Climate Bulletin For Sri Lanka (19 November 2021)

 

Highlights          

                   

 • Heavy rainfall is predicted for Northern province from 20th Nov - 24th Nov. Greater likelihood of wet tendency is predicted for Sri Lanka from Dec to Feb.

 • Heavy rainfall was experienced in Northern and Central provinces with max of 132.5 mm in Mullaitivu district on 11th Nov.

 •  From 10th Nov - 17th Nov, up to 50 km/h Westerlies and Southwesterlies were experienced across the island.

 •  Sea surface temperatures were above 0.50C in the Western seas while neutral to the rest of the island.

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Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 

From 18^th – 24^th  November:  

Total rainfall by Provinces

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

From 25^th – 1^st  November: 

Total rainfall by Provinces:

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

MJO based OLR predictions:

For the next 15 days: 

MJO shall be neutral during 18^th November – 22^nd November, MJO shall be active during 23^rd November – 27^th November giving slightly suppressed rainfall and during 28^th November – 2^nd December giving severely suppressed rainfall.   

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: November 10, 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 early-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 above 0.5⁰C in the Western seas while neutral around the rest of the island.

Interpretation

Monitoring

Rainfall: 

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

Wind: 

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

Temperature: 

The temperature anomalies were below normal by 1⁰C – 3⁰C in some parts of Central, North Central and North Western provinces and near-neutral for the rest of the island last week, driven by the warm SST’s.

Predictions

Rainfall:

During the next week (20^th November – 24^th November) heavy rainfall is predicted for the following province: Northern.   

Temperature:

The temperature remains slightly normal during 20^th November – 28^th November 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 neutral during 18^th November – 22^nd November, MJO shall be active during 23^rd November – 27^th November giving slightly suppressed rainfall and during 28^th November – 2^nd December giving severely suppressed rainfall. 

Seasonal Precipitation: 

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