3024: METAR

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METAR
In the aviation world, they don't use AM/PM times. Instead, all times are assumed to be AM unless they're labeled NOTAM.
Title text: In the aviation world, they don't use AM/PM times. Instead, all times are assumed to be AM unless they're labeled NOTAM.

Explanation[edit]

In aviation, the METAR (Meteorological Aerodrome Report) is used to give pilots a brief overview of the current meteorological conditions at an airport or other suitably equipped location. The METAR follows a specific structure and makes heavy usage of abbreviations, which makes it hard to read for anyone not familiar with it. The comic makes fun of that by assuming meanings of the METAR words based on what non-aviation people might think they mean. The METAR in the comic is fairly alarming, describing dangerously fast winds, a possible tornado, freezing volcanic ash (in New York!), lightning, and impossibly high atmospheric pressure.

Code Real meaning Comic text Meaning according to the comic
METAR Type: Meteorological Aerodrome Report "METER" (usually misspelled) The comic assumes that this is just a spelling error and it should be "meter" (or, indeed, "metre").
KNYC Station ID: 4 character identifier; for an airport, this would be the ICAO code. In this instance the identifier represents the automated weather station at Belvedere Castle in Central Park, Manhattan, New York City. Airport, weather and radio station call signs share a common heritage. Station ID "Station ID", which is actually correct, although people unfamiliar with METAR-reporting stations could presume that this is a radio or TV broadcaster's call sign. Among radio stations, KNYC is not a current call sign (though WNYC is, and indeed serves New York City), while KNYC-TV is a television station based in Brooklyn.
251600Z Time of observation: 25th day of the month at 4 PM UTC. Z is not part of the time, but simply global shorthand for "Zulu" time, i.e. UTC. Normally most stations would report at a particular time every hour, in this particular case either 15:51 or 16:51 would apply, but more frequent reports are made during unusual and rapidly changing weather events (as may be the situation, in this case). Time (25:16:002) Misreading the "25" as the hour instead of the day, pushing the trailing zeros into seconds which METAR doesn't use, and "Z" as a 2 on the end of seconds, all resulting in a nonsensical time.
18035G45KT Wind direction and speed: Wind direction 180° (directly from the south, degrees based on 0°=true north), speed 35 knots, gusting to 45 knots. This is quite stormy weather. Wind speed has been 18,035 knots for a good 45 minutes now Instead of interpreting the first 5 digits as direction and speed, it is assumed that it is one big number and the G45 stands for the time span in which this was observed with "G" standing for "good". 18,035 knots is an unrealistically high wind speed, faster than orbital velocity; the jet stream typically contains the highest winds on Earth, and may reach about 250 knots.
6SM 6 statute miles of visibility, meaning that objects can be seen clearly up to 6 miles away.[1] This indicates clear enough weather to fly without instruments; the value has a max range of 10SM. Observer is a size 6 small The comic interprets "6SM" to humorously mean a "Size 6 Small".
VCFCFZVA In the vicinity (VC): funnel cloud (FC) and freezing (FZ) volcanic ash (VA). This sounds somewhat unusual for New York City.[citation needed] Sorry, the station cat walked on the keyboard A riff on the repeated letters which give off the impression the string is constructed by random keypresses on the keyboard, as exemplified by a cat on the keyboard. There is a long history of this problem, as well as attempted solutions.

This string may or may not actually look like the pattern of characters that a walking cat could produce (and be reliably detected). All the letters are in a cluster at the lower left of the (QWERTY) keyboard, with some adjacently paired characters perhaps indicative of stepping on multiple keys and other neighbouring keys having been stepped over, not uncommon of an oblivious feline wandering across your desk. But the repeated cluster of "CFCF", and other implied paw-press events, seem less likely to emerge even from a rapid quadrupedal gait. A more casual stroll would likely also create single-character duplications, unless the keyboard repeat delay was set unnaturally high. It could, though, come from a repeated pawing at the keyboard.

