Questions tagged [meteorology]

The study of the weather, especially important for aviation purposes.

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What is a squall line and how it is created?

How are squall lines created and what are they exactly? If we encounter them how we deal with them? I know that it is a narrow band of thunderstorms that is moving, but is there any other weather ...
Valentinos's user avatar
6 votes
1 answer
2k views

What is the difference between QNH and QFF?

I am wondering what is the difference between QFF and QNH?
AIRWAYLOVER's user avatar
0 votes
1 answer
53 views

Over which types of ground surfaces do we have more updraught?

When a light airplane is flying around 2000-3000 ft AGL, over which places will it deal with updraught more?
AIRWAYLOVER's user avatar
3 votes
1 answer
460 views

How can I determine the level of clouds of operational significance in METAR?

Considering that Minimum sector altitude of the airport = 10500 feet Airport elevation from MSL = 2500 feet What is the level of clouds of operational significance in METAR for this airport? Should we ...
Rebin Salar's user avatar
4 votes
1 answer
232 views

Can new thermals be generated above a cloud layer?

Thermals rise from the ground due to uneven heating from the sun, then stop rising once they start condensing into clouds. My question is can new thermals be formed at the top of this cloud layer? I ...
rhobot's user avatar
  • 43
11 votes
3 answers
3k views

With existing tech and knowledge of meteorology, can aircraft be designed to reliably improve their range or loiter using updrafts to gain altitude?

Just what the question says. I want to know if aircrafts' range, loiter time, or other measures of merit can be dramatically and reliably increased using our current understanding of meteorology and ...
Sorghum's user avatar
  • 113
1 vote
1 answer
131 views

What is the "Model TA-M" I marked in yellow in the table?

What is the "Model TA-M" I marked in yellow in the table? I think it represents a weather chart, but I don't know if it's an abbreviation or what the explanation is. The table image was ...
pilot162's user avatar
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2 votes
0 answers
111 views

How can cold air inflow in high tropospheric layers create a depression?

I’m studying meteorology for PPL and after learning the big differences between cyclones and anticyclones, I came across a question that flipped all my knowledge on its head: What pressure pattern ...
GANoob4eva's user avatar
3 votes
3 answers
1k views

How can I check before my flight that the cloud separation requirements in VFR flight rules are met?

How can I check before my flight that the cloud separation requirements in VFR flight rules are met? As it is known, in order to fly VFR, the rules of 1000 feet vertical and 1500 meters horizontal ...
pilot162's user avatar
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0 votes
1 answer
121 views

What exactly is the interval and duration of occurrence represented by the acronym TEMPO?

What exactly is the interval and duration of occurrence represented by the acronym TEMPO? When we look at this How to interpret BECMG and TEMPO in TAF? question, we see the following in the answer ...
pilot162's user avatar
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2 votes
1 answer
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The weather balloon began to bounce less as it entered the stratosphere

We launched a weather balloon where one of the sensors was an accelerometer. The data from it show all parts of the flight (1 launch (0 m), 3 bursts of the balloon (35,800 m), 4 landing (0 M)). We ...
Saturn V's user avatar
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4 votes
3 answers
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Difference between Mountain Breeze/Katabatic Winds and Valley Breeze/Anabatic Winds

I am studying Meteorology for my CPL exams, and taking EASA's 2020 Learning Objectives as a guideline for the topics I have to study. In the topic of local winds, there are subtopics for Anabatic &...
Uzair's user avatar
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-2 votes
3 answers
734 views

Difference between "pressure levels raising on warm days causing lower IA" and "TA being higher than IA on warm days" [duplicate]

IA: Indicated altitude TA: True altitude I have seen this picture before: Concept 1 and I understand this. On cold days, the pressure gradient is shorter which means the indicated altitude at a ...
Jonathan's user avatar
  • 1,137
4 votes
1 answer
1k views

What is a "polar front low" and what is its usual direction of movement?

As part of my learning to the meteorology exam for PPL I seen the following question - "What is the usual direction of movement of a polar front low?" the answer is - "Parallel to the ...
Meir Tolpin's user avatar
22 votes
5 answers
4k views

Would building a large asphalt square or painted dark black area create a "thermal generator" for glider use?

Imagine if you build a "parking lot" square of asphalt and paint it the deepest black possible to absorb maximum heat...would that spot essentially be a thermal generator that you could fly ...
ljac3's user avatar
  • 339
2 votes
1 answer
509 views

What is the explanation of R28///// in METAR? [duplicate]

In an Aviation Routine Weather Report (METAR), what is the explanation for R28///// in the RVR section? R28 stands for Runway 28 ...
Krishna Kanth's user avatar
1 vote
1 answer
103 views

Formation of Clouds in High Pressure Systems (Western Australia - Perth) [closed]

High pressure systems are normally correlated with stable atmospheric conditions with little to no cloud cover, but due to this minimal cloud cover, doesn't that open up the ocean / ground moisture to ...
JandyPilot's user avatar
4 votes
2 answers
1k views

How does pressure affect formation of clouds?

