Climate Bulletin For Sri Lanka (24 December 2020)

                        Highlights                             

•   The NOAA weekly rainfall forecast predicts; Dangerously heavy rainfall of 140 mm expected  in Jaffna district and Heavy rainfall in Northern & Eastern Provinces during 30th Dec – 5th Jan.

  •   Extremely high rainfall was experienced in Eastern province. Up to 214 mm max rainfall in Batticaloa on 21st Dec.

•  From 15th - 21st Dec: up to 8 km/h Northeasterly winds were experienced on the entire island.

•  Sea surface temperature was observed above 0.5 0C to the West of Sri Lanka and neutral to the East

Download full report ↓

---

Monitoring

Rainfall

Weekly Monitoring: 

Date	Rainfall
15th December	Up to 80 mm in Jaffna district.
16th December	Up to 40 mm in Kegalle district.
17th December	Up to 50 mm in Anuradhapura, Vavuniya, Kegalle, Nuwara Eliya and Ratnapura districts.
18th December	Up to 50 mm in Jaffna, Kilinochchi, Mullaitivu, Vavuniya, Trincomalee, Anuradhapura, Kegalle, Ratnapura, Galle and Matara districts.
19th December	Up to 90 mm in Polonnaruwa district.
20th December	Up to 70 mm in Batticaloa district.
21st December	Up to 214 mm in Batticaloa district.

Total Rainfall for the Past Week: 

The RFE 2.0 tool shows Cumulative rainfall by Districts:

• 200 – 300 mm - Trincomalee, Polonnaruwa, Batticaloa, Matale
• 150 – 200 mm - Anuradhapura, Kandy, Nuwara Eliya, Kegalle, Badulla, Moneragala, Ampara
• 100 - 150 mm - Kurunegala, Gampaha, Vavuniya, Mannar, Mullaitivu, Kilinochchi 
• 75 – 100 mm - Hambantota, Ratnapura, Kalutara, Colombo, Galle, Puttalam, Jaffna
• 50 - 75 mm    - Matara 

Total rainfall Anomalies by Districts

Rainfall Excess

• 100 – 200 mm - Trincomalee, Polonnaruwa, Batticaloa, Matale, Kandy, Nuwara Eliya, Kegalle, Badulla, Ampara
• 50 – 100 mm   - Vavuniya, Mannar, Mullaitivu, Kilinochchi, Kurunegala, Gampaha, Ratnapura, Moneragala
• 25 - 50 mm     - Colombo, Gampaha, Kalutara, Galle, Puttalam, Jaffna
• 10 – 25 mm    - Hambantota

Monthly Monitoring: 

In the first 10 days in December 2020, there was heavy rainfall was observed in Northern and Western provinces, probably due to cyclone storm “BUREVI”

During December; Dekadal Rainfall by Districts: 

• 18 mm-Jaffna, Kilinochchi, Mullaitivu, Mannar, Trincomalee
• 16 mm- Gampaha, Colombo, Kegalle, Vavuniya, Anuradhapura, Puttalam
• 10 mm- Polonnaruwa, Kurunegala, Batticaloa, Badulla, Moneragala
• 8 mm  - Ratnapura, Matale, Kandy, Nuwara Eliya, Kalutara, Ampara
• 5 mm  - Galle, Matara, Hambantota 

 Predictions

Rainfall

14-day prediction: 

NOAA NCEP models: 

From 23^rd – 29^th December:

Total rainfall by Provinces: 

140 mm -Northern

55 mm  - Eastern

35 mm  - North-central

25 mm  - Central

15 mm  - North-western, Western, Southern, Sabaragamuwa, Uva 

From 30^th December – 5^thJanuary:

Total rainfall by Provinces:

140 mm - Northern

105 mm - Eastern

95 mm   -  North-central

65 mm   - Central, North-western

55 mm   - Western, Southern, Sabaragamuwa, Uva 

MJO based OLR predictions:

For the next 15 days: 

MJO shall slightly suppress the rainfall during 22^nd – 26^th Dec, neutral during 27^th – 31^st Dec and slightly enhance the rainfall during 1^st – 5^th Jan

Ocean State (Text Courtesy IRI)

Pacific sea state: December 16, 2020 

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

Indian Ocean State

The SST in the Indian Ocean is still warmer by 0.5 degrees than is seasonable to the West of Sri Lanka but near seasonable on the Eastern.