What does this metar mean ?
 

R24 is an RVR figure for runway 24; the "P" stands for "increasing."

1600 is the Met Vis.

Met Visibility and RVRs are measured by seperate methods. The two are not expected to be equal.

P does not stand for increasing!!
It indicates the RVR is in excess of the maximum that can be read for a particular runway.
D (decreasing), U (increasing) not presently used in UK, but are in rest of Europe. There is also a code for staying the same (which I cannot recall at present).

P1500=Runway Visual range greater than 1500metres. The RVR is measured by a set of either visual lights or elecronically by a set of transmisometers set along the edge of the runway.......the aerodrome visibility may often be differant from the runway visibility. RVR's are usually also quoted for Touchdown, midpoint and stop end.

It means it's time for numbnuts to stay on the ground and drink tea. :rolleyes:

Often abbreviated as NNSOGADT

So that explains something else on the METARS and TAFs.

P.s. If I were being picky I'd say transmissometers has 4 Ss in it.

P.p.s. PS on a METAR = Pea Soup??

or simply PS = Pretty !!!!!ty.

Metar means we lost our old airways code which was just like a favorite pair of slippers. I know, we were probably the only country out of step but I still miss it.

As R4 says, it means greater than 1500m. That is the upper range of most transmissometers used so it just means that they are using them as well as tower visibility (1600m in this example) to back up the vis report.

Surely there's no need to include the RVR in this METAR?

For one, at 1600m met vis then there are unlikely to be many instrument approach restrictions and second an RVR which is LOWER than the met vis (because the RVR can't read greater than 1500m) is about as useful as the proverbial chocolate teapot.

By the way, I did see chocolate teapots for sale in a sweet shop in Le Touquet a couple of years ago - I have a picture somewhere.

In this case the METAR also states BCFG (fog patches) - and it's RVRs that we use for approach minima - sod's law says that the fog patch will be just where you don't want it - at the RVR transmissometer :hmm:

The rules for METAR coding in the UK (which do not include all reported elements that are possible) are published in CAP 746.

On the basis of these rules the METAR in question appears to be incorrect in that the RVR value should not have been included.

The relevant extracts from CAP 746 are:
However, the rules for reporting IRVR to aircraft by ATC are slightly different. CAP 493 (a.k.a. MATS Part 1) says:
So it looks like the METAR has been coded up using the rules for passing IRVR reports to aircraft by ATC.

TAF AMD KRIV 2705/2804 05012KT 9999 SKC WSCONDS QNH3008INS
BECMG 2716/2717 03009KT 9999 SCT200 QNH3011INS WND 320V070
TEMPO 2720/2801 03012G18KT
BECMG 2801/2802 VRB06KT 9999 SCT200 QNH3004INS T21/2721Z
T03/2715Z AMD 270511=

Can anyone explain to me what QNH3008INS means? Firtly, why is there a 3 in there? Secondly what does that INS mean?

Finally. T21/2721Z. Is that like saying temperature is 21 at 21 Zulu on 27th?

Thanks :)

My best guess is that the QNH is 30.08 inches? I don't think TAFs incude temperatures do they?

Oh crap. Thats right. I've been looking at QNH's in Hpa all day that I completely forgot about Inches in Mg. Whoops.

Why can't everyone just use the same damn thing.

30 point 08 inches of mercury I believe? How that is converted to Millibars I can't remember.
Edit: everyone beat me to it (must learn to type)

Yeah, got that. But any idea what INS stands for?

EDIT: And since it is given in Inches of MG. Shouldn't it have been preceded with an "A" instead of a "Q"?

INS = Inches