Weekly Hydro-meteorological Report, 22 January, 2015

Highlights

Monitoring and Prediction

More or less no rainfall was observed throughout the country during the past week. Only rainfall for the week was observed in south-western region on 17th January which was up to 10 mm. During the next week rainfall is predicted to be low but thereafter rainfall might increase significantly in central and eastern regions of the country.
Download Full Report




Summary

Monitoring


Weekly Monitoring::Dry condition persisted all over the country during the past week, 13th -19th January. The highest rainfall for the week was observed on 17th in south-west region averaging upto 10 mm in Galle and Matara areas.


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 heavy showers shall not be expected during 21st -27th January. But heavy rainfall may occur during 28th January-3rd February in central and eastern regions of the country exceeding 125 mm in magnitude.

IMD WRF Model Forecast & IRI forecast:According to the IMD WRF model light rainfall is expected in Ratnapura and Northern regions on the 23rd and 24th. IRI models doesn’t predict any rainfall during the next 6 days .

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 weak therefore it shall not affect the rainfall in Sri Lanka.