Weekly Hydro-meteorological Report, 05 November, 2015

Highlights:


Up to 40 mm rainfall was observed in northern, north eastern and western regions of the country during the time period 27th October – 2nd November. Heavy rainfall up to 160 mm was observed in Trincomalee on 27th October and Kekirawa on 2nd November. Rainfall up to 120 mm was observed in Mankulam, Punewa, Mihintale and Trincomalee on 1st November. Every prediction model predict increase of rainfall during the next week.
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Summary

Monitoring


Weekly Monitoring:During 27th October – 2nd November northern, north eastern and western regions mostly received rainfall. Rainfall up to 160 mm was observed in the ocean near Trincomalee on 27th October while Tricomalee received rainfall up to 140 mm. On 28th October rainfall up to 70 mm was observed in Kalkudah and the ocean near Batticaloa. On 29th October Jaffna and Katugastota received rainfall up to 30 mm and the ocean near Galle received rainfall up to 65 mm while ocean near Jaffna, Trincomalee and Ampara also received rainfall up to 40 mm. Rainfall up to 55 mm was observed around Nikaweratiya on 30th October while ocean near Trincomalee received rainfall up to 90 mm. On 31st October Nelumkulama and Tissamaharama received rainfall up to 30 mm and the ocean near Kilinochchi received rainfall up to 65 mm. Rainfall up to 120 mm was observed around Mankulam, Punewa, Mihintale and Trincomalee on 1st November. Rainfall up to 160 mm was observed around Kekirawa on 2nd November while Hasalaka, Hettipola and Negombo also received rainfall up to 120 mm.


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

Predictions

14-day prediction: NOAA NCEP models predict relatively high rainfall in northern and eastern regions of the country compared to the rest of the country during 4th November – 10th November. Total rainfall above 135 mm is expected during the week in the northern and eastern regions and total rainfall up to 115 mm is expected in south western and north central regions. Rest of the country is expected to receive rainfall up to 95 mm. These models predict the rainfall to increase during 11th- 17th November and total rainfall above 135 mm is expected in almost entire country and total rainfall up to 115 mm is expected in southern and western regions of the country.

IMD WRF Model Forecast & IRI forecast: According to the IMD WRF model rainfall up to 65 mm is expected around Kalawana, Galle and Beliatta on 6th November while south western region shall receive rainfall up to 35 mm and rest of the country also shall receive slight amounts of rainfall. On 7th November, rainfall is expected up to 125 mm around Galle, Matara, ocean near Galle and Batticaloa. Northern and eastern regions also shall receive rainfall up to 35 mm. IRI CFS models predict total rainfall up to 200 mm in south eastern region of the country during 4th – 9th November.

Seasonal Prediction:As per IRI Multi Model Probability Forecast for November to January, 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 October 15, 2015 :During late September through mid-October 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 October-December 2015 season in progress. Some slightly further strengthening is possible into later fall, with the event slowly weakening during spring 2016.
INDIAN OCEAN STATE : 1.5 degrees Celcius above average temperature was observed around Sri Lanka.
MJO STATE :MJO phase is in 3 therefore shall slightly enhance rainfall in Sri Lanka.