+BLUP Heavy (+) blowing (BL) unknown precipitation (UP) Weird noise the sky made earlier Riffing on the fact that it looks like an onomatopoetic word
NOSIG No significant change is expected to the reported conditions within the next 2 hours Observer has no significant other :( The comic assumes that the transmitter of the METAR report wants the receivers to know that they do not have a significant other, which the comic finds sad. The observer could be trying to abuse the METAR report as a dating platform.
LTG OHD Lightning overhead We overheard someone saying there was lightning OHD is interpreted as "overheard" instead of "overhead", indicating that they did not observe it themselves and instead just overheard people talking about it.
A3808 Altimeter setting: the (calculated) air pressure corresponding to mean sea level at the airport is 38.08 inches of mercury (inHg) ("A" is for inHg, used primarily in USA, Canada and Japan; "Q" would indicate a value in hPa). The value of 38.08 is extremely high: the standard atmospheric pressure used in aviation is 29.92 inHg, and the highest recorded surface pressure on Earth was 32.01 inHg.[2] This is used to adjust the altimeter in the aircraft to the local air pressure, instead of using the standard setting used in higher air spaces. Hey look, an Airbus A380-800! The comic says that the observer saw an Airbus A380-800, a very large passenger plane. Note: The ICAO aircraft type code for the Airbus A380-800 is A388 and not A3808.
RMK Beginning of the section with remarks Remarkable! Remarkable. Likely a comment about the A380 (as stated previously, it is quite large).
AO2 The weather station is automated (A) and has a precipitation discriminator (O2), which can tell the difference between liquid and frozen precipitation. Fanfic archive equipped with a precipitation sensor A reference to the fanfic site Archive of Our Own, often abbreviated as AO3 (Archive of Our Own, or "AOOO"). It's nonsensical to describe this site as having a precipitation discriminator.[citation needed]
SLP130= Sea-level pressure is 1013.0 hPa (approx. 29.91 inHg). The equals sign signifies the end of the METAR. Observer got sleepy around 1:30 "SLP" interpreted as abbreviation for sleepy, the numbers as a time, and the = sign as "around" (maybe confused with ≈)
NOTAM (title text) Not part of a METAR report, but instead another aviation abbreviation. It stands for Notice to Air Missions (previously Notice to Airmen). All times are assumed to be AM unless they're labeled NOTAM. Parsed as "not A.M.", indicating that a given time is to be interpreted as P.M. While AM and PM are indeed not used in aviation, as the comic says, they use a 24-hour clock system, not an "A.M.-by-default" 12-hour clock system.

Transcript[edit]

Decoding a METAR report:
[A METAR report is shown with annotations above and below. The report is:]
METAR KNYC 251600Z 18035G45KT 6SM VCFCFZVA
+BLUP NOSIG LTG OHD A3808 RMK A02 SLP130=
[The annotations are:]
  • METAR "METER" (Usually misspelled)
  • KNYC Station ID
  • 251600Z Time (25:16:002)
  • 18035G45KT Wind speed has been 18,035 knots for a good 45 minutes now
  • 6SM Observer is a size 6 small
  • VCFCFZVA Sorry, the station cat walked on the keyboard
  • +BLUP Weird noise the sky made earlier
  • NOSIG Observer has no significant other :(
  • LTG OHD We overheard someone saying there was lightning
  • A3808 Hey look, an Airbus A380-800!
  • RMK Remarkable!
  • A02 Fanfic Archive equipped with a precipitation sensor
  • SLP130= Observer got sleepy around 1:30

Trivia[edit]

The actual last three KNYC METAR strings, that were generated at about the actual time of publication, were: 

KNYC 131651Z AUTO VRB03KT 10SM CLR M01/M14 A3066 RMK AO2 SLP374 T10061144 $
  • New York, Central Park : 13/Dec/2024, 16:51 UTC (11:51am local time) : Fully Automated Report : Variable wind, no more than 3 knots : 10 (or more) statute miles visibility : No clouds below 12,000 ft (3,700 m) : −1 °C (about 30 °F), dew point at −14 °C (about 7 °F) : Altimeter at 30.66 inHg (1038.3 hPa) : Precipitation discriminator present : Sea-level pressure at 1,037.4 hPa (30.63 inHg) : Temperature -0.6 °C (conversion from exactly 31 °F) , dew point -14.4 °C (from exactly 6 °F) : Maintenance check required (indicated by dollar sign)
KNYC 131751Z AUTO 10SM CLR 00/M16 A3066 RMK AO2 SLP374 T00001156 10000 21028 56006 $
  • New York, Central Park : 13/Dec/2024, 17:51 UTC (12:51pm local time) : Fully Automated Report : (no wind measured) : 10 (or more) statute miles visibility : No clouds below 12,000 ft (3,700 m) : 0 °C (about 32 °F), dew point at −16 °C (about 3 °F) : Altimeter at 30.66 inHg (1038.3 hPa) : Precipitation discriminator present : Sea-level pressure at 1,037.4 hPa (30.63inHg) : Temperature ±0.00 °C (from exactly 32 °F), dew point -15.6 °C (from exactly 4 °F) : 6 hour maximum 0.00 °C (32 °F) : 6 hour minimum -10.28 °C (from 13.5 °F) : 3 hour pressure tendency, falling by 0.6 millibars (0.018 inHg) : Maintenance check required
KNYC 131851Z AUTO 10SM CLR 00/M16 A3066 RMK AO2 SLP377 T00001156 $
  • New York, Central Park : 13/Dec/2024, 18:51 UTC (1:51pm local time) : Fully Automated Report : (no wind measured) : 10 (or more) statute miles visibility : No clouds below 12,000 ft (3,700 m) : 0 °C (about 32 °F), dew point at −14 °C (about 7 °F) : Altimeter at 30.66 inHg (1038.3 hPa) : Precipitation discriminator present : Sea-level pressure at 1,037.7 hPa (30.64 inHg) : Temperature -0.6 °C (from exactly 31 °F), dew point -15.6 °C (from exactly 4 °F) : Maintenance check required



