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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0answers
37 views

Application of vorticity tendency equation

I have a question about the dynamics of westward propagating vortices. In meteorology, the vorticity tendency is often used to explain the westward propagation of vortices (cyclonic circulation). A ...
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1answer
162 views

What is the synoptic/atmospheric setup that is causing the U.S. severe weather outbreak in May 2019?

I asked this in the chat and it was suggested I ask on the main site. There's been a seemingly perpetual severe weather outbreak over the central and eastern U.S. over the past two weeks. Killer EF3s ...
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1answer
39 views

Do cloud formations change depending on the season?

I'm currently working on some software for cloud masking, and thus far I have only been using satellite data as recent as spring (northern hemisphere). However, I'm wondering if cloud coverage or ...
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36 views

Oscillating dew point throughout the year?

I was searching for the climate of Saudi Arabia and I noticed that the city of Abha (altitude of 7000 feet) has a "strange" behavior in its dew point, as numbeo suggests: https://www.numbeo.com/...
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25 views

Do less trees equal less rain? [duplicate]

It is said the the Sahara desert was once a dense forest until it was cut. Do trees contribute to precipitation and less trees equal less rain locally?
3
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1answer
44 views

Get atmospheric pressure values through JavaScript

I'm working on a programming project in which I want to show isobars on a map with OpenStreetMap and the HTML tag canvas. The main problem that I'm facing is the dificulty of retrieving consistent ...
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48 views

Thermal likelihood formula

Background: I use the X-Plane flightsimulator for flying and gliding. In the program we have real weather (clouds, winds, etc...) but thermals are not well implemented, they don't have any connection ...
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41 views

Are there more meteorological catastrophic events due to climate change?

I was told by a sedimentologist there is no evidence of more climatic catastrophic events at the geological register previous to Pleistocene, when climate was warmer. My question is if meteorologists ...
6
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1answer
76 views

What is brown carbon?

There is a lot of interest in brown carbon in the atmospheric science community these days. There is a paper in the journal, "Atmospheric Chemistry and Physics" titled, "Black carbon or brown carbon? ...
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23 views

How does a change in the tilt of the Earth effect climate? [duplicate]

Could the Earth survive if the axis was less or more of the tilt of that what it is now, and by how much? How would the Earth act if the axis was pushed to an extreme tilt or lack there of?
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1answer
138 views

Do Siberia and Canada have a rasputitsa?

The rasputitsa is a muddy season that happens twice per year in West Russia, Ukraine, and Belarus. It happens in mid-October to late November due to rains, and mid-March to late April due to thaws (...
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1answer
69 views

Computation of geostrophic wind

I am attempting to calculate the zonal and meridional components of geostrophic wind using the equations below: $u_g = -\frac{g_0}{f} \cdot \frac{1}{r} \cdot \frac{\partial \Phi }{\partial \phi}$ $...
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1answer
46 views

What exactly are “ambient aerosols”?

I see this term being used everywhere, but I have not been able to find a formal definition for "ambient aerosols".
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2answers
65 views

Can I interpolate rainfall data from stations outside of watershed for the watershed?

I have only few station inside the watershed so I want to use the stations outside if I can to get better results
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65 views

Initiation of Rossby waves during MJO

I am trying to understand the basic dynamics of MJO, where I find several studies which relate it to the initiation of equatorial Rossby and Kelvin waves. Though MJO is an eastward propagating wave, I ...
4
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1answer
122 views

Why is potential vorticity so emphasized in technical work, but often neglected in maps on weather websites?

When I was first introduced to potential vorticity, I was told that it is a very important tool for meteorologists to learn. Sure, it solved a simple problem in dynamics, but it wasn't apparent to me ...
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73 views

Characteristics of saddle points in stream line charts

I am trying to locate saddle points or commonly known as "col" in synoptic meteorology. This is "z" in the following figure. References Here are some of the references regarding this. a). http://www....
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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?
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1answer
64 views

How big of an event is needed to trigger a long winter?

Could a small meteor or natural nuclear explosion melt an ice cap on Earth to trigger a mini ice age without the event being observed by people? Can the Earth have an overlaying thermal cycle that ...
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91 views

Does this weather pattern have a name?

The past few weeks of spring in northern Ohio I believe I have noticed a weather pattern where the weather forecast will show a string of days with rain, but what happens is the day is mostly clear, ...
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3answers
413 views

Algorithmically Determining the Rainy Season

I have historical precipitation data for hundreds of cities around the world. I would like to algorithmically determine when the rainy season (if exists) is for each location. Are there any algorithms ...
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1answer
102 views

How to improve this prediction about the climate in future?

The more carbon dioxide in the atmosphere the more global warming. The more global warming the more cloud formations that cool the earth and clean the air from carbon dioxid when rain- and snowfall, ...
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0answers
48 views

Can extratropical cyclones force global cooling?

We are living in a historical period of global warming since about 20,000 years ago. This global warming period is one of about ten in human history. Those periods may very well be forced to start by ...
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0answers
73 views

Atmospheric pressure in weather forecasts: actual pressure or sea-level pressure [duplicate]

What is the usual way to report surface pressure in weather forecasts online, in smartphone apps, on TV/radio? Is it the actual local pressure or the sea-level adjusted value? Does it differ by ...
12
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2answers
890 views

From where do weather radar maps get their data?

