IT'S a great thing that Coffs Harbour residents and emergency services can rely on accurate rainfall data as part of the city's investment in a flood early warning system.
Why? Because the official Bureau of Meteorology gauge at the Coffs Harbour Airport is so hit and miss, not just by the low rainfall it records during most weather events due to its beachside location but also because it has a history of breaking down when it is needed most.
The March 31st rainfall event in 2009 - the last time the Coffs Harbour city centre flooded - stands as an anomaly in the bureau's weather history records for Coffs Harbour.
The official rainfall figure for that record breaking day is officially recorded as dash, dash, dash when it comes to the accurate rainfall reading measured in millimetres that fell that day.
As Coffs Harbour received falls up to 130mm in most parts overnight, the bureau gauge was down again recording just 0.8mm of rainfall for the 24 hour period.
The Advocate has today received a host of emails, texts and Facebook messages on the issue with that measurement recorded across a host of weather apps and websites.
Fortunately for the city, the rainfall and creek height gauges installed by the Coffs Harbour City Council after the 2009 flood accurately show how much rain the city has received across a number of key locations.
The bureau's weather readings under its automated system at the Coffs Harbour Airport have proven so dodgy, key weather sites like weatherzone and elders weather often display Grafton or Dorrigo forecasts and observations when the 2450 Coffs Harbour postcode is entered.
As long-term amateur weather observer Lester Tolhurst explained the bureau's observation building was established at the airport during World War II to provide pilots with accurate weather readings.
The problem since has been the rainfall, wind and temperatures recorded by the beachside gauge are vastly different to weather readings elsewhere across the city.
The weather station used to be manned, but has been automated for almost five years now.
Here's the 24-hour rainfall figures for Coffs Harbour showing the council's rain gauge readings and the official BOM reading.