Climate Bulletin For Sri Lanka (27 November 2020)

              Highlights                             

 • The NOAA weekly rainfall forecast predicts Between 26th Nov -2nd  Dec: high rainfall over the Eastern Province the drop in rainfall over the rest of the country.

 • Cyclonic circulation: emnants shall weaken as it going inland into Tamil Nadu in the next days.  The impacts on Sri Lanka were heavy rainfall and high wind in the Mullaitivu and Jaffna districts and the surrounding seas

 • Between 19th - 25th Nov: up to 90 mm in Jaffna, Mullaitivu and Vavuniya districts on 24th  Nov.

 • MJO shall slightly enhance the rainfall during 25^th – 29^th Nov and Significantly suppress during 30^th Nov - 9^th Dec over Sri Lanka.

 • From  18th - 24th Nov:up to 8 km/h  Northeasterly winds were experienced by the nothern of the island

 • 0.50C above-average sea surface temperature was observed in the seas around Sri Lanka which shall likely change as the La Nina sets in more fully.

Download full report ↓

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Monitoring

Rainfall

Weekly Monitoring:

Date	Daily Maximum Rainfall
19th November	Up to 30 mm in Galle, Matara, Ratnapura and Kalutara districts.
20th November	Up to 60 mm in Galle and Matara districts.
21st November	Up to 60 mm in Galle and Kalutara districts.
22nd November	Up to 70 mm in Trincomalee district.
23rd November	Up to 60 mm in Mullaitivu, Kilinochchi and Jaffna districts.
24th November	Up to 90 mm in Jaffna, Mullaitivu and Vavuniya districts.
25th November	Up to 70 mm in Jaffna district.

Total Rainfall for the Past Week: 

The RFE 2.0 tool shows total up to 200 – 300 mm in Jaffna and Mullaitivu districts; up to 150 – 200 mm in Kilinochchi, Mannar, Vavuniya, Anuradhapura, Trincomalee, Polonnaruwa and Batticaloa districts; up to 100 – 150 mm up to in Puttalam district; up to 75 – 100 mm in Kurunegala, Ampara, Moneragala, Matara, Galle, Matale and Kalutara districts; up to 50 -75 mm in Colombo, Gampaha, Hambantota, Ratnapura, Kegalle, Kandy and Badulla districts; up to 25 – 50 mm in Nuwara Eliya district.

Above rainfall average up to 100 – 200 mm in Jaffna, Mullaitivu and Trincomalee districts; up to 50 – 100 mm in Kilinochchi, Mannar, Vavuniya, Anuradhapura, Polonnaruwa, Batticaloa and Galle districts; up to 25 – 50 mm in Puttalam, Ampara, Moneragala and Matara districts;up to 10 – 25 mm Kurunegala, Hambantota and Kalutara districts;  Below rainfall average up to 50 – 100 mm in Gampaha, Kegalle and Nuwara Eliya districts; up to 25 – 50 mm in Colombo, Ratnapura, Badulla, Kandy and Matale districts.  

Monthly Monitoring: 

Overall, October had been drier than normal. However, as November is the wettest month in Sri Lanka, the rainfall was high. During October; Above average rainfall conditions up to 4 mm in Vavuniya, Anuradhapura, Badulla, Ampara and Moneragala districts; up to 2 mm in Mannar, Batticaloa, Ratnapura and Hambantota districts; Below average rainfall up to 8 mm in Galle, Kalutara and Colombo district; up to 6 mm in Matara, Gampaha, Kegalle, Nuwara Eliya, Kandy, Kurunegala, Puttalam, Jaffna districts; up to 4 mm in Kilinochchi, Mullaitivu, Polonnaruwa, Matale and Trincomalee districts. 

