All Questions
Tagged with weather or meteorology
1,216 questions
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Why does northeastern Asia have dry winters?
Northeastern mainland Asia such as northeastern China, North Korea, most of South Korea and parts of Siberia are classified as a Dwx climate, meaning they have dry winters. Why is this despite being ...
- 133
5
votes
1
answer
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How does LIDAR work? Why is scattering not weakening the beam?
Let's say LIDAR is used for atmospheric vertical sounding. If backscattering takes place some amount of the outgoing radiation is scattered back to the LIDAR. But if this is the case, the vertical ...
- 985
11
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2
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Is the southern hemisphere colder than the northern one or is it just me?
When comparing the same latitude at each hemisphere I've got the impression that the southern hemisphere is generally colder.
Tasmania and New Zealand's North Island for instance are around 36-43 ...
- 133
0
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18
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How to Accurately Adjust NetCDF Time Data to Reflect Local Solar Time Using Xarray?
I have a NetCDF dataset with a variable (let's call it s) that depends on local solar time. The current time dimension is in UTC, and the dataset has the following dimensions: lat, lon, and time (...
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2
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43
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How to calculate horizontal wind shear (esp. via Python)?
I would like to ask about horizontal wind shear. In most cases, we frequently talk about vertical wind shear (VWS), which is the change in wind speed and direction with height or within a given layer/...
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11
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2
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Is a heat wave in the Northern Hemisphere likely to be accompanied by a cold wave in the Southern Hemisphere?
I grew up and live in the Northern Hemisphere. In high school, I first learned that the northern and southern hemispheres have opposite seasons. I thought it interesting how this might imply that the ...
- 273
2
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1
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68
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How would no ozone change temperature?
If the ozone in the ozone layer were to completely disappear would global temperature averages increase or decrease?
Seems like it might be simple but to me it isn't because the sun's radiation would ...
HGA
5
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2
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470
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Alternative solution to Meterological weather forecasting systems
As a alternative to Weather forecasting systems, Can machine learning prediction algorithms assist in predicting hurricanes?
What will be the input dataset for predicting future hurricanes which will ...
- 183
3
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1
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36
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Why is it generally cloudier and drizzlier during the winter (or high latitudes) while during summer (and in tropics) rains are short but intense?
High latitude regions, as well as temperate regions during the wintertime, experience a lot of cloudy, 'drizzly' and/or 'misty' days....
...while tropical areas (and temperate places in the summer) ...
- 857
2
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1
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77
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What does 10E, 09L, 10L mean after a hurricane or tropical storm name
I am looking at an aviation weather chart and see T.S Isaac 10L and Hurricane Helene 09L and hurricane John 10E.
What do these numbers mean after the name (10E, 10L, 09L) ?
A similar question talks ...
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Arctic polar vortex collapse
What if the Arctic vortex collapses (not forming during cold months) due to anthropogenic global warming and the warming of the Arctic Ocean?
If it "dies" in the coming decades, is it likely ...
4
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1
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164
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For glacier winds to exist, are circulation cells needed?
When air close to a glacier surface gets cooled, it becomes heavier and flows down the glacier slope as glacier winds. I am a glaciologist trying to study and model glacier winds. I am confused about ...
- 173
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1
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43
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Rainfall Rate - unit conversion
when converting the Rainfall Rate unit from mm per HR (Sq. m) to inch per HR (Sq. ft)
why are they multiplying by 25.4 only and not considering the conversion from m2 to ft2
for example
mm/m2 --> ...
- 3
1
vote
1
answer
300
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Are there technologies available today that could be used to steer hurricanes or cyclones?
I was reading a news article on CNN which dates back to 2012 regarding Hurricane Sandy which was the second-costliest hurricane in United States history. The article states:
Hours after Super-storm ...
- 11
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1
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46
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Why is there so much activity in the upper atmosphere, even though it is usually colder?
My son thought the atmosphere (that is, above our heads as humans) is hotter than what we experience, and I told him that it is typically cooler. (I suppose there can occasionally be an "...
- 103
4
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1
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209
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Why are these three "disturbed weather" events called "Invest" and what to the subsequent numbers and letters mean?
