Question about a radar image

[therock1811]

I have a question. Why would there be a smoke like return on a radar image. I have an example below.

[Guest]

Thats intresting rock..............Its the first time i have seen that myself...............Well does anyone know anything about this??????????

[wxman57]

Looking at the scale on the left side of the radar, you've circled echoes in the 30-35 DBZ range (light gray). This would indicate possibly light to moderate rain on that scale. What were the sky conditions at the time? Any showers reported? Were the echoes moving?

Really, the only "unusual" thing I see is that DBZ color scale on the left - the gray shades for 35 DBZ and lower.

[therock1811]

As I said in my PM, it's supposed to be blue and green for that I think?

[WidreMann]

Graphics problem. This happens on my radar occasionally as well.

[Colin]

Yes, WidreMann is right... Occasional graphic problems can happen, and that's what causes the gray smokey appearance.

[ColdFront77]

Why would it be a graphics problem if gray is the color for DBZ's 35 and below, as wxman57 indicates?

[polarbear]

My best guess is that's either ground clutter or very light precipitation. Regional observations from that time indicate cloudy skies but no precipitation. The gray shading of the <35 dBZ reflectivity is a glitch in web output of the GEMPAK radar images. This occasionally happens, usually only for one volume. The lack of color for the lower reflectivities and no looping makes it difficult to say exactly what that is (also since it was over a month ago). I'm not aware that there was any fires in that area.

Sometimes smoke is visible on the WSR-88D radars. It may appear as splotches where the fire is occuring (usually < 30 dBZ) or streams, if there is a brisk wind.