Monitoring and Prediction
November is usually the month with the heaviest rainfall in Sri Lanka (average up to mm/ month). After the extremely high rainfall two weeks back, the last week had been relatively dry all over Sri Lanka. However, the US NOAA GFS model predicts rainfall in excess of 125 mm for the coming week from 12-18th of November; the forecast is for high rainfall for the following week as well - 19th-25th of November. This NOAA-CFS model has been skillful lately. The rainfall predictions from the Indian Meteorological Department also predict high rainfall in the next three days.
|NCEP GFS Ensemble Rainfall forecast 12th- 18th November 2014|
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Weekly Monitoring::On 5th of November slight rain was observed within the country. From 6th November to 9th November no significant rainfall was observed in the entire country. On 10th November around 20 mm rainfall was observed in the area surrounding Dambulla. Rainfall was observed in the entire country on the 11th with more rain observed in the western half of the country reaching up to 30- 40 mm.
Monthly Monitoring:An average rainfall of 14 mm-16 mm was observed throughout the country with higher precipitation observed in the south-western regions of Sri Lanka during October. Highest rainfall during this month was observed in Uva, Sabaragamuwa and Central provinces. Also the decadal rainfall average was around 14 mm-18 mm.
14-day prediction:The entire country shall receive total rainfall excess of 125 mm during both weeks of 12th-18th November and 19th-25th November.
IMD WRF Model Forecast & IRI forecast: According to the IMD WRF model the entire country shall receive average rainfall around 7.6 mm on 14th and 15th of November. Light rainfall is expected in the entire southern region during 10th-15th November with heavy rainfall in Northern peninsula around 100 mm in average.
Seasonal Prediction:As per IRI Multi Model Probability Forecast issued in October for the season November 2014 to January 2015, Rainfall shall remain climatological while the temperature shall be above normal with a high probability.
PACIFIC SEAS STATE November 6, 2014 :During September through October the observed ENSO conditions retreated from those of a borderline El Niño to a warmish ENSO-neutral state. However, most of the ENSO prediction models continue to indicate development of weak El Niño conditions during the October-December season in progress, peaking at weak strength during winter 2014-15 and lasting through most of northern spring 2015.
INDIAN OCEAN STATE :Around 0.50C below average sea surface temperature was observed towards north-east coast.
MJO STATE :MJO is in Phase 8 in Western Hemisphere and therefore shall slightly enhance the rainfall in Sri Lanka.