Highlights
• High
likelihood of heavy rainfall (100 -150mm) is predicted for the Western,
Sabaragamuwa, North Western, Southern provinces and fairly heavy rainfall (50 -
100mm) is predicted for the Central, North Central, and Uva provinces during 21
- 27 May.
• For SL, 150 mm rainfall was received during
15 - 20 May. Apart
from Western region, upto 4 - 12mm deficit of rainfall was observed during
April. Depression 99B in the BoB is predicted to
reach cyclone status and then track away from SL.
• Winds at 850mb (1.5 km) were north westerly
from 12 - 18 May reaching up to 3 m/s. Winds at 850mb (1.5 km) are predicted north
westerly from 22 - 28 May reaching up to
20 m/s due to depression 99B (JTWC classification).
• Average
land surface temperature was 30.3ºC in
the last week with warmer anomalies of +1-3ºC. Sea surface temperature around Sri Lanka was
0.5 - 2.0ºC above normal. The temperature has dropped slightly
Predictions
Rainfall
14-day prediction:NOAA NCEP models:
From 21st May - 27th May:
Total rainfall by Provinces
- 115 mm - Western
- 105 mm - North Western, Southern, Sabaragamuwa
- 95 mm - Central
- 75 mm - North Central, Uva
- 65 mm - Northern
- 55 mm - Eastern
From 28th May - 3rd June:
Total rainfall by Provinces
- 65 mm - North Western, Western
- 55 mm - Southern, Sabaragamuwa
- 45 mm - Central
- 35 mm - North Central, Northern
- 25 mm - Uva, Eastern
MJO based OLR predictions:
For the next 15 days:
MJO shall moderately enhance the
rainfall during 21st - 25th May, near neutral the
rainfall during 26th - 30th May, and moderately suppress the
rainfall during 31st May - 4th June for Sri Lanka.
Ocean State (Text Courtesy IRI)
Pacific Sea Sate: May 20, 2024
El Niño is transitioning
toward ENSO-neutral. Equatorial sea surface temperatures (SSTs) are above average in the western
and central Pacific Ocean, and below-average SSTs are emerging in east central and eastern Pacific
Ocean. La Niña may develop in
June-August 2024 (49% chance) or July-September (69% chance).
Indian Sea Sate
Sea
surface temperature around Sri Lanka was 1.5℃ above normal for the country
in 30th April - 6th
May 2024.
Cyclone
'Remal'
IMD predicts that the cyclonic storm in Bay of Bengal
shall intensify into a cyclone by the 25th and as typically for this
season shall steer away from SL. However, if the cyclone stalls there could
continue to be severe winds and heavy rainfall in the western slopes of the
mountains in SL.
Interpretation
Monitoring
Rainfall: : During the last two weeks, there had been very heavy rainfall
over the following area: Kesbewa.
Daily Average Rainfall in the Met stations for previous week of (18th May - 21st May) = 23.1 mm
Maximum Daily Rainfall: 214.5 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 |
29.0 |
31.6 |
25.3 |
|
Eastern hills |
2.8 |
27.2 |
20.5 |
|
Eastern plains |
11.1 |
32.8 |
25.5 |
|
Western hills |
19.5 |
26.1 |
20.3 |
|
Western plains |
45.4 |
29.6 |
24.6 |
|
Southern plains |
2.2 |
31.3 |
25.4 |
|
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 |
23.4 |
88.0 |
0.0 |
Wind: North westerly winds prevailed in the sea area and around the island last week.
Temperatures: The temperature
anomalies were above normal for the country except some parts of the Northern, Eastern, and Western provinces driven
by the warm SST’s.
Predictions
Rainfall: During the
next week (21st May - 27th May), heavy rainfall (100 - 150
mm) is predicted for the Western,
Sabaragamuwa, North Western, and Southern provinces and fairly heavy rainfall (50 - 100 mm) is
predicted for the rest.
Temperatures: The temperature will
remain below normal for some parts of the Central, Western, North Western,
Southern, and Northern provinces and above normal some parts of eastern
province during 22nd - 28th May.
Teleconnections: MJO shall moderately enhance the
rainfall during 21st - 25th May, near neutral the
rainfall during 26th - 30th May, and moderately suppress
the rainfall during 31st May - 4th June for Sri Lanka.
Seasonal Precipitation: The
precipitation forecast for the June-July-August, 2024 season shows a 50% or
more tendency toward above normal precipitation for the country.
