Southern,  Western
•  135 mm - Eastern
•  125 mm - Uva

From 2^nd – 8^th  December: 

Total rainfall by Provinces:

• >135 mm - Northern
•  125 mm - North Western, Western
•  115 mm - Sabaragamuwa
•  105 mm - Central, North Central, Southern
•   95 mm - Eastern
•   85 mm - Uva

MJO based OLR predictions:

For the next 15 days: 

MJO shall be active during 25^th November – 29^th November giving slightly enhanced rainfall. MJO shall be neutral during 30^th November – 4^th December and active during 5^th December – 9^th December giving slightly suppressed rainfall. 

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: November 17, 2021 

Equatorial SSTs were near-to-below average across most of the equatorial Pacific Ocean and were above average in the western Pacific Ocean in the mid-November. A large majority of the model forecasts predict a transition from ENSO-neutral to La Niña is favored in the next couple of months and La Niña to continue through the Northern Hemisphere fall and winter.

Indian Sea Sate

Sea surface temperatures were neutral for the entire island.

Interpretation

Monitoring

Rainfall: 

During the last two weeks, there had been heavy rainfall over the following Provinces: Central and Northern. 

Wind: 

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

Temperature: 

The temperature anomalies were above normal by 1⁰C – 3⁰C in some parts of Southern province and near-neutral for the rest of the island last week, driven by the warm SST’s.

Predictions

Rainfall:

During the next week (27^th November – 1^st December) heavy rainfall is predicted for the following provinces: Central, Northern, North Central, North Western, Sabaragamuwa, Southern and Western.  

Temperature:

The temperature remains normal during 27^th November – 5^th December for the entire island. 

Teleconnections:

La Nina -The SST forecast indicates that ENSO-neutral are present and a transition from ENSO-neutral to La Niña is favored in the next couple of months.

MJO shall be active during 25th November – 29th November giving slightly enhanced rainfall. MJO shall be neutral during 30th November – 4th December and active during 5th December – 9th December giving slightly suppressed rainfall. 

Seasonal Precipitation: 

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