Highlights
• Heavy rainfall is predicted for central and sabaragamuwa provinces and
less rainfall is expected for the rest of the country during 26th - 31st August.
• During the last week, the average daily
rainfall over Sri Lanka was 1.9 mm and hydro catchment areas have received 6.8
mm on average.
• From 16th- 22nd August, westerly to
south-westerly of 10m/s winds were experienced at 850 mb
level over the island. Up to 10m/s of south-westerlies expected for the next
week.
• Sea surface temperature around Sri Lanka was
above 0.5℃ to the north and south of Sri Lanka. Land surface temperature
remained near normal.
Predictions
Rainfall
14-day prediction:NOAA NCEP models:
From 25th August
– 31st August:
Total rainfall by Provinces:
- > 100 mm - Central, Sabaragamuwa
- 95 mm - Southern, Western, Uva
- 85 mm - Eastern
- 75 mm - North-central, North-western, Northern
From 1st September – 7th September:
Total rainfall by Provinces:
- 85 mm - Sabaragamuwa, Central
- 75 mm - Western
- 65 mm - Southern, Uva, North-western
- 55 mm - Eastern
- 45 mm - North-central, Northern
MJO based OLR predictions:
For the next 15 days:
MJO
shall slightly enhance the rainfall during 25th
August - 8th September.
Ocean State (Text Courtesy IRI)
Pacific Sea Sate: August 17, 2022
Equatorial sea surface temperatures (SSTs) are below average across most of the Pacific Ocean in mid-August. The tropical Pacific atmosphere is consistent with La Niña. A large majority of the models indicate, a La Niña is favored to continue through 2022 with the odds for La Niña decreasing into the Northern Hemisphere late summer (July - September 2022) before increasing through the Northern Hemisphere fall and early winter 2022.
Indian Sea Sate
Sea
surface temperature around Sri Lanka was above 0.5℃ to the north and south of
Sri Lanka. Across the Indian Ocean, a classical negative Indian Ocean
Dipole prevails as is typical during a La Niña.
Interpretation
Monitoring
Rainfall:
During the last two weeks, there had been fairly heavy rainfall over the following area: Nuwara Eliya
Daily Average
Rainfall in the Met stations for previous
week of (17th Aug - 24th Aug) = 1.9 mm
Rmax: 29.3 mm & Rmin: 0.0 mm.
Region | Average rainfall for the Last 8 days |
Northern Plains | 2.4 mm |
Eastern | 1.3 mm |
Western | 2.8 mm |
Southern Plains | 0.0 mm |
The Hydro Catchment
Areas recorded 6.8 mm of average rainfall for the last week
Rmax: 96.5 mm & Rmin: 0.0 mm.
Wind:
Westerly to South-westerly winds prevailed in the sea area
and around the island last week.
Temperature:
The temperature
anomalies were above normal for the Sabaragamuwa and Central provinces, driven
by the warm SST’s.
Predictions
Rainfall:
During the next week (26th - 31st August)
heavy rainfall
is predicted for Central and Sabaragamuwa provinces and fairly heavy rainfall is expected for the rest of the
country.
Temperature:
The temperature will remain slightly above normal
to the East and North of the island during 26th August – 1st September.
Teleconnections:
La Niña - La Niña is favored to continue through 2022 with
the odds for La Niña decreasing into the Northern Hemisphere late summer
(July-September 2022) before increasing through the Northern Hemisphere fall
and early winter 2022.
MJO shall slightly enhance the rainfall
during 25th August - 8th September.
Seasonal Precipitation:
The precipitation forecast for the September-October-November
season shows a higher tendency for below-normal precipitation for the country.