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Wednesday, July 25, 2018

Weekly Hydro-meteorological Report, 25, July 2018


  •   The IRI weekly rainfall forecast predicts total rainfall up to 50 mm in Colombo, Kalutara, Ratnapura and Galle districts during 24th -29th July.
  •   Between 16 - 22 Jul: up to 20 mm of rainfall was recorded in Nuwara Eliya district on the 16th.
  •   From 15 - 21 Jul: minimum temperature of 20 OC was recorded from Nuwara Eliya district while eastern coastal regions including Jaffna, Kilinochchi, Vavuniya and Anuradhapura districts recorded a maximum temperature between 35-40 OC.
  •  From 16 - 22 Jul: up to 36 km/h, westerly winds were experienced by the entire island.
  •   0.5 OC below average sea surface temperature was observed in the seas around Sri Lanka.

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Weekly Monitoring: On the 16th, Nuwara Eliya districts received up to 20 mm of rainfall; and Matale, Kandy, Badulla, Monaragala, Kegalla, Ratnapura, Gampaha, Colombo, Kalutara and Galle districts up to 5 mm. No significant rainfalls were recorded in any part of the island on the 17th and 18th. On the 19th, Kurunegala, Matale, Kandy, Badulla, Nuwara Eliya and Batticaloa districts received up to 5 mm of rainfall. No significant rainfalls were recorded in any part of the island during 20th – 22nd. 

Total Rainfall for past week :  The RFE 2.0 tool shows total rainfall 10-25 mm of total rainfall in Ratnapura, Monaragala, Badulla and Ampara districts; and up to 5-10 mm in Matale, Kandy and Mannar districts. Below average rainfall up to 25-50 mm is shown for Colombo, Kalutara and Ratnapura districts; and up to 10-25 mm is shown for Puttalam, Kurunegala, Matale, Badulla, Monaragala, Gampaha, Kegalla, Kandy, Nuwara Eliya, Galle, Matara Trincomalee districts.  

Monthly Monitoring: During June - above average rainfall conditions were experienced by the western and south-western regions of the island. Ratnapura district received up to 210 mm above average rainfall; Kegalla, Nuwara Eliya and Kalutara districts up to 150 mm; and Puttalam, Kurunegala, Colombo, Galle and Matara districts up to 60 mm. The CPC Unified Precipitation Analysis tool shows up to 500 mm of total rainfall in Ratnapura district; up to 300 mm Kegalla, Colombo and Kalutara districts; up to ~200 mm Gampaha, Galle and Nuwara Eliya districts; and up to 150 mm in Jaffna, Vavuniya, Anuradhapura, Trincomalee, Polonnaruwa, Kurunegala, Matale, Kandy, Badulla, Monaragala, Ampara and Hambantota districts.  


14-day prediction:
From 24th – 29th Jul: Total rainfall between 15-25 mm in Colombo, Ratnapura, Kegalla, Kandy, Nuwara Eliya, Matara and Trincomalee districts.

From 29th Jul – 4th Aug: Total rainfall between 35-45 mm in Trincomalee district; and between 25-35 mm in Colombo, Kegalla and Nuwara Eliya, Ratnapura, Galle, Matara, Anuradhapura, Vavuniya and Kilinochchi districts.

IMD WRF Model Forecast: 

26th July: Up to 10 mm of rainfall in Nuwara Eliya and Badulla districts.

27th July: Up to 10 mm of rainfall in Badulla district.

IRI Weekly forecast:
From 24th – 29th Jul: Total rainfall up to 50 mm expected in Colombo, Kalutara, Ratnapura and Galle districts.

Ocean State (Text Courtesy IRI)
PACIFIC SEAS STATE : July 18, 2018
In mid-July 2018, the east-central tropical Pacific waters reflected ENSO-neutral conditions, with slightly above average SST. The key atmospheric variables also suggested neutral conditions. The subsurface water temperature continued to be above-average. The official CPC/IRI outlook calls for neutral conditions through northern summer season, with a 65% chance of El Niño development during fall, rising to 70% for winter 2018-19. An El Niño watch is in effect. The latest forecasts of statistical and dynamical models collectively favor weak El Niño development by late summer or early fall, growing to weak or moderate strength during late fall and winter; forecasters are largely buying into this scenario now that the spring barrier is largely passed.

INDIAN OCEAN STATE :   0.5 OC below average sea surface temperature was observed in the seas around Sri Lanka.

MJO STATE :  MJO shall suppress the rainfall in Sri Lanka.

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