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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2
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1answer
106 views

How are wind speeds typically distributed?

What probability distribution do wind speed measurements typically follow? I have seen a Weibull distribution used, but the page was a bit lacking on background information so I would appreciate ...
1
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1answer
123 views

Is there a formula for heat retained by an atmosphere, based on density and composition?

I'm looking for a formula, either precise or an approximation (it's for a video game so it's ok to have somewhat rough numbers), that determines heat retained from the sun by an atmosphere, based on ...
2
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1answer
232 views

Definition of “hundreds of ice accretion”

I saw this line today in a NWS weather alert: ACCUMULATIONS...A FEW HUNDREDS OF ICE ACCRETION. Is this standard terminology? Does "hundreds (of)" somehow refer to a unit of measure, or is there a (...
3
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0answers
137 views

Downscaling global meteorology data

Can some one explain me the basics of downscaling (interpolate to a smaller cell) a global meteorology data to a local scale (2 km × 2 km). IF would be very thankful if you provide a link at least. is ...
10
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1answer
4k views

Why is the South Pole colder than the North Pole?

This question popped into my head because I am designing a fictional world map, and I was wondering what factors influence the amount of ice at poles. I want to know why there is much more ice ...
2
votes
1answer
538 views

What causes the aurora borealis [duplicate]

I heard of the aurora borealis in North America and I've also seen the picture which made me to wonder that what causes the aurora borealis and does it have any advantages or disadvantages?
16
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2answers
4k views

Why do clouds sometimes form a ring around the Sun?

Someone shared a video with me in which clouds were forming a ring around the Sun. I took this screen shot of that video: What is the reason behind this?
8
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1answer
333 views

Why does the road appear wet on a sunny day?

Whenever I'm travelling by road on a hot sunny day and I look towards the horizon, it appears as though there is puddle ahead but as I approach it, it disappears. Why does this happen?
2
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3answers
220 views

How can I merge weather data from different time zones?

Does anyone know of any simple means for merging (inverse distance weighting method) hourly weather files (precip, temp, etc.) from different time zones? I am creating weather data for HUC8s, and am ...
9
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1answer
161 views

Dependence of solar irradiation through the atmosphere on Sun's altitude

I want to show that the higher the Sun's altitude, the higher the solar irradiation through the atmosphere, through simple experiments. However, I don't have the instrument that measures irradiation. ...
4
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1answer
229 views

Is there a differential angular rotation on Earth?

I asked a question about solar day difference between two latitudes on the same longitude here on the Earth surface. The answer was clear due to constant angular rotation time is the same. Tangential ...
23
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3answers
56k views

How do I convert specific humidity to relative humidity?

How do I convert specific humidity to relative humidity? What variables are needed (e.g. air temperature, pressure, etc.)?
3
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1answer
808 views

How do weather services measure wind

I'm curious to know where commercial weather services like the Weather Channel and Weather Underground get their wind speed and direction measurements, to produce maps like this one (http://www....
2
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1answer
342 views

Does cloud fraction of 0 for low clouds means it was raining?

What information does cloud fraction provide about weather on a certain day? Do low-level (1000-700 hPa) cloud fraction, optical thickness of all clouds and total cloud fraction provide any ...
14
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1answer
4k views

Are cloudy nights warmer than nights without clouds?

I have noticed this winter that nights without clouds (especially when the 12h before the night where not cloudy) were way colder than the cloudy ones. It makes sense to me because the clouds can ...
6
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1answer
220 views

Eliminating range folding error in doppler radar returns

With weather radar, it's not uncommon to see large areas of the image blocked out due to detected range folding. It's my understanding that this occurs when a reflection outside of range comes back ...
5
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0answers
44 views

What is the strongest observed static stability in the troposphere?

I know that typical values for the Brunt–Väisälä frequency, $N$, are of the order $10^{-2} \mathrm{s}^{-1}$, but what is the strongest observed stability? And how deep are such strong layers? I am ...
3
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1answer
600 views

Using Range Height Indicator scan of radar

I am learning about the several modes of radar that are used to study structure of thunder storms and mesoscale systems. There are three modes of radar scans as documented here - Weather Radar Systems ...
2
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1answer
386 views

How will axial precession affect the weather in the northern hemisphere (UK latitudes)?

Unless there's a twin star to our sun in which case axial precession might be an illusion the Earth's wobble won't effect the total amount of energy received from the sun as is expected from increased ...
4
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0answers
91 views

meaning of Grid resolution [duplicate]

I have some queries regarding grid. What does this mean. The grid has spatial resolution of 1/2 degrees latitude × 2/3 degrees longitude.?
-19
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2answers
1k views

Why aren't there more questions and concerns about chemtrails? [closed]

Chemtrails are amazingly obvious in our daily life but why aren't we more concerned? The information and patents for the chemicals we? are spraying are readily available. The chemicals are huge ...
11
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1answer
520 views

What does the term “Snow Interval” mean?

When looking Weather Station readings from the National Weather Service website, what does the term "Snow Interval (inches)" actually mean? 6 hr and 24 hr readings are obvious, but I can't seem to ...
6
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0answers
98 views

Worldwide weather maps database

I am searching for a database (a free one would be great) that would give me, for any chosen rectangular area on earth, historic data about pressure, sea water temperature, wind (including both speed ...
4
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1answer
711 views

How is a UV Index calculated?

I have three parameters for a particular location, namely: Ozone:- A numerical value representing the columnar density of total atmospheric ozone at the given time in Dobson units Elevation: The ...
8
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1answer
696 views

How is the vertical velocity defined in sigma-pressure-coordinates?

