Autometar

[zappa2009]

In NZ Metservice is putting in more and more Autometar stations and the quality of our weather information for GA pilots has deteriorated considerably - especially that of cloud and visibility. Do others find this to be the case also?

[White Hart]

we have a semi-automated system (SAMOS) at some airfields here in the UK. The automatic readings have to be manually corrected by an Observer before transmission to the Met Office, usually because they are so wide of the mark. When the machine is working in full 'Auto' mode, its garbage - period.

Automated systems will have to be radically improved before they could ever be relied upon to provide truly accurate automatic reports, and especially in the absence of an Observer to keep an eye on things.

[slackie]

AUTOMETARs aren't worth a pinch of sh!t. We (controllers) have access to the data that the met stations output now, and although they are useful when formulating the hourly METAR (because we know what they are reporting), the information is absolutely useless in isolation.

As a pilot I fell into the trap a while ago when heading for YP. Got the NR AUTOMETAR that said no cloud...whereas when I finally got hold of NR TWR whilst still on the western side of the ranges (sth of AP) they reported that although it was clear at NR the cloud was substantial out towards the west and there was no way under/through/over from Taupo direction all the way as far south as they could see.

AUTOMETARs might as well be a randomly generated report, they bear no resemblance to actual weather. How CAA allows them to purport to be an aviation weather report is beyond me!!

[bentleg]

They are OK for wind, temp and QNH, but have severe limitations (useless sometimes) for cloud or viz.

[Curved Approach]

hey are OK for wind, temp and QNH, but have severe limitations (useless sometimes) for cloud or viz.

Spot on, all you need to fly an approach is the wind, temp and QNH. These are of course accurate in the AUTO form whereas cloud and visibility will generally be qualified by NDV (nil directional variation). Hence take with a grain of salt and just really for informational purposes for IFR flights to give an idea of whether and when you will become visual on an approach.

Using the AUTO Metar to determine whether or not you can fly VFR into or out of an airport is to be used with caution; hence the qualifying remarks are used such as AUTO and NDV.