Weekly Hydro-meteorological Report, 11, February 2016

Highlights:


Dry weather conditions continued throughout the country during the week 3rd – 9th February where only ocean around Kalutara received rainfall up to 80 mm on 7th February. Western region of Kalutara received rainfall up to 70 mm and few regions in Colombo, Ratnapura and Galle received rainfall in the same day. NOAA NCEP model predict rainfall in eastern, north western and south western regions in next week.
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Summary

Monitoring


Weekly Monitoring:During the week 3rd – 9th February, only Kalutara, Ratnapura, Colombo and Galle received significant amount of rainfall. On 3rd, 4th and 5th February, no rainfall was observed in the entire country and the south eastern ocean received rainfall up to 20 mm on 4th and 5th February. No rainfall was observed in any part of the country on 6th February. On the 7th ocean near Kalutara received rainfall up to 80 mm while western region of Kalutara received rainfall up to 70 mm. Southern region of Colombo, northern region of Galle and western region of Ratnapura also recived rainfall up to 40 mm on this day. On 8th February, no rainfall was observed in any part of the country. Sinharaja forest reserve and the eastern region of Kandy received rainfall up to 20 mm on 9th February.


Monthly Monitoring:In January 2016 dry conditions were seen throughout the country. Below average rainfall was observed in the entire country except in Batticaloa district and some parts in Polonnaruwa, Trincomalee and Ratnapura districts where up to 4 mm/day rainfall was observed.

Predictions

14-day prediction:NOAA NCEP models predict rainfall up to 75 mm in Batticaloa and up to 55 mm in north western region during 10th – 16th February. South western region is expected to receive rainfall up to 45 mm on this period. Eastern region is expected to receive slight amounts of rainfall up to 25 mm and no rainfall is expected in the rest of the country during the following week 17th – 23rd February.

IMD WRF Model Forecast & IRI forecast:According to the IMD WRF model, no rainfall is expected in the entire country during 12th and 13th February 2016. Ocean around eastern and southern regions are expected to receive slight amounts of rainfall. IRI CFS models predict up to 50 mm rainfall in eastern region of the country during 10th- 15th February. The sea east of Kalmunai and south eastern ocean is expected to receive rainfall up to 75 mm during this week.

Seasonal Prediction:As per IRI Multi Model Probability Forecast for February to April, the total 3 month precipitation has 50% likelihood 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 January 21, 2016 :During mid-January 2015 the tropical Pacific SST was at a strong El Niño level, having peaked in November and December. 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 January-March 2016 season in progress. The beginning of a gradual weakening of the SST anomaly is underway, with the event dissipating to neutral conditions by late spring or early summer 2016.
INDIAN OCEAN STATE :Neutral sea surface temperature was observed around Sri Lanka.
MJO STATE :MJO shall be in phase 4 therefore shall slightly enhance rainfall in Sri Lanka.