Weekly Hydro-meteorological Report, 08 November 2012

Highlights

Monitoring and Prediction
Monitoring: During the last week (31st October-6th November), heavier than usual rainfall (upto 165 mm) was received particular in the South-West. Predictions: In the coming week, rainfall of up to 135 mm is expected with less in the North. The El Nino is weakening but the Indian Ocean Dipole continues to favour heavier than normal rainfall till December.

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Summary

Monitoring


Weekly Monitoring: During 31st October-6th November, Rainfall ranged between 0-165 mm with highest amount of precipitation observed in Colombo district on the 31st of October 2012. On 31st October and 1st November entire Island received heavy rainfall between 5-165 mm. On 2nd and 3rd, rainfall was lowest compared to the rest of the days of the week. During 4th-6th 5-70 mm of rainfall was observed for the entire country.

Monthly Monitoring: In October, entire Sri Lanka received above average rainfall. Entire country received more than 100 mm of above average rainfall per month and except for South eastern regions of the island; received 5-80 mm of above average rainfall per month.


Predictions

7-day prediction: During this week, entire Sri Lanka shall receive more than 135 mm rainfall except for the Jaffna peninsula and South-eastern regions of the island shall receive 65-105 mm rainfall

IMD WRF Model Forecast & IRI forecast: Updates of IMD WRF model predictions are not available at this time. NOAA models forecast less than 50 mm of rainfall for the Northern regions of Sri Lanka and rest of the island shall receive 50-75 mm of rainfall.

1 Month Prediction: Overall- During 9-11th November rainfall shall increase and shall decrease gradually till 18th. Thereafter rainfall shall increase gradually till 29th November. Western Slopes- Same rainfall pattern shall exsists till 18th November. Therafter rainfall shall increase gradually till 25th and shall decrease during 25th-28th November. Eastern slopes- Rainfall shall increase during 8th-10th and it shall drastically decrease till 15th November. Therafter it shall gradually increase till 29th November with fluctuations during 17th-19th and 25th-26th. Northern- Rainfall shall increase during 8th-11th and it shall decrease gradually till 19th with fluctuation during 14th-15th. Therafter rainfall shall increase gradually till the end of November.

Seasonal Prediction: As per IRI Multi Model Probability Forecast for November 2012 to January 2013, issued in October 2012, there is a 50%-60% probability for temperature to be above normal in the country while the rainfall is to be climatological.