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-   -   EGLL (Heathrow) METAR reports (https://www.pprune.org/atc-issues/611957-egll-heathrow-metar-reports.html)

METARHIMS 7th Aug 2018 23:15

EGLL (Heathrow) METAR reports
 
METAR COR EGLL 072150Z AUTO 28010KT 9999 //////CB 21/14 Q1006
NOSIG=

METAR COR EGLL 071950Z AUTO 24007G19KT 9999 //////TCU 24/14
Q1006 TEMPO SHRA=

METAR COR EGLL 071350Z AUTO 23012KT 9999 //////CB 28/14 Q1007
NOSIG=

Some select observations from Heathrow on August 7th. How are these acceptable/compliant? Significant clouds but no heights reported? For Europe's busiest airport?

Great Charmer 8th Aug 2018 14:23

I wonder how the AWOS manages to detect the type of cloud but not the height. Or maybe with that type of convective cloud it was too ‘chaotic’ for the system to provide a reliable height?:confused:

ZOOKER 8th Aug 2018 14:48

Recently, another major U.K. airport was giving NSC, while a thunderstorm was in progress just to the north of it.

METARHIMS 8th Aug 2018 17:16


Originally Posted by Great Charmer (Post 10218265)
I wonder how the AWOS manages to detect the type of cloud but not the height. Or maybe with that type of convective cloud it was too ‘chaotic’ for the system to provide a reliable height?:confused:

AWOS uses ceilometers to measure cloud height and interpolate sky condition. Typically, if cloud doesn't pass over the sensor in the last 30 minutes it will report NCD.

I don't know about the UK, but in France radar and lightning strike data are used to determine TCU, CB and TS. The AWOS itself is not detecting cloud type, but it is being added on from radar analysis.

good egg 8th Aug 2018 18:09

In Japan they do something similar...

”In automated METAR/SPECI, thunderstorms (TS) and convective clouds of operational significance (CB and TCU) are identified using data from ground weather radar and JMA’s Lightning Detection Network System (LIDEN) via the calculation process outlined below.

Algorithm for identification of thunderstorms (TS), cumulonimbus clouds (CB) and towering cumulus clouds (TCU)
CB/TCU information*1 is produced every 10 minutes based on the Radar Lightning Analysis Index*2 and other data.
TS, CB and TCU are identified every 5 minutes along with their location and movement direction (based on difference from the previous location) using CB/TCU information and cloud-to-ground lightning data from LIDEN.
If composite weather radar data cannot be obtained due to system failure, the term TSCBNO (“thunderstorm and significant convective cloud information not available”) is used. In the event of LIDEN failure, the term TSNO (“thunderstorm information not available”) is used in the RMK section of automated METAR/SPECI.
*1 CB/TCU information: Automatically produced data showing estimated CB and TCU cells based on extraction of convective cloud cells from Radar Lightning Analysis Index data and subsequent threshold-based classification.
*2 Radar Lightning Analysis Index: An index expressing lightning potential (i.e., the status of convective clouds). Values are calculated every 10 minutes using composite ground weather radar data on radar echo intensity, radar echo top height, vertically integrated liquid (VIL) and other variables.”

So I suspect the something similar is used in UK. I.e. whilst the weather station is not detecting any cloud (below 5000ft) there are other sources which are using data and extrapolation to determine that CB/TCU/TS are likely/possible.

Seems like a worthwhile addition to an AUTO METAR (which, of course, is verified by a human observer...).

expediteoff 8th Aug 2018 20:02

If it's not acceptable/compliant then MOR/ASR it -
Otherwise, welcome to the future..............

METARHIMS 9th Aug 2018 01:03

While similar automation is done in Japan and other countries as noted in this thread, Heathrow is the only airport that does this automation during busy (daylight) hours apparently without augmentation.

I can get better weather reports from an unmanned airport in deepest Mississippi.

good egg 9th Aug 2018 04:10


Originally Posted by METARHIMS (Post 10218740)
While similar automation is done in Japan and other countries as noted in this thread, Heathrow is the only airport that does this automation during busy (daylight) hours apparently without augmentation.

I can get better weather reports from an unmanned airport in deepest Mississippi.

