Highlights
• Heavy rainfall (≥ 105 mm) is predicted for
the Southern, Sabaragamuwa, Western, Uva, Central, North Western provinces during 26 Oct - 1 Nov. Heavy rainfall (≥ 125 mm) is predicted for
the country during 2 - 8 Nov.
• During
the last week, average daily rainfall over Sri Lanka was 13.5 mm and hydro
catchment was 15.7 mm. Heavy rainfall (> 100 mm) is predicted for
Southern and Western regions during next week and following week.
• From 17 - 23 Oct, up to 3 m/s of north westerly winds were at 850 mb (1.5 km). During 27 Oct - 2 Nov, up to 5 m/s of
easterly winds are expected at 850 mb (1.5 km).
• Sea surface temperature around Sri Lanka was
0.25 - 1.0ºC above normal. From 18 - 25 Oct, maximum daily temperature
was recorded in Vavuniya (34.5ºC), Polonnaruwa (33.1ºC), and Anuradhapura (33.1ºC).
Predictions
Rainfall
14-day prediction:NOAA NCEP models:
From 26th October - 1st November:
Total rainfall by Provinces
- > 135 mm - Southern, Sabaragamuwa, Western
- 135 mm - Uva
- 115 mm - Central
- 105 mm - North Western
- 95 mm - Eastern
- 85 mm - Northern, North Central
From 2nd November - 8th November:
Total rainfall by Provinces
- > 135 mm - Southern, Sabaragamuwa, Western, Uva, Eastern, Central
- 135 mm - North Western, North Central
- 125 mm - Northern
MJO based OLR predictions:
For the next 15 days:
MJO shall slightly suppress
the rainfall during 26th - 30th October, slightly enhance
the rainfall during 31st October - 4th November, and moderately
enhance the rainfall during 5th - 9th November for Sri
Lanka.
Ocean State (Text Courtesy IRI)
Pacific Sea Sate: October 23, 2023
El Nino Mode has set in according
to NOAA since 8th of June. Equatorial sea surface temperatures
(SSTs) are above average across the central and eastern Pacific Ocean late-October.
El Niño conditions are anticipated
to continue through the Northern Hemisphere spring (with an 80% chance during
March-May 2024).
Interpretation
Monitoring
Rainfall: During the last two weeks, there had been very heavy rainfall
over the following areas: Anuradhapura, Hambantota
Daily Average Rainfall in the Met stations for previous week of (18th October - 25th October) = 13.5 mm
Maximum Daily Rainfall: 161.5 mm & Minimum Daily Rainfall: 0.0 mm.
Daily Average Rainfall in the Met stations for previous week of (18th October - 25th October) = 13.5 mm
Maximum Daily Rainfall: 161.5 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 |
7.3 |
31.6 |
24.3 |
|
Eastern hills |
13.8 |
25.3 |
18.1 |
|
Eastern plains |
9.7 |
31.4 |
23.8 |
|
Western hills |
13.7 |
27.0 |
19.1 |
|
Western plains |
24.1 |
30.3 |
24.2 |
|
Southern plains |
18.7 |
30.3 |
23.9 |
|
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 |
15.7 |
78.0 |
0.0 |
Wind: North westerly winds prevailed in the sea area and around the island last week.
Temperatures: The
temperature anomalies were seasonably near normal for the country driven by the warm SST’s.
Predictions
Rainfall: During the next week (26th October
- 1st November), heavy rainfall (≥ 105 mm) is predicted for the Southern, Sabaragamuwa, Western, Uva,
Central, and North Western provinces and fairly heavy rainfall (≥ 85 mm)
is predicted for the Eastern, Northern, and North Central provinces.
Temperatures: The temperature will remain seasonably near normal
for the country during 27th October - 2nd November.
Teleconnections: A positive Dipole Mode has set in across the Indian Ocean since 8th
of June.
MJO
shall slightly suppress the rainfall during 26th - 30th October,
slightly enhance the rainfall during 31st October - 4th
November, and moderately enhance the rainfall during 5th - 9th
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.
