Maybe people with more experience have seen it before, but it’s the first time for me:
METAR LSZH 221950Z 00000KT CAVOK 13/10 Q1022 NOSIG=
What’s special about it ? It’s clear with no wind.
Never seen one – no weather.
You have to look in more often… I’ve issued countless like that in the last few years and days…
But if you are suggesting that that is perfect weather, I don’t agree.
Surely a 10kt wind straight down the runway saves a lot of tyre and brake wear.
BTW you can have CAVOK but winds so strong that nobody can fly.
Or CAVOK and still a solid cloud deck above which would make night VFR or climbing to VFR on top impossible. Admittedly that is not often, but CAVOK doesn’t mean “no cloud”.
Incidentally, for those of us who have been reading the METAR runes for a long time.
METAR LSZH 221950Z 00000KT CAVOK 13/10 Q1022 NOSIG=
Shouts “yeah, but it’ll be foggy before you get there, as the 13 falls towards the 10 and there is no wind to blow it away.”
CAVOK = no clouds below 5000 feet (AAL) or MSA (whichever is higher) and no CB or TCU
Very nice at LSGS with MSA 17900 to the south ;)
Shouts “yeah, but it’ll be foggy before you get there, as the 13 falls towards the 10 and there is no wind to blow it away.”
Although I would also be cautious and think in this way 
, I’m not sure about fog forming in 0 wind conditions. AFAIK some 3 kts (or so) are needed to trigger it.