A proactive state of emergency has been called in the US state of Florida because Invest 97L may be on its way. I looked at https://zoom.earth/storms/97l-2024/ and then started going arond the world ...
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What's the mathematical idea behind weather forecasting POP (probability of precipitation) by slices of time?
How should I think about the maths (and actual probabilities of rain), with weather forecasting POP (probability of precipitation)?
Taking for example Weather Network for Vancouver
Mostly I am curious ...
2
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0
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237
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Could the electrical potential difference between the Windward and Leeward sides of a mountain range generate electrical current?
I would like to know if it is possible that the electrical potential difference between the Windward side and the Leeward side of a mountain range, due to a thunderstorm occurring on the Windward side,...
user23275
2
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0
answers
39
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Reading MSG Native(.nat) file with satpy
I am trying to read an MSG (Meteosat Second Generation) file given in the native(.nat) format using satpy. I tried using:
...
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1
answer
90
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Combining data with different future climate scenarios
I have climate data for future projection scenarios of the RCP type only (i.e., RCP 4.5 and RCP 8.5) and land cover data for future projection scenarios of the SSP - RCP type (i.e., SSP 2 – RCP 4.5, ...
- 13
2
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1
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67
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What is this band of reflectivity return caused by?
On the reflectivity scan from TIAH on 20240624 at 2058z, a couple of thunderstorm cells pop up to the West of the radar site. Just beyond these cells, a narrow North-South band of reflectivity return (...
- 21
5
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2
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234
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Why does it snow in Harbin, China but not in Venice, Italy?
Both cities have the same latitude. Why does it snow in Harbin but not in Venice?
1
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1
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88
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Up to what radius/distance/area maximum do weather parameters remain constant?
Up to what radius/distance/area maximum do weather parameters remain constant? For example, precipitation is so variable that it can vary even within a few meters, while sunshine durations may not ...
0
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0
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120
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NCEP GFS data products: ANL and FH000
I'm confused with the GFS model data products, presented at NCEP Products Inventory website. There are two types of products for analysis: ANL ("**.anl") and FH000 ("*.f000"). As ...
- 101
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0
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26
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Does the UV index over a day form a Gaussian?
If you go to a website such as this that shows a plot of the UV index throughout the day, you will see that the plot for each day resembles a Gaussian distribution. Perhaps someone with access to raw ...
- 121
4
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1
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38
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How does ERA5 reanalysis data deal with wildfires?
I am trying to investigate the likelihood of a fire occuring in the Amazon rainforest based on environmental variables, including ERA5Land data such as temperature, wind speed and relative humidity (...
1
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0
answers
12
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How is cloud column water calculated in GDAS model files?
The question
NOAA helpfully provides model outputs from the Global Data Assimilation System (GDAS) for the past 10 days (https://nomads.ncep.noaa.gov/pub/data/nccf/com/gfs/prod/). Products include ...
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34
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Is there some science behind the cloud color of "electric blue"
I do notice that the bottom of thunderheads have a dark grey blue hue(here in the PNW they do where I live and T-storms are not common but they do happen). And many times when I see a cloud bank ...
- 273
4
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1
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109
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What would be the atmospheric pressure if the atmosphere was 2/3 the density of water?
I came across a theory that proposed that earth's atmosphere must have had a density of 660 kg/m^3 during the mesozoic, and the gigantic size the dinosaurs attained on land was only possible due to ...
- 41
2
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0
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82
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Absolute and potential vorticity conservation
The source processes for (vertical) vorticity in the baroclinic vorticity equation are the stretching, tilting and solenoidal terms. I understand that all of these terms go to zero in a barotropic ...
- 51
3
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0
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76
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How can friction and Coriolis force balance each other out in the Ekman layer?
In most derivations of the Ekman spiral we begin by assuming a steady state in which only frictional (drag) and Coriolis forces are acting- and then we equate them to get the spiral. I have two issues ...
- 51
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1
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76
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Weather patterns and national borders
I've been observing weather patterns, especially rain, and to me it looks like there is a correlation with national borders.
Of course it is nonsense to think rain clouds stop at national borders to ...
- 143
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1
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112
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Where does snow falling at the polar ice caps originate?
