Bracing for another storm, I have a question

sorrygottarunway

Well-Known Member
I've been having a habit of using government "raw" radar returns for my own weather forecasting (weather channel has too many adds and is too plebian)

But sometimes with these winter storms, you get bright red-purple-white returns, as if these are some serious supercells.

What causes these returns? Just upper air flakes? Does this ever reach the ground? Radar return error?

-B

 

Tim06

New Member
If you choose a different radar site, such as Philly instead of Brookhaven's radar, it doesn't have false echos.
 

sorrygottarunway

Well-Known Member
thats the thing... these are true echos, since they correlated with other radar sites. If it were the "orange dust" then that would put me to rest, but these are- how can I put it- orange echoes, even though they aren't that strength?
 

Avi8er10

New Member
Now I am no expert on radar meteorology so feel free to correct me if I am wrong but, the reason for the orange and red and even purple echoes is because the radar is probably in what's called "Clear air mode." There are two main modes that radars can go in. One being clear air mode and the other being precipitation mode. Clear air mode is much more sensitive, hence the darker colors. When in clear air mode you can pick up things such as a flock of birds going by. In precipitation mode, the radar is for the most part only showing where heavier bands of precip is. Although, it is not guaranteed that the precip is hitting the ground....thats another story.


One other tid bit, if you go to the NWS site and look at the different radars you can choose between base reflectivity or composite reflectivity. From my understanding, if you choose composite relfectivity you can get a better understanding of how high some clouds are, even though the radar does not show cloud coverage. The base reflectivity scans the area at one angle, while the composite reflectivity scans at multiple angles, allowing you to see some precip that might not be at the ground yet but is aloft. If you have echoe returns in your area, you might notice a difference in what the composite reflectivity and base reflectivity are showing.

Like I said earlier, I might be wrong on some of that but, I do believe it to be correct.


Ciao,
Andy
 
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