Weekly Hydro-meteorological Report, 16 July, 2015

Highlights:


During 8th July – 14th July 2015 Western and Southern provinces mostly received rainfall up to 20-50 mm. On 10th July rainfall up to 125 mm was observed in the ocean near Matara while 50 mm rainfall was observed in Ratnapura and Kalutara. Rainfall up to 70 mm was observed in the southern region of Nuwara Eliya on 11th July. NOAA models predict high rainfall in south western region of the country in the next fortnight.
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Summary

Monitoring


Weekly Monitoring::During the time period 8th July – 14th July 2015, south western region of the country mostly received rainfall. There was no rainfall on 8th July, and on 9th July rainfall up to 30 mm/day was observed in eastern region of Kalutara, western region of Ratnapura and the northern region of Galle districts. Rainfall up to 125 mm was observed in the ocean near Matara district while Ratnapura, Kalutara, southern region of Kegalle and Colombo, eastern region of Kandy districts received rainfall up to 40 mm on 10th July. On 11th July the ocean near Galle received rainfall up to 40 mm. Rainfall up to 70 mm was observed in the southern region of Nuwara Eliya district on 12th July and on 13th July eastern region of Badulla received rainfall up to 10 mm followed by up to 10 mm rainfall on 14th July Colombo, Kalutara, Galle, Matara, Hambantota, Ratnapura and the southern region of Moneragala.


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 15th – 21st July. Up to 85 mm total rainfall is expected during the week in the south western region while the rest of the country shall receive rainfall up to 50 mm. Less rainfall (about 55 mm) is expected during 22nd- 28th in the south western region of the country.

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 Ratnapura district and northern region of Galle shall receive rainfall up to 65 mm on 17th July. The rest of the country shall receive slight amounts of rainfall. The same pattern of rainfall is expected on the 18th as well. IRI CFS model also predicts high rainfall in south western region of the country during 15th – 20th 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 July 9, 2015 :During late June through early-July 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 0C above average temperature was observed around Sri Lanka and the anomaly goes further up towards the south sea.
MJO STATE :MJO is in Phase 8 and therefore shall suppress rainfall in Sri Lanka in a significant manner.