Climate Bulletin for Sri Lanka ( 2 January 2020)

                                                      Highlights                                

• The NOAA weekly rainfall forecast predicts up to 75 mm of total rainfall in the western and central regions during 1- 6 Jan

• Between 24-30 Dec: up to 60 mm of rainfall were recorded in the southwestern regions of the island on the 24th and 25th

• From 24-30 Dec: up to 18 km/h, northeasterly winds were experienced by the entire island.

• 0.5 0C above-average sea surface temperature was observed in the seas around Sri Lanka

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Monitoring

Rainfall

Weekly Monitoring:

Date	Rainfall
24th December	Up to 60 mm in Colombo district; up to 30 mm in Jaffna, Kilinochchi, Gampaha and Kalutara districts; and up to 20 mm in Mullaitivu, Ratnapura, Galle and Hambantota districts.
25th December	Up to 60 mm in Galle and Matara districts; up to 50 mm in Kalutara and Ratnapura districts; up to 30 mm in Anuradhapura, Kegalle, Colombo, Nuwara Eliya and Monaragala districts; and up to 20 mm in Polonnaruwa, Puttalam and Hambantota districts.
26th December	Up to 30 mm in Ratnapura district; and up to 20 mm in Nuwara Eliya district.
27th December	No Rainfall.
28st December	No Rainfall.
29th December	Up to 5 mm in Kurunegala district.
30th December	No Rainfall.

Total Rainfall for the Past Week: The RFE 2.0 tool shows total up to 50-75 mm in Galle district; up to 25-50 mm in Kalutara and Matara districts; and up to 10-25 mm in Anuradhapura, Polonnaruwa, Colombo, Ratnapura and Hambantota districts. Above average rainfall up to 10-25 mm is shown for Galle district. Below-average rainfall up to 25-50 mm is shown for Jaffna, Kilinochchi, Mannar, Vavuniya, Mullaitivu, Anuradhapura, Trincomalee, Polonnaruwa, Badulla, Monaragala, Batticaloa and Ampara  districts; and up to 10-25 mm in Puttalam, Kurunegala, Matale, Kandy, Kegalle, Gampaha and Colombo districts.

Monthly Monitoring: During December – Above average rainfall conditions up to 300 mm were experienced by Trincomalee, Anuradhapura and Ampara districts; up to 240 mm in Mullaitivu, Puttalam, Polonnaruwa, Kurunegala, Matale, Kandy, Nuwara Eliya, Badulla, Monaragala, Galle, Colombo, Jaffna and Hambantota districts; and up to 60 mm in Kegalle, Kalutara and Matara districts. The CPC Unified Precipitation Analysis tool shows up to 500 mm were experienced by Mullaitivu, Anuradhapura, Polonnaruwa, Matale, Badulla, Monaragala, Batticaloa and Ampara districts; and up to 200-300 mm in Jaffna, Kilinochchi, Mannar, Puttalam, Kandy, Nuwara Eliya, Ratnapura, and Hambantota districts.

 Predictions

Rainfall

14-day prediction: 

NOAA NCEP models: 

IMD NCMWRF Forecast:
From 1^st – 7^th Jan: Total rainfall more than 45 mm in Trincomalee, Anuradhapura, Polonnaruwa, Badulla, Batticaloa and Ampara districts; up to 25-35 mm in most parts of the island.
From 8^th – 14^th Jan: Total rainfall more than 45 mm in Batticaloa and Ampara districts; up to 25-35 mm in Polonnaruwa, Badulla and Monaragala districts.

IRI Model Forecast: 
From 1^st – 6^th Dec: Total rainfall up to 75 mm is expected in Puttalam, Kurunegala, Kegalle, Kandy, Nuwara Eliya, Badulla, Ratnapura, Colombo and Kalutara districts.

MJO based OLR predictions:

For the next 15 days: 
MJO shall suppress the rainfall in Sri Lanka in the next 5 days and shall not have an impact in the following 10 days.

Ocean State (Text Courtesy IRI)

Pacific sea state: December 19, 2019

SSTs in the east-central Pacific were neutral, but near the borderline of weak El Niño levels during mid-December. Patterns in most atmospheric variables have maintained neutral conditions. Most model forecasts favor warm-neutral to borderline weak El Niño SST conditions during early winter, returning to ENSO-neutral from late winter to spring and even early summer. The official CPC/IRI outlook is consistent with these model forecasts.

Indian Ocean State
0.5 ⁰C above-average sea surface temperature was observed in the seas around Sri Lanka.