Fiji Sugar Cane Rainfall Outlook from February 2017 Planting Season
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FIJI METEOROLOGICAL SERVICE Fiji Sugar Cane Rainfall Private Mail Bag (NAP0351) Nadi Airport, Fiji Ph: +679 6724888, Fax: +679 6720430 Outlook from February 2017 Email: [email protected] See online version at http://www.met.gov.fj Planting Season Volume: 13 Issue: 1 January 25, 2017 Introduction This outlook contains the rainfall projections for the three-month period beginning February 2017, and the following three months (May to July 2017), for the Fiji sugar cane “belt”. The chances of normal to above normal predictions are given as probabilities and presented in tables on pages 2 to 4. The Fiji Meteorological Service (FMS) currently uses a statistical climate prediction model known as the Seasonal Climate Outlook for Pacific Island Countries (SCOPIC) for seasonal rain- fall guidance. For the Fiji region, the model uses recent monthly anomalies of sea surface temperature from parts of the Pacific Ocean (central - eastern equatorial Pacific regions) as predictors of Fiji’s rainfall. Summary Statement The tropical Pacific continues to show neutral El Niño-Southern Oscillation (ENSO) conditions, though cloud- iness and rainfall in the southwest Pacific are displaying a weak La Niña like characteristics; It is likely that neutral ENSO conditions (i.e. neither El Niño nor La Niña) will persist through most of the first half of 2017; Normal to above normal rainfall has been received over the sugarcane growing areas in the last three months (October to December 2016); Normal or above normal rainfall is predicted over the sugarcane growing areas through both the February to April and the May to July 2017 periods. The chances of below normal rainfall is least likely; The Tropical Cyclone season began on 01 November 2016 and will end on 30 April 2017. For Fiji, 2 to 3 cyclones can be expected to pass through the Fiji Waters, with 1 anticipated to reach category 3 status; It should be noted that January to March is the peak period for tropical cyclone activity in the Fiji region. 1 Volume: 13 Issue: 1 January 25, 2017 Fiji Sugar Cane Rainfall Outlook from February 2017 Statement from the Sugar Research Institute of Fiji - Advice to Farmers The sugarcane growing areas have received normal to above normal rainfall during the past 3 months and the same is expected for next 3 months. The predicted weather will favour rapid weed growth and growers must adopt integrated weed management that includes manual weeding followed by weedicides application to control the weeds. Fertilizers must be applied by early February for all plant and ratoon cane. Drainage is another area that growers need to focus on and ensure that the field and main drains in and around their farms are cleaned to allow easy drainage of excess water from the fields to avoid water logging conditions. Source: Sugar Research Institute of Fiji Three Month February to April 2017 Rainfall Outlooks Sigatoka District Dry 33% Normal 67% Wet Olosara 21 527 35 747 44 Cuvu 22 574 34 748 44 Lomawai 20 561 37 795 43 Above normal rainfall favoured across the Sigatoka District. Outlook confidence: good. Lautoka District Dry 33% Normal 67% Wet Lautoka Mill 23 677 37 926 40 Lovu 25 741 33 916 42 Drasa 26 741 32 934 42 Above normal rainfall favoured across the Lautoka District. Outlook confidence: moderate. Nadi District Dry 33% Normal 67% Wet Nadi Airport 20 659 36 910 44 Malolo 23 600 30 824 47 Navo 22 644 33 815 45 Meigunyah 22 635 39 922 39 Natova 21 691 39 969 40 Normal or above normal rainfall favoured in the Nadi District. Outlook confidence: moderate to good Ba District Dry 33% Normal 67% Wet Rarawai Mill 22 775 38 1074 40 Koronubu 19 907 39 1155 42 Mota 21 900 38 1200 41 Navatu 23 763 35 970 42 Normal or above normal rainfall favoured in the Ba District. Outlook confidence: moderate to good. Tavua District Dry 33% Normal 67% Wet Tavua 19 669 35 943 46 Tagitagi 24 657 33 904 43 Vatukoula 18 854 36 1121 46 Above normal rainfall favoured across the Tavua District. Outlook confidence: good to high. 2 Volume: 13 Issue: 1 January 25, 2017 Fiji Sugar Cane Rainfall Outlook from February 2017 Three Month February to April 2017 Rainfall Outlooks Rakiraki District Dry 33% Normal 67% Wet Penang Mill 23 827 37 1103 40 Dobuilevu 31 861 31 1081 38 Normal or above normal rainfall favoured in the Rakiraki District. Outlook confidence: low to moderate. Labasa District Dry 33% Normal 67% Wet Seaqaqa 23 870 36 1145 41 Waiqele 21 964 36 1155 43 Vunimoli 21 869 37 1250 42 Labasa Mill 17 841 40 1106 43 Vunivutu 18 818 38 1305 44 Wainikoro 21 797 36 1104 43 Above