Highlights
• Fairly heavy rainfall is predicted for the
Eastern, North Central, Northern, North Western, Central, Uva provinces, and
moderately heavy rainfall is expected for rest of the country during 27th Jan - 2nd Feb. Highest rainfall is expected from 31st Jan - 2nd Feb as
there is a storm in Bay of Bengal.
• During
the last week, maximum daily rainfall over Sri Lanka was 71.2 mm and
hydro catchment areas received 65.0 mm and highest average
rainfall 7.1 mm in the southern plains of the country.
• From 18th - 24th Jan, up to 8m/s of north easterly winds were experienced at 850 mb level over the
island. During 28th Jan - 3rd Feb, north easterly
winds are expected for the country.
• Sea surface temperature around Sri Lanka was
near-neutral for the entire island. Land surface temperature remained near
normal.
Predictions
Rainfall
14-day prediction:
NOAA NCEP models: From 27th January – 2nd February:
Total rainfall by Provinces:
- 65 mm - Eastern, North Central
- 55 mm - Northern, North Western, Central, Uva
- 45 mm - Western, Sabaragamuwa
- 35 mm - Southern
From 3rd February – 9th February:
Total rainfall by Provinces:
- 35 mm - Western, Southern, Eastern, Sabaragamuwa
- 25 mm - North Western, North Central, Central, Uva
- ≤ 15 mm - Northern
MJO based OLR predictions:
For the next 15 days:
MJO shall moderately enhance the rainfall during
27th – 31st January, slightly enhance the rainfall during
1st – 5th February, and slightly suppress the rainfall
during 6th – 10th February for Sri Lanka.
Ocean State (Text Courtesy IRI)
Pacific Sea Sate: January 23, 2023
Equatorial
sea surface temperatures (SSTs) are below average across most of the Pacific
Ocean mid - January. The tropical Pacific atmosphere is consistent with La Niña. A
large majority of the models indicate a transition from La Niña to ENSO-neutral anticipate during the
February-April 2023 season by Northern Hemisphere spring (March-May 2023), the
chance for ENSO-neutral is 82%.
Indian Sea Sate
Sea surface temperature around Sri
Lanka was near neutral for the whole country in 18th
January, 2023. 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 heavy rainfall over the following area: Ampara
Daily
Average Rainfall in the Met stations for
previous week of (19th January – 25th January) = 3.5 mm
Rmax:
71.2 mm & Rmin: 0.0 mm.
Region | Average rainfall for the Last 8 days |
Northern Plains | 2.6 mm |
Eastern | 4.2 mm |
Western | 3.1 mm |
Southern Plains | 7.1 mm |
The Hydro Catchment Areas recorded 3.5
mm of average rainfall for the last week
Rmax: 65.0 mm & Rmin: 0.0 mm.
Wind:
North easterly winds prevailed in the sea area
and around the island last week.
Temperature:
The temperature anomalies
were near neutral for the whole county, driven
by the warm SST’s.
Predictions
Rainfall:
During the next week (27th January
– 2nd February), fairly heavy rainfall (≥ 55 mm) is predicted for the
Eastern, North Central, Northern, North Western, Central, Uva provinces, and moderately heavy rainfall is expected for rest of the country.
Temperature:
The temperature will remain below normal for some
parts of the Central, Uva, and Eastern provinces during 28th January – 3rd February.
Teleconnections:
A transition from La Niña
to ENSO-neutral is anticipated during the February-April 2023 season by
Northern Hemisphere spring (March-May 2023), the chance for ENSO-neutral is 82%.
MJO
shall moderately enhance the rainfall during 27th – 31st
January, slightly enhance the rainfall during 1st – 5th
February, and slightly suppress the rainfall during 6th – 10th
February for Sri Lanka.
Seasonal Precipitation:
The precipitation
forecast for the February-March-April 2023 season shows a higher tendency of near-normal
precipitation for the country.