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.
912
questions
2
votes
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
vote
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
vote
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
vote
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
vote
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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(...
