7
votes
Accepted
How big does a lake have to be to have its own Sea Breeze?
Lake breezes(similar to sea breezes) are fundamentally a feature of mesoscale meteorology and the peer reviewed reference Small Lake Daytime Breezes:
Some Observational and
Conceptual Evaluations ...
- 6,287
5
votes
Accepted
The climatological variance of albedo, soil moisture in weather models
WRF model development is done in such a way that users can run the model independently before you start adding more complex options to ingest observations. There is even an "ideal" mode that new ...
- 12.9k
4
votes
Accepted
What causes these periodic high-pressure blobs along the west coast of South America?
It's really not clear from their website what data source those maps are showing. They could be derived purely from surface observations, purely from model output, some atmospheric analysis ...
- 3,791
3
votes
Does storm seasonality vary with latitude?
It really depends on how you define storms. For tropical storms, there are some regions where they are not usually a threat. Likewise, for extratropical storms, there are latitudes where such things ...
- 8,629
3
votes
Accepted
Why do clouds sometimes form in "plumes"?
These look to be Thermals to me . They form as a result of strong day time heating and vertical ascent in the lowest part of the planetary boundary layer. It's not clear what time of day the ...
- 6,287
3
votes
Accepted
How do upper-level cyclones and anticyclones affect surface level winds?
High pressures and low pressures at any height do not exist in isolation. Had to remind myself a lot of this (so anyone feel free to correct), but the first thing worth highlighting is that the ...
- 8,394
3
votes
The climatological variance of albedo, soil moisture in weather models
For soil mosture you can initialize the model with a dataset that provides that information. If you are doing historical retrospective you are likely going to initialize from a reanalysis dataset and ...
- 14k
3
votes
Accepted
Why did Hurricane Harvey have so much lightning associated with it?
The storm and basics:
Here is an animation I got from this NOAA Tweet of the lightning in Harvey hours before landfall:
This link, where I found the imagery, offers some basic thoughts, including the ...
- 8,394
2
votes
Accepted
Derivative of Exner function
Start with the original equation. Let's first write the Hydrostatic equation:
$$\frac{\partial p}{\partial z}=-\rho g$$
So let's prove that $$-g=c_p\theta\frac{\partial \pi}{\partial z}$$
If we ...
- 8,629
2
votes
How are thermals really released?
I fly too, so I have first hand experience with movement of air below 13000 feet (Cessna 172). I have my simple version: in an otherwise calm weather a thermal has three stages which looked from ...
- 164
2
votes
Accepted
Required temperature difference between land and sea for sea breeze
So wind is caused by differences in atmospheric pressure which in turn is a result of temperature induced density differences.
1. Required temperature diference:
A quick search brought up this ...
- 316
2
votes
Accepted
Why do tropical cyclones get more attention than extratropical cyclones?
Extratropical cyclones are relatively well understood. They often follow the Norwegian Cyclone model, which was developed in the 1910's and 1920's. Because of their spatial extent, extratropical ...
- 8,629
2
votes
Accepted
Where can I find high-resolution, historic weather data for urban areas (like ERA5 but higher spatial resolution)?
I think the ERA5-Land dataset suits your purpose. See https://www.ecmwf.int/en/era5-land. As the website says, 'The data is a replay of the land component of the ERA5 climate reanalysis with a finer ...
- 133
2
votes
How to statistically downscale wind speeds?
Regarding 2:
The roughness length is dependent on height, eg:
$$z_0 = Az\exp(-u(z)/\sigma_u)$$
where $A=\frac{\sigma_u}{u_*}k$. ($k$ is the Von-Karman constant and $\sigma_u/u(z)$ represents the ...
- 431
1
vote
Does storm seasonality vary with latitude?
Yes, In he tropics where humidity is more ubiquitous moist air currents feed systems that allow for storms. In temperate climates these storms proliferate where it's warm and humid and die off in ...
- 721
1
vote
Derivative of Exner function
After looking back into this I found my error to lie in the long equation
$\dfrac{\partial \pi}{\partial z}=\left(\frac{1}{p_0}\right)^{\frac{R}{c_p}}\dfrac{\partial}{\partial z}\exp\left(\frac{R}{...
- 83
1
vote
Accepted
How can I learn to make mesoscale/synoptic analyses of major weather events?
You're definitely on the right path with wanting to dig into raw data yourself. RAP has always been a pretty solid source of useful basic data.
But in terms of making sense of the data, it indeed ...
- 8,394
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