Climate Bulletin for Sri Lanka ( 31 October 2019)

                                                      Highlights                                

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

• Between 23 – 28 Oct: up to 100 mm of rainfall was recorded in Batticaloa district on the 28^th.

• From 22 – 28 Oct: up to 18 km/h, southeasterly winds were experienced by the entire island

• 0.5 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
23rd October	Up to 70 mm in Jaffna district; up to 50 mm in Kilinochchi, Mullaitivu, Puttalam, Gampaha, Colombo, Kalutara, Batticaloa, Galle, Matara and Hambantota districts; up to 30 mm in Mannar, Vavuniya, Kurunegala, Kegalle, Kandy, Ratnapura, Badulla, Monaragala, Ampara and Polonnaruwa districts; and up to 20 mm in rest of the island.
24th October	Up to 60 mm in Galle district; up to 50 mm in Ratnapura district; up to 30 mm in Kalutara, Matara, Hambantota, Nuwara Eliya, Monaragala and Ampara districts; and up to 20 mm in Kurunegala, Matale, Ampara, Kandy, Badulla, Kegalle, Gampaha and Colombo districts.
25th   October	Up to 30 mm in Mullaitivu district; and up to 20 mm in Jaffna, Kilinochchi, Anuradhapura and Trincomalee districts.
26th October	Up to 70 mm in Batticaloa and Ampara districts; up to 50 mm in Polonnaruwa and Monaragala districts; up to 30 mm in Badulla district; and up to 20 mm Trincomalee, Matale and Kandy districts.
27th October	Up to 70 mm in Trincomalee, Batticaloa, Ampara, Badulla and Monaragala districts; up to 60 mm in Mullaitivu, Vavuniya, Anuradhapura, Polonnaruwa, Nuwara Eliya and Hambantota districts; up to 50 mm in Jaffna, Kilinochchi, Mannar, Puttalam, Kuruegala, Matale, Kandy, Ratnapura and Matara districts; up to 30 mm in Kegalle, Colombo, Kalutara and Galle districts; and up to 20 mm Gampaha district.
28th October	Up to 100 mm in Batticaloa district; up to 70 mm in Polonnaruwa, Trincomalee, Ampara, Monaragala, Hambantota and Galle districts; up to 60 mm in Anuradhapura, Ratnapura and Matara districts; up to 50 mm in Mullaitivu, Badulla and Kalutara districts; up to 30 mm in Jaffna, Kilinochchi, Vavuniya, Matale, Kandy and Nuwara Eliya districts; and up to 20 mm in rest of the island.

Total Rainfall for the Past Week: The RFE 2.0 tool shows total up to 150-200 mm in Trincomalee, Polonnaruwa, Ampara, Monaragala, Badulla, Hambantota and Matara districts; up to 100-150 mm in Kilinochchi, Vavuniya, Mannar, Mullaitivu, Anuradhapura, Matale, Kandy, Nuwara Eliya, Ratnapura, Kalutara and Galle districts; and up to 75-100 mm in Kurunegala and Kegalle. Above-average rainfall up to 100-200 mm is shown for Batticaloa, Ampara, Hambantota and Monaragala district; up to 50-100 mm in Jaffna, Kilinochchi, Mullaitivu, Trincomalee, Polonnaruwa, Badulla, Nuwara Eliya, Ratnapura, Matara and Galle districts; and up to 25-50 mm in Kalutara, Kandy, Matale, Mannar and eastern regions of Anuradhapura district. Below average rainfall up to 25-50 mm is shown for Gampaha, Kurunegala, Puttalam and western regions of Anuradhapura district; and up to 10-25 mm in Colombo and Kegalle districts.

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: 

IMD NCMWRF Forecast:
From 30^th Oct – 5^th Nov: Total rainfall more than 115 mm in Puttalam and Kurunegala districts; up to 85-95 mm in Mannar, Kilinochchi, Gampaha, Kegalle, Matale and Ratnapura districts; and up to 75-85 mm in Jaffna, Vavuniya, Anuradhapura, Kandy, Colombo and Kalutara districts.
From 6^th – 12^th Nov: Total rainfall more than 105 mm in Ratnapura, Galle, and Matara districts; up to 85-95 mm Gampaha, Kegalle, Puttalam and Kurunegala districts; and up to 65-75 mm in Matale, Kandy, Badulla and Monaragala districts.

IRI Model Forecast: 
From 30^th Oct – 4^th Nov: Total rainfall up to 150 mm is expected in Badulla district; up to 100 mm in Matale, Kandy, Nuwara Eliya, Ratnapura, and Monaragala districts; up to 75 mm in Polonnaruwa, Kurunegala, Kegalle, Hambantota, Ampara, Batticaloa and Jaffna districts; and up to 50 mm in rest of the island.

MJO based OLR predictions:

For the next 15 days: 

MJO shall not have an impact on the rainfall in Sri Lanka in the next 5 days and shall suppress in the following 10 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.