Climate Bulletin for Sri Lanka ( 24 October 2019)

                                                      Highlights                                

·    The NOAA weekly rainfall forecast predicts up to 200 mm of total rainfall in Jaffna district during 23 – 28 Oct.

·    Between 16 – 22 Oct: up to 140 mm of daily rainfall was recorded in Kilinochchi district on the 22nd.

·    From 15 – 21 Oct: up to 5 km/h, southeasterly 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
16th October	Up to 70 mm in Mullaitivu and Vavuniya districts; up to 60 mm in Mannar and Anuradhapura districts; up to 50 mm in Trincomalee, Puttalam, Kurunegala, Matale, Kandy and Badulla districts; up to 30 mm in Kilinochchi, Polonnaruwa, Ampara and Ratnapura districts; and up to 20 mm in Jaffna, Batticaloa, Gampaha, Colombo, Kalutara, Galle, Matara, Hambantota, Nuwara Eliya and Monaragala districts.
17th October	Up to 50 mm in Mannar, Vavuniya, Anuradhapura, Puttalam, Kurunegala, Matale, Polonnaruwa and Badulla districts; up to 30 mm in Jaffna, Mullaitivu, Kandy, Nuwara Eliya and Ratnpura districts; and up to 20 mm in Kilinochchi, Trincomalee, Kegalle, Kalutara. Gampaha, Matara, Hambantota and Monaragala districts.
18th   October	Up to 50 mm in Gampaha and Kegalle districts; up to 30 mm in Puttalam, Kurunegala, Colombo, Kalutara and Ratnapura districts; and up to 20 mm in Matale, Kandy, Nuwara Eliya and Badulla districts.
19th October	Up to 60 mm in Colombo and Galle districts; up to 50 mm in Puttalam, Kurunegala, Anuradhapura, Ratnapura, Kalutara and Matara districts; up to 30 mm in Matale, Kegalle, Monaragala and Hambantota districts; and up to 20 mm Vavuniya, Jaffna, Kilinochchi, Polonnaruwa, Ampara, Kandy, Nuwara Eliya, Badulla and Ampara districts.
20th October	Up to 60 mm in Puttalam, Kurunegala and Gampaha districts; up to 50 mm in Jaffna, Anuradhapura, Matale, Kegalle, Colombo and Ratnpura districts; up to 30 mm in Kilinochchi, Mullaitivu, Vavuniya, Mannar, Batticaloa, Kandy, Nuwara Eliya, Galle and Matara districts; and up to 20 mm Trincomalee, Polonnaruwa, Ampara, Badulla, Monaragala and Hambantota districts.
21st October	Up to 120 mm in Batticaloa and Ampara districts; up to 70 mm in Monaragala, Galle and Ratnapura districts; up to 60 mm in Mannar, Kalutara and Polonnaruwa districts; up to 50 mm in Puttalam, Kurunegala, Gampaha, Kegalle, Kandy, Nuwara Eliya, Badulla and Matara districts; up to 30 mm in Jaffna, Kilinochchi, Mullaitivu, Vavuniya, Anuradhapura, Trincomalee, Matale and Hambantota districts; and up to 20 mm in rest of the island.
22nd October	Up to 140 mm in Kilinochchi district; up to 120 mm in Mannar district; up to 60 mm in Mullaitivu district; up to 50 mm in Jaffna, Vavuniya and Ratnapura districts; up to 30 mm in Puttalam and Anuradhapura districts; and up to 20 mm in Trincomalee, Kurunegala, Nuwara Eliya, Galle and Matara districts.

Total Rainfall for the Past Week: The RFE 2.0 tool shows total up to 150-200 mm in Puttalam, Kurunegala, Anuradhapura, Gampaha, Colombo, Kalutara. Kegalle and Ratnapura districts; up to 100-150 mm in Galle, Matara, Nuwara Eliya, Kandy, Polonnaruwa, Ampara, Badulla and Monaragala districts; and up to 50-75 mm in rest of the island. Above-average rainfall up to 100-200 mm is shown for Ampara district; up to 50-100 mm in Puttalam, Kurunegala, Anuradhapura. Matale, Gampaha, Colombo, Kalutara, Kegalle, Ratnapura, Monaragala, Badulla and Batticaloa districts; and up to 25-50 mm in most parts of the island.

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 23^rd – 29^th Oct: Total rainfall more than 135 mm in Jaffna, Kilinochchi, Mullaitivu, Mannar, Vavuniya, Anuradhapura, Polonnaruwa, Batticaloa. Puttalam and Kurunegala districts; up to 115-125 mm in Gampaha, Colombo, Matale, Kegalle, and Ratnapura districts; and up to 95-105 mm in Ampara, Kandy, Galle and Matara districts.
From 30^th Oct – 5^th Nov: Total rainfall more than 135 mm in Puttalam, Kurunegala, Gampaha, Colombo, Mannar, Kilinochchi and Jaffna districts; up to 125-135 mm Vavuniya, Anuradhapura, Matale, Kandy, Kegalle, Ratnapura, Galle and Matara districts; and up to 105-115 mm in Trincomalee and Polonnaruwa districts.

IMD NCMWRF Forecast:

IRI Model Forecast: 
From 23^rd – 28^th Oct: Total rainfall up to 200 mm is expected in Jaffna district; up to 150 mm in Kilinochchi, Mannar, Mullaitivu, Vavuniya, and Trincomalee districts; up to 100 mm in Puttalam, Anuradhapura, Batticaloa. Ampara, Monaragala and Hambantota 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 in the next 10 days and shall suppress in the following 5 days.

Ocean State (Text Courtesy IRI)

Pacific sea state: October 18, 2019
SSTs in the east-central Pacific maintained ENSO-neutral levels during September and early October, despite some warming in October. Patterns in some atmospheric variables show weak El Niño conditions, but this is attributed to intraseasonal variability and the collective assessment is for ENSO-neutral conditions. Model forecasts generally favor ENSO-neutral through autumn, winter, and spring, with slightly higher chances for El Niño than La Niña. The official CPC/IRI outlook is consistent with these model forecasts. 

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