Weekly Hydro-meteorological Report, 15 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 Mahiyangana area on 6th January which was up to 30mm. Rainfall is expected to increase during 16th to 27th of January.
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Summary

Monitoring


Weekly Monitoring::The highest rainfall for the week was observed on 6th in Mahiyangana averaging upto 30mm. On the same day rainfall was observed in Puttalam and south-west region of the island. During 7th to 12th no rainfall was observed in any part of the country.


Monthly Monitoring:During December an average rainfall of 8mm to 20mm was observed throughout the country with higher precipitation in the central, north-eastern and eastern regions of the island. Highest rainfall in December was observed in Batticaloa district.Decadal rainfall average was significantly decreased during 1st to 10th January with compared to the last week of December.

Predictions

14-day prediction:NOAA NCEP models predict that the eastern region shall receive rainfall around 45mm during 14th to 20th January. Rainfall is expected to increase in eastern region of the country during 21st to 27th January resulting in high rainfall (more than 125mm in total).

IMD WRF Model Forecast & IRI forecast:According to the IMD WRF model eastern,central and south west regions shall receive slight rainfall on 16th January. Also slight amount of rainfall is expected in southern region on 17th January. No significant rainfall is expected in any part of the country during the period 13th-18th of January.

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 January 8, 2014 :During December 2014 through early January 2015 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 6 in Maritime Continent and therefore shall suppress the rainfall in Sri Lanka.