Weekly Hydro-meteorological Report, 07, April 2016

Highlights:


East, south, west, central and south west regions of the country received rainfall during 30th March- 5th April. Highest rainfall of 90 mm was observed around Ratnapura and Balangoda on 30th March and 3rd April while central regions of Kegalle and Kurunegala and Haputale received rainfall up to 60 mm on these days. NOAA NCEP model predicts up to 25 mm total rainfall in south western regions of the country during 6th –12th April and around central, western and south western regions during 13th- 19th April. MJO is in phase 3 and shall slightly enhance rainfall in Sri Lanka.
Download Full Report




Summary

Monitoring


Weekly Monitoring:Rainfall received in south west, central, east, south and west regions of the country during 30th Mar- 5th Apr. Ratnapura received up to 90 mm rainfall on 30th March while southern region of Kegalle, Nikaweratiya, Wariyapola and Kuruwita received up to 60 mm rainfall. Central regions of Kurunegala and Kegalle, Northern region of Ratnapura and south western region of Monaragala received rainfall up to 40 mm on the same day. Up to 30 mm rainfall was seen only in the south western sea on 31st March. Katugastota received rainfall up to 40 mm and Wattegama, Matale area received up to 30 mm rainfall on 1st April. It did not rain in the entire country on 2nd April. Up to 90 mm rainfall was seen near Balangoda while the surrounding region received rainfall up to 70 mm on 3rd April. Buttala, Wellawaya and the surrounding region of Balangoda received rainfall up to 40 mm on the same day. Eastern and central regions of Ratnapura and south western region of Monaragala received rainfall up to 40 mm on 4th April while up to 30 mm rainfall observed in western sea close to Negombo on 5th April.


Monthly Monitoring:During March 2016 most regions of the country received below average rainfall. Rainfall received by Ratnapura, Kaluthara and southern and western parts of Puttalam was about 10 mm/day less than the historical average for this month. Above average rainfall was only seen in Kegalle, Kandy, Matale districts and the southern region of Kurunegala district.

Predictions

14-day prediction:NOAA NCEP models predict up to 25 mm rainfall in each week, during 6th – 12th April and 13th – 19th April in the south western region of the country.

IMD WRF Model Forecast & IRI forecast:According to the IMD WRF model, up to 60 mm rainfall is expected in Ratnapura, Galle and Colombo on 8th April while slight amount of rainfall is expected in the rest of the country except eastern and north eastern coastal regions. Kalutara, Galle, Puttalam and western coastal region can expect rainfall up to 60 mm on 9th April. IRI CFS models predict up to 75 mm total precipitation around Nuwara Eliya, Kandy, Badulla and up to 50 mm total precipitation in Monaragala, Kegalle, Rathnapura and western region of the country during 6th-11th April.

Seasonal Prediction:As per IRI Multi Model Probability Forecast for April to June, the total 3 month precipitation shall be climatological. The 3 month temperature has more than 70-80% likelihood in the entire country of being in the above-normal tercile during this period.

PACIFIC SEAS STATE March 17, 2016 :During mid-March 2016 the tropical Pacific SST was weakening, but still at a strong El Niño level. All atmospheric variables continue to support the El Niño pattern, including weakened trade winds and excess rainfall in the east-central tropical Pacific, extending eastward. Most ENSO prediction models indicate continued weakening El Niño conditions over the coming several months, returning to neutral by late spring or early summer 2016, and a chance for La Niña development by fall.
INDIAN OCEAN STATE :1OC above average sea surface temperature was observed around Sri Lanka.
MJO STATE :MJO phase is in 3 therefore shall slightly enhance rainfall in Sri Lanka.