Weekly Hydro-meteorological Report, 14, January 2016

Highlights:


During the week 6th – 12th January, ocean near Kattankudy received the highest rainfall up to 180 mm on 6th January while Relatively high rainfall was observed in several regions in Batticaloa, Ampara and Polonnaruwa on the same day. No significant rainfall was observed during the rest of week. NOAA NCEP models predict decrease of rainfall during next week in the entire country. MJO shall be in phase 1 which shall enhance rainfall conditions in Sri Lanka.
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Summary

Monitoring


Weekly Monitoring:Only eastern, central and south western regions of the country received rainfall during 6th – 12th January. Rainfall up to 180 mm was observed around the ocean near Kattankudy on 6th January while region from Kalkudah to Kalmunai received rainfall up to 160 mm. Eastern region of Polonnaruwa and northern region of Ampara received rainfall up to 90 mm and Galle received rainfall up to 50 mm on the same day. On 7th January, eastern region of Matale, Dehiattakandiya, and region around Ginigathhena to Nallathanniya, Kuruwita and Pelawatta received rainfall up to 20 mm. No significant rainfall was observed in entire country where only Sinharaja forest reserve received rainfall up to 30 mm on 9th January.


Monthly Monitoring:North province, northern regions of Central, Uva and Sabaragamuwa provinces, northern region of Ampara, Colombo and Polonnaruwa received above average rainfall while eastern province, south province, northern region of Mannar, north eastern region of Anuradhapura, western region of Mullaitivu and the ocean around Trincomalee to Ampara, Galle to Hambantota received below average rainfall.

Predictions

14-day prediction: NOAA NCEP models predict slight rainfall up to 25 mm in eastern region of the country during 13th – 19th January. Rest of the country is not expected to receive rainfall in this period. The rainfall is expected to increase slightly during 20th – 26th January and total rainfall up to 45 mm is expected around northern, central, eastern and western regions and the southern region is not expected to receive rainfall.

IMD WRF Model Forecast & IRI forecast: According to the IMD WRF model, only eastern coastal region around Batticaloa is expected to receive slight amounts of rainfall. Apart from that rainfall is not expected in any part of the country. IRI CFS models do not predict any significant rainfall event during 13th to 18th January 2016.

Seasonal Prediction:As per IRI Multi Model Probability Forecast for January to March, the total 3 month precipitation has 50% likelihood of being below average. 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 December 17, 2015 :During mid-December 2015 the tropical Pacific SST was at a strong El Niño level. All atmospheric variables strongly support the El Niño pattern, including weakened trade winds and excess rainfall in the east-central tropical Pacific. The consensus of ENSO prediction models indicate continuation of strong El Niño conditions during the December-February 2015-16 season in progress. Further strengthening is possible, but unlikely, into mid-winter 2015-16, with the event slowly weakening during spring 2016.
INDIAN OCEAN STATE : 10C above average Sea Surface temperature was observed around Sri Lanka.
MJO STATE :MJO shall be in phase 1 in the next few days, which shall slightly enhance rainfall in Sri Lanka