 Predictions

Rainfall

14-day prediction: 
NOAA NCEP models: 

From 26^th November – 2^nd December: Total rainfall up to 135 mm in Eastern province; up to 125 mm in Northern and North central provinces; up to 95 mm in North western province: up to 85 mm in Central, and Uva provinces; 75 mm in Western and Sabaragamuwa provinces and 55 mm in Southern province.

From 3^rd – 9^th December: Total rainfall up to 95 mm in Eastern province; up to 75 mm in Northern and North central provinces; up to 65 mm in Central, North western, Western, Sabaragamuwa and Uva provinces and up to 55 mm in Southern province.

IRI Model Forecast: 

From 24^th – 29^th September: Total rainfall up to 75 mm in Badulla district; up to 50 mm in Ampara, Moneragala, Ratnapura, Nuwara Eliya, Kandy, Matale, Polonnaruwa, Anuradhapura, Batticaloa, Trincomalee, Vavuniya, Mullaitivu, Kilinochchi and Jaffna districts; and up to 25 mm in Mannar, Puttalam, Kurunegala, Kegalle, Gampaha, Colombo, Kalutara, Galle, Matara and Hambantota districts. 

MJO based OLR predictions:

For the next 15 days: 

MJO shall slightly enhance the rainfall during 25^th – 29^th Nov and Significantly suppress during 30^th Nov - 9^th Dec over Sri Lanka.

Ocean State (Text Courtesy IRI)

Pacific sea state: November 18, 2020 

Equatorial Eastern Pacific SST reached La Niña threshold in mid-November, and the atmospheric variables were either ENSO-neutral or indicative of weak La Niña conditions. 

Indian Ocean State

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

Climate Bulletin For Sri Lanka (20 November 2020)

              Highlights                             

 • The NOAA weekly rainfall forecast predicts Between 18th-24th Nov: high rainfall over the Eastern Province the drop in rainfall over the rest of the country.

 • Cyclonic circulation has emerged in the Bay of Bengal and it is predicted to intensify and track several hundred to the North-East of Sri Lanka on the 25^th of November. 

 • Between 11th - 17th Nov: up to 200 mm in Puttalam and Kurunegala districts on 15th  Nov.

 • MJO shall severely enhance the rainfall during 17^th – 26^th Nov and slightly enhance during 27^th Nov - 1^st Dec over Sri Lanka.

 • From 10th - 16th Nov: up to 8 km/h  Easterly winds were experienced by the entire island.

 • 0.50C above-average sea surface temperature was observed in the seas around Sri Lanka which shall likely change as the La Nina sets in more fully.

Download full report ↓

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Monitoring

Rainfall

Weekly Monitoring:

Date	Daily Maximum Rainfall
11th November	Up to 50 mm in Colombo and Kalutara districts.
12th November	Up to 70 mm in Puttalam and Kurunegala districts.
13th November	Up to 180 mm in Kurunegala and Gampaha districts.
14th November	Up to 40 mm in Kandy, Ratnapura, Kalutara, Galle and Matara districts.
15th November	Up to 200 mm in Puttalam and Kurunegala districts.
16th November	Up to 40 mm in Mannar, Vavuniya, Polonnaruwa, Trincomalee, Batticaloa and Hambantota districts.
17th November	Up to 70 mm in Kurunegala district.

Total Rainfall for the Past Week: 

The RFE 2.0 tool shows total up to 200 – 300 mm in Gampaha, Kegalle, Kurunegala and Puttalam districts; up to 150 – 200 mm in Kalutara, Colombo and Ratnapura districts; up to 100 – 150 mm up to in Galle, Matara, Nuwara Eliya, Kandy, Matale and Anuradhapura districts; up to 75 – 100 mm in Polonnaruwa, Batticaloa, Moneragala and Mannar districts; up to 50 -75 mm in Hambantota, Badulla, Amapara, Trincomalee, Vavuniya, Mullaitivu, Kilinochchi and Jaffna districts.