I have a problem in deriving/understanding the vertical velocity in sigma-pressure coordinates. The vertical coordinate is defined as: $$\sigma(x,y,p)=\frac{p(x,y)-p_t}{p_s(x,y)-p_t}$$ where $p(x,y)...
4
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1answer
86 views

NCDC Snowfall Data - Interpretation?

This is my first time using this dataset, so I have probably made an elementary mistake. I am having trouble understanding a file from the NCDC's climate normal dataset: http://www1.ncdc.noaa.gov/pub/...
6
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2answers
2k views

Historical NWS GFS forecast data

The National Weather Service (NWS) makes the results from its Global Forecast System model (GFS) available for download as GRIB2 files. While accessing current (or recent) forecasts is straight-...
1
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2answers
316 views

Appearance of Tornado

Does the appearance of a tornado come from the dust or is there some characteristic of swirling wind? Additionally many experiments shows a tornado-like phenomena in a jar of water, is this possible ...
2
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0answers
362 views

Great Lakes Earth: The Americas [closed]

Related to If the Oceans Were Deeper The Appalachian Range, at first glance, doesn’t seem so different—low-lying hills covered in forest dominating the eastern landscape. However, they are taller—7,...
10
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1answer
239 views

Does this optical phenomenon have a name?

Last summer, I snuck out with a row boat around 4am. Eventually with the sun risen but still quite low in the horizon, I was rowing in the middle of the absolutely still lake when I witnessed an ...
7
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2answers
1k views

How do I represent wind direction on a UTM (Universal Transverse Mercator) map projection?

What does it mean when I say "the wind direction is 50o" on a UTM map? Which direction is the 0o reference? For example, if I draw a wind vector V as seen in the ...
9
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0answers
248 views

What is the finest horizontal grid spacing that Eulerian grid-cell air-dispersion models should use?

My colleagues run the Advanced Research Weather Research & Forecasting (WRF) model in predictive mode, and then test the skill of the model anywhere from 12 - 84 hours out from the initialization ...
2
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1answer
54 views

Meteorology in Canada

I'm interested in understanding how meteorology works in Canada (esp. from an Open Data perspective). Can someone explain, or provide resources, that indicates an overview of the actors involved on ...
2
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0answers
137 views

Correlation of El Nino and south indian monsoon

A recent article in New Scientist reports the following claim made by Wenju Cai at CSIRO Melbourne. Southern India is having a lot of rain as it goes into winter, having come out of the dry ...
5
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2answers
6k views

Why doesn't it snow even when it is below freezing?

I know the temperature of a place is determined by various factors, a few of which I can think of are: Altitude, distance from sea, latitude, wind etc. My question is basically regarding latitude. ...
4
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1answer
95 views

Are oceans a major factor in creating high winds on a planet?

This question only pertains to oceans of water and how much they account for the process of creating high winds on a planet with any type of atmosphere.
4
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2answers
145 views

Need help understanding variables that relate to meterology terminology

I am working on a project in predicting the weather and I had a few brief questions. I understand that radar works by bouncing waves off of precipitation and measuring reflectivity. I have a variable ...
20
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2answers
4k 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 ...
2
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1answer
94 views

References on hurricanes

Would anyone know of references (available online or not) that give detailed explanations and especially the physics behind violent meteorological events such as hurricanes?
1
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0answers
74 views

What happens if humidity is 100%? [duplicate]

What happens when the humidity is 100% in atmosphere. Does it heavily rains or fog formation occurs? Or is there any other possibilities?
1
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3answers
2k views

El Nino in the Middle East

According to reports and charts meteorological phenomenon El Niño is close to Iran, but the question is, El Niño phenomenon in Iran is likely to achieve? What are the consequences?
8
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1answer
266 views

What's with this anomaly in this sounding (the CAPE and CIN readings)?

This sounding is from 2 hours after the 2.6 mile wide El Reno tornado on May 31 2013.
9
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1answer
935 views

Evaporation loss formulas

A while ago I created a spreadsheet to calculate evaporation loss. I found several formulas to do that, two from Kevin Rafferty and one from Engineering Toolbox. The one from Engineering Toolbox was ...
4
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1answer
352 views

Why is it always rainy in Addis Ababa?

I watch the news and in the weather forecast it's always rainy in central Africa, especially in Addis Ababa. Why is that?
3
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1answer
492 views

Website that contains the maps of atmospheric pressure and wind speeds

Is there a website that contains the maps of atmospheric pressure and wind speeds for specific climatic events such as hurricanes day after day ?
8
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2answers
937 views

How are 'Morning Glory' clouds maintained?

Reading the Physics.SE question What is the current physical theory of what causes the 'Morning Glory' roll cloud over Northern Australia? (pictured below): Image source: NASA Astronomy picture of ...
6
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0answers
81 views

Spatial variability in ocean surface winds

For the near-surface winds over the ocean, many model products and satellite footprints have spatial resolutions on the order of tens of kilometers. I'm interested in knowing how much the winds (both ...
5
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0answers
80 views

NCEP reanalysis latitude and longitude represent center of cell?

I can't find any information regarding the lat and long in the NCEP Reanalysis. Do they represent the center of the cell?
2
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0answers
54 views

What determines the number of Hadley cells on a planet? [duplicate]

I know it has something to do with the rotation speed, but what exactly? And why?
10
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1answer
432 views

Optimal vertical coordinate for complex topography

There are plenty of choices in models in so far as choice of vertical coordinate is concerned for meteorological models. Five that I know of: The sigma coordinate system - Hybrid coordinate system(...

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