Weekly Hydro-meteorological Report, 8 October, 2015

Highlights:


Up to 40 mm rainfall was observed in northern, north eastern, western, south western and southern regions of the country during the time period 29th September- 5th October. Southern region of Anuradhapura received heavy rainfall up to 110 mm on 25th September and rainfall up to 70 mm was observed in Badulla on 1st October and in Moneragala on 2nd October. Every prediction model predict increase of rainfall during the next week.
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El Nino persists in Pacific as Indian Ocean stays warm

The current El Niño Pacific Ocean warming event is producing sea surface temperatures not seen since the 1997–98 event while the Indian Ocean remains exceptionaly warm, according to the Australian Bureau of Meteorology (BoM).

Tropical Pacific sea surface temperatures are more than 2 °C above average, exceeding El Niño thresholds by well over 1 °C. Most international climate models surveyed by the BoM indicate El Niño is likely to peak towards the end of 2015 and persist into 2016, a story published by the reportingclimatescience.com yesterday.

The tropical Pacific ocean and atmosphere are reinforcing each other, maintaining a strong El Niño that is likely to persist into early 2016. Tropical Pacific sea surface temperatures are more than 2 °C above average, exceeding El Niño thresholds by well over 1 °C, and at levels not seen since the 1997–98 event. In the atmosphere, tropical cloudiness has shifted east, trade winds have been consistently weaker than normal, and the Southern Oscillation Index (SOI) is strongly negative.

Most international climate models surveyed by the Bureau of Meteorology indicate El Niño is likely to peak towards the end of 2015. Typically, El Niño is strongest during the late austral spring or early summer, and weakens during late summer to autumn.

The Indian Ocean Dipole (IOD) is in a positive phase, having exceeded the +0.4 °C threshold for the past 8 weeks. Recent values of the IOD index have been at levels not seen since the strong 2006 positive IOD event. Conversely, the Indian Ocean remains very warm on the broader scale.

Four out of five international models suggest the 2015 positive IOD event will persist until November, when it typically breaks down due to monsoon development.

El Niño is usually associated with below-average spring rainfall over eastern Australia, and increased spring and summer temperatures for southern and eastern Australia. A positive IOD typically reinforces the drying pattern, particularly in the southeast. However, sea surface temperatures across the whole Indian Ocean basin have been at record warm levels, and appear to be off-setting the influence of these two climate drivers in some areas.

Warm anomalies persist along the equator from the South American coast to the Date Line and across most of the Pacific Ocean east of the Date Line in the northern hemisphere. Compared to two weeks ago, sea surface temperature (SST) anomalies have increased slightly in the eastern equatorial Pacific and remain similar in the central and western equatorial Pacific.

Anomalies for the week ending 27 September 2015 exceed +2 °C across most of the equatorial Pacific east of 170°W. Warm anomalies are also present in areas to Australia’s west, and across the majority of the Indian Ocean.

All five NINO indices remain above +1 °C this week, and both NINO3 and NINO3.4 remain at or above +2 °C. NINO3 and NINO3.4 were last at these levels during the 1997–98 El Niño.

Source: www.island.lk

Weekly Hydro-meteorological Report, 1 October, 2015

Highlights:


Up to 40 mm rainfall was observed in south western, western and north eastern regions of the country during the time period 22nd-28th September. Ocean near Kalutara received heavy rainfall up to 160 mm on 25th September and Galle received heavy rainfall up to 120 mm on 28th September. Every prediction model predict decrease of rainfall during the next week.
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Weekly Hydro-meteorological Report, 23 September, 2015

Highlights:


Up to 30 mm rainfall was observed in southern and western regions of the country during the time period 15th-21st September. Southern region of the country received heavy rainfall on 18th September up to 80 mm. Every prediction model predict high rainfall in eastern and south western regions during the next week.
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Weekly Hydro-meteorological Report, 17 September, 2015

Highlights:


Up to 30 mm rainfall was observed in few parts of the country during the time period 8th-14th September. Rainfall was mostly observed in western and south western regions of the country. Western region of the country received heavy rainfall on 10th September up to 70 mm. Every prediction model predict high rainfall in western and south western regions during the next week.
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Weekly Hydro-meteorological Report, 10 September, 2015

Highlights:


Up to 40 mm rainfall was observed in various parts of the country during the time period 1st-7th September. Rainfall was mostly observed in northern and north central regions of the country. The entire country received rainfall on 3rd September where Badulla received rainfall up to 100 mm. Trincomalee and southern region of Moneragala received 70 mm rainfall on 6th September. Every prediction model predict high rainfall in western and south western regions during the next week.
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Weekly Hydro-meteorological Report, 03 September, 2015

Highlights:


Up to 40 m rainfall was observed in various parts of the country during the previous week. Rainfall was mostly observed in the south western region of the country and also in the northern region. Every prediction model predict an increase in rainfall during the next week. Heavy rainfall events are also predicted in Polonnaruwa district during the next week.
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