Hail, Meso, TVS indicators?

[rdale]

You need to have a very good eye to find UNCO/3DCO shears as they usually have no meteorological value and are usually just a result of the algorithm... And you need to look at all tilts (and I mean _all_) to find it.

- Rob

 

[Glen Romine]

Originally posted by Andrea Griffa
This is because sometimes it seems to me that some UNCO or 3DCO are wrong. That is sometimes storm doesn't rotate from radial velocity and also from basic reflectivity but Wether tap show rotations. I don't know why...

Weathertap does not run their own algorithms to find this rotation - these shear zones are found by the algorithms run by the weather service - and a text product of these features is sent with the radar data feed, including the locations of the features (in range - azimuth from radar) tied with storm ids. What weathertap does is map the features over the radar images. A problem that often appears in the display is that the radar images don't update at the same time that the storm attribute table does - which can lead to considerable offset. Further, the images you are seeing are interpolated from the level II data, which is in polar coordinates, to level III data that is in cartesian coordinates, and this can lead to smoothing of features. Further, as rdale noted, the algorithm looks at all levels - not just the scan elevation you might be looking at, to find storm features. There can often be considerable tilt in the storm - so the strongest shear zone identified by the algorithm might be offset pretty far from the scan elevation you are looking at.

Glen

 

[rdale]

And again it is showing the indication over the storm centroid as opposed to the actual location like GRLevel3 uses...