Questions tagged [meteorology]

The study of how the earth's atmosphere works, including weather forecasting. Use this tag for questions about the earth's weather. When asking questions specifically about the atmosphere, also include the [atmosphere] tag.

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10
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2answers
178 views

Why does the rising of high clouds due to climate change impart positive radiative feedback on radiative forcing?

As seen in the figure below. The larger the temperature difference between surface and cloud, the more positive the radiative forcing is from the cloud. So as the cloud moves up, it supposedly ...
13
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2answers
176 views

Are clouds significantly easier to simulate in weather models than climate models?

Cloud forcing is still one of the major uncertainties of radiative forcing in climate modeling because there are so many uncertainties in it (and parametrizations). But also because the timescale of ...
6
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1answer
1k views

Why are most cirrus clouds present over the equator and over tropical continents?

As quoted from the AR5 IPCC report (chapter 7) here. Most high cloud (mainly cirrus and deep cumulus outflows) occurs near the equator and over tropical continents, but can also be seen in ...
4
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1answer
320 views

How does the lapse rate in clouds compare with the lapse rate of air?

So moisture decreases the temperature lapse rate (relative to the dry adiabat). My question is this: does a cloud decrease the lapse rate at the same rate as 100% humidity would decrease it? Or would ...
8
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3answers
1k views

A good book or source for climate science and meteorology basics?

I have a mainly a hydro-geological and geo-statistical background, I would like to have a basic introduction to meteorological, climatic processes and modelling techniques related to these fields. Any ...
15
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2answers
767 views

What factors affect the size of rain shadows?

Rain shadows are dry areas on the lee side of mountains. Due to humid air condensing and precipitating as they are lifted up and over the mountains, they lose moisture by the time they reach the lee ...
12
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2answers
394 views

Bifurcation Scenarios in the Atmosphere

I read that the mathematical definition of bifurcation is that, at a critical value of a parameter that governs the dynamical system, the system changes to a topologically different system than the ...
16
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3answers
3k views

Why does the so called “tornado alley” exist?

75% of the world's tornadoes occur in the USA, and within the USA these tornadoes are most likely to occur in particular regions of the country, such as the well known "tornado alley". The diagram ...
19
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2answers
263 views

Will tropical cyclones form and be sustained in areas they previously were not due to global climate change?

With global climate change, is it possible that tropical cyclones (as seen in the Atlantic basin for example) are going to form and be sustained in regions where they previously did not, for example ...
19
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1answer
5k views

Where does wind come from?

Wind is (according to Wikipedia) the flow of gases on a large scale.On the surface of the Earth, wind consists of the bulk movement of air. What forces would cause such a mass movement of air?
11
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2answers
5k views

How can I plot a Skew-T log-P diagram?

For displaying atmospheric soundings the use of Skew-T Log-P diagrams is very common. The manual THE USE OF SKEW T, LOG P DIAGRAM IN ANALYSIS AND FORECASTING from the Air Weather Service explains what ...
44
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5answers
12k views

Why do snowflakes form into hexagonal structures?

Snowflakes are known to form into pretty hexagonal structures. The image below shows a variety of such structures that are possible (although by all means not an exhaustive list): What is the ...
18
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2answers
5k views

Why does the Hadley cell descend at 30 degrees?

George Hadley's initial model of the Hadley cell described air as being heated at the equator, ascending, and then moving aloft pole-wards where it would cool and descend. Meanwhile surface air would ...
11
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1answer
777 views

Why does the meandering pattern of the jet stream itself propagate?

It is well known that the jet stream follows an overall meandering pattern, but what is less well known is that this meandering pattern itself moves as a wave with a velocity much slower than the ...
23
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2answers
1k views

What is the cause of the jet streams?

Jet streams are fast-flowing currents of air in our earth's atmosphere. An enormous amount of energy is necessary to keep a jet stream going. Where does this come from and why?
23
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1answer
2k views

What causes 'positive' lightning to be rarer, higher charged, and longer lasting than 'negative' lightning?

Why is 'positive' lightning rarer, brighter, higher charged, and longer lasting than 'negative' lightning? Are there any other unique characteristics to positive lightning that sets it apart from ...
16
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1answer
5k views

What do quasi-geostrophic and ageostrophic mean?

I know that geostrophic flow means straight wind flow that is balanced by the pressure gradient and Coriolis forces. But what do quasi-geostrophic and ageostrophic mean specifically?
18
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1answer
359 views

How is global weather model skill measured?

The models I have in mind are the major global models such as the Global Forecast System (GFS) and the European Center for Medium range Weather Forecasting (ECMWF). These models produce numerous ...
17
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1answer
813 views

Why do tropical cyclones not tear themselves apart?

A tropical cyclone is the generic term for a hurricane, typhoon, or tropical storm. Tropical cyclones derive their energy from evaporation of water at the ocean surface which ultimately recondenses ...
19
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5answers
5k views

Is it true that a butterfly flapping its wings can result in a tornado in a distant location?

I have heard that extreme storm events can be caused simply by a butterfly flapping its wings somewhere in a distant location. Is it true that such a small disturbance in the air in one location can ...
9
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1answer
6k views

What are the key differences between warm and cold core cyclones?

