Climate Bulletin for Sri Lanka ( 23 April 2020)

                                                      Highlights                             

•          The NOAA weekly rainfall forecast predicts up to 150 mm of total rainfall in Kandy, Nuwara Eliya and Badulla districts during 22 - 27 Apr.

•          Between 15 - 21 Apr: up to 140 mm of rainfalls were recorded in the Anuradhapura district on the 17^th.

•          From 14 - 20 Apr: up to 18 km/h, easterly winds were experienced by the entire island

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

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Monitoring

Rainfall

Weekly Monitoring:

Date	Rainfall
15th April	Up to 70 mm in Matale and Kandy districts; up to 50 mm in Kurunegala, Hambantota, Kegalle, Ratnapura, Kandy, Galle, Matara, Nuwara Eliya, Badulla and Monaragala districts; up to 30 mm in Polonnaruwa and Ampara districts; and up to 20 mm in Gampaha and Colombo districts.
16th   April	Up to 50 mm in Anuradhapura, Ratnapura and Matara districts; up to 30 mm in Kandy, Badulla, Monaragala, Kegalle, Hambantota and Galle districts; and up to 20 mm in Kurunegala, Matale, Kalutara, Colombo and Nuwara Eliya districts.
17th April	Up to 140 mm in Anuradhapura district; up to 70 mm in Matale and Kurunegala districts; up to 60 mm in Gampaha and Colombo districts; up to 50 mm in Ratnapura, Badulla, Monaragala, Galle and Kalutara districts; up to 30 mm in Polonnaruwa, Kegalle, Kandy and Nuwara Eliya districts; and up to 20 mm in Hambantota district.
18th April	Up to 120 mm in Kegalle and Colombo districts; up to 100 mm in Kurunegala and Ratnapura districts; up to 70 mm in Kandy and Kalutara districts; up to 60 mm in Gampaha and Nuwara Eliya district; up to 50 mm in Anuradhapura, Matale, Badulla, Matara and Galle districts; up to 30 mm in Ampara district; and up to 20 mm in Hambantota district.
19th April	Up to 70 mm in Kurunegala and Puttalam districts; up to 50 mm in Monaragala district; up to 30 mm in Kegalle and Ratnapura districts; and up to 20 mm in Anuradhapura, Matale, Kandy, Nuwara Eliya, Badulla, Kalutara and Galle districts.
20th April	Up to 60 mm in Kegalle, Kurunegala and Puttalam districts; up to 50 mm in Kandy and Ratnapura districts; up to 30 mm in Gampaha and Nuwara Eliya districts; and up to 20 mm in Kalutara, Badulla and Monaragala districts.
21st April	Up to 120 mm in Ratnapura district; up to 100 mm in Kandy and Monaragala districts; up to 70 mm in Mannar, Vavuniya, Anuradhapura, Kalutara, Galle and Badulla districts; up to 50 mm in Puttalam, Kurunegala, Kandy, Nuwara Eliya, Galle, Colombo, Matara and Hambantota districts; and up to 20 mm in Ampara district.

Total Rainfall for the Past Week: The RFE 2.0 tool shows total up to 150-200 mm in Ratnapura, Kegalle and Colombo districts; up to 100-150 mm in Kurunegala, Kandy, Anuradhapura, Puttalam, Gampaha, Kalutara, Galle, Matara and Monaragala districts; up to 75-100 mm in Matale district; and up to 50-75 mm in Mannar district. Above average rainfall up to 50-100 mm is shown for in Kurunegala, Puttalam, Kegalle, Colombo, Ratnapura, Badulla, Monaragala and western regions of Anuradhapura district; up and to 25-50 mm in Matale, Kandy, Galle and Matara districts. Below average rainfall up to 25-50 mm is shown for in Kilinochchi, Vavuniya, Mannar, Mullaitivu, Trincomalee, Gampaha and northern regions of Anuradhapura district; and up to 25-50 mm in Polonnaruwa, Batticaloa and Ampara districts.

Monthly Monitoring: During March – Below average rainfall conditions up to 240 mm were experienced by Anuradhapura, Kurunegala, Matale, Polonnaruwa, Ampara, Badulla, Monaragala, Kandy, Nuwara Eliya, Kegalle, Ratnapura, Colombo, Kalutara, Galle, Matara and Hambantota districts; and up to 150 mm in rest of the island. The CPC Unified Precipitation Analysis tool shows up to 100 mm of total rainfall in Kurunegala, Kegalle, Ratnapura, Nuwara Eliya, Kalutara, Galle and Matara districts; and up to 75 mm in Puttalam, Gampaha, Colombo, Badulla and Kandy districts.

 Predictions

Rainfall

14-day prediction: 

NOAA NCEP models: 

IMD NCMWRF Forecast:
From 22^nd – 28^th Apr: Total rainfall up to 55 mm in Ratnapura, Matara and Hambantota districts; up to 45 mm in Colombo, Gampaha, Puttalam, Kurunegala, Kegalle, Badulla and Monaragala districts; and up to 35 mm in Kandy, Nuwara Eliya and Ampara districts.

From 29^th Apr - 5^th May: Total rainfall up to 55 mm in Puttalam, Kurunegala, Gampaha, Colombo, Kegalle, Ratnapura, Matara and Hambantota districts; up to 45 mm in Kandy, Nuwara Eliya, Badulla and Monaragala districts; and up to 35 mm in Matale and Ampara districts.

IRI Model Forecast: 
From 22^nd – 27^th Apr: Total rainfall up to 150 mm in Kandy, Nuwara Eliya and Badulla districts; up to 100 mm in Ratnapura and Monaragala districts; up to 75 mm in Matale, Kurunegala, Kegalle, Polonnaruwa and Ampara districts; and up to 50 mm in Batticaloa, Anuradhapura, Colombo, and Hambantota districts.

MJO based OLR predictions:

For the next 15 days: 
MJO shall enhance the rainfall in Sri Lanka.

Ocean State (Text Courtesy IRI)

Pacific sea state: April 20, 2020 

SSTs in the east-central Pacific were near the borderline of weak El Niño during mid-April. However, patterns in atmospheric variables were mainly neutral. Most model forecasts favor warm-neutral SST conditions during the rest of spring, cooling to average by summer. The official CPC/IRI outlook is consistent with these model forecasts, calling for a continuation of ENSO-neutral through fall.

Indian Ocean State

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