> Pilots have to know how to read and understand this stuff. Only justification I can think of is that like mathematical notation, this shorthand, once learned, is unambiguous and conveys meaning better than prose. I don't know if that's really true though.
You're correct. It's straightforward for pilots. They can quickly read a NOTAM and understand everything.
Also, it's pretty standard and unambiguous worldwide.
That would be true in an ideal world, but pilots are also only human, so at least some of them will sometimes misread or ignore all that gibberish. To quote Wikipedia:
> In July 2017, Air Canada Flight 759 nearly crashed into four other airliners as it attempted to land on a San Francisco taxiway misidentified as a runway: the adjacent runway was closed but the information was buried in the NOTAM. As a consequence, in September 2018, from the findings during its investigation, the National Transportation Safety Board (NTSB) stated NOTAMs were unintelligible and ignored, and recommended a more effective information presentation for better relevance. NTSB chairman Robert Sumwalt described NOTAMs as "a bunch of garbage that nobody pays any attention to". This led to an ICAO initiative to reform the NOTAM system.
I prefer the encoded version of weather, TAF (Terminal Area Forecast). That makes it easier to visually scan down and see how the weather is forecast to change in the terminal area. (Is it improving? Getting worse? Is there a time when the winds change significantly [meaning a frontal passage is happening]?)
Same for a time sequence of METARs, especially when you cross-compare the METARs to the TAF (to know if the forecast is holding or was blown.)
Visually scanning the encoded text of weather is easier. (The entire NOTAM system is a mess, encoded or not.)
Here's Indy's METARs, showing generally good weather with broken clouds, developing into light rain-mist-solid overcast, then heavy rain-mist-overcast, then light rain-mist-broken clouds. (Read from bottom-up.) I'd quickly read that as improving and generally following the TAF (below it), meaning the forecast is probably a good one.
This all seems quite reminiscent of when the US National Weather Service used to issue super-cryptic forecast background summaries, and then slowly non-meterologists started building systems to decode them.
You're correct. It's straightforward for pilots. They can quickly read a NOTAM and understand everything.
Also, it's pretty standard and unambiguous worldwide.
As for the specific example you provided, today is your lucky day! That exact example has been decoded on Wikipedia here: https://en.m.wikipedia.org/wiki/METAR#North_American_METAR_c...