Weekly Hydro-meteorological Report, 02 July, 2015

Highlights:


During 24th – 30th July 2015 Western and Eastern provinces mostly received rainfall up to 20-50 mm. On 26th and 28th June, rainfall up to 30 mm was observed in Western province and the ocean near Western province. Rainfall up to 50 mm was observed in Ampara on 29th June. NOAA models predict high rainfall in south western and southern regions of the country in the next fortnight. MJO is in phase 7 and this shall lead to a suppression in rainfall significantly.
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Summary

Monitoring


Weekly Monitoring::During the time period 24th June – 30th June 2015, rainfall was mostly observed in Western and Eastern regions. On 24th and 25th June, there was no significant rainfall was observed in the country except Puttalam district which received rainfall up to 30 mm and the ocean near Western region received rainfall up to 30 mm. On 26th June Western province, Galle, Matara, Kegalle, Western region of Ratnapura received rainfall up to 20-30mm while Gampaha, Southern regions of Galle and Matara received highest rainfall up to 30 mm. On 27th and 30th June, only light rainfall was observed in the country and on 28th up to 30 mm rainfall was observed in Western and Sabaragamuwa provinces, Galle, Matara and the Southern regions of Puttalam and Kurunegala. And also the ocean near Western province received rainfall up to 30 mm. On 29th June up to 50 mm rainfall was observed in the Northern region of Ampara 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 1st – 14th July. Up to 55 mm total rainfall is expected during the first week. Rainfall shall reach up to 75 mm in the following week in south western region of the country.

IMD WRF Model Forecast & IRI forecast: According to the IMD WRF model on the 3rd of July Western region of the country shall receive rainfall up to 35 mm/day while Kegalle district shall receive rainfall up to 65 mm. The rest of the country shall receive slight amounts of rainfall. The rainfall shall continue on 4th July and Gampaha and Kegalle districts shall receive rainfall up to 65 mm while the rest of the country shall receive slight rainfall. IRI CFS model also predicts high rainfall in Western province on 1st – 6th 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 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 7 and therefore shall suppress rainfall in Sri Lanka in a significant manner.