Above rainfall average up to 200 – 300 mm in Kurunegala, Puttalam and Gampaha districts; up to 100 – 200 mm in Colombo, Kalutara, Kegalle and Ratnapura districts; up to 50 – 100 mm in Galle, Kandy, Matale, Nuwara Eliya, Anuradhapura and Mannar districts; up to 25 – 50 mm in Matara, Polonnaruwa and Vavuniya districts; up to 10 – 25 mm in Hambantota, Moneragala, Badulla, Batticaloa, Trincomalee, Mullaitivu and Kilinochchi districts; Below rainfall average up to 25 – 50 mm in Ampara, district. 

Monthly Monitoring: 

During October – Above average rainfall conditions up to 4 mm in Vavuniya, Anuradhapura, Badulla, Ampara and Moneragala districts; up to 2 mm in Mannar, Batticaloa, Ratnapura and Hambantota districts; Below average rainfall up to 8 mm in Galle, Kalutara and Colombo district; up to 6 mm in Matara, Gampaha, Kegalle, Nuwara Eliya, Kandy, Kurunegala, Puttalam, Jaffna districts; up to 4 mm in Kilinochchi, Mullaitivu, Polonnaruwa, Matale and Trincomalee districts. 

 Predictions

Rainfall

14-day prediction: 

NOAA NCEP models: 

From 18^th – 24^th November: Total rainfall up to 115 mm in East of the island; up to 105 mm rainfall in Northeast of the island; up to 85 mm rainfall in North, Central and Southeast of the island: up to 75 mm in Southwest of the island; 65 mm in Northwest and Southwest of the island and 55 mm in west of the island.

From 25^th November – 1^st December: Total rainfall up to 115 mm in Northeast of the island; up to 105 mm rainfall in East and North of the island; up to 85 mm in Northwest, Central and West of the island; up to 55 mm in South, Southwest and Southeast of the island.

IRI Model Forecast: 

From 24^th – 29^th September: Total rainfall up to 75 mm in Badulla district; up to 50 mm in Ampara, Moneragala, Ratnapura, Nuwara Eliya, Kandy, Matale, Polonnaruwa, Anuradhapura, Batticaloa, Trincomalee, Vavuniya, Mullaitivu, Kilinochchi and Jaffna districts; and up to 25 mm in Mannar, Puttalam, Kurunegala, Kegalle, Gampaha, Colombo, Kalutara, Galle, Matara and Hambantota districts. 

MJO based OLR predictions:

For the next 15 days: 

MJO shall severely enhance the rainfall during 17^th – 26^th Nov and slightly enhance during 27^th Nov - 1^st Dec over Sri Lanka.

Ocean State (Text Courtesy IRI)

Pacific sea state: November 11, 2020 

Equatorial Eastern Pacific SST reached La Niña threshold in mid-November, and the atmospheric variables were either ENSO-neutral or indicative of weak La Niña conditions. 

Indian Ocean State

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

Climate Bulletin For Sri Lanka (13 November 2020)

              Highlights                             

 •  The NOAA weekly rainfall forecast predicts Between 11th-17th Nov: very high rainfall over the Eastern and Southern Provinces the drop in rainfall over the rest of the country.

 •  Between 3rd - 9th Nov: up to 240 mm in Ratnapura and Moneragala districts on 9th  Nov.

 •  MJO shall slightly enhance the rainfall during 10^th – 14^th Nov and significantly enhance during 15^th - 24^th Nov over Sri Lanka.

 •  From  3rd - 9th Nov: up to 6 -8 km/h  northeasterly winds were experienced by the Northern of the island.

  •  0.50C above average sea surface temperature was observed in the seas around Sri Lanka which shall likely change as the La Nina sets in more fully.

Download full report ↓

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Monitoring

Rainfall

Weekly Monitoring:

Date	Daily Maximum Rainfall
3rd November	Up to 90 mm in Galle, Kalutara and Ratnapura districts.
4th November	Up to 90 mm in Anuradhapura district.
5th November	Up to 90 mm in Kegalle district.
6th November	Up to 40 mm in Puttalam and Kurunegala districts.
7th November	Up to 40 mm in Gampaha, Kalutara and Galle district.
8th November	Up to 140 mm in Gampaha district.
9th November	Up to 240 mm in Ratnapura and Moneragala districts.

