Weekly Hydro-meteorological Report, 11, April 2019

Highlights:

•   The IRI weekly rainfall forecast predicts up to 75 mm of total rainfall in Badulla and Nuwara Eliya during 10 – 15 Apr.
•   Between 3 – 9 Apr: up to 30 mm of rainfalls were recorded in Gampaha districts on the 3rd.
•  From 2 – 8 Apr: up to 10 km/h, easterly winds were experienced by the entire island.
•   0.5 ⁰C above average sea surface temperature was observed in the eastern seas around Sri Lanka.

Download Full Report




Summary

Monitoring

Weekly Monitoring: On April 3rd, Gampaha district received up to 30 mm of rainfall; and Colombo district up to 20 mm. No significant rainfalls were recorded in any part of the on the 4th. On the 5th, Monaragala district received up to 20 mm of rainfall. On the 6th, Monaragala and Hambantota districts received up to 5 mm of rainfall. No significant rainfalls were recorded in any part of the island on the 7th. On the 8th, Monaragala and Badulla districts received up to 5 mm of rainfall. On the 9th, Monaragala, Badulla, Kandy and Matale districts received up to 5 mm of rainfall.

Total Rainfall for past week :  The RFE 2.0 tool shows total up to 10-25 mm in Monaragala, Gampaha and Colombo districts; and 5-10 mm in Ratnapura district. Below average rainfall up to 50-100 mm is shown for Puttalam, Gampaha, Colombo, Kalutara, Galle, Matara, Kegalle, Ratnapura, Kandy, Matale, Badulla and Monaragala districts; up to 25-50 mm in Kurunegala, Anuradhapura, Matale, Galle, Matara, Hambantota, Trincomalee, Ampara and Batticaloa districts; and up to 10-25 mm is shown for rest of the island.

Monthly Monitoring: During March – Above average rainfall conditions up to 60 mm were experienced in coastal regions of Galle and Matara districts. Below average rainfall conditions up to 180 mm were experienced by Anuradhapura, Polonnaruwa, Batticaloa, Ampara, Monaragala, Ratnapura, Nuwara Eliya, Badulla, Kandy, Kegalle, Matale, Kurunegala and Puttalam districts; and up to 60 mm in rest of the island. The CPC Unified Precipitation Analysis tool shows up to 100 mm of total rainfall in Gampaha, Ratnapura and Kalutara districts; up to 75 mm in Kegalle, Colombo, Galle and Nuwara Eliya districts; up to 50 mm in Puttalam, Kurunegala Kandy, Matara, Monaragala and Badulla districts; and up to 25 mm in Mannar, Anuradhapura, Matale, Batticaloa, Ampara and Hambantota districts. 

Predictions

14-day prediction:
NOAA NCEP Models:

From 10th – 16th Apr: Total rainfall up to 15 mm in Puttalam, Gampaha, Colombo, Kegalle, Ratnapura, Galle and Matara districts.

From 17th – 23rd Apr: Total rainfall up to 55 mm in Galle and Matara districts; up to 35-45 mm Ratnapura and Hambantota districts; up to 25-35 mm in Colombo, Kegalle, Nuwara Eliya, Badulla, Monaragala and Ampara districts; and up to 15-25 mm in Gampaha, Puttalam, Kurunegala, Matale and Kandy districts.

IMD WRF Model Forecast: 

12th Apr: Up to 160 mm of rainfall in Anuradhapura, Kandy, Badulla, Nuwara Eliya, Kegalle, Ratnapura, Matara, Hambantota and Monaragala districts; and up to 40 mm in Mannar, Vavuniya and Kurunegala districts.

13th Apr: Up to 80 mm of rainfall in Ratnapura district; and up to 20 mm in Anuradhapura district; and up to 10 mm in Matale and Vavuniya districts.

IRI Weekly forecast:
From 10th – 15th Apr: Total rainfall up to 75 mm is expected in Badulla and Nuwara Eliya districts; and up to 50 mm in Matale, Kandy, Kegalle, Gampaha, Colombo, Ratnapura, Monaragala and Ampara districts.

Ocean State (Text Courtesy IRI)
PACIFIC SEAS STATE : April 11, 2018

SSTs in the tropical Pacific maintained a weak El Niño level during March and early April, while subsurface waters continued to be warmer than average. Patterns in the atmosphere also continue to show El Niño conditions. Collective model forecasts show a continuation of at least weak El Niño-level SSTs lasting through 2019. The somewhat more cautious official CPC/IRI outlook, with an El Niño advisory, calls for an approximate 65% chance of El Niño prevailing during Jun-Aug, decreasing to 50-55% for Sep-Nov.

INDIAN OCEAN STATE :   0.5 ⁰C above average sea surface temperature was observed in the eastern seas around Sri Lanka.

MJO STATE :  MJO shall not have an impact on the rainfall in Sri Lanka in the next 5 days; shall enhance in the following 5 days; and again, shall not have an impact in the next 5 days.