Relative Humidity is the key factor in determining cloud formation but i believe prevailing pressure system in the surrounding has to do with how fast the cloud can be formed and how long will it ...
Krishna Kanth's user avatar
2 votes
2 answers
707 views

Air density decreases as temperature increases - but air also gets cooler as it expands; does this create a feedback loop? [closed]

First, I apologize for the sloppy title. I had a tough time phrasing this as a concise question. For a column of air at a given pressure, density decreases (the air expands) as temperature increases. ...
Ethan B's user avatar
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0 votes
1 answer
438 views

Wind direction on a chart? [duplicate]

Does the below suggest wind is from the SW (ie: you standing in the middle facing north with wind to tour rear left) or it's blowing from NE towards SW?
user13555's user avatar
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12 votes
5 answers
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Why are pressure levels raised on warm days?

As I'm studying for the PPL knowledge exam, I had the following note: Pressure levels are raised on warm days and the indicated altitude is lower than true altitude. (source: AOPA) But I don't quite ...
Jonathan's user avatar
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0 votes
2 answers
401 views

Climb calculation from meteorology ground school

I have problem understanding what kind of answer is expected in meteorology question as follows: ...
kpx1894's user avatar
  • 119
0 votes
2 answers
978 views

How can I calculate the "stability state" of air from a given set of data?

I would like to know the answer for the above question, it is about how to find whether atmosphere is stable or unstable using DALR (dry adiabatic lapse rate), SALR (saturated adiabatic lapse rate) ...
Pash's user avatar
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3 votes
1 answer
109 views

What are RW values in Venule increments?

In US AIP differences from ICAO: 12.3.1.7 d/e/f U.S. controllers do not give wind speed, visibility, or RVR values in metric terms. RVR values are given in 100- or 200-foot increments while RW values ...
user avatar
3 votes
1 answer
634 views

What is the westerly index?

The westerly index, appears in a CPL syllabus but I can't find much info on it, I assume it is a measure of how systems move from west to east in the southern hemisphere. How exactly is it calculated, ...
a568's user avatar
  • 131
2 votes
1 answer
1k views

What front is going to form after a cold air mass meets a warm air mass?

What front is going to form after a cold air mass meets a warm air mass -- I think it will form a cold front or an occluded front, but I'm not sure. Today I learned that different fronts gives ...
Grey's user avatar
  • 29
1 vote
0 answers
66 views

A scenario question regarding meteorology

In the image attached, I’m struggling to find out why the answer is the way it is; maybe is me not being able to visualise it, but some help would be greatly appreciated.
De_'s user avatar
  • 43
4 votes
1 answer
455 views

What does this symbol mean?

Does anybody know what the icon inside the circle mean ? Found at aviationweather.gov
Yuzard 01's user avatar
3 votes
1 answer
468 views

What does the SOG part of this METAR mean?

CWKX 231700Z AUTO 12001KT M05/M07 RMK AO1 SOG 32 6023 SLP123 T10471068 Does anyone know what “SOG 32 6023” means? Also why is that type of metar have a bunny icon in it instead of the M or the ...
Yuzard 01's user avatar
2 votes
3 answers
2k views

What weather should we expect when temperature and dew point are similar?

What should i expect during my flight planning when i see both temperature and dew point are the same? I understand there will be fog but what else? could it mean icing? any difference between 20/20 ...
Adham81's user avatar
  • 685
1 vote
2 answers
7k views

What is the difference between Cloud Ceiling and Cloud Base?

By definition, Cloud Ceiling is the height above the ground or water of the base of the lowest layer of cloud below 6000 meters (20,000 feet) covering more than half the sky. So does, Cloud Ceiling ...
Nish's user avatar
  • 597
2 votes
1 answer
159 views

How can air stability be predicted?

After several weeks of being grounded due to low clouds, I was looking forward to the cool air, clear skies, high pressure and light winds that arrived this morning as forecasted. However, there is an ...
StephenS's user avatar
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0 votes
1 answer
2k views

1.VRB02KT: Is it varying more or less than 180°? 2.VRB03KT: Is it surely varying more than 180°? [duplicate]

Based on the following ICAO Annex 3 criteria for the use of the abbreviation VRB (not FAA, which is different and evident): when the total variation is 60° or more and less than 180° and the wind ...
Marcos's user avatar
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1 vote
1 answer
1k views

What is the difference between mist and haze in terms of relative humidity?

