Velocity couplets on terminal doppler (TDWR) radars

[Dan Robinson]

I normally use the St. Louis terminal doppler radar (TSTL) when chasing in/near the metro area instead of the WSR-88D (KLSX). During the QLCS/embedded supercell events yesterday, TSTL was showing some intense-looking couplets on many of the mesovorticies while KLSX only showed broader rotation with no strong gate-to-gate returns. Some of the stronger TSTL couplets were persistent through several scans and had me certain that there were tornadoes associated with them. Again though, KLSX did not show these strong returns and there were no CC drops with them.

Are there known artifacts (like sidelobe contamination) unique to the TDWRs?

 

[Mark Gressman Jr]

I wonder if the typically lower base scan elevation of some of the TDWRs compared to WSR 88S were picking up gustnadoes formed in the eddies of the gust front. I've noticed something similar on several occasions with TDWR in Philly. Did you have a visual on any of the areas where the couplets showed up?