Weekly Hydro-meteorological Report, 7 January, 2015

Highlights

Monitoring and Prediction

Less rainfall was observed throughout the country during the past week. Maximum rainfall for the week was observed in Badulla area on 31st December which was up to 30mm.During the next week rainfall is predicted to be lower than the previous weeks, but there shall be high rainfall in the eastern coast. Rainfall shall increase during 13th to 19th January for the most parts of the country.
Download Full Report




Summary

Monitoring


Weekly Monitoring::Compared to the past week a significantly less rainfall was observed throughout the week 31st December – 5th January. Highest rainfall during this week was observed on 31st of December. On that day 30mm rainfall was observed in Badulla while rest of the country received rainfall up to 10mm. Thereafter rainfall has gradually decreased and completely ceased by 4th of January.


Monthly Monitoring:An average rainfall of 8mm to 20mm was observed throughout the country with higher precipitation observed in the central, north-eastern and eastern regions of Sri Lanka during December. Highest rainfall during this month was observed in Batticaloa district. Also the dekadal rainfall average increased from 12mm to 18mm within a week.

Predictions

14-day prediction:NOAA NCEP models predict that the north-central region shall receive rainfall up to 45mm and eastern region shall receive rainfall up to 75mm during 6th to 12th January. Rainfall shall increase throughout the country during 13th to 19th January resulting in rainfall above 125mm in eastern region.

IMD WRF Model Forecast & IRI forecast:According to the IMD WRF model, no rainfall is predicted on 8th of January. Eastern costal area shall receive light rainfall on 9th January. During 5th – 10th January South-Western and region shall receive total rainfall up to 50 mm while significant rainfall is not expected in any other region of the country.

Seasonal Prediction:As per IRI Multi Model Probability Forecast issued in November for the season December 2014 to February 2015, Rainfall shall remain climatological while the temperature shall be above normal with about 70% probability.

PACIFIC SEAS STATE December 18, 2014 :During November through early December the SST exceeded thresholds for weak Niño conditions, although only some of the atmospheric variables indicate an El Niño pattern. Most of the ENSO prediction models indicate weak El Niño conditions during the December-February season in progress, continuing through most or all of northern spring 2015.
INDIAN OCEAN STATE :Neutral SST was observed in the sea around Sri Lanka.
MJO STATE :MJO is in Phase 5-Maritime Continent and therefore shall suppress the rainfall in Sri Lanka.