References[edit]

  1. ↑ https://weather.cod.edu/notes/metar.html#:~:text=6SM%2DVisibility,SM)%20up%20to%2010%20SM.
  2. ↑ https://learn.weatherstem.com/modules/learn/lessons/125/18.html

Actual Metar Decoder


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Discussion

OMG RANDALL ADDED AN AO3 REFERENCE 42.book.addictTalk to me! 19:43, 13 December 2024 (UTC)

must've been reading the fic of bill Caliban (talk) 21:04, 13 December 2024 (UTC)

I love the things I learn from these thingsRustykid52 (talk) 19:48, 13 December 2024 (UTC)

Was the explanation of wind speed written by a European? The punctuation after "18" is a comma, not a period, so they it means over 18 thousand knots. Barmar (talk) 19:59, 13 December 2024 (UTC)

Yes, it was. I'm sorry. Janfred (talk) 20:50, 13 December 2024 (UTC)
If windspeed interpreted at "european style", i.e. 18 and 35/1000 knots, it s still funny, beacouse such precision of wind speed measurement is 1] unreachable (variability at space & time is several horders higher), 2] useless (fraction of knot make no difference for pilots). 172.68.213.78 (talk) 21:23, 13 December 2024 (UTC) (please sign your comments with ~~~~)

"38.08 inches of mercury" seems a very high pressure, even for a station that is well below sea level. (1290 hPa Pressure around the dead sea is typically 1060hPa).. Is that physically realistic, or is it part of the joke? I know funnel clouds, freezing and volcanic ash in the same location are unlikely outside of the apocalypse, but can be justified by the rule of funny. 172.70.160.135 20:11, 13 December 2024 (UTC)

Indeed, 31.80 is the reference high limit. Still, is Randall a pilot? The structure of a METAR is horribly familiar to us pilots but pretty much a blank stare to anyone else. 172.68.245.25 21:03, 13 December 2024 (UTC)
Feeding it into a calculator gives an altitude of -2080m (-6825'). So it's entirely reasonable as long as your weather station is in a deep mine. BunsenH (talk) 21:08, 13 December 2024 (UTC)
But isn't the value always put in reference to MSL? I.e. I'm at an airport at 1000ft, the pressure reads 977 hPa, but I'll put 1013 hPa in the METAR. (QNH in METAR vs QFE at the station) Janfred (talk) 21:14, 13 December 2024 (UTC)
There may be various complicated pressure differences from the tornado having dumped a load of possibly Iclandic pyroclastic tephra upon the station. 141.101.98.181 21:36, 13 December 2024 (UTC)
"outside of the apocalypse" - we are talking about NYC :P 172.69.64.171 00:04, 14 December 2024 (UTC)
With a Bostonian leading the discussion 👹 162.158.42.157 16:51, 14 December 2024 (UTC)
The difference between the altimeter setting and the SLP is also pretty concerning. My understanding (which is based only on a few minutes of googling, not any actual experience) is that one does not correct for temperature while the other does, based on a 12 hour average. So maybe the high value is due to crazy temperatures? Haven't done any calculations, but it would fit the apocalyptic scenario. 172.70.247.9 08:40, 14 December 2024 (UTC)
That sounds about right for the weather station located at the ZIP code -10021... 172.70.91.11 09:37, 14 December 2024 (UTC)
Your understanding is correct. Both QNH (altimeter setting) and SLP are "pressure reduced to sea level." But QNH assumes standard atmosphere while SLP attempts to use actual weather conditions. It might be just a temperature correction or it might be more. 162.158.167.192 (talk) 17:53, 16 December 2024 (please sign your comments with ~~~~)

Damn, Randall says you got No Bitches.Xurkitree10 (talk) 06:20, 14 December 2024 (UTC)