Where did the water originally evaporate when snow falls at the polar and Greenland ice caps?
I can think of two ideas:
The water mostly evaporates from the nearest ice-free ocean because water ...
- 615
1
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3
answers
109
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Do tropical cyclones impact climate?
Do tropical cyclones (TCs) have a global impact on climate? Maybe in terms of their impact on air-sea heat or gas fluxes? For example cooling the surface ocean, or enhancing CO2 fluxes?
The motivation ...
- 652
2
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32
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Can frictional force be un-aligned with wind direction?
There is a well known solution to Navier-Stokes equations for atmospheric boundary layer according to Ekman (see for instance PalArya's book "Introduction to Micrometeorology" or Holton's &...
- 985
3
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40
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How does coastal fog form on the Chilean coast?
When traveling through the northern parts of Chile (La Serena, Antofagasta) during November and December, I noticed a thin layer of coastal fog very close to the coastline.
Since this fog was present ...
- 131
2
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1
answer
111
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2023-2024 El Nino Season 5th Strongest on Record Meaning
I was reading the Press Release of World Meteorological Organization press release that was dated March 5, 2024 and I was curious on what they meant by the sentence "The 2023-24 El Niño season ...
- 23
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0
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74
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What are the current theories on the formation of satellite tornados
I have already searched the web for information on the formation of satellite tornadoes but all the sites say the mechanism is unknown.
What are the current leading theories for their formation?
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0
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58
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metpy divergence module array indexing error
i am trying to find out moisture divergence using metpy divergence module and i used
qu12=q3b*u3b
qv12=q3b*v3b
HMD12 = mpcalc.divergence(qu12, qv12)
here qu12 ,...
- 41
2
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2
answers
127
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How does the wind transport latent heat?
I'm a meteorology student, and this sentence in my lab book confused me: "Both sensible and latent heat are transferred by winds."
I understand how sensible heat could be transported by wind—...
- 23
1
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0
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40
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Is this the correct way to extract U and V wind components from NEXRAD weather radar?
I am working with NEXRAD radar data, and I am trying to plot the U and V wind velocity for each point on a grid. There is a channel in the data called "Velocity" described as "A measure ...
- 11
2
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1
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71
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Units of meteorological data from the NOAA website
I want to check the precipitation, temperature, and rainfall data of South Asian locations.
I downloaded the data from: https://www.ncei.noaa.gov/access/search/data-search/global-hourly?stations=...
- 165
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2
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398
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Explanation of geopotential height
I am currently struggling to really understand geopotential height on a conceptual level.
Let's say we look at the geopotential height of 500hPa over Europe, where it is usually around 5.5km.
Does it ...
- 113
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47
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How do I know where clouds form from a skew-T diagram?
I should know where clouds form in the atmosphere from the skew-T diagram below. The anwer should be that there is a big stromcloud from a height of 300hPa to 900hPa, but I don't get why.
My reasoning ...
3
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1
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118
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2
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1
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85
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Where can I obtain the raw atmospheric data that weather forecast images are based on?
There is a lot of weather forecast data available online, such as this one
https://www.wetter3.de/animation_dt.html
But as a student, where do I get according raw GFS data instead of images to do my ...
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0
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57
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What is the correct velocity to calculate propagation speed of a Rossby Wave?
Rossby Waves have different phase- and group velocities.
For a pure zonal wave with wave number k they are
$$v_p=\overline u - \frac{\beta}{k^2}$$
$$v_g=\overline u + \frac{\beta}{k^2}$$
So group ...
- 985
1
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2
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109
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How can gaseous abundance in ppm be converted to density?
Consider a measurement of the concentration of a gas such as ozone in Earth's atmosphere in pseudo-units of parts-per-million (ppm). What is needed to convert such a measurement to density of the gas? ...
- 11
4
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101
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Are clouds aerosol?
I recently came across a science writer's page according to which clouds are liquid water. I pointed out to this author that in reality clouds are made up of a dispersion of water micro-droplets in a ...
- 161
2
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1
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64
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How Low pressure moves across land
I understand that low pressure systems (like hurricanes), can move across oceans since they are constantly fed by warm air from below.
But what is it that enables it to move across land? Especially in ...
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