What are the key differences between warm and cold core cyclones? What is an example of each?
81
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3answers
25k views

Impossible or improbable? Hurricane crossing the equator

No known hurricane has ever crossed the equator. Hurricanes require the Coriolis force to develop and generally form at least 5° away from the equator since the Coriolis force is zero there. Are ...
21
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2answers
3k views

How do tropopause folds form and do they have any impact on synoptic scale weather?

What is the process that creates a tropopause fold? Do these features have any significant impact(s) on weather patterns or the atmosphere?
14
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1answer
1k views

How can I estimate a 2 m temperature from / in an atmospheric model?

Numerical models of the atmosphere usually have their first atmospheric grid level well above 2 m, but the temperature at 2 m above ground level is something one often wants to calculate with such a ...
8
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1answer
445 views

Can overshooting tops enter the stratosphere, or will they rather push the tropopause upward?

Convective overshooting tops reach above the normally horizontal flat layer of the convective system, a layer that should coincide with the tropopause. If we have such an overshooting top, does this ...
15
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1answer
89k views

Does a green or yellow sky actually indicate a tornado?

It seems to be a fairly widely held belief that if the sky is green or yellow, a tornado may be developing/approaching. But is there any truth to it? Could the color of the sky actually be associated ...
24
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3answers
7k views

What do weather forecasters mean when they say “50% chance of rain”?

What do weather forecasters mean when they say "50% chance of rain"? Even more confusing: weather report often says something like "30% chance of rain. >10mm", then the next day "70% chance of rain &...
14
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2answers
1k views

Why don't cold fronts and other steep-gradient weather effects just dissipate?

Why don't cold fronts and other steep-gradient weather effects just dissipate? Why do they last so long? Why doesn't the heat dissipate toward the cooler region?
11
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1answer
263 views

Are sandstorms like regular storms?

What's the difference between sandstorms and regular storms? Are they more than just strong wind within deserts?
12
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1answer
180 views

Why does every tsunami travel differently?

Tsunamis are quite interesting, as they only happen after a large displacement of water. Usually, the waves travel quite weirdly. Sometimes there are waves which bounce off of land and go back to sea....
11
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2answers
589 views

How do we measure (or empirically calculate) the amount of entropy in the atmosphere and oceans?

Here's a paper on the entropy budget1, where moist entropy is defined in equation (8) as $$ s = (1-q_t)(C_{pd} \ln T - R_d \ln p_d) + q_t C_l \ln T + \frac{q_v L_v}{T} - q_v R_v \ln \mathcal{H} $$ ...
14
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1answer
349 views

What are the impacts of sublimation on an annual mountain snowpack?

Massive amounts of freshwater rests atop the world's mountains in the form of ice, snow, permafrost, and glaciers. Many areas of the world rely upon the melting of snow and ice to recharge their ...
11
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1answer
199 views

Why is heavy precipitation from atmospheric rivers more likely to hit the West Coasts than the East Coasts?

As an example of an atmospheric river, see http://www.wired.com/2014/03/california-atmospheric-river-rain/. These events have been known to hit areas like California and Bergen, Norway.
6
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1answer
244 views

How can I calculate the average latitudinal temperature anomaly between a city and all other locations along the city's latitude?

E.g. How could I calculate the average temperature anomaly between, say, Boulder, CO and all other locations along the 40N parallel? What about Boulder, CO, and all other locations along 40N at ...
16
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1answer
478 views

How will cloud feedback effects on the climate change as the result of global warming?

So global warming will increase the tropospheric temperatures, which, in turn, would make the clouds higher than they otherwise would be. And higher clouds (especially cirrus clouds) tend to trap in ...
20
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2answers
3k views

What are the major differences between weather models and climate models?

Some weather models include GFS (Global Forecast System) and NAM (North American Mesoscale Model). Some climate models include CCSM (Community Climate System Model) and the NASA GISS (Goddard ...
29
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4answers
4k views

How do weather models work?

We use different weather models all the time, such as the ECMWF and the GFS. These models are simply amazing to me. How do these models work? I know they have to take in various data points - what ...
17
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3answers
1k views

How do I explain why the Tibetan plateau is colder than lowlands at similar latitudes?

A common layman explanation for why does it get colder to higher elevations (considering only the troposphere here) qualitatively boils down to The Sun heats the Earth's surface and the Earth's ...
9
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1answer
1k views

How does the pole-to-equator temperature gradient scale with height contours?

Are the pole-to-equator temperature gradients lower at higher heights than at lower heights (like 850 mb/500 mb)? If so, why is it the case? Especially given that the zonal circulation tends to be ...
17
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1answer
495 views

Why are weather kites no longer used (much) operationally?

Figure 1.12 from the IPCC AR5 WG1 report (reproduced below) illustrates the different instruments that have been used for weather forecasting. Most of the methods have been in continuous use since ...
12
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2answers
7k views

What determines how fast clouds move?

Do cirrus clouds in the upper troposphere move faster than cumulus and stratus clouds in the lower atmosphere? What about clouds associated with extratropical systems, compared with clouds in the ...
9
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1answer
115 views

Are there any quantities defined analogically to the virtual temperature, but for other gases?

The virtual temperature is a pseudo-temperature taking into account water vapour in the atmosphere in such a way, that the resulting quantity can be used with the ideal gas law and the molar mass for ...
14
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1answer
147 views

Have there been any attempts to measure profiles through deep convective systems using dropsondes?

In-situ measurements in deep convective systems, tropical cyclones, etc., are difficult to perform. Few if any people would like to fly a small aircraft close to its core, and radiosondes or larger ...