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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11
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1answer
3k views

Winds in a northern hemisphere hurricane

In the Northern Hemisphere, do surface winds around the center of a hurricane move counterclockwise and inward or counterclockwise and outward? I'm guessing they move inward.
12
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2answers
152 views

What is a source of worldwide temperature data that also includes extreme weather?

I often need to calculate heat balances for large biogas plants, an important factor is outside temperature. I normally use the weather data from Klimadiagramme.de where I can find the mean monthly ...
14
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2answers
5k views

July/August hottest months (northern hemisphere): because of continued warming or other effects?

In the northern hemisphere, July and August are the hottest months statistically1, but the days start shortening after June 21st. Is this just because the Northern Hemisphere keeps heating up after ...
14
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3answers
13k views

If it rains harder, does it mean the rain's duration will be shorter?

If it rains real hard, is there a chance the rain's duration will be shorter? I think the if the rain in the clouds disperses with such force the rain will be over faster than if it was just a light ...
11
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3answers
221 views

Is it right practice to validate temperature data with reanalysis data?

For a project I am working on I received raw data from many meteorology stationes. Is it right practice to test this data against air temperature from noaa's ncep/ncar data?
19
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2answers
14k views

Where can I get archived hourly temperature data?

I am looking for historical hourly temperature data from many cities in the US what other data sources are there except wunderground? UPDATE: I will use the data to compare stations from the same ...
11
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1answer
218 views

Synoptic weather predictibility under climate change scenarios

Under climate change scenarios, it is quite certain that high latitude regions will experience more warming than at low latitudes. For example, in winter the reduced area of sea ice and snow cover ...
23
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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 ...
10
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1answer
6k views

What is the primary cause of the “Norwester” winds that affect parts of India & Bangladesh?

I am primarily interested to know: What is Norwester (localy called Kalboishaku as because in occurs during the Bengali Month Boishak which falls between Mid April to Mid May). What causes Norwester....
14
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1answer
240 views

How do climatologists define the “start” of a rainy season in a unimodal monsoonal climate?

For a number of gridcells, all between the 500mm and 800mm rainfall isohyets in sub-Saharan Africa, I've got dekadal rainfall (from FEWS). They are pretty spread out over the continent and there are ...
13
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5answers
4k views

How to reduce the atmospheric temperature artificially?

Is there any gas/substance which absorbs/reduces atmospheric temperature? Ozone filters UV rays from the sun light and allows in infrared rays. In my knowledge these infrared rays are the cause of ...
11
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2answers
307 views

How do meteorologists grade their past forecasts?

In every professional field, practitioners may come home at the end of the day and say "Yeah! I knocked it out of the park!", or alternatively "Oh, man. Gotta do better tomorrow." What about ...
16
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1answer
5k views

What is the range of possible atmospheric pressures on the surface of the Earth?

I'm developing an Android app which uses a pressure sensor. Due to storage limitations I have to normalize and scale the atmospheric pressure values. For this I need to know the extreme values of ...
3
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0answers
86 views

Is the number of high/low pressure regions different at low pressure levels at high pressure levels?

Is there a higher number of mid-latitude high/low pressure regions at 850 mb, as compared to the number of high/low pressure regions at 200 mb? And if so, why?
8
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1answer
223 views

How does El Niño affect thunderstorm/tornado/CAPE activity in the central United States?

Or in other words, does it increase the amount of heat+moisture advection from the Gulf of Mexico into the Central United States? And is this increase associated with increased CAPE/tornado/...
1
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1answer
569 views

How to perform precipitation data analysis? [closed]

I want to make precipitation data analysis for the Latvian territory. I only have meteorological stations and reanalysis data. My data from meteorological stations are in the format: ...
14
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1answer
585 views

How long does it take for the atmosphere to mix?

If I release a say, one litre of gas, at a particular point on the planet, how soon, on average, would it take to be distributed evenly (mixed) across the entire earth's atmosphere?
26
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1answer
2k views

What factors determine the number of Hadley cells for a planet?

We know (think?) that Earth has three Hadley cells per hemisphere, but from observing gas giants such as Jupiter, we see that they have many more cells. According to a link from a comment in this ...
8
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1answer
8k views

Why does the wind periodically change direction?

Image Subtitle: Wind going across the page - and changing direction To clarify, imagine you were sat in a boat in the middle of a lake recording the wind direction every minute. You notice that the ...
8
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1answer
407 views

How does the amount of mass in an atmosphere affect the seasonal changes and dynamics of the planet's climate?

I was thinking about this question, which may turn out to be simple, about climate dynamics: How does the amount of mass in an atmosphere affect the seasonal changes and dynamics of the planet's ...
7
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1answer
179 views

Why is the warm phase of the Pacific Decadal Oscillation associated with stronger El Niños?

This is a question inspired by the post at Cliff Mass Weather Blog: "Is a Super El Nino Coming Next Winter?". There is something else. You ever hear of the Pacific Decadal Oscillation? This is ...
12
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1answer
2k views

Is there any correlation between La Niña/El Niño and seismic activity?

