Climate Bulletin For Sri Lanka (10 November 2023)

          

Highlights          

 • High probability of heavy rainfall (100 - 130 mm) is predicted for Sabaragamuwa, Uva, Northern provinces and fairly heavy rainfall is predicted for rest of the country during 10 - 16 November.

 • During the last week, average daily rainfall over Sri Lanka was 17.7 mm and hydro catchment was 22.4 mm. Extreme rainfall (≥ 150 mm/day) was in Ratnapura, Kurunegala and Anuradhapura. The rainfall of last week was twice as normal.

 • From 30 Oct - 5 Nov, up to 3 m/s of east-south easterly winds were at 850 mb (1.5 km). During 9 - 15 Nov, up to 5 m/s of north easterly winds are expected at 850 mb (1.5 km). 

 • Sea surface temperature around Sri Lanka was 1.0 - 2.0ºC above normal. From 1 - 8 Nov, maximum daily temperature was recorded in Ratnapura  (33.9ºC) and Maha Illuppallama  (33.1ºC).

Download full report ↓

---

Predictions

Rainfall

7-day prediction: 
NOAA NCEP models: 

From 10^th November - 16^th November:  

Total rainfall by Provinces

• 70 - 130 mm - Sabaragamuwa, Uva, Northern
•  ≤ 40 mm - Western, Eastern, Central, Southern, North Central, North Western

MJO based OLR predictions:

For the next 15 days: 

MJO shall slightly suppress the rainfall during 8^th - 17^th November and near neutral the rainfall during 18^th - 22^nd November for Sri Lanka.

Ocean State (Text Courtesy IRI)

Pacific Sea Sate: November 6, 2023 

El Nino Mode has set in according to NOAA since 8^th of June. Equatorial sea surface temperatures (SSTs) are above average across the central and eastern Pacific Ocean early-November. El Niño is anticipated to continue through the Northern Hemisphere spring (with an 80% chance during March-May 2024).

Indian Sea Sate

Sea surface temperature around Sri Lanka was 0.5 ℃ above normal to the Western and Southern half of the country in 17^th - 23^rd October, 2023. A positive Dipole Mode has set in across the Indian Ocean since 8^th of June.

Interpretation

Monitoring

Rainfall: During the last two weeks, there had been very heavy rainfall over the following areas:

Ratnapura, Kurunegala

Daily Average Rainfall in the Met stations for previous week of (1^st November - 8^th November) =

17.7 mm

Maximum Daily Rainfall: 146.9 mm & Minimum Daily Rainfall: 0.0 mm.

Region	Average rainfall for last 8 days (mm)	Average temperature for last 8 days (ºC)
		Maximum	Minimum
Northern plains	26.4	31.4	24.1
Eastern hills	11.9	25.9	18.4
Eastern plains	8.7	31.3	24.2
Western hills	19.6	28.3	19.2
Western plains	18.4	31.6	24.0
Southern plains	9.8	31.1	24.2

Region	Average rainfall for last 8 days (mm)	Daily maximum rainfall for last 8 days (mm)	Daily minimum rainfall for last 8 days (mm)
Hydro catchment	22.4	95.5	0.0

Wind: East-south easterly winds prevailed in the sea area and around the island last week.

Temperatures: The temperature anomalies were above normal for some parts of the Sabaragamuwa and Central provinces of the country driven by the warm SST’s.

Predictions

Rainfall: During the next week (10^th November - 16^th November), heavy rainfall is predicted for the Sabaragamuwa, Uva, and Northern provinces and fairly heavy rainfall is predicted for the rest of the country.

Temperatures: The temperature will remain seasonably near normal for the country during 9^th November - 15^th November.

Teleconnections: A positive Dipole Mode has set in across the Indian Ocean since 8^th of June. 

MJO shall slightly suppress the rainfall during 8^th - 17^th November and near neutral the rainfall during 18^th - 22^nd November for Sri Lanka.

Seasonal Precipitation: The precipitation forecast for the November-December-January, 2024 season shows a 40 - 45% tendency toward above normal precipitation.