Almost an hour into this replay of an archived case and some thoughts on the Single Site AzShear using this image as an example.

I can count at least 8 areas that AzShear shows potential areas of rotation that need a closer look.  Advantage.  The rapid update every volume scan means there isn’t a wait for the 2-minute Merged AzShear products to arrive.  Advantage.  However, there is a lot of noise, especially along the leading edge of the gust front/line of storms to the southwest of the KMMX radar site.  Not shown is the single-radar AzShear from KEOX which is not as noisy but is also looking at the mid-level of the storms.  Disadvantage.  The strength of the AzShear signatures depends on which radar you are looking from and the orientation to the beam.  Disadvantage.  Features are range-dependent so if you are looking for a low-level feature from a distant radar without a radar closer to the area of interest; Disadvantage.

So, how may the Merged AzShear products come into play?  We’ll use this as an example (which is taken from the same time and space as the image above):

The first thing to notice is that there is much less noise; the merged product has a lot of the small +/- AzShear values around the KMXX radar site removed but still holds on to the stronger areas that may need closer inspection.  Advantage.  For the line southwest of KMXX, northwest of KEOX, again, many of the less interesting/noisy features are reduced leaving the areas of stronger shear in for closer inspection.  Advantage.  However, the biggest disadvantage is the time-lag; since the merged AzShear products arrive every 2 minutes, any quickly intensifying areas of rotation can be missed.  The merged product also has trail of where the strongest AzShear values are which can be used for tracking purposes; Netural.

As it stand right now, I’d say that I like the single-radar AzShear for storm interrogation purposes since it arrives nearly real-time with every scan.  It is also useful because it gives me the base information that gets fed into the merged products which then goes into the MRMS Rotation Track.  I’m a big fan of knowing what is going on “behind the curtain” and the single radar AzShear product gives me that information.

-Dusty