normal rainfall favoured for the Labasa District. Outlook confidence: moderate to good. Following Three Month May to July 2017 Rainfall Outlooks Sigatoka District Dry 33% Normal 67% Wet Olosara 18 217 37 301 45 Cuvu 14 204 39 280 47 Lomawai 17 161 40 282 43 Normal or above normal rainfall favoured in the Sigatoka District. Outlook confidence: high Lautoka District Dry 33% Normal 67% Wet Lautoka Mill 14 152 41 235 45 Lovu 14 135 42 233 44 Drasa 17 151 39 226 44 Normal or above normal rainfall favoured in the Lautoka District. Outlook confidence: high Nadi District Dry 33% Normal 67% Wet Nadi Airport 19 141 38 245 43 Malolo 23 123 38 213 39 Navo 26 134 34 250 40 Meiguynah 14 133 42 231 44 Natova 16 143 41 240 43 Normal or above normal rainfall favoured in the Nadi District. Outlook confidence: low to high. Ba District Dry 33% Normal 67% Wet Rarawai Mill 21 150 36 256 43 Koronubu 22 159 36 242 42 Mota 20 159 37 257 43 Navatu 21 122 36 209 43 Above normal rainfall favoured across the Ba District. Outlook confidence: generally good to high. 3 Volume: 13 Issue: 1 January 25, 2017 Fiji Sugar Cane Rainfall Outlook from February 2017 Following Three Month May to July 2017 Rainfall Outlooks Tavua District Dry 33% Normal 67% Wet Tavua 19 126 36 227 45 Tagitagi 13 124 40 233 47 Vatukoula 22 149 34 248 44 Above normal rainfall favoured across the Tavua District. Outlook confidence: good to high. Rakiraki District Dry 33% Normal 67% Wet Penang Mill 20 178.5 38 297 42 Dobuilevu 25 246.4 35 365 40 Normal or above normal rainfall favoured in the Rakiraki District. Outlook confidence: moderate to good. Labasa District Dry 33% Normal 67% Wet Seaqaqa 19 158 37 278 44 Waiqele 22 166 39 289 39 Vunimoli 21 160 41 272 38 Labasa Mill 20 179 38 253 42 Vunivutu 17 187 39 348 44 Wainikoro 20 174 39 292 41 Normal or above normal rainfall favoured in the Labasa District. Outlook confidence: moderate to good. Explanatory Notes - El Niño and La Niña El Niño Southern Oscillation (ENSO) is an irregular cycle of persistent warming and cooling of sea surface temperatures in the tropical Pacific Ocean. The warm extreme is known as El Niño and cold extreme, La Niña. The term El Niño is given to a local warming of the ocean near the Peruvian coast in South America that appears around Christ- mas. Scientists now refer to an El Niño event as sustained warming over a large part of central and eastern equatorial Pacific Ocean. This warming is usually accompanied by persistent negative values of Southern Oscillation Index (SOI), a decrease in the strength or reversal of the equatorial trade winds and a reduction in rainfall over most of Fiji (not immediate effect as there is a lag period) which can, especially during moderate to strong event, lead to drought. La Niña is sustained cooling of the central and eastern equatorial Pacific Ocean. The cooling is usually accompanied by per- sistent positive values of SOI, an increase in strength of the equatorial trade winds and higher than normal rainfall for most of the Fiji (not immediate effects as there is a lag period), with frequent and sometimes severe flooding, especially during the wet season (November to April). Rainfall Outlook: Rainfall Probabilities - ‘dry’, ‘wet’ and ‘normal’ conditions The rainfall outlook probability presents three monthly rainfall in three different categories. The below normal range is one where rainfall is less than the 33rd percentile. That is, rainfall for the period (in this case three months) which is in the lowest one third of occurrences. Here, three-month rainfall is arranged for a particular period from the highest on record to lowest on rec- ord. Rainfall below the one-third point would be considered below normal. Rainfall in the middle third would be considered normal and upper third above normal. A rainfall prediction of 48:31:21, for example, has the highest probability of rainfall in the below normal category (48%). This means that rainfall is most likely to be below normal for the on-coming three months. However, there is still a 31% chance of normal rainfall and 21% chance of above normal rainfall. Similarly, with a prediction of 20:40:40, means normal to above normal rainfall would be expected. In the case of 33:33:34 there are equal chances of receiving below normal, normal or above normal rainfall (climatology). The success or hit rate of the predictions is highest during the wet season and lowest during the dry season and transition months (dry to wet and wet to dry). The success rate is also high during El Niño and La Niña events. Predictions during neutral periods, especially during the dry season and transition months, are the least successful.