Climate Bulletin For Sri Lanka (10 December 2021)

 

Highlights                             

• Heavy rainfall is predicted for Eastern, Northern, North Central and Southern provinces from 11th Dec - 14th Dec. 

• Heavy rainfall was experienced in Sabaragamuwa, Southern and Uva provinces with max of 128.5 mm in Hambantota district on 2nd Dec.

• From 29th Nov - 6th Dec, up to 40 km/h Northeasterlies were experienced across the island.

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

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Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 

From 8^th – 14^th  December: 

Total rainfall by Provinces

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

From 15^th – 21^st  December: 

Total rainfall by Provinces:

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

MJO based OLR predictions:

For the next 15 days: 

MJO shall be active during 11^th December – 22^nd December giving severely suppressed rainfall for the entire island.

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: December 1, 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-December. 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 and neutral around the rest of the Island.

Interpretation

Monitoring

Rainfall: 

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

Wind: 

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

Temperature: 

The temperature anomalies were 1⁰C-3⁰C above neutral in the Central, Sabaragamuwa, North Central and Uva provinces last week, driven by the warm SST’s.

Predictions

Rainfall:

During the next week (11^th December – 14^th December) heavy rainfall is predicted for Eastern, Northern, North Central and Southern provinces.

Temperature:

The temperature remains normal during 11^th December – 18^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 11^th December – 22^nd December giving severely suppressed rainfall for the entire island.

Seasonal Precipitation: 

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