I see maps like this one all the time online and in the news. A moving map that shows clouds and stuff moving around with time. Where do they get the data from? Is it from a single source location or ...
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2answers
453 views

Centrifugal Force in the Navier Stokes Equations

The Navier-Stokes equations are a set of nonlinear differential equations that diagnose wind speed and direction. They are (approximately) expressed as $$\frac{d\vec{u}}{dt}=-\frac{1}{\rho}\nabla P+f\...
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2answers
13k views

Why are deserts mostly located on the western side of continents?

I read somewhere in a book that mostly desert found in the western part of a continent. So my question is that why is it so? I searched on the internet but I didn't get a reasonable answer for that.
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Using salinity to predict rainfall

Recently, a new method has been proposed by Ray Schmitt (WHOI) and collaborators to use salinity patterns in the ocean to predict weather events (more specifically, rainfall) at scales from weeks to ...
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2answers
122 views

Is pollution a contributing factor to freezing rain?

I have been to different places with nearly the same freezing temperatures, around -2°C, but only at some specific places I repetitively experienced freezing rain. One common factor at these places ...
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144 views

Modification of an air mass

If an air mass that exists in North America starts moving south west or south east what kind of modification will affect it and how would you characterize it in it's final state? My answer is that it ...
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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 ...
19
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1answer
1k views

Why is there no middle ground between tornadoes and hurricanes?

A tornado has an effective area of destruction about the size of a city block. A hurricane spans several hundred kilometers. However, there doesn't seem to be a continuum between the two. Why are ...
18
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6answers
14k views

Why doesn't the 71% water of the earth dry or evaporate?

Perhaps a simple question, we know 71% of the earth's surface contains water as oceans. If Earth's age is 4.543 billion years, then I guess it should be decreased with drying or should have been dried ...
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0answers
386 views

Is it possible for a sting jet to form over a continental landmass?

Sting jets are thought to be responsible for some of the most damaging winds associated with extratropical cyclones in the mid-latitudes. So far they have only been confirmed in the European region, ...
24
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2answers
2k views

What is the steepest surface that can hold snow?

I know it depends on the type of snow (dry or wet) and the rougness of the surface. I'm looking for an approximate rule of thumb answer. Assuming a reasonably smooth surface, at what angle it's likely ...
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3answers
3k views

What causes clouds to appear blue?

In a thunderstorm cloud about sunset time, I saw these clouds, including some (in the upper right) that were a unique shade of blue. I don't think I've seen clouds quite that color before. I tried ...
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0answers
106 views

How to plot orography for vertical profile of a certain variable along pressure levels in GRADS

I am using GRADS (1, 2, 3) to plot ERA reanalysis relative humidity profile for latitudinal average of 15N to 37N, and along the longitude from 40E to 130E. The orography is quite obvious and thus ...
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1answer
2k views

Why does wind blow offshore in the morning?

I live in San Diego, CA, and surfers capitalize on dawn hours because the offshore (seaward) winds help "hold up" the waves, i.e. prevent them from crashing before the surfer gets to ride it a while. ...
3
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2answers
791 views

What was the density and composition of Earth's atmosphere during the Cretaceous warmest period?

There was time during the age of dinosaurs when the polar regions were ice free. The earth was obviously much warmer but a run-away greenhouse effect did not occur. This was most likely because the ...
6
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1answer
261 views

Madden-Julian Oscillation (MJO) - How to interpret the index?

How the Madden-Julian Oscillation (MJO) index can be interpret? Let's suppose I have got an MJO index value of 0.6 in a given day, what this does mean? Does 0.6 represents a weak MJO? Data from ...
2
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1answer
338 views

How to calculate relative humidity from temperature, dew point, and pressure?

Is there a formula given the temperature, dew point, and pressure to find relative humidity? I have seen several calculators like this one, but I would like to know how to calculate this myself. I ...
4
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2answers
146 views

Did temperature for the US state of Illinois reach an all-time record low 1/31/2019?

The State Climatologist Office for Illinois says the all time low temperature of Illinois was -36 °F, with a report of -37 °F in 2009 being disqualified. This morning, the station Sinnissippi ...
12
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1answer
504 views

Two severe cyclones connected by a monsoonal trough

At the time of writing, areas around the Northern Territory (TC Lam) and Queensland (TC Marcia) in Australia are in the path of severe cyclones (category 4 at the moment, with the Queensland one - TC ...
10
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1answer
1k views

How to calculate relative humidity?

I am involved in developing a weather based application which needs to calculate relative humidity and display it. I grab other weather variables like temperature, precipitation, wind speed and ...
3
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1answer
194 views

How can temperature be calculated given relative humidity and dew point?

While looking into the better indicator of how miserable it feels outside, either dew point or relative humidity, I came across this statement: The optimum combination for human comfort is a ...
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0answers
36 views

Just how dry could Ben Nevis get? Is this surprising?

The BBC article Soggy Ben Nevis can be remarkably dry describes results of a crowdscience effort to transcribe historical meteorological records recorded manually by researchers living on top of "Ben ...
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2answers
5k views

Can relative humidity be over 100% near (within 30-60m) the surface?

I am processing a big meteorological data set, which is a global forcings dataset derived by other datasets and observations, and calculating relative humidity from qair,temperature, and pressure ...
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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 ...
2
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2answers
111 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
159 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 ...