Can someone please explain something about this weather radar image?

[Duer 157099]

This has bugged me for a long time now, and I know somebody here will have the answer.

If you go to this link right now (or soon):

http://classic.wunderground.com/radar/radblast.asp?zoommode=pan&prevzoom=zoom&num=6&frame=0&delay=15&scale=1.000&noclutter=0&ID=DAX&type=N0R&showstorms=0&lat=38.34606171&lon=-122.70011902&label=Rohnert%20Park,%20CA&map.x=400&map.y=240&scale=1.000¢erx=400¢ery=240&showlabels=1&rainsnow=0&lightning=0&lerror=20&num_stns_min=2&num_stns_max=9999&avg_off=9999&smooth=0

you will see a storm system moving over the north bay area of San Francisco. The spot where the target is (Santa Rosa) always seems to have a clear wedge section and I can never understand if this is 1) an artifact of the radar system or 2) a topographical feature of the landscape that results in less precipitation in that wedge or 3) really no rain there for unknown reason.

Can someone please, please explain this for me?

[shraby]

1. It's probably the limit of a section a particular radar covers

and where another covers. They don't overlap but leave a gap.

[Duer 157099]

6. That was my working assumption, but it totally sucks

I feel like I'm getting cheated out of my weather report. I always have to mentally fill in the blanks and sometimes the edge of the storm system is in that area and I really don't know what's going on.

Thanks for the reply

[davidinalameda]

11. you could always crack open a window

and stick your head out to see if it's raining or not

just a suggestion

[Duer 157099]

12. Heh, yeah, I could

Although sometimes I'm not actually at home but want to know what the weather at home is like so I can time a commute.

[NYC_SKP]

2. Number 1; an artifact of the radar system.

Either a blind spot for some reason, like an obstacle, or a fault in the tracking.

I've seen the same thing in other radar images, always a wedge shape radiating out from the center.

:P

[msongs]

3. probably a mountain between the radar and the target....we have the same thing here in

riverside where there is a range of 3000 ft high hills with one peak of 5600 feet (Santiago Peak) and it makes a radar "shadow" depending on which radar one is looking at

[GoCubsGo]

4. It's an artifact of the radar

When you look at the area using the radar out of San Francisco, rather than Sacramento, the wedge is no longer there.

[Duer 157099]

10. Do you have a link for the SF radar? Is it on the WU site? n/t

[leeroysphitz]

5. When did they move Fort Bragg?

[Duer 157099]

8. Last summer, I think

It was a bitch to move, too.

[nadinbrzezinski]

7. radar artifact

[CountAllVotes]

9. that little white circle you see on the coastline is ...

Above it you see the name Fort Bragg - the marker is the little white circle.

I took cartography for awhile and it is a standard marker for a town.

Not a great map IMO. :crazy:

[8 track mind]

13. looks like shading

the radar should be able to view it 360 degrees. It seems to me that something is very close to the TX/RX array in one certain spot, effectively blocking it. When its up close it will produce a shape like that

[FredStembottom]

14. I know that radars can't see the weather directly overhead

... and for a certain number of miles around the radar's location.

But that shows as a circle.