Monday, November 19, 2012

Some Ground Clutter This Morning - 19 November 2012

There is not much in the way of weather this morning across much of the United States. However, I was checking the national radar composite at the CoD web page and noticed some echoes that seemed suspect.

The image above is base reflectivity for Flagstaff, Arizona, at about 7 am MST this morning. The White Mountains are painting a strong echo area. The two highways heading north and northwest out of Flagstaff are also showing  lines of strong reflectivity. So, the radial velocities are playing a role in the clutter suppression procedure failing. Graphic below is Storm Total precipitation for Flagstaff at the same time. This image indicates that precipitation is accumulating, and probably going into the NWS radar archives to lie in wait for some future researcher to puzzle over.

Image below is base reflectivity from Sacramento, California (a site notorious for its ground clutter problems). Sacramento is also showing echoes over or along major highways. Even more interesting is the circular blob of stronger echo that appears to be near the Sacramento River Delta. I thought that this might be due to birds or bugs, but a look at the radar loop indicates it is stationary and thus clutter from something.

I had put a clutter post up several months ago and David Blanchard (NWS Flagstaff) alerted me as per below. But, there seem to still be some problems at some of the radars.

RDA/RPG Build 11 included the CMD (Clutter Mitigation Decision) algorithm. This was an enhanced, automated feature to remove clutter.

Build 12 was the first build to support Dual-Pol. Unfortunately, it was based on the older Build 10 which did NOT have the CMD.

Build 13, to be deployed this summer, will have CMD once again. So we can expect some improvement in clutter removal. Some information can be found here: 

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