Summary Statement



Rainfall for October 2017 (Refer to Table 1)

Rainfall for the month of October was below-normal at Nadzab and Wewak stations, normal at Madang and Misima and above normal at New Guinea Islands and Port Moresby.



Accumulated rainfall for August to October 2017, including outlook verification (Refer to Table 2)

Rainfall for the last three months was below-normal at Madang, normal at Nadzab, Wewak and Misima, while the remaining three stations recorded above-normal. Forecasts were consistent at Madang and Momote, inconsistent at Kavieng and Port Moresby, and near-consistent for the rest of the monitoring stations. Skills range from very low to very high.



Outlook for December 2017 to February 2018

1. SCOPIC (Refer to Table 3)

The SCOPIC seasonal rainfall outlook for December 2017 to February 2018 shows little guidance as the chances of above-normal, normal and below-normal rainfall are similar for the country (Climatology). The exception is the outlook for Port Moresby which shows a near-equal likelihood of above-normal and normal rainfall. Below-normal is the least likely.

  • Confidence range from very low to good skill.




2. POAMA (Refer to Table 4)

The POAMA model favours below-normal rainfall for Wewak with normal the next most likely. At all the other stations above-normal rainfall is favoured or most likely outcome.



Valid As Of: 2017-11-20 14:55:25

Table 1: Monthly Rainfall - October 2017
StationAugust 2017September 2017October 201733%tile Rainfall (mm)67%tile Rainfall(mm)Median Rainfall (mm)Ranking
Madang (1944-2017)8.03.4239.0207.1284.4252.930/68
Nadzab (1973-2017)119.6104.654.471.0114.097.411/43
Wewak (1894-2017)137.2238.4152.6191.5265.6223.310/62
Vanimo (1918-2047)145.4315.2144.6221.3175.1
Goroka (1948-2017)27.030.0117.7169.5148.0
Momote (1949-2017)267.0450.6287.4183.0265.0227.748/64
Kavieng (1916-2017)256.8207.8304.4163.1275.1213.967/90
Misima (1917-2017)131.2255.8259.6124.7309.5227.550/92
Port Moresby (1975-2017)34.48.0113.210.132.218.7115/120
Table 2: Three Month Rainfall - August to October 2017
Station3 Months Total33%tile Rainfall (mm)67%tile Rainfall (mm)Median Rainfall (mm)RankingForecasted ProbsVerification
Madang (1944-2017)250.4406.4629.5495.611/6870/23/7 (25)Consistent
Nadzab (1973-2017)278.6242.1395.1331.815/4251/22/27 (3.1)Near-consistent
Wewak (1894-2017)528.2495.8662.1574.826/6172/20/8 (26.4)Near-consistent
Vanimo (1918-2047)485.6553.8521.236/36/28 (-1.8)
Goroka (1948-2017)272.3378.2335.234/32/34 (-2.6)
Momote (1949-2017)1005.0646.4901.2758.054/6333/30/37 (-1.5)Consistent
Kavieng (1916-2017)769.0507.4711.5625.461/8435/31/34 (-2.0)Inconsistent
Misima (1917-2017)646.6456.0766.7617.150/9165/31/4 (29.1)Near-consistent
Port Moresby (1975-2017)155.658.896.475.196/10542/23/35 (-0.5)Inconsistent
Table 3: Seasonal Climate Outlook using SCOPIC for December 2017 to February 2018
Predictors and Period used: NINO3.4 SST anomalies for September to October 2017
StationBelow Normal (prob)33%ile rainfall (mm)Normal (prob)67%ile rainfall (mm)Above Normal (prob)Leps Rate(%)Hit Rate (%)
Madang (1944-2017)36926.1301107.0349.645.5
Nadzab (1973-2017)37422.835515.9283.342.9
Wewak (1894-2017)28363.336460.5362.543.3
Vanimo (1918-2047)34716.932918.034-2.624.5
Goroka (1948-2017)33632.134738.733-2.234.0
Momote (1949-2017)35759.632915.933-0.230.0
Kavieng (1916-2017)39841.029985.33210.445.9
Misima (1917-2017)32685.233879.7351.136.9
Port Moresby (1975-2017)26421.236554.13811.243.3
Table 4: Seasonal Climate Outlook using POAMA2 for December 2017 to February 2018
StationLower Tercile (prob)33%ile rainfall (mm)Middle Tercile (prob)67%ile rainfall (mm)Upper Tercile (prob)
Madang2594030111045
Nadzab304161250458
Wewak493813046121
Momote257533087245
Kavieng278462195652
Misima12646588183
Port Moresby30423650864
Daru56344080455