22 votes
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Why One Side of Mountain Range is Lush

The Cascade Mountain Range in the US Pacific Northwest is a good example to use to explain this. The predominant wind direction is from the West - over the Pacific Ocean. The air over the ocean picks ...
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  • 4,319
19 votes

Why are there no CO2 snowfalls on Earth?

There is more to phase change than just what you see on that graph. At temperatures and pressures that support multiple states (e.g. solid and gas) you have to look at the saturation vapor pressure ...
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  • 13.9k
17 votes
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Is there a database of global rainfall time series?

Yes. Nearly global satellite and radar derived rainfall data are hosted by NASA Goddard Space Flight Center, namely: Tropical Rainfall Measurement Mission (TRMM) aboard the TRMM Microwave Imager (TMI)...
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  • 4,935
15 votes
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Why does it rain more at night than during the day?

First off, your observation that Tamil Nadu gets more rainfall in the evening is partially backed by records. Sahany, Venugopal, and Nanjundiah, 2010 provide data on diurnal scale rainfall ...
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  • 3,294
14 votes

Is there a database of global rainfall time series?

If you are looking for a dataset going back a bit further, but still sticking to satellite and radar data, GPCP (Global Precipitation Climatology Project) goes back to 1979. The limitation of certain ...
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  • 1,787
13 votes
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What is the methodology to analyze future climatic extremes using the results of climate models?

Your question is fairly broad, and slightly vague so I don't know if I will be able to answer it in one go. If you would like any clarification, let me know. How are predictions made? The basic ...
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  • 5,337
13 votes

Transfer precipitation forecast in mm to expected snowfall in cm

@Peter Jansson provides a much more thorough answer, but for a quick conversion of expected liquid water equivalent to expected snow depth: 1 inch liquid water = 10 inches snow for warm storms 1 ...
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  • 231
12 votes

How to reconcile hourly vs. daily probability of precipitation in the forecast?

The probability of precipitation is most likely to mean the proportion of models in an ensemble or weather models in which precipitation was observed at a particular location over a particular time ...
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10 votes
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Snow from Fire: Could graupel, or even snow, fall from pyrocumulus clouds?

It is likely snowing somewhere in these clouds and graupel exist transiently on their way to becoming hail, but its not likely that you will see either at the surface. You can make a first order ...
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9 votes

Why is Egypt so dry?

If you take a look at the atmospheric circulation pattern, the Hadley Cells in particular, they tell the story. The northern edge of Africa is on the descending edge of a Hadley Cell, which means ...
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  • 1,027
8 votes

Is there a database of global rainfall time series?

WorldClim is an alternative. It is a set of climate layers with spatial resolution of 1 square kilometer. It provides current conditions, forecast and historical data. Besides rainfall there are data ...
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8 votes

Why One Side of Mountain Range is Lush

I'll augment the other answer with an example. Consider a theoretical north-south oriented mountain range that rises 2000 m above sea level and the land on either side of the range is at sea level. A ...
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8 votes
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Confusion with precipitation values in CORDEX MPI-ESM rcp data

TLDR; The precipitation values (and possibly some other variables; see below) need to be divided by 24. Background The global attributes of the netCDF file in the question provide an URL to a ...
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7 votes

Am I observing orographic rainfall?

700 m elevation difference on the windward side will be definitely enough to trigger orographic influences on precipitation. Thus from your description it seems very plausible that the mountains ...
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  • 1,673
7 votes

Is there a risk with putting out smouldering underground coal reserves?

There isn't a risk to putting it out other than the attempt failing, it is just impractical to do so once a large coal vein catches fire. You can read more about the Centralia, PA coal fire on ...
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  • 13.9k
7 votes

Is there any place on Earth that is permanently a desert?

UserLTK, above, has mentioned the Dry Valleys of Antarctica and the Atacama desert as two notable examples of "permanent" deserts. It's likely that these two locations have been deserts for at lease ...
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6 votes

Predicting school closures with historical weather prediction data?

I'm not aware of any datasets that are quite what you want (archived point forecasts for the next day). There is less digestible data out there though. NOAA NCDC archived messages This website has ...
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6 votes

Predicting school closures with historical weather prediction data?

The National Digital Forecast Database (NDFD) is archived by NCDC here: http://nomads.ncdc.noaa.gov/data/ndfd/ The NDFD contains gridded forecasts across the U.S. produced by NWS forecasters. You can ...
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6 votes

How can there be a hot summer with rain and no thunderstorms and lightning?

This is an El Nino summer, and a very strong one and a very weird one at that. Weather patterns are messed up world-wide. Apparently a stable high pressure cell has set up that oscillates back and ...
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6 votes
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Why doesn't it snow even when it is below freezing?

Farrenthorpe is right, a little surfing the net for snow distribution would clarify the picture for you. However, I think you are referring to certain times when it rains further north and snows ...
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6 votes
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ERA Interim, how to handle total precipitation

First of all, these netCDF files follow the CF Metadata Conventions, which describe the use of scale_factor and add_offset in ...
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  • 3,303
6 votes
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How much rain falls on the Earth each year?

That's a tricky question, it will vary from year to year but we can narrow it down with some assumptions so I can give an answer. The assumptions will be: All precipitation over the sea will become ...
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6 votes
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At what latitudes does the precipitation water for Europe evaporate?

A challenge is going to be "which moisture is from where". Because the atmosphere doesn't ever completely empty of moisture, for any given precipitation, which water molecules were from ...
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5 votes

How to reconcile hourly vs. daily probability of precipitation in the forecast?

The hours are not independent of each other. For example, suppose there's a chance of a hurricane hitting the area. If it hits, it will be rainy every hour of the day. If it misses, it will not rain ...
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5 votes
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Does over-cropping large areas really change the amount of rainfall?

For an example of how bad agricultural practices can cause soil loss and end up with dust and sand, see the conditions that preceded the dust bowl in the USA. Certain crops are bad for soil and if ...
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5 votes
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Where can I get historic hourly precipitation data for Italy?

The US NCDC has this link to surface hourly global data which I was indeed able to find Napoli on. It appears, based upon this page describing the World Data Center For Meteorology, that there may be ...
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5 votes

How does temperature impact the elevation distribution of orographic precipitation?

Examining two extreme cases, one very cold and the other very warm, the amount of precipitable water in the very cold one will be far less than that in the very warm one. Even fully saturated, the ...
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  • 348
5 votes

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

Yes, you can interpolate the rainfall from stations outside the watershed. However, the quality of the interpolation will depend on the distance between the stations and the watershed, the prevailing ...
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  • 4,319
5 votes

Drought in Scotland?

No there isn't a drought in Scotland, but there doesn't have to be for there to be a high fire risk. As you say, the west coast is often wet which means the conditions are ideal for the (slow) build ...
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