Questions tagged [meteorology]

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

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2answers
105 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) ...
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1answer
71 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 ...
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1answer
501 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, ...
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1answer
295 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 ...
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2answers
859 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 ...
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0answers
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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.
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1answer
235 views

What does this symbol mean?

Does anybody know what the icon inside the circle mean ? Found at aviationweather.gov
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1answer
147 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 ...
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3answers
126 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 ...
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1answer
101 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 ...
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2answers
254 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 ...
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1answer
426 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 ...
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1answer
316 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.
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4answers
739 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 ...
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1answer
68 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 ...
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2answers
6k 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 ...
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6answers
1k 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 ...
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3answers
3k 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 ...
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1answer
2k views

How do pilots clear an aircraft to fly through a hurricane?

This video shows a pilot (Tim Gallagher/NOAA) flying what looks like a small jet into the eye of hurricane Matthew by Miami. It's clear that it is quite an interesting ride. The (small) caption states ...
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1answer
251 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. ...
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1answer
324 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?...
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1answer
71 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?
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1answer
5k 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 ...
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1answer
139 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 <...
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2answers
451 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 ...
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1answer
125 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 ...
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3answers
2k 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 ...
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1answer
5k 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....
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2answers
266 views

Is the size of hail on the ground any indication of the winds and updrafts of a thunderstorm?

Is there any rule of thumb or way to estimate the wind speeds or up and down drafts inside a storm by the size of hail that reaches the ground?
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2answers
5k views

Icing conditions temperature range: SAT or TAT?

Considering the general rule of thumb defining potential icing conditions: temperature between +10 and -40 degrees C and presence of visible moisture, is the temperature range regarding TAT (total ...
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5answers
4k views

Why on weather surface charts high pressure is blue and low pressure is red?

Is there any relation with the temperature of the air or is it just a standard procedure?
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0answers
108 views

How do subjective experiences in the airliner cabin correlate with meteorological conditions?

There must be a better way of phrasing this, but: given the passenger's experience of riding through the air, what are the outside conditions that are responsible for that experience? For example, if ...
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1answer
342 views

What is the physical definition of turbulence?

To aviators, the definition of turbulence by measuring the results is widely known: example. But if we were to generate a turbulence forecast as a meteorologist, there need to be some kind of physical ...
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2answers
7k views

How should I interpret this TAF involving TEMPO and BECMG blocks?

with the reference in the TAF below , I was looking for the VIS at 0500 UTC and I was little bit confused because of the " TEMPO " And the TAF was ...
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1answer
195 views

To what extent are (non-urgent) PIREPs used by meteorologists?

It's inevitable. At some point during your weather briefing, some underpaid, underappreciated briefer will say "Pilot reports are requested." and you'll say "Certainly, my good sir or madam! Why, the ...
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1answer
1k views

Is there much turbulence in the Doldrums?

A place over the equator called the Doldrums are know for the severe lack of sailing winds. In the atmosphere above it is there any presence of turbulence anywhere? Where would the least year round ...