I am an aviation meteorologist and I struggle to distinguish the two of them.
Rebin Salar's user avatar
9 votes
4 answers
2k views

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

I have never seen the "VRB" (for wind direction variations < 60°; e.g. VRB12003KT) and "G" annotation (for gusts > 10KT wind speed difference; e.g. 12003GT30KT) being combined in a METAR. Until ...
Cyb3rKo's user avatar
  • 205
0 votes
1 answer
109 views

Help to understand a specific SNOWTAM

My questions are: According to the article ''H''; what about the other runway/runways when I want to add extra info other runway/runways too; there is just one runway in here? According to the ...
Volkan Eroğlu's user avatar
3 votes
3 answers
26k views

How to interpret BECMG and TEMPO in TAF?

I'm still confused on the change indicator BECMG. I am sure of the definition of TEMPO being only a temporary fluctuations in the time frame given, but will a TAF with a change of BECMG continue on ...
Aget Aviano's user avatar
10 votes
3 answers
4k views

How does latitude affect the air temperature at 8 km altitude where planes fly?

Is the air temperature (at 8km) above the North or South poles colder than the same altitude above the equator? Why? Ground level air temperature difference between coldest and warmest places on ...
Gnudiff's user avatar
  • 225
1 vote
1 answer
900 views

Why jet stream is stronger in winter?

I notice in a website taling about jetstream https://www.weather.gov/jetstream/jet It says: The winds blow from west to east in jet streams but the flow often shifts to the north and south. ...
Flying777's user avatar
3 votes
1 answer
1k views

How does ceiling relate to IFR and VFR?

I'm working on a Python script that takes in metar data and decides if an airport is VFR/IFR/MVFR etc. This is the website that I'm getting the info from: https://www.aviationweather.gov/metar/data?...
Matt Damoz's user avatar
10 votes
6 answers
3k views

What would the altimeter indication be through a cold front?

Cold air is heavier than hot air because of its greater density, so the QNH of an airport inside a cold front would be higher. Flying towards the cold front would be, "low to high, hello sky". But I ...
Cristóbal Ibarra's user avatar
0 votes
1 answer
101 views

Are cirrus clouds stratiform?

Cirrus clouds: Are they warmer than the environment? - Cumuliform. Or are they cooler? - Stratiform What differences do cirrus clouds have to the "Cirro" versions of a cumulus or stratus?
Noah's user avatar
  • 458
13 votes
1 answer
9k views

What is wind "CALM"?

What is the exact criteria for wind speed to be considered "CALM". Different countries might have different values and i do not mind getting answers from those. But an answer from an ICAO annex would ...
Aget Aviano's user avatar
3 votes
1 answer
482 views

Is the "PROB" in a TAF only applying to the next group or all following ones?

Let's assume I have a TAF that reads: [...] PROB40 TEMPO 0815/0822 5000 -SHSN BKN008 OVC015 TEMPO 0822/0909 1000 SN VV003 BECMG 0902/0904 16012KT Which of the <...
Florian's user avatar
  • 3,849
1 vote
1 answer
187 views

Does heavy air pollution improve takeoff performance?

As you all probably know by now, aircraft have much better takeoff performance when and where the air is denser; this is why flights need to either use longer runways or jettison passengers and cargo ...
Vikki's user avatar
  • 28.3k
3 votes
2 answers
469 views

How do barometric altimetry systems compensate for nonstandard pressure lapse rates?

Barometric altimetry relies on atmospheric pressure dropping at a steady rate with altitude, starting from a measured ground-level pressure. This, in turn, relies on atmospheric density dropping at a ...
Vikki's user avatar
  • 28.3k
8 votes
2 answers
617 views

Can pilots tell if a cloud or fog is made out of water droplets or ice crystals when flying through it?

I understand that clouds can be made out of water droplets or ice crystals. And that fog is nothing else than low-lying clouds. However, I've experienced fog in a wide ranges of temperatures. I like ...
Camilo Rada's user avatar
  • 1,251
14 votes
7 answers
7k views

What is Density Altitude?

I'm trying to get a deep understanding of the term: Density Altitude. So I have read the explanations in my instruction book, and online articles. One source explained it differently then the other ...
Julian's user avatar
  • 459
7 votes
3 answers
4k views

What’s the setting range altimeters can handle?

What’s the setting range altimeters can handle? Is there a standard requiring a certain range for aircraft to be certified? Are there many occasions where a QNH is so high or low that airplanes have ...
Florian's user avatar
  • 3,849
2 votes
1 answer
9k views

What is the difference between microburst and windshear?

When I read about these weather phenomena, I find that both of them depict the same thing, and have the same actions to avoid. So why are they differentiated? http://www.myairlineflight.com/windshear....
wiaim's user avatar
  • 2,781