Weekly Hydro-meteorological Report, 09 July, 2015

Highlights:


During 30th June – 6th July 2015 Western, Eastern and Southern provinces mostly received rainfall up to 20 mm. Rainfall up to 20 mm was observed in Western, North Western, Eastern and Uva provinces on 30th June and 1st July. On 2nd July western region of Ampara received rainfall up to 30 mm and on 4th July heavy rainfall up to 70 mm was observed in the ocean near Galle. NOAA models predict high rainfall in south western and southern regions of the country in the next fortnight.
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Summary

Monitoring


Weekly Monitoring::During the time period 30th June – 6th July 2015, slight amounts of rainfall were observed in the country. On 30th June Kurunegala, Gampaha, Colombo and Ampara received rainfall up to 20 mm and on 1st July, northern region of Moneragala received rainfall up to 20 mm. Western region of Ampara had rainfall up to 30 mm on 2nd July while western region of Ratnapura, eastern region of Nuwara Eliya received rainfall up to 20 mm. On 3rd July the ocean near Galle received rainfall up to 20 mm while Ampara, Moneragala and western province received light rainfall up to 15 mm. Heavy rainfall was observed in the ocean near Galle up to 70 mm on 4th July while Kegalle and Gampaha received rainfall up to 20 mm. On 5th July, rainfall decreased and only Kalutara and the ocean near Southern province received light rainfall up to 15 mm and on 6th July light rainfall up to 15 mm was observed in the southern region of Kalutara district.


Monthly Monitoring:: In the month June 2015, western, Sabaragamuwa and south eastern regions of the country received above average rainfall of upto 8 mm/day. The rest of the country received below average rainfall during this month.

Predictions

14-day prediction: NOAA NCEP models predict high rainfall in southern region of the country during 8th – 21st July. Up to 85 mm total rainfall is expected during each week.

IMD WRF Model Forecast & IRI forecast: According to the IMD WRF model Western region of the country shall receive rainfall up to 35 mm/day while Kegalle district shall receive rainfall up to 65 mm on 10th July. The rest of the country shall receive slight amounts of rainfall. The rainfall shall continue on 11th July and Kegalle district shall receive rainfall up to 125 mm while Gampaha, Colombo, southern region of Kurunegala shall receive rainfall up to 65 mm and the rest of the country shall receive slight rainfall. IRI CFS model also predicts high rainfall in Western province on 8th – 13th July.

Seasonal Prediction:As per IRI Multi Model Probability Forecast for July to September, the total 3 month precipitation has a 40% chance 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 June 18, 2015 :During late May through early-June 2015 the SST was at a moderate El Niño level. The atmospheric variables 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 moderate El Niño conditions during the June-August 2015 season in progress, likely strengthening further between summer and fall, and lasting into early 2016.
INDIAN OCEAN STATE : 1.5 0C above average temperature was observed around Sri Lanka.
MJO STATE :MJO is in Phase 7 and therefore shall suppress rainfall in Sri Lanka in a significant manner.