Weekly Hydro-meteorological Report, 10 December, 2015

Highlights:


Heavy rainfall was observed in the entire country during the 1st- 7th December 2015. The Sea around the country also received extremely heavy rainfall during this week. NOAA NCEP models predict a decrease in the rainfall in northern and north central regions of the country but very heavy rainfall shall continue in the eastern region during the next two weeks. The sea surface temperature around the country is neutral. The MJO shall be in phases 5 and 6 during the next week which shall suppress rainfall.
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Summary

Monitoring


Weekly Monitoring:During 1st – 7th December northern and the entire country received rainfall. On 1st December, ocean near Puttalam received heavy rainfall up to 160 mm while ocean near Trincomalee received rainfall up to 130 mm. On 2nd December rainfall up to 50 mm was observed around Buttala, Bandarawela, Kuruvita and ocean around Jaffna. On 3rd December, ocean near Kalmunai received rainfall up to 70 mm. Rainfall up to 90 mm was observed in the ocean near Galle on 4th December while Dehiattakandiya, Girandurukotte, Hasalaka and western region of Matale received rainfall up to 70 mm. Rainfall up to 100 mm was observed in the south eastern ocean on 5th December, and on 6th December only Kuruvita received rainfall up to 40 mm while the rest of the country received light rainfall. On 7th December, the western province and the nearby sea received rainfall up to 80 mm while Trincomalee, Mullaitivu and ocean around eastern and northern provinces received rainfall up to 40 mm.


Monthly Monitoring::In November 2015, almost entire country received above average rainfall while the ocean near eastern and southern provinces, southern region of Galle and Matara received below average rainfall.

Predictions

14-day prediction: NOAA NCEP models predict relatively high rainfall in eastern region of the country compared to the rest of the country during 9th – 15th December. Total rainfall above 135 mm is expected during the week in eastern region and total rainfall up to 85 mm is expected in rest of the country. These models predict the rainfall to decrease during 16th – 22nd December and total rainfall above 135 mm is expected in eastern region, total rainfall up to 55 mm is expected in rest of the country

IMD WRF Model Forecast & IRI forecast: According to the IMD WRF model rainfall up to 65 mm is expected around Somawathi Sanctuary, Kattankudy, Kalmunai and Yala on 11th December while rest of the country shall receive slight amounts of rainfall. On 5th December Kalmunai shall receive rainfall up to 65 mm and rest of the country shall receive slight amounts of rainfall. IRI CFS models prediction is not available in this week

Seasonal Prediction:As per IRI Multi Model Probability Forecast for December to February, 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 November 19, 2015 :During late October through early November 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 November-January 2015-16 season in progress. Some slightly further strengthening is possible into early winter 2015-16, with the event slowly weakening during spring 2016.
INDIAN OCEAN STATE : Neutral sea surface temperature was observed around Sri Lanka.
MJO STATE :MJO MJO phase is in 5 therefore shall slightly suppress rainfall in Sri Lanka.