Without augmentation? Those looked like METAR COR(rections) to me...as if somehow the original METAR had been augmented?

Gonzo 9th Aug 2018 07:14


Originally Posted by METARHIMS (Post 10218740)
While similar automation is done in Japan and other countries as noted in this thread, Heathrow is the only airport that does this automation during busy (daylight) hours apparently without augmentation.

I can get better weather reports from an unmanned airport in deepest Mississippi.

....and Luton, Stansted, Glasgow, Aberdeen, Cardiff, Manchester.



METARHIMS 10th Aug 2018 12:05


Originally Posted by Gonzo (Post 10218899)


....and Luton, Stansted, Glasgow, Aberdeen, Cardiff, Manchester.



You are correct. I should have clarified I was comparing Heathrow to the services available at other major airports in continental Europe.

Gonzo 10th Aug 2018 23:16

If you have concerns, suggest you send an email to the address at the bottom of the linked PDF

UK AIC Y 069/2015

ZOOKER 11th Aug 2018 08:13

TangoAlphad,

Yes, using the 6sec/NM rule over a couple of discharges, it was about 2.5 NM away. I was indoors, but the area of sky I could see at the time was totally grey. It's odd that we now seem to have Wx observations that are far less detailed than those made 20 years ago. With the current emphasis on climate change, I would have thought we need more comprehensive observational data, not less.

mike current 11th Aug 2018 16:48


Originally Posted by ZOOKER (Post 10220587)
TangoAlphad,

Yes, using the 6sec/NM rule over a couple of discharges, it was about 2.5 NM away. I was indoors, but the area of sky I could see at the time was totally grey. It's odd that we now seem to have Wx observations that are far less detailed than those made 20 years ago. With the current emphasis on climate change, I would have thought we need more comprehensive observational data, not less.

Zooker,
maybe the ATCO was providing a combined Tower/Ground/Approach radar service, as well as Met Observer, at the time.
The accuracy of each task tends to decrease as the number of tasks increase!!

ZOOKER 11th Aug 2018 20:21

It wouldn't surprise me at all mike, but I think it's still done by an ATSA during the day. Mind you, when good egg's 'Digital Nirvana' finally kicks in, they can do it all on the telly......No need to look out of the window, they won't have one anyway!

cossack 11th Aug 2018 20:54


Originally Posted by ZOOKER (Post 10220587)
It's odd that we now seem to have Wx observations that are far less detailed than those made 20 years ago. With the current emphasis on climate change, I would have thought we need more comprehensive observational data, not less.

When Mrs cossack was a Met Office weather observer, the observations were done for the Met Office's benefit and aviation benefited as a bonus. Now the bare minimum observations are made because they are required by ATC and Nats was no longer willing to pay the Met Office what they were asking. Whether the Met Office still maintains as detailed records is doubtful.

ZOOKER 11th Aug 2018 21:10

I don't think they do Cossack. As you will know, many U.K. airfields, (both civil and military), were full synoptic observing stations. How many of them still exist today is unclear. I think many of the sources the Met office uses today are provided by hobbyists.

Gonzo 11th Aug 2018 22:28


Originally Posted by cossack (Post 10221090)
When Mrs cossack was a Met Office weather observer, the observations were done for the Met Office's benefit and aviation benefited as a bonus. Now the bare minimum observations are made because they are required by ATC and Nats was no longer willing to pay the Met Office what they were asking. Whether the Met Office still maintains as detailed records is doubtful.

Im not sure it was NATS who paid the Met Office for on-airport observers, wasn’t it the airport operator?

cossack 11th Aug 2018 22:41


Originally Posted by ZOOKER (Post 10221106)
I don't think they do Cossack. As you will know, many U.K. airfields, (both civil and military), were full synoptic observing stations. How many of them still exist today is unclear. I think many of the sources the Met office uses today are provided by hobbyists.

I think most remaining observers are at military airfields.

cossack 11th Aug 2018 22:43


Originally Posted by Gonzo (Post 1022115)
I'm not sure it was NATS who paid the Met Office for on-airport observers, wasn’t it the airport operator?

I have no idea to be honest.


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