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What does W13/S3 mean in this METAR report?

From metar-taf.com: Information about the sea Weather stations located at sea can report the temperature of the sea water and the height of the waves. W12/S8 means ...
randomhead's user avatar
  • 15.6k
15 votes

Why do NOTAMs consist of code instead of plain language?

The NOTAM format is from the time when people still would call the value of individual bits over a phone line. Ok, that may not have happened, but my point is that data transfer was incredibly slow ...
DeltaLima's user avatar
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14 votes
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What constitutes a wind gust in a METAR report?

The definition of "Wind Gust" for METAR reports can be found in the Federal Meteorological Handbook No. 1, chapter 5: 5.4.4 Wind Gust. The wind speed data for the most recent 10 minutes shall be ...
Greg Hewgill's user avatar
  • 9,152
14 votes

How is wind direction reported (blowing from or blowing to)?

I always use the old saying; The North wind doth blow, and we shall have snow... Since this saying originated in England and in England it is colder to the North, we can conclude that a North wind ...
Oscar Bravo's user avatar
13 votes

What are the criteria for "variable" in METAR reports?

There are two official sources to take into account: ICAO Annex 3 to the Chicago Convention is the reference for meteorological information. Annex 3 applies to all ICAO members (countries), unless ...
mins's user avatar
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13 votes
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Why does GR mean hail in a METAR?

The French word for hail is grêle which is abbreviated GR. METAR is an international standard so you will see some non-English words included in the METAR.
DLH's user avatar
  • 5,809
13 votes

What does W13/S3 mean in this METAR report?

These values are related to sea state, and originate from a helideck. W13/S3 means: Sea surface temperature = 13± 0.5°C Waves are slight, that is between 0.5m and 1.25m METAR from helidecks, like ...
mins's user avatar
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13 votes
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Are airport codes with digits valid or pseudo ICAO codes?

No, those are not ICAO codes. ICAO airport identifiers consist of four letters, full stop. But that does not mean that any code which is other-than-four-letters is "invalid" or "...
randomhead's user avatar
  • 15.6k
12 votes

What are ISA +10, ISA -15 and ISA -30?

First of all: I have found out that an ISA atmosphere is: 15 degC temperature 05 degC dewpoint 1013.25 pressure Not entirely correct. The temperature and pressure are ISA values at mean sea ...
Sami's user avatar
  • 2,164
12 votes
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What does I1001 mean in a METAR remarks?

It indicates ice accretion (buildup). This seems to be very obscure, I finally found it in some NOAA release notes for ASOS software v3.07: (S01126) ADD ICE ACCRETION REMARK TO METAR/SPECI ...
Pondlife's user avatar
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12 votes
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How can I check before my flight that the cloud separation requirements in VFR flight rules are met?

Make it simple: OVC: It's a ceiling. The only thing you're concerned about is the altitude of the base. BKN: It's also considered a ceiling. The only thing you're concerned about is the altitude of ...
John K's user avatar
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11 votes
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What are ISA +10, ISA -15 and ISA -30?

ISA+X is the ISA atmosphere with X°C of variation. It´s used to determine how diferent (in terms of Temperature) of the Standard the actual condictions are and adjust the calculations. ISA as you ...
Andreas Almeida's user avatar
11 votes

What is the difference between RVR and visibility?

The definitions are somewhat different: Visibility for aeronautical purposes is the greater of: the greatest safe distance at which a black object of suitable dimensions, situated near the ground, ...
Bianfable's user avatar
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10 votes
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What are the meanings of the phrases DAY, RWYCC, 6/6/6 in ATIS?

RWYCC 6/6/6 means "Runway Condition Codes" of 6 (dry) for the first, middle, and last third of the runway. RCC's, as they're also known, are a relatively new way to report the state of the ...
Ralph J's user avatar
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9 votes
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Can the "G" and "VRB" wind conditions be combined in METARs?

Yes, it is possible for a METAR to contain both VRB and G. VRB10G25KT is valid. The reason it rarely happens is because, as wind speed increases, major variations in wind directions tend to disappear....
60levelchange's user avatar
8 votes
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How to programmatically access AIP data, METAR, TAF, NOTAMs?

ICAO is offering a very nice API for retrieval of, for example, aerodrome names/ICAO codes and NOTAM's. It is currently in public beta, which means that it is free to use. Once they finish testing it, ...
60levelchange's user avatar
8 votes
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What is 0650// in the metar?

This is most likely the minimum visibility (in metres), with the compass direction given as "//" (not possible to determine). A single slash is more common, i.e. ...
Thomas's user avatar
  • 171
8 votes
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What does BLU+ mean in a METAR?

Per the German Meteorological Service, the + means a ceiling 20,000 feet or higher. BLU: visibility>=8000m, ceiling 2500 - <20000 ft BLU+: visibility>=8000m, ceiling >=20000 ft
fooot's user avatar
  • 73.4k
8 votes

Can the "G" and "VRB" wind conditions be combined in METARs?

As other answers say, yes, this is valid. It appears approximately 150K times in our database of 85 million METARs[1]. This database is built from data provided by NOAA and covers roughly 16 months.[2]...
Tim M.'s user avatar
  • 181
8 votes
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What do these two METAR codes mean?

The term 27/10 is the temperature (27°C) and dew point (10°C). The RF term in the remark section is used to indicate the accumulated rainfall (in this case 0, so no rain): What is the meaning of the ...
Bianfable's user avatar
  • 56.5k
8 votes
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What does AO2A in the remarks of a METAR mean?

AO2 Automated station without manual augmentation AO2A Automated station with manual augmentation. That means this is an automated station but some elements have been added manually. 15.13.4 ...
mins's user avatar
  • 74.7k
7 votes

What is this weird format (R06L/CLRD62) in METAR for runway being cleared?

The format follows a standard, although this one is different because of the R at the front... The format is the "Runway State Group": First two digits are the ...
Ron Beyer's user avatar
  • 36.2k
7 votes
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How long is a METAR valid for after issuance?

A METAR is a report of conditions at a specific time, so it's only valid when it's issued. It's not a forecast, the weather could be different 5 minutes later. TAFs are forecasts that have a time ...
GdD's user avatar
  • 54k
7 votes
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Can gusts be reported as lower than wind speed?

WMO standard defines a gust as the maximum wind speed exceeding the "mean speed" by 5 m/s (10 knots) during the 10-minute interval. With this definition, I would never expect to see a ...
hemp's user avatar
  • 579
6 votes
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How are altimeter settings estimated?

The instrument they are using is not certified, hence the ESTMD. When they get a certified one, the ESTMD will drop off the METAR. Technically, the primary certified instruments are inop or ...
mongo's user avatar
  • 17.8k
6 votes

Why do NOTAMs consist of code instead of plain language?

As I understand your question is mainly about line E of a NOTAM, right? Well, this one is in fact meant to use 'plain' English language, in contrast to all other lines, where location and reach as ...
Raffzahn's user avatar
  • 555
6 votes

Why do NOTAMs consist of code instead of plain language?

1 - It's always been done that way. 2 - You'd be surprised how many government computer systems are still using ancient hardware and operating systems.
Steven Brame's user avatar
6 votes

What do the remarks of this metar mean? "RMK SC1SC5AC1 AC TR SLP116"

So the posted parts means the following: ...
Pascal's user avatar
  • 797
6 votes

What does NSC mean in a METAR?

NSC means No significant clouds.
Kartik Gupta's user avatar

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