Climate Bulletin For Sri Lanka (28 August 2020)

 

                        Highlights                             

•   The NOAA weekly rainfall forecast predicts up to 75 mm Monaragala, Ampara, Kandy, Nuwara Eliya and Badulla district during 27th August -1st
 September. 

•   Between 20th - 26th August: up to 50 mm of rainfall was recorded in Moneragala district on 26th August.

•   From 19th - 25th August: up to 8 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
20th August	Up to 10 mm in Jaffna district.
21st August	Up to 2.5 mm in Moneragala district.
22nd August	Up to 5 mm in Badulla, Colombo, Gampaha, Kaluthara, Kegalle, Kurunegala, Matale, Moneragala, Nuwara Eliya and Ratnapura districts.
23rd August	up to 30 mm in Matale and Polonnaruwa districts; up to 20 mm in Ampara, Badulla and Monaragala districts; up to 15 mm in Kandy districts; up to 10 mm in Kurunegala and Kegalle districts; and up to 5 mm in Gampaha, Puttalam and Batticaloa districts.
24th August	Up to 20 mm in Badulla district; up to 15 mm in Nuwara Eliya, Kandy and Ampara districts; and up to 5 mm in Kegalle, Monaragala, Gampaha, Matale and Polonnaruwa districts.
25th August	Up to 40 mm in Monaragala and Badulla districts; up to 30 mm in Batticaloa and Kandy districts; up to 20 mm in Matale district; up to 15 mm in Polonnaruwa district; and up to 10 mm in Nuwara Eliya and Ratnapura districts.
26th August	Up to 50 mm in Ampara and Monaragala districts; up to 40 mm in Badulla and Anuradhapura districts; up to 30 mm in Vavuniya and Kandy districts; up to 20 mm in Matale and Batticaloa districts; up to 15 mm in Kurunegala, Polonnaruwa and Nuwara Eliya districts; and up to 10 mm in Gampaha, Colombo, Kegalle, Ratnapura and Trincomalee districts.

Total Rainfall for the Past Week: 

The RFE 2.0 tool shows total up to 75 mm in Ampara and Badulla districts; up to 50 mm in Kandy, Nuwara Eliya, Monaragala and Matale districts; and up to 25 mm in Gampaha, Colombo, Kegalle, Kurunegala, Ratnapura, Vavuniya, Anuradhapura, and Polonnaruwa districts; and up to 10 mm in Puttalam, Kalutara, Batticaloa and Trincomalee districts.

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

 

Monthly Monitoring: 

During July – Above average rainfall conditions up to 8 mm were experienced by Anuradhapura, Matale, Polonnaruwa and Vavuniya districts; up to 6 mm in Ampara, Badulla, Hambantota, Jaffna, Kandy, Kilinochchi, Kurunegala, Mannar, Moneragala, Mullaitivu, Nuwara Eliya, Puttalam, Ratnapura, and Trincomalee districts; and up to 4 mm in Batticaloa, Colombo, Galle, Gampaha, Kalutara, Kegalle, and Matara districts.

 Predictions

Rainfall

14-day prediction: 

NOAA NCEP models: 

From 27^th August – 2^nd September: Total rainfall up to 75 mm in Galle, Kalutara and Matara districts; up to 65 mm in Ratnapura and Monaragala districts; up to 55 mm in Gampaha, Colombo, Kegalle, Kandy, Nuwara Eliya, Monaragala and Badulla districts; and up to 45 mm in Kurunegala, Matale and Hambantota districsts; up to 35 mm in Puttalam, Matale and Ampara districts; up to 25 mm in Polonnaruwa and Batticaloa districts; and up to 15 mm in Anuradhapura district.

From 03^rd September – 09^th September: Total rainfall up to 125 mm in Galle, district; up to 115 mm in Kalutara and Matara districts; up to 105 mm in Ratnapura and Hambantota districts; up to 95 mm in Kegalle, Nuwara Eliya and Badulla districts; up to 85 mm in Gampaha, Kandy and Monaragala  districts; up to 75 mm in Ampara and Kegalle districts; and up to 65 mm in Kurunegala and Matale districts; up to 55 mm in Puttalam district; up to 45 mm in Polonnaruwa and Batticaloa districts; up to 35 mm in Jaffna district; up to 25 mm in  Anuradhapura district and up to 15 mm in Kilinochchi, Mannar, Mullaitivu and Vavuniya districts.

IRI Model Forecast: 

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

MJO based OLR predictions:

For the next 15 days: 

MJO shall slightly enhance rainfall during 26^th -30^th August and significantly enhance rainfall during 31^st August – 9^th September. 

Ocean State (Text Courtesy IRI)

Pacific sea state: August 19, 2020 

SSTs in the east-central and central Pacific decreased to near the La Niña threshold in mid-august, 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.