36
votes
Accepted
Why aren't weather balloons left in the atmosphere permanently?
In addition to radiosondes that do a single ascent over a few hours, there are also driftsondes that stay in atmosphere for days or weeks, typically with their buoyancy set up to track a particular ...
- 3,940
33
votes
Accepted
What is this "crystal ball" located at a meteorological station?
It's a Campbell-Stokes sunshine recorder, used to record the times at which the sun is shining. It acts as a lens, focusing the sunlight onto a piece of card. If the sun is shining, the focused beam ...
- 5,431
25
votes
Why aren't weather balloons left in the atmosphere permanently?
It depends on what each weather balloon is measuring; what data they are capturing.
Most weather balloons are released as specific times during a 24 hour cycle. Such balloons measure altitude, ...
- 24.6k
14
votes
Is it typically colder after a storm?
The major factors in temperature change from precipitation...
First, fundamentally rain is falling to the ground from higher in the sky.
Precipitation typically comes from a location where it is ...
- 8,713
14
votes
Why aren't weather balloons left in the atmosphere permanently?
There are several reasons for this. One of them is air traffic concerns. The parts of the atmosphere that are interesting for weather (namely, the troposhere and lower stratosphere) also happen to be ...
- 313
13
votes
Accepted
Why do forecast areas on weather.gov appear as twisted squares?
The equal-area projection used to create the continental U.S. grid for weather forecasting does not represent lines of latitude and longitude as straight lines. Instead, they are curved (note the ...
- 13.5k
13
votes
Accepted
Why don't weather forecast models normally take solar eclipses into account?
Total solar eclipses are rare. Globally, they only happen every 18 months. In any given spot, they are much, much rarer, with a recurrence period of many hundreds of years.
Solar eclipses are ...
- 11.6k
11
votes
Accepted
Are the storm cones introduced by Robert Fitzroy still in use?
A page in the book Come Rain or Shine, A Weather Miscellany states that the cones were discontinued on June 1, 1984, due to their being superseded by radio broadcasts and other methods.
- 1,178
10
votes
Accepted
If Earth had rings would gravity exerted by Earth decrease?
Rings wouldn't decrease the gravity much, but the exact amount would depend on the exact geometry of the rings. One reason is that the gravity of one side of the ring would partially cancel the ...
- 17.6k
10
votes
Accepted
Are airliners sensors used to feed weather prediction models?
Indeed, airlines are equipped to measure atmospheric data and then put into weather models. The WorldMeteorological Organization's program is called AMDAR. Several articles highlight the impact that ...
- 8,684
10
votes
Do wind predictions have confidence scores?
We've grown accustomed to seeing percentages for probability of precipitation. Why don't they do this for wind?
No single model simulation has confidence/uncertainty associated with it. Confidence ...
- 13.5k
9
votes
Accepted
Long-term Wind Speed Forecasting: reality or wishful thinking?
Warning: "long-term wind-speed forecasting for generation" has (at least) two very different meanings. One refers to forecasting a distribution of wind speeds; the other refers to hour-by-hour (or ...
- 4,090
9
votes
Accepted
Interpolate Gaussian grids to regular fixed grids using bilinear interpolation?
climate data operators (CDO)
define grid
We define a lat-lon target grid with 1°x1° grid cell size 30x30 grid cells starting at 40°N and -10°E (=10°W):
...
- 2,661
9
votes
Accepted
Weather forecast based on pressure, temperature and humidity only (for implementation in Arduino)
Such simple algorithms are empirical and for the same reason very local, so depending on your location they can have very bad performance. In the other hand, some people argue that properly calibrated ...
- 17.6k
9
votes
Do wind predictions have confidence scores?
Following up on Farrenthrope's answer (which I think is worthy of acceptance more than this answer) I do want to add additional detail that may not be appropriate as a comment.
There is a problem with ...
- 8,684
9
votes
What is a wind chill formula that will work from -10 C to +50 C and uses wind speed in km/h?
Wind chill is only relevant for cold temperatures. During hot temperatures, the affect of wind is to increase the felt temperatures.
What would be more appropriate would be apparent temperature, also ...
- 24.6k
8
votes
Help interpreting a wind rose diagram
No, you've misunderstood it. There's lots of information you're missing. Every data point is information, and you've listed a tiny proportion of them.
Furthermore, 4-7 km/h and 11-16 km/h aren't ...
- 4,090
8
votes
Can the forecast N+1 days ahead be more certain than the forecast N days ahead?
Typically, days with conditions which might produce local instabilities would produce a less certain forecast than a day with a stabilize pattern even if the more stable day was further in the future. ...
- 626
8
votes
How do spectral methods work in the context of numerical weather prediction models?
Presume that the atmosphere can be modeled with waves of different frequencies. Therefore, the atmosphere can be written as a series of sine and cosine functions with different frequencies and ...
- 8,684
8
votes
Accepted
What wind forecast datasets are available for forcing a wave forecast model?
Yes, the GFS model is a global model. The data is released in the public domain, so you can use it for free for any lawful purpose. See complete terms of use here. You can get the data here.
- 8,684
8
votes
Are there any weather services that provide hourly forecasts beyond 7 days?
The trouble is, any skill above climatology beyond about 5-7 days is very very low.
So sites could offer such forecasts, but they wouldn't be worth much of anything.
The main thing they could offer ...
- 8,713
8
votes
Why aren't weather balloons left in the atmosphere permanently?
The vast majority of weather balloons are designed to collect vertical profiles of the nature of the Earth's atmosphere. That would not be possible with a balloon that stays aloft at more or less ...
- 23.1k
7
votes
Are we changing Earth's weather with global warming?
First, regarding your assumptions, here is a graphic from this online textbook.
As you can see, your first assumption is correct, surface radiation is much more significant than thermals. Your ...
- 3,366
7
votes
Accepted
Is there a standardized way to define weather icons based on quantifiable data?
Some historical standards formed due to instrumentation. Cloud cover observations were setup based upon okta, which are eighth fractions of the sky covered overhead during the past hour (perhaps 8 ...
- 8,713
7
votes
Is there a standardized way to define weather icons based on quantifiable data?
The icons that are used are really just a visual way of describing the phrasing that is used in the forecast. You can see an example of one set of icons offered by Weather Underground here. And they ...
- 13.5k
7
votes
Accepted
Freely available and re-distributable weather observations over the US?
Such a dataset can be found via the NCDC. Here is the main gateway. My 'go to' place for high temporal resolution data from NCDC is the 5-minute ASOS data.
- 8,684
7
votes
Why don't weather forecast models normally take solar eclipses into account?
In addition to the rarity, there is also the problem of additional computations. To find out if there is a solar eclipse, you need extra calculations. Since the introduction of additional calculations ...
- 8,684
7
votes
Why don't weather forecast models normally take solar eclipses into account?
Doesn't look like the ECMWF does.
Perhaps part of it has to do with the fact the weather changes due to eclipses are usually fairly friendly/tame. This GOES 16 satellite loop from the southeast US ...
- 8,713
7
votes
Accepted
How/where is randomness/stochasticity used in weather prediction
Probability is used in weather forecasting. I will only highlight some examples due to my lack of knowledge in some areas.
Before initializing a forecast model the data needs to be assimilated. That ...
- 1,145
Only top scored, non community-wiki answers of a minimum length are eligible