Highlights
• Moderately heavy (≥ 40 mm) rainfall is
predicted for the Sabaragamuwa, Uva, and Eastern provinces during 24th - 30th November.
• During the last week, the average daily
rainfall over Sri Lanka was 0.8 mm & hydro catchment areas received 0.8 mm
on average and the highest average rainfall (1.6 mm) was
received to the Eastern plains of the country.
• From 14th - 20th Nov, up to 6m/s of north-easterly winds were experienced at 850 mb level over the
island. Wind Direction has changed from arriving from South-West to arriving
from North East.
• Sea surface temperature around Sri Lanka was
above normal to the Southern half of the country. Land surface temperature remained near normal.
Predictions
Rainfall
14-day prediction:NOAA NCEP models:
From 24th November – 30th November:
Total rainfall by Provinces:
- 70 mm - Uva, Sabaragamuwa
- 40 mm - Eastern
- 20 mm - Southern, Central, North Western, North Central
- ≤ 10 mm - Northern, Western
MJO based OLR predictions:
For the next 15 days:
MJO shall moderately suppress the rainfall during
23rd – 27th November, slightly suppress the rainfall
during 28th November – 2nd December, and remain near
normal during 3rd – 7th December for Sri Lanka.
Ocean State (Text Courtesy IRI)
Pacific Sea Sate: November 21, 2022
Equatorial sea surface
temperatures (SSTs) are below average across most of the Pacific Ocean late - November.
The tropical
Pacific atmosphere is consistent with La Niña. A large majority of the models indicate La Niña is favored to continue
through during the Northern Hemisphere winter (December-February) 2022-23, with
a transition to ENSO-neutral favored in February-April 2023 (57% chance).
Interpretation
Monitoring
Rainfall:
During
the last two weeks, there had been very heavy rainfall over the
following areas: Kegalle,
Avissawella
Daily Average Rainfall in the Met stations for previous week of (15th November – 22nd November) = 0.8 mm
Rmax: 30.5 mm & Rmin: 0.0 mm.
Region | Average rainfall for the Last 8 days |
Northern Plains | 0.0 mm |
Eastern | 1.6 mm |
Western | 0.5 mm |
Southern Plains | 0.8 mm |
The Hydro Catchment Areas recorded 0.8 mm of average rainfall for the last week
Rmax: 14.8 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 below normal for some parts of the North Central, North Eastern and
Central provinces, driven by the warm
SST’s.
Predictions
Rainfall:
During the next week (24th – 30th
November),
moderately heavy (≥ 40 mm) rainfall is predicted for the Uva, Sabaragamuwa,
and Eastern provinces; and less rainfall
is expected for the rest of
the country.
Temperature:
The temperature will remain below normal for some
parts of the Central and Uva provinces during 24th – 30th
November.
Teleconnections:
La Niña is favored to
continue through during the Northern Hemisphere winter (December-February)
2022-23, with a transition to ENSO-neutral favored in February-April 2023 (57%
chance).
MJO
shall moderately suppress the rainfall during 23rd – 27th
November, slightly suppress the rainfall during 28th November – 2nd
December, and remain near normal during 3rd – 7th
December for Sri Lanka.
Seasonal Precipitation:
The precipitation
forecast for the December-January-February 2023 season shows a higher tendency
for near-normal precipitation to the country.