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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3
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0answers
65 views

Roughly what proportion of a cloud does 'rain out'?

What proportion of the water in a cloud will 'rain out'? Or, comparing the cloud before and after it has rained, what proportion of the water is left afterwards? I really have no idea so am just ...
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2answers
113 views

Temperature Advection using finite differences with gridded data

Advection of a scalar quantity, such as temperature (T), by the horizontal wind, is defined as follows: $-\textbf{U}\cdot\nabla T$ where $\textbf{U}$ is the horizontal wind vector, $\textbf{U}=(u,v)$...
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2answers
170 views

What are the farthest Time Zone locations? [closed]

What place in the world has the farthest time zone? I heard it was Kiribati but then I found that Apia (Samoa) is further. So, is there anyplace that is the farthest in time than these two? What about ...
2
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2answers
54 views

Data for plotting tephigrams

I want to plot some tephigrams. Where can I find pressure, temperature and dewpoint data in text format?
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0answers
42 views

Any appreciable differences in microclimate on the shores of small mountain streams?

I have land in India (the tropics), in the hills, on a slope from 6800 feet - 5200 ft altitude (roughly). At that lowest point there's a stream of about 10-15m across. On one side is our land, on the ...
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1answer
145 views

How do I interpret this “sky cover” chart?

The image below is a screenshot of forecasted sky cover in percentage for various parts of Arizona. Is the sky cover percentage the percentage of each pixel that has cloud, or is it the percentage of ...
2
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1answer
118 views

Why is convective precipitation associated with heavy rains?

Why is convective precipitation associated with heavy rains? As per wikipedia's page on Atmospheric Convection: "Moist convection leads to thunderstorm development, which is often responsible for ...
7
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2answers
956 views

What causes a rainbow, its colours and its shape?

What is the cause of rainbows? Do they appear due to rainfall or any other natural phenomenon. What makes it form a semi-circle in the atmosphere and its colours?
12
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2answers
310 views

How to tell if fog is made out of water droplets or ice crystals?

I understand that clouds can be made out of water droplets and/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 ...
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?
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2answers
91 views

Does snow melt on ice?

I looked up nearly everywhere on the internet, but couldn't find any evidence that snow wouldn't melt because of ice. When I look it up, it instead tells me how salt can melt snow. I'm NOT looking up ...
5
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2answers
109 views

Would the enthalpy of fusion for melting ice fields be a causative factor for colder winter weather?

Would the enthalpy of fusion for melting ice fields be a causative factor for colder winter weather? As an example, NASA estimated the annual loss of the Greenland ice field 2002-2013 as more than ...
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1answer
132 views

Where can I find information about monthly seasonal change in a given area?

I have searched Google for almost an hour with no result. I'm looking for something like, "Indonesia, January to August is rain season, September to December is hot season". I can't use the old ...
4
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1answer
134 views

How averaging works in GFS model from NOAA?

We have downloaded grib2 files for GFS model from NOAA and extracted irradiance (Downwards shortwave radiation flux) data. Following is a sample output for cordinates at [52.0,4.0]: ...
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1answer
1k views

Why do anticyclones bring clear skies in summertime?

It's obvious that in summer anticyclones bring hot weather. But why clear skies? Heat evaporates the moisture and should lead to the cloud formation, shouldn't it?
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 ...
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0answers
36 views

Topography and flash flooding

I'm looking for a study or document showing the effect of the topography, slopes, the sea level and the tide on flash flooding occurrence. Thanks in advance
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2answers
346 views

What are the sunniest places on Earth? (including oceans)

This question did arise when thinking on offshore solar power plants, what's their potential, and how efficient would they be compared with land based counterparts. Recently, it is becoming more ...
18
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2answers
5k views

Where is the calmest place on Earth?

I have done some research online, and I've found out that Antarctica has the calmest winds (lowest maximum wind speed) recorded on Earth. However, it is uninhabitable for human life. Other very calm ...
5
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2answers
972 views

Easterly Jet Stream

If most of jet streams are westerly, that is to say, they blow from west to east, why does the tropical/equatorial jet stream blow from east to west?
2
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1answer
35 views

Where can I find a list of snow fall recording stations in my zip code?

Where can I find the locations on snow fall recording stations in a particular United States county or zip code? Is there a way that I can find an hour by hour recent history of snow fall? Hour by ...
2
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1answer
894 views

WRF vertical integrated moisture flux using NCL

Does anyone know how to calculate the vertical integrated moisture flux using NCL in WRF. It would be best if you can share a NCL script. Here is my code, I used this code to calculate the averaged ...
12
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1answer
424 views

Relation between direction of shear and tropical cyclone formation

In an earlier question/answer Why are there no cyclones in the southern Atlantic basin there was a point raised about direction of shear(abetting/retarding) cyclone formation. It appears ...
7
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1answer
766 views

What is the consensus among geologists about climate change being caused by humans?

I'm terribly frustrated with the way that climate change has been debated in Europe. I live in the Netherlands and members of one of the biggest parties here, the Party for Freedom (PVV), frequently ...
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4answers
1k views

Have there ever been simultaneous cyclones in the same ocean but different hemispheres?

I'm teaching a physics class, and I'm getting to the point where we are talking about the Coriolis effect. I usually show a couple of photos/videos showing a storm in the Northern Hemisphere and a ...
10
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1answer
112 views

Rainbow dynamics?

How would steam refract light compared to fog and how would the rainbow appear? Does the temperature of the water drop or ice crystal effect the rainbow in any way? I know the size of the water drop ...
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1answer
336 views

If storms form above low pressure regions, why doesn't the eye of a hurricane, a low pressure region, have any storms?