Alright, who here on this wiki lacks significant others? (I personally have zero (0) maidens) Caliban (talk) 19:51, 15 December 2024 (UTC)
By "observer", the report means the person who's observed the weather and/or data and created the report, not the person who's observing the report or the comic page. BunsenH (talk) 20:42, 15 December 2024 (UTC)
That's what Randall wants us to think so we don't realise he roasted us. Caliban (talk) 09:19, 17 December 2024 (UTC)

llama-3.1-405b-instruct (poor context, likely contains mistakes):

New York, Central Park: 25th of the month, 16:00 UTC (11:00 am local time): Wind from the south at 35 knots (about 40 mph), with gusts up to 45 knots (about 52 mph): 6 statute miles visibility: In the vicinity, a funnel cloud and freezing volcanic ash: Heavy blue precipitation: No significant change in weather expected: Lightning overhead: Altimeter at 38.08 inches of mercury (about 1022.8 hPa): Precipitation discriminator present: Sea-level pressure at 1013.0 hPa (30.00 inHg, but note that this value is not explicitly stated in the METAR report, and the 'SPL130' code is not a standard way to report sea-level pressure).

...

I should have mentioned that the codes "+BLUP" are not standard METAR codes.

METAR is specified by the International Civil Aviation Organization (ICAO) in the document "Annex 3 to the Convention on International Civil Aviation: Meteorological Service for International Air Navigation". This document defines the standard format and codes used in METAR reports.

In the United States, the Federal Aviation Administration (FAA) also publishes guidelines for METAR reporting in the document "Aviation Weather Services Advisory Circular" (AC 00-45).

The World Meteorological Organization (WMO) also publishes guidelines for METAR reporting in the document "Manual on Codes" (WMO-No. 306).

These documents define the standard codes and formats used in METAR reports, but they do not include codes like "+BLUP", which are likely used in a humorous or fictional context.

...

With this transcription, I can see that the main difference is in the "SPL" code, which is now transcribed as "SLP". This makes more sense, as "SLP" is a standard METAR code for "sea-level pressure".

Here's the updated translation:

"New York, Central Park: 25th of the month, 16:00 UTC (11:00 am local time): Wind from the south at 35 knots (about 40 mph), with gusts up to 45 knots (about 52 mph): 6 statute miles visibility: In the vicinity, a funnel cloud and freezing volcanic ash: Heavy blowing unknown precipitation: No significant change in weather expected: Lightning overhead: Altimeter at 38.08 inches of mercury (about 1022.8 hPa): Precipitation discriminator present: Sea-level pressure at 1013.0 hPa (30.00 inHg)."

...

For example, let's imagine a scenario where a massive volcanic eruption has occurred in the vicinity of New York City, causing a massive ash cloud to blanket the area. The eruption is so powerful that it's creating a rare phenomenon known as "volcanic lightning," which is causing the lightning overhead.

Meanwhile, the ash cloud is interacting with a severe thunderstorm system, causing the formation of a funnel cloud in the vicinity of Central Park. The winds are so strong that they're blowing the ash and precipitation around, creating a situation where the precipitation discriminator is unable to accurately determine the type of precipitation.

In this scenario, the freezing volcanic ash could be a result of the ash cloud interacting with the cold air aloft, causing the ash particles to freeze into small ice crystals.

The heavy blowing unknown precipitation could be a result of the intense winds blowing the ash and precipitation around, making it difficult to determine the exact type of precipitation.

In this highly unlikely and extreme scenario, the METAR report could be more accurate. However, it's worth noting that even in this scenario, the report is still pushing the limits of what's physically possible in terms of weather phenomena.

So, while it's possible to imagine a scenario where the METAR report is more accurate, it's still a highly unlikely and extreme situation that's not representative of typical weather conditions.

172.68.26.24 01:40, 15 December 2024 (UTC)

A 24h-clock is a am-by-default clock. If there is a number of 1-11 it's AM by default. 12-23 tell you it's not am but pm. --172.69.109.92 14:55, 16 December 2024 (UTC)

Somebody wanna call maintenance for that station in Central Park? :) Doctorhook (talk) 00:10, 18 December 2024 (UTC)

Not being familiar with the technical details of how METAR works, I'm wondering: is their any humorous significance the the combination of the +BLUP and AO2 strings? According to the current given explanation, +BLUP means the the precipitation is unknown, and AO2 means the station has the capacity to identify if the precipitation is liquid or frozen. To me that reads like the report is saying, "We should be able to tell you what kind of precipitation this is, but for some reason we can't identify it", implying some mysterious new type of precipitation that is neither liquid nor frozen.162.158.167.88 23:27, 18 December 2024 (UTC)

New interpretation of NOSIG: this user does not use 4 tildes (~~~~) to sign their comments in Talk Pages. 42.book.addictTalk to me! 22:09, 20 December 2024 (UTC)

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