WSD-88D Base velocity image

[Richard]

See the attached.

Am I correct in saying the velocity increases due to landform? Or is that a "phantom" due to type of radar? One reason I suspect the latter is because it's only in the NW quadrant that velocity increase is noted.

 

[gismo]

See the attached.

Am I correct in saying the velocity increases due to landform? Or is that a "phantom" due to type of radar? One reason I suspect the latter is because it's only in the NW quadrant that velocity increase is noted.

I think it's more likely that what you see there is a wind direction shift not a velocity increase but I'm not certain of that. Keep in mind that the indicated velocity only represents the vector towards or from the antenna site.

 

[Richard]

I think it's more likely that what you see there is a wind direction shift not a velocity increase but I'm not certain of that. Keep in mind that the indicated velocity only represents the vector towards or from the antenna site.

CORRECTION: It is WSR-88D. It's technical name is WSR-88D, which stands for Weather Surveillance Radar, 1988, Doppler.

 

[Richard]

I think it's more likely that what you see there is a wind direction shift not a velocity increase but I'm not certain of that. Keep in mind that the indicated velocity only represents the vector towards or from the antenna site.

Yeah, I was confused by thinking of speed rather than direction relative to the antenna. Doppler, Doppler, Doppler...Doh!

Still, I don't understand why wind direction would be more important than speed, or at least direction and speed. The antenna is at a low elevation angle so it's not looking for convection or tornadic cells.

WSRs are not used to compile station observations, right?

 

[gismo]

Yeah, I was confused by thinking of speed rather than direction relative to the antenna. Doppler, Doppler, Doppler...Doh!

Still, I don't understand why wind direction would be more important than speed, or at least direction and speed. The antenna is at a low elevation angle so it's not looking for convection or tornadic cells.

WSRs are not used to compile station observations, right?

Nope. AFaIK they're mostly used to locate and track TRW and associated severe weather. The original intended purpose of the doppler capability was to help identify rotation within cells.

 

[Richard]

My understanding is the WSR-88D was to provide information on winds to aid aircraft routing information.

My question WRT radar being used to compile (or augment) station observations was I was speculating that this would explain why wind velocity (relative to the antenna) is given.

 

[bobmrg]

Yeah, I was confused by thinking of speed rather than direction relative to the antenna. Doppler, Doppler, Doppler...Doh!

Still, I don't understand why wind direction would be more important than speed, or at least direction and speed. The antenna is at a low elevation angle so it's not looking for convection or tornadic cells.

WSRs are not used to compile station observations, right?

The antenna is at an elevation of 0.5 degrees at the beginning of a base reflectivity scan but then tilts upward for each successive scan for composite reflectivity. Chapter 4 in Aviation Weather Services (AS 00-45F) is worth reading.

Bob Gardner