Highlights
• Fairly heavy rainfall is predicted for the
Western, Southern, Sabaragamuwa, North
Central and Central provinces during 26th Oct - 1st Nov. During 2nd - 8th Nov heavy rainfall (> 100mm) is predicted for Sabaragamuwa, Southern and
Western provinces.
• Southwest
of SL experienced very heavy rainfall (<250 mm) during the
last week. The average daily rainfall over Sri Lanka was 13.2 mm & hydro
catchment areas received 24.5 mm on average.
• From 17th -23rd Oct, up to 8m/s of north-westerly winds were experienced at 850 mb level over the
island. During 27th Oct - 2nd Nov, north easterlies are expected to the north and north westerlies
are expected to south of the country
• Sea surface temperature around Sri Lanka was
above normal to the north of the country. Land surface temperature remained
near normal.
Predictions
Rainfall
14-day prediction:NOAA NCEP models:
From 26th October – 1st November:
Total rainfall by Provinces:
- 85 mm - Western, Sabaragamuwa, Southern
- 55 mm - North Western, Central
- 45 mm - Northern, Uva
- 35 mm - North Central, Eastern
From 2nd November– 8th November:
Total rainfall by Provinces:
- 135 mm - Sabaragamuwa
- 125 mm - Southern, Western
- 95 mm - Central
- 85 mm - North Western, Uva, Northern
- 75 mm - Eastern, North Central
MJO based OLR predictions:
For the next 15 days:
MJO shall significantly suppress the rainfall during
26th– 30th October and slightly suppress the rainfall
during 31st – 9th November for Sri Lanka.
Ocean State (Text Courtesy IRI)
Pacific Sea Sate: October 24, 2022
Equatorial sea surface
temperatures (SSTs) are below average across most of the Pacific Ocean late -
October. The tropical
Pacific atmosphere is consistent with La Niña. A large majority of the models indicate La Niña is favored to continue
through the Northern Hemisphere winter (December-February) 2022-23, with a 54%
chance for ENSO-neutral in February-April 2023.
Interpretation
Monitoring
Rainfall:
During the last two weeks, there had been very heavy rainfall
over the following area: Galle
Daily Average
Rainfall in the Met stations for previous
week of (18th - 25th October) = 13.2 mm
Rmax: 169.7 mm & Rmin: 0.0 mm.
Region | Average rainfall for the Last 8 days |
Northern Plains | 11.8 mm |
Eastern | 7.2 mm |
Western | 22.8 mm |
Southern Plains | 0.8 mm |
The Hydro Catchment
Areas recorded 24.5 mm of average rainfall for the last week
Rmax: 105.3 mm & Rmin: 0.0 mm.
Wind:
North-westerly winds prevailed in the sea area and around the island last week.
Temperature:
The temperature anomalies
were below normal for the North Western, North Central provinces and some parts
of the Western and Eastern provinces, driven
by the warm SST’s.
Predictions
Rainfall:
During the next week (26th
October – 1st November) fairly heavy rainfall (85
mm) is predicted for the Western, Sabaragamuwa and Southern provinces; and below 55 mm of rainfall is
expected for the rest of
the country.
Temperature:
The temperature will remain above normal to the whole
country during 27th October– 2nd November.
Teleconnections:
La Niña is favored to
continue through the Northern Hemisphere winter (December-February) 2022-23,
with a 54% chance for ENSO-neutral in February-April 2023.
MJO shall significantly suppress the
rainfall during 26th– 30th October and slightly suppress
the rainfall during 31st – 9th November for Sri Lanka.
Seasonal Precipitation:
The precipitation
forecast for the November-December-January 2023 season shows a higher tendency
for above-normal precipitation in the north half of the country.
