Climate Bulletin for Sri Lanka ( 17 October 2019)

                                                      Highlights                                

·  The NOAA weekly rainfall forecast predicts up to 100 mm of total rainfall in central regions during 16 – 21 Oct.

· Between 9 – 14 Oct: up to 140 mm of daily rainfalls were recorded in Ratnapura and Kurunegala districts on the 11th and 13th respectively.

·  From 8 – 14 Oct: up to 5 km/h, easterly 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
9th October	Up to 70 mm in Mannar and Vavuniya districts; up to 60 mm in Mullaitivu and Kurunegala districts; up to 50 mm in Anuradhapura, Matale and Badulla districts; up to 30 mm in Trincomalee, Kandy, and Monaragala districts; and up to 20 mm in Kilinochchi, Puttalam, Kegalle, Nuwara Eliya, Ratnapura and Ampara districts.
10th October	Up to 30 mm in Polonnaruwa district; and up to 20 mm in Anuradhapura and Matale districts.
11th October	Up to 140 mm in Ratnapura district; up to 60 mm in Nuwara Eliya and Badulla districts; up to 50 mm in Kilinochchi, Kegalle, Colombo, Kalutara and Monaragala districts; up to 30 mm in Jaffna, Mullaitivu, Mannar, Puttalam, Gampaha and Galle districts; and up to 20 mm in Anuradhapura, Kurunegala and Matara districts.
12th October	Up to 50 mm in Badulla district; up to 30 mm in Nuwara Eliya, Ratnapura and Monaragala districts; and up to 20 mm in Anuradhapura, Trincomalee, Kegalle, Gampaha, Colombo and Kalutara districts.
13th October	Up to 140 mm in Kurunegala district; up to 70 mm in Kandy district; up to 60 mm in Puttalam district; up to 50 mm in Anuradhapura, Matale, Monaragala, Badulla, Ratnapura, Kegalle, Gampaha, Colombo and Kalutara districts; up to 30 mm in Trincomalee, district;  and up to 20 mm Mannar, Polonnaruwa, Ampara, Galle, Matara and Hambantota districts.
14th October	Up to 30 mm in Ratnapura, Matara and Hambantota districts; and up to 20 mm in Kalutara, Galle, Monaragala and Ampara districts.

Total Rainfall for the Past Week: The RFE 2.0 tool shows total up to 100-150 mm in Kurunegala, Anuradhapura, Nuwara Eliya, Ratnapura, Badulla and Monaragala districts; up to 75-100 mm in Vavuniya, Puttalam, Gampaha, Colombo, Kalutara, Galle, Kegalle and Kandy districts; up to 50-75 mm in Kilinochchi, Matale, Matara, and Hambantota districts; and 25-50 mm in most parts of the island. Above-average rainfall up to 50-100 mm is shown for Kurunegala, Vavuniya, Colombo, Ratnapura, Nuwara Eliya, Badulla, Monaragala and western regions of Anuradhapura district; up to 25-50 mm in Gampaha, Colombo, Kalutara and Kandy districts; and up to 10-25 mm in Kilinochchi and Mannar districts. Below-average rainfall up to 50-100 mm is shown for Polonnaruwa district; and up to 25-50 mm in Trincomalee, Batticaloa, Ampara and eastern regions of Anuradhapura district

Monthly Monitoring: During September – Above average rainfall conditions up to 450 mm were experienced by Gampaha district; up to 360 mm in Puttalam, Colombo, Kalutara, Galle, Matara, Hambantota, Monaragala and Ratnapura districts; up to 240 mm in Kurunegala, Kegalle, Jaffna, Kilinochchi, Vavuniya, Anuradhapura, Trincomalee, Polonnaruwa, Batticaloa, Badulla, Ampara, Kandy and Nuwara Eliya districts; and up to 120 mm in rest of the island. The CPC Unified Precipitation Analysis tool shows up to 750 mm of total rainfall in Gampaha, Colombo, Kalutara, and Galle districts; up to 500 mm in Kurunegala, Puttalam, Kegalle, Ratnapura, Matara, Hambantota and Monaragala districts; up to 300 mm in Nuwara Eliya and Badulla districts; and up to 200 mm in Kandy, Matale, Ampara and Batticaloa districts.

Predictions

Rainfall

14-day prediction: 

NOAA NCEP models: 

• From 16^th – 22^nd Oct: Total rainfall more than 135 mm in Puttalam, Kurunegala, Gampaha, Colombo, Kegalle, and Ratnapura districts; up to 115-25 mm in Galle and Matara districts; up to 95-105 mm in Mannar, Anuradhapura, Matale, Kandy and Nuwara Eliya districts; and up to 85-95 mm in most parts of the island.
• From 23^rd – 29^th Oct: Total rainfall more than 135 mm in Puttalam, Kurunegala, Gampaha and Ratnapura districts; up to 115-125 mm in Jaffna, Mannar, Galle, and Matara districts; up to 105-115 mm in Kilinochchi, Vavuniya, Anuradhapura, Matale, Kandy and Hambantota districts; and up to 85-95 mm most parts of the island.

IMD NCMWRF Forecast:

16^th   of  Oct: Not Available

17^th  of  Oct: Not Available 

IRI Model Forecast: 

From 16^th – 21^st Oct: Total rainfall up to 150 mm is expected in Polonnaruwa, Matale, Kandy, Nuwara Eliya, Badulla, Monaragala and Ampara districts; up to 100 mm in Trincomalee, Anuradhapura, Kuruegala, Kegalle, Gampaha, Colombo, Ratnapura and Batticaloa districts; and up to 75 mm in rest of the island.

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: October 10, 2019

SSTs in the east-central Pacific maintained ENSO-neutral levels during September and early October, despite some warming in October. Patterns in most of the key atmospheric variables are also showing ENSO-neutral conditions. Model forecasts generally favor ENSO-neutral through autumn, winter and into spring, with slightly higher chances for El Niño than La Niña. The official CPC/IRI outlook is consistent with these model forecasts.