If this is due to the Coriolis Effect, my other question would be how does the wind go upwards to form the storm clouds?
10
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1answer
310 views

Unstable North Polar Vortex?

What would cause a polar vortex to become unstable a split into 3 smaller ones? How rare is this and what long term effects could this cause if the vortex stays unstable? http://www.severe-weather.eu/...
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0answers
49 views

Figuring out the temperature at the tropopause

Either I am misunderstanding something, or reading conflicting information. Likely the former. First off, the tropopause is defined as the boundary between the troposphere and the stratosphere. That ...
4
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1answer
256 views

Do solar storms affect Earth's weather?

Solar storms have a direct effect on Earth, creating charged particles. What are the direct and indirect effects of large solar storms on Earth's atmosphere? Do solar storms affect Earth's weather?
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1answer
146 views

How much further can weather forecasting models go before the limits of Chaos Theory set in?

Refer to a report here that mentions the huge advancement in weather forecasting models since the 1980s: How much better? “A modern five-day forecast is as accurate as a one-day forecast was in ...
4
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1answer
212 views

Were there any polar vortexes in 2018?

Were there any polar vortexes in 2018? On what dates? I want to see what the weather looked like on those dates: https://www.youtube.com/watch?v=FPuDPxK88g0 Yes I know. You would think that I could ...
17
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2answers
4k views

Does the US National Weather Service use Celsius or Fahrenheit?

This tweet from the National Weather Service in LaCrosse, Wisconsin, USA says: We have officially hit -30 here at the NWS La Crosse office as of 520 a.m. The wind chill is -54. Be sure to dress ...
7
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1answer
504 views

Computing Isentropic Potential Vorticity from Hybrid Sigma Pressure levels

My task is to compute isentropic potential vorticity on a grid. All data (ECMWF ens) are given on a hybrid sigma pressure grid. Since I really cannot find reference, I assume (!) that relative ...
4
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1answer
149 views

Why would geostrophic theory be invoked in the tropics with regards to the MJO?

In this paper reviewing the Madden-Julian Oscillation, frequently geostrophic theory (or approximately geostrophic) is often invoked. However, for geostrophic theory to be invoked, $$Ro=\frac{U}{f_0L}&...
3
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1answer
133 views

Circular rain cloud observed in rain radar

This circular rain pattern was observed in Sydney’s rain radar today. It remained for the entire loop, wiggling around a bit but mostly staying in the same place. The fact that it’s centred around ...
2
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1answer
56 views

Does wind chill work in deserts?

Wind chill works by removing the layer of heated air around your body. However in a hot area, say a desert, wouldn't the air around be hotter than your body or at least much closer to it than cold air?...
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0answers
80 views

How can I convert a CERA-20C total precipitation dataset of "monthly means of daily means' (edmo) to mm/month?

I downloaded an edmo dataset of 1 ensemble of the cera-20c model. I want to convert these data, which are in [m], to mm/month. Further specifications: 0.125/0.125 grid, -29/30/-30/31 area. Example of ...
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2answers
182 views

What happens if it rains above the boiling point of water?

The freezing point of water is 32°F. If it rains at a temperature lower than that, it will snow. However, let's say we dig a deep hole not filled with water that goes like 10,000 feet below sea level. ...
2
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0answers
26 views

What is the accepted measure for Wind Coherency (Strength and Direction)

I have wind data from a Met station (Speed and Direction), and I'm looking for a way to characterize a strong coherent wind. AKA - Wind that averages 12 m/s out of the East for 2 days would have a ...
13
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3answers
3k views

How is it possible to use up the water in a region?

The Dead Sea, rivers in California and the Aral Sea are said to be shrinking due to water usage, e.g. for agriculture. Yet the water must go somewhere. After the fields are irrigated, the water ...
2
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1answer
301 views

How to calculate Wind direction from uwind and vwind?

How to calculate wind direction from uwind and vwind? if uwind and vwind are -1.82 , -3.18 respectively
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0answers
78 views

how to calculate the average moisture flux over a period of time

I wanna calculate the average moisture flux over a period of time. For example the average moisture flux over an entire summer. I don't have a meteorological background. I have a conceptual confusion ...
12
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2answers
4k views

Is spectrum of sunlight the same in the summer as in the winter?

Of course we receive less sunlight in winter, because the sun is lower in the sky, so the light has to travel through more atmosphere, and loses strength. Does this mean that the blue light is more ...
3
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1answer
71 views

Is it certain that hundred year floods have finite variance?

It just occurred to me to ask this. It's easy to get a statistical distribution that does not have finite variance. For example, you can sometimes get that when the thing that is measured comes from ...
3
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1answer
127 views

Are there “transparent” clouds?

Comments below this answer to the question Why are lightning towers at launch pads topped with big hollow tubes with spiral windings and not “lightning rod-shaped” lightning rods? link to a 2013 ...
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8answers
8k views

Is it possible to create an enclosed manmade weather system?

There are plenty of experiments, usually geared toward kids, that involve "making a cloud in a bottle" or something similar. These exercises are neat for what they are, but pale in comparison to the ...
5
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3answers
1k views

Does the Coriolis Effect affect a wind from East to West?

I'm studying meteorology for a pilot license and there I was taught as a rule of thumb that wind at higher altitudes is approximately turned 30° clockwise to the wind on the surface due to the ...
2
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2answers
296 views

What is are the benefits of map 500 hPa geopotential for weather forecasting?

From the weather forecasting perspective: what is the main reason for showing just map of 500 hPa geopotential? Are there any practical or theoretical reasons? Why do not show 600 hPa geopotential or ...