PAPUA NEW GUINEA GOVERNMENT

National Weather Service

Summary Statement



Rainfall for September 2017 (Refer to Table 1)

Rainfall for the month of September was below normal for Goroka and Port Moresby, normal at Nadzab and above normal for the rest of the monitoring stations in the country.



Accumulated Rainfall for July to September 2017, including outlook verifications (Refer to Table 2)

Rainfall for the last three months was normal for Port Moresby whilst above normal for the other stations recorded. Forecasts were consistent at Vanimo and Momote, Near-consistent for Port Moresby and Kavieng and inconsistent for Nadzab. The skills range from very low to very high.



Outlook for November 2017 to January 2018

1. SCOPIC (Refer to Table 3)

The SCOPIC seasonal rainfall outlook for November 2017 to January 2018 shows little guidance as the chances of above-normal, normal and below-normal rainfall are similar for the country (climatological). At Port Moresby there is a near-equal chance of normal or above-normal rainfall, the least likely outcome is below-normal at the nation's capital.

  • Confidence range from very low to high skill.




2. POAMA 9Refer to Table 4)

The POAMA model shows below-normal rainfall as the most likely for Wewak, normal the most likely for Daru, while at all the other stations above-normal rainfall is the favored or most likely outcome.



Valid As Of: 2017-10-31 15:10:04

Table 1: Monthly Rainfall - September 2017
StationJuly 2017August 2017September 201733%tile Rainfall (mm)67%tile Rainfall(mm)Median Rainfall (mm)Ranking
Madang (1944-2017)75.4180.4121.4
Nadzab (1973-2017)487.6119.6104.655.8132.8104.622/43
Wewak (1894-2017)101.0238.4147.2207.0180.450/61
Vanimo (1918-2047)384.2145.4315.2124.1188.7149.359/62
Goroka (1948-2017)27.030.068.0123.096.66/55
Momote (1949-2017)808.4267.0450.6195.0277.0248.161/64
Kavieng (1916-2017)384.4256.8207.8141.3201.0165.862/90
Misima (1917-2017)188.4131.2105.1257.7193.0
Port Moresby (1975-2017)0.234.48.010.333.418.531/120
Table 2: Three Month Rainfall - July to September 2017
Predictor: NINO3.4 SST Anomalies Period: April to May 2017
Station3 Months Total33%tile Rainfall (mm)67%tile Rainfall (mm)Median Rainfall (mm)RankingForecasted ProbsVerification
Madang (1944-2017)333.4481.0409.552/39/9 (12.7)
Nadzab (1973-2017)711.8257.8464.0372.641/4240/27/33 (-1.9)Inconsistent
Wewak (1894-2017)467.1589.9551.172/21/7 (26.3)
Vanimo (1918-2047)844.8458.5558.7516.054/5827/31/42 (-0.1)Consistent
Goroka (1948-2017)200.0284.0248.032/32/36 (-2.1)
Momote (1949-2017)1526.0748.41047.0885.766/6827/30/43 (0.6)Consistent
Kavieng (1916-2017)849.0509.8724.1611.668/4830/35/35 (-1.6)Near-consistent
Misima (1917-2017)332.0609.2464.073/24/3 (32.5)
Port Moresby (1975-2017)42.641.889.266.633/10737/29/34 (-1.9)Near-consistent
Table 3: Seasonal Climate Outlook for November 2017 to January 2018
Predictors: NINO3.4 SST Anomalies Period: August to September 2017
StationBelow Normal (prob)33%ile rainfall (mm)Normal (prob)67%ile rainfall (mm)Above Normal (prob)Leps Rate(%)Hit Rate (%)
Madang (1944-2017)34953.0321120.034-0.840.0
Nadzab (1973-2017)34370.733474.533-2.614.3
Wewak (1894-2017)29435.935544.7369.150.8
Vanimo (1918-2047)33642.233832.534-1.431.2
Goroka (1948-2017)34516.432642.034-2.324.4
Momote (1949-2017)34736.634894.732-0.038.3
Kavieng (1916-2017)34784.732954.134-0.935.0
Misima (1917-2017)31599.334780.6352.338.1
Port Moresby (1975-2017)27299.737424.63616.346.2
Table 4: Seasonal Climate Outlook using POAMA2 for November 2017 to January 2018
StationLower Tercile (prob)33%ile rainfall (mm)Middle Tercile (prob)67%ile rainfall (mm)Upper Tercile (prob)
Madang24960.0371116.039
Nadzab42345.012416.046
Wewak39427.025506.036
Momote30720.018888.052
Kavieng39767.012942.049
Misima36553.022738.042
Port Moresby42272.09411.049
Daru5441.059531.036