Climate Bulletin For Sri Lanka (31 July 2020)

 

                        Highlights                             

•   The NOAA weekly rainfall forecast predicts up to 150 mm in Colombo, Galle, Kalutara, Matara, Ratnapura and Hambantota districts during 27th July -1st August. 

   •  Between 19th July - 25th  July: up to 50 mm of rainfall was recorded in Galle, Matara and Badulla district on 23rd July.

•   From 22 th- 28th July: up to 10 km/h, northwesterly winds were experienced by the entire island

•   1 0C above average sea surface temperature was observed in the seas around Sri Lanka.

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Monitoring

Rainfall

Weekly Monitoring:

Date	Rainfall
19th July	Up to 40 mm in Badulla, Puttalam, Gampaha and Kurunegala districts; up to 30 mm in Ampara, and Hambantota districts; and up to 20 mm in Colombo, Kegalle, Katutara, Ratnapura, Monaragala, Matale, Kandy and Polonnaruwa districts; up to 15 mm in Galle, Mannar and Anuradhapura districts; up to 10 mm in Matara, Nuwara Eliya, Vavuniya, Mullaitivu and Kilinochchi districts.
20th July	Up to 40 mm in Jaffna district; up to 30 mm in Kilinochchi district; up to 15 mm in Kalutara, Galle, Matara, and Hambantota districts; and up to 10 mm in Mannar, Kilinochchi, Vavuniya, Puttalam, Gampaha, Colombo, Ratnapura, Nuwara Eliya, Badulla, Monaragala and Ampara districts.
21st July	Up to 2.5 mm in Monaragala, Batticaloa and Ampara Districts.
22nd July	Up to 10 mm in Gampaha, Puttalam, Kurunegala, Kegalle, Kandy, Matale, Nuwara Eliya, Polonnaruwa, Badulla, Ampara and Batticoloa districts.
23rd July	Up to 50 mm in Galle, Matara and Badulla districts; up to 40 mm in Monaragala district; up to 30 mm in Nuwara Eliya, Kandy, Colombo, Kalutara and Hambantota districts; up to 20 mm in Gampaha, Ratnapura and Ampara districts; and up to 15 mm in Trrincomalee district; and up to 10 mm in Kurunegala, Matale, Polonnaruwa, Anuradhapura and Kegalle districts.
24th July	Up to 30 mm in Ampara and Batticaloa districts; and up to 20 mm in Monaragala district.
25th July	Up to 15 mm in Mannar district; and up to 10 mm in Colombo, Gampaha, Katutara, Ratnapura, Galle, and Vavuniya districts.

Total Rainfall for the Past Week: 

The RFE 2.0 tool shows total up to 50– 75 mm in Monaragala, Badulla, Ampara, Mannar, Jaffna and Batticaloa districts; up to 25 – 50 mm in Kilinochchi, Mullaitivu, Puttalam, Vavuniya, Trincomalee, Anuradhapura, Polonnaruwa, Kurunegala, Matale,  Ratnapura, Colombo, Gampaha, Kalutara, Kandy, Matale, Nuwara Eliya, Galle, Matara and Hambantota districts.

Above rainfall average up to 50-100 mm in Ampara, Badulla, Jaffna, Kilinochchi, Mannar and Monaragala districts; up to 25 – 50 mm in Mullaitivu, Vavuniya, Trincomalee, Batticaloa, Anuradhapura, Polonnaruwa, Kurunegala, Matale, Kandy, Nuwara Eliya, Ratnapura, Galle, Matara and Hambantota districts; and up to 10-25 mm in Colombo, Gampaha, Kalutara, Puttalam and Kegalle districts.

 

Monthly Monitoring: 

During June – Above average rainfall conditions up to 6 mm were experienced by Vavuniya and Anuradhapura districts; up to 4 mm in Mannar, Kurunegala, Polonnaruwa, Trincomalee, Kegalle, Kandy, Badulla, Ampara, Batticaloa, Monaragala and Hambantota districts and below average rainfall conditions upto 2 mm were experienced by Galle, Matara and Ratnapura districts.

 Predictions

Rainfall

14-day prediction: 

NOAA NCEP models: 

From 30^th July – 5^th August: Total rainfall up to 45 mm in Kalutara, Colombo, Galle, Matara, Ratnpura and Hambantota districts; up to 35 mm in Gampaha, Kegalle, Badulla, Nuwara Eliya, and Monaragala districts; up to 25 mm in Kandy, Matale, Kurunegala, Puttalam, Polonnaruwa, Anuradhapura and Ampara districts; and up to 15 mm in Mannara and Vavuniya districts. 

From 6^th August – 12^th August: Total rainfall up to 55 mm in Kalutara, Kegalle, Ratnapura, Galle and Matara, districts; up to 45 mm in Colombo, Gampaha, Kandy, Hambantota, Badulla, Nuwara Eliya, and Monaragala districts; up to 35 mm in Matale, Kurunegala, Puttalam, Trincomalee and Anuradhapura districts; and up to 25 mm in Mannar, Batticaloa , Mullaitivu, Polonnaruwa, Ampara and Vavuniya districts. 

IRI Model Forecast: 

From 27^th July – 1^st August: Total rainfall up to 150 mm in Gampaha, Colombo, Kalutara, Galle, Matara, Ratnapura and Kegalle districts; up to 100 mm in Puttalam, Kurunegala, Kandy and Nuwara Eliya; up to 75 mm in Hambantota and up to 50 mm in Anuradhapura , Polonnaruwa, Matale, Badulla, Monaragala, Ampara, Batticaloa, Trincomalee, Vavuniya, Mullaitivu, Kilinochchi and Jaffna districts.

MJO based OLR predictions:

For the next 15 days: 

MJO shall enhance rainfall during 29^th July - 2^nd August and shall remain neutral during 3^rd – 12^th August.

Ocean State (Text Courtesy IRI)

Pacific sea state: June 24, 2020 

SSTs in the east-central Pacific decreased to near the La Niña threshold in early June, and the atmospheric variables were either ENSO-neutral or indicative of weak La Niña conditions. The average of the forecasts of many models just short of the borderline of weak La Niña SST conditions through fall, becoming slightly weaker beginning in early winter. The official CPC/IRI outlook is somewhat similar to these model forecasts, calling for a likely continuation of ENSO-neutral in summer, with approximately equal chances of ENSO-neutral or La Niña for fall and winter. 

Indian Ocean State

1 ⁰C above average sea surface temperature was observed in the seas around Sri Lanka.