Climate Bulletin For Sri Lanka (17 December 2021)

 

Highlights          

                   

 • Fairly heavy rainfall is predicted for Eastern, Uva, North Central, Northern,and Southern provinces from 18th Dec – 22nd Dec.Highest rainfall for the period is predicted for Jaffna on the 18th Dec.

 • Very heavy rainfall was experienced in Western and Uva provinces with max of 179 mm in Badulla district on 12th Dec.

 •  From 8th Dec - 15th Dec, up to 45 km/h Northeasterlies were experienced across the island.

 • Sea surface temperatures were above 10C around the entire island.

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Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 

From 16^th November – 22^nd  December:  

Total rainfall by Provinces

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

From 23^rd – 29^th  December: 

Total rainfall by Provinces:

• 85 mm - Eastern
• 55 mm - Northern, Uva
• 45 mm - Southern, North Central
• 35 mm - Central, North Western, Sabaragamuwa, Western

MJO based OLR predictions:

For the next 15 days: 

MJO shall be active during 18^th – 30^th Dec giving severely suppressed rainfall from 18^th – 25^th Dec and significantly suppressed rainfall from 26^th – 30^th Dec for the entire island.

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: December 8, 2021 

Equatorial sea surface temperatures (SSTs) are below average across the central and east-central Pacific Ocean in early-December. The tropical Pacific atmosphere is consistent with La Niña conditions. A large majority of the model forecasts indicate 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 above 1⁰C around the entire island.

Interpretation

Monitoring

Rainfall: 

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

Wind: 

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

Temperature: 

The temperature anomalies were neutral for some parts of Southern, Uva and Eastern provinces while 1⁰C-3⁰C above neutral for the rest of the island last week, driven by the warm SST’s.

Predictions

Rainfall:

During the next week (18^th December – 22^nd December) fairly heavy rainfall is predicted for Eastern, Uva, North Central, Northern, Southern provinces. 

Temperature:

The temperature remains normal during 18^th December – 26^th December for the entire island. 

Teleconnections:

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

MJO shall be active during 18^th – 30^th Dec giving severely suppressed rainfall from 18^th – 25^th Dec and significantly suppressed rainfall from 26^th – 30^th Dec for the entire island.

Seasonal Precipitation: 

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