I've read in the past that extreme precipitation levels may have an effect on seismic activity, and wondered if anyone has ever analysed the La Niña / El Niño cycles to see if there are any ...
13
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2answers
2k views

What is the difference between a high-resolution model and a regular model run?

So we have high-resolution models like the HRRR (High Resolution Rapid Refresh). But what exactly is the difference between a high-resolution model and a regular model? I realize that the higher ...
5
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1answer
112 views

How common is it for warm fronts to be responsible for record high temperatures?

Warm fronts are associated with an increase in temperature and precipitation. But are they often associated with record high daily maximum temperatures, given that they often result in an increase in ...
8
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2answers
174 views

What determines the differences in results between various weather models?

It's often said that the ECMWF model is more accurate than the GFS. But what are the reasons why? Also, how does the NAM compare with these two and other forecasting models?
4
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0answers
40 views

What determines the eastward speed that mid-latitude high pressure/low pressure systems move at?

Do they move at the group velocity of Rossby Waves? Or do they move at the phase velocity of Rossby Waves? Or some other speed?
4
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1answer
440 views

How are jet streaks formed?

"Jet Streak Dynamics I: The four-quadrant model" - explains their effects on frontogenesis. But how are they formed to begin with?
11
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1answer
502 views

Why is Montana warmer than Wyoming?

The National Climatic Data Center (NCDC) data shows the mean temperature from 1971-2000 for Montana was 5.97°C (42.74°F) and Wyoming's was 5.54°C (41.98°F). Montana is at a higher latitude, so this ...
23
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0answers
377 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, ...
15
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1answer
541 views

What constitutes a blizzard in meterological terms?

Blizzards are most commonly associated with a large amount of snowfall and low visibility. However, snow squalls can induce low visibility whereas a 12" snowfall doesn't have to induce low visibility. ...
14
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2answers
3k views

Why is the Atlantic Hurricane Season defined as being between June 1 and November 30?

Historically, the Atlantic Hurricane Season has shifted, as close as June 15 to October 31, but since 1965, it has been between June 1 and November 30(1). Why is the Atlantic Hurricane Season defined ...
13
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1answer
2k views

How accurate are climate proxies in giving us a clear picture of global average temperatures throughout Earth history?

Since reliable modern records of climate only began in the 1880s, proxies provide a means for scientists to determine climatic patterns before record-keeping began, though it appears that the the ...
11
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1answer
590 views

What is the motivation of using the Enhanced Fujita Scale in place of the Fujita Scale?

In 2007, the US started using an Enhanced Fujita Scale in place of the Fujita Scale. From a "civilian's" perspective, the Fujita Scale seemed to measure wind whereas the Enhanced Fujita Scale measures ...
8
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1answer
6k views

What is the difference between a “flood” and a “flash flood”?

Whenever weather warnings come up, I have heard of both a flood watch/warning and a flash flood watch/warning. What is the difference between a "flood" and a "flash flood"? Are there any specific ...
19
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1answer
2k views

Why do more tornadoes happen late in the day?

According to the graph below, which appears to be sourced from the US National Oceanic and Atmospheric Administration, more tornadoes happen late in the day - why is this?
13
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1answer
935 views

Cloud-to-ground lightning in Florida?

I was looking into the odds of getting hit by lightning and ran across this map: My first thought for this was due to a higher number of thunderstorms in Florida. However, the map for that doesn't ...
13
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2answers
24k views

Transfer precipitation forecast in mm to expected snowfall in cm

What conversion functions exist to transfer precipitation forecast in mm to expected snowfall in cm? Simple rules of thumbs as well as more advanced methods would be of interest.
21
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2answers
5k views

Does Earth's air leak into space over time?

From my current understanding, Earth's atmosphere and air are held by the balance of two forces: 1. Earth's gravity and 2. Air pressure from air out to space. Is my understanding correct? So, do ...
10
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2answers
176 views

Why does the rising of high clouds due to climate change impart positive radiative feedback on radiative forcing?

As seen in the figure below. The larger the temperature difference between surface and cloud, the more positive the radiative forcing is from the cloud. So as the cloud moves up, it supposedly ...
13
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2answers
175 views

Are clouds significantly easier to simulate in weather models than climate models?

Cloud forcing is still one of the major uncertainties of radiative forcing in climate modeling because there are so many uncertainties in it (and parametrizations). But also because the timescale of ...
6
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1answer
1k views

Why are most cirrus clouds present over the equator and over tropical continents?

As quoted from the AR5 IPCC report (chapter 7) here. Most high cloud (mainly cirrus and deep cumulus outflows) occurs near the equator and over tropical continents, but can also be seen in ...
4
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1answer
318 views

How does the lapse rate in clouds compare with the lapse rate of air?

So moisture decreases the temperature lapse rate (relative to the dry adiabat). My question is this: does a cloud decrease the lapse rate at the same rate as 100% humidity would decrease it? Or would ...