Total Rainfall for the Past Week: 

The RFE 2.0 tool shows total up to 300 – 500 mm in Ratnapura and Moneragala districts; up to 200 – 300 mm in Badulla, Colombo, Kalutara, Gampaha and Matara districts; up to 150 – 200 mm in Kegalle, Galle, Nuwara Eliya, Hambantota, Mullaitivu, Vavuniya, Anuradhapura, Trincomalee districts; up to 100 – 150 mm in Kilinochchi, Puttalam, Kurunegala and Kandy districts; up to 75 – 100 mm in Matale, Mannar, Polonnaruwa and Jaffna districts; up to 50 – 75 mm in Batticaloa and Ampara districts.   

Above rainfall average up to 200 – 300 mm in Moneragala and Ratnapura districts; up to 100 – 200 mm in Hambantota, Badulla and Matara, Gampaha, Colombo, Kalutara, Mullaitivu, Vavuniya, Anuradhapura, and Trincomalee districts; up to 50 – 100 mm in Galle, Kegalle and Nuwara Eliya districts; up to 25 – 50 mm in Puttalam, Mannar, Kilinochchi and Jaffna districts; up to 10 – 25 mm in Kurunegala district; Below rainfall average up to 25 – 50 mm in Ampara, Batticaloa, Polonnaruwa, Matale and Kandy districts. 

Monthly Monitoring: 

During October – Above average rainfall conditions up to 4 mm in Vavuniya, Anuradhapura, Badulla, Ampara and Moneragala districts; up to 2 mm in Mannar, Batticaloa, Ratnapura and Hambantota districts; Below average rainfall up to 8 mm in Galle, Kalutara and Colombo district; up to 6 mm in Matara, Gampaha, Kegalle, Nuwara Eliya, Kandy, Kurunegala, Puttalam, Jaffna districts; up to 4 mm in Kilinochchi, Mullaitivu, Polonnaruwa, Matale and Trincomalee districts. 

 Predictions

Rainfall

14-day prediction: 

NOAA NCEP models: 

From 11^th – 17^th November: Total rainfall up to 140 mm in East, South and Southwest of the island; up to 125 mm rainfall in Southeast and Central of the island; up to 115 mm rainfall in West and Northeast of the island and up to 105 mm in North and Northwest of the island.

From 18^th – 24^th November: Total rainfall up to 140 mm in East of the island; up to 135 mm rainfall in Central and Southwest of the island; up to 125 mm in South, Southeast and Northeast of the island; up to 105 mm in Northern and Western of the islands and up to 95 mm in Northwest of the island.  

IRI Model Forecast: 

From 24^th – 29^th September: Total rainfall up to 75 mm in Badulla district; up to 50 mm in Ampara, Moneragala, Ratnapura, Nuwara Eliya, Kandy, Matale, Polonnaruwa, Anuradhapura, Batticaloa, Trincomalee, Vavuniya, Mullaitivu, Kilinochchi and Jaffna districts; and up to 25 mm in Mannar, Puttalam, Kurunegala, Kegalle, Gampaha, Colombo, Kalutara, Galle, Matara and Hambantota districts. 

MJO based OLR predictions:

For the next 15 days: 

MJO shall slightly enhance the rainfall during 10^th – 14^th Nov and significantly enhance during 15^th - 24^th Nov over Sri Lanka.

Ocean State (Text Courtesy IRI)

Pacific sea state: November 4, 2020 

Equatorial Eastern Pacific SST reached La Niña threshold in early-November, and the atmospheric variables were either ENSO-neutral or indicative of weak La Niña conditions. 

Indian Ocean State

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