Highlights
• During 25 Sep - 1 Oct, high likelihood of Moderate rainfall (25-50 mm) is predicted for the Sabaragamuwa, North Western, Central, Uva, Southern and Western provinces and Light Showers (12.5 mm) is predicted for the Northern, Eastern and North Central provinces of SL
• On average, 0.7 mm/day was received in SL and rainfall was concentrated in the Western plains (2.3 mm/day) and hills (2.3 mm/day) for last 8 days. On average, 2.7 mm/day was received in the hydro catchments in SL; Lakshapana received the highest daily rainfall (27mm/day) for last 8 days. Highest daily rainfall was in Ratnapura on 24 Sep (14.7 mm/day).
• From 17 Sep - 23 Sep, winds at 850mb (1.5km) were north westerly, reaching up to 15 m/s. From 27 Sep - 3 Oct, winds are predicted to be southerly, reaching up to 5 m/s.
• Average land surface temperature was 31.5ºC in the last week with warmer anomalies from seasonal average of 1-3 ºC. Eastern plains was warmest followed by Northern, Southern and Western plains. Sea surface temperature around Sri Lanka was 1.0℃ above average from 3 – 9 Sep 2024.
Monitoring
Rainfall: During the last two weeks, there has been Moderate rainfall over the following area: Guruluwana (Ratnapura)Average Rainfall in the Met stations for the previous week of (19 – 25 Sep) = 0.7 mm/dayMaximum Daily Rainfall: 14.7 mm & Minimum Daily Rainfall: 0.0 mm.
Region
Average
rainfall for 11 – 18 Sep (mm/day)
Average
temperature for 11 – 18 Sep (ºC)
Maximum
Minimum
Northern plains
0.1
34.1
26.7
Eastern hills
0.0
31.1
18.6
Eastern plains
0.0
36.3
25.1
Western hills
2.3
27.4
19.4
Western plain
2.3
31.7
26.8
Southern plains
0.3
33.2
25.3
Region
Average
rainfall for 11 – 18 Sep (mm/day)
Daily
maximum rainfall for 11 – 18 Sep (mm)
Daily
minimum rainfall for 11 – 18 Sep (mm)
All SL
0.7
14.7
0.0
Hydro catchment
2.7
27.1
0.0
Wind: North Westerly winds prevailed in the sea area and around the island last week.Temperatures: The temperature anomalies were above normal for Sri Lanka except some parts of Northern and North Western provinces driven by the warm SSTs anomalies.
Rainfall: During the last two weeks, there has been Moderate rainfall over the following area: Guruluwana (Ratnapura)
Average Rainfall in the Met stations for the previous week of (19 – 25 Sep) = 0.7 mm/day
Maximum Daily Rainfall: 14.7 mm & Minimum Daily Rainfall: 0.0 mm.
|
Region |
Average
rainfall for 11 – 18 Sep (mm/day) |
Average
temperature for 11 – 18 Sep (ºC) |
|
|
Maximum |
Minimum |
||
|
Northern plains |
0.1 |
34.1 |
26.7 |
|
Eastern hills |
0.0 |
31.1 |
18.6 |
|
Eastern plains |
0.0 |
36.3 |
25.1 |
|
Western hills |
2.3 |
27.4 |
19.4 |
|
Western plain |
2.3 |
31.7 |
26.8 |
|
Southern plains |
0.3 |
33.2 |
25.3 |
|
Region |
Average
rainfall for 11 – 18 Sep (mm/day) |
Daily
maximum rainfall for 11 – 18 Sep (mm) |
Daily
minimum rainfall for 11 – 18 Sep (mm) |
|
All SL |
0.7 |
14.7 |
0.0 |
|
Hydro catchment |
2.7 |
27.1 |
0.0 |
Wind: North Westerly winds prevailed in the sea area and around the island last week.
Temperatures: The temperature anomalies were above normal for Sri Lanka except some parts of Northern and North Western provinces driven by the warm SSTs anomalies.
Predictions
Rainfall
14-day prediction:NOAA NCEP models:
From 25th September - 1st October:
Total rainfall by Provinces
- 45 mm - Southern, Western
- 35 mm - Sabaragamuwa, North Western
- 25 mm - Central, Uva
- ≤15 mm - Northern, Eastern, North Central
From 2nd October - 8th October:
Total rainfall by Provinces
- 35 mm - Southern, Western, Sabaragamuwa
- 25 mm - North Western
- ≤15 mm -Northern, Eastern, North Central, Central, Uva
MJO based OLR predictions:
For the next 15 days:
MJO shall slightly suppress the rainfall during 25 Sep – 9 Oct for Sri Lanka.
Ocean State (Text Courtesy IRI)
Pacific Sea Sate: September 24, 2024
ENSO-neutral conditions are present. Equatorial sea surface temperatures (SSTs) are near-to-below-average in the central and eastern Pacific Ocean. La Niña favored to emerge in September-November (71% chance) and is expected to persist through January-March 2025.
Indian Sea Sate
Sea surface temperature around Sri Lanka was 1.0℃ above average from 3 – 9 Sep 2024.
Interpretation
Monitoring
Rainfall: During the next week (25 Sep - 1 Oct), Moderate rainfall (25-50 mm) is predicted for the Sabaragamuwa, North Western, Central, Uva, Southern and Western provinces and Light Showers (12.5 mm) is predicted for the Northern, Eastern and North Central provinces.
Wind: The wind was flowing North Westerly and was quite high.
Predictions
Rainfall: During the next week (25 Sep - 1 Oct), Moderate rainfall (25-50 mm) is predicted for the Sabaragamuwa, North Western, Central, Uva, Southern and Western provinces and Light Showers (12.5 mm) is predicted for the Northern, Eastern and North Central provinces.
Temperature: The temperature will remain above normal for the Northern, Eastern, North Central and Uva provinces during 26 Sep – 2 Oct.
Teleconnections:MJO shall slightly suppress the rainfall during 25 Sep – 9 Oct for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the October-November-December, 2024 season shows a 40% or more tendency toward above-normal precipitation for the Eastern part of the country.
