Previous storms - Hook Echo w/ 75+ dBZ?

[Jon Gossin]

Does anyone know of any storms that have had a very well defined hook echo and at the same time a return of 75 dbz or higher?

Thanks.

 

[Simone Lussardi]

If I am not wrong, "the hook" of 3 May 1999 when tornado roared trough moore shows more than 75 dbz near the center of the meso.

See if you find it:

http://okfirst.ocs.ou.edu/train/casestudie...s/19990503.html

:wink: :wink:

 

[Aaron Kennedy]

Ya, but that reflectivity was due to debris.... don't think that counts. What about the May 13th storm a few days ago. I heard (haven't actually seen the radar data yet) that it had both large hooks and had very high reflectivity.

Aaron

 

[Greg Stumpf]

The 12 May 2005 South Plains storm had some reflectivity gates at 70.5 dBZ up between 15-25 kft, just prior to the hail munch.

Bear in mind that reflectivity values can be affected by radar miscalibration as well. One radar's 70 dBZ may not be the same as another radar's 70 dBZ. Hopefully, these issues will be resolved in the network by a supercalibration procedure soon (supercalibrate several radars in the network, and then adjust remaining neighboring overlapping radars).

 

[Glen Romine]

I'd also add that beyond a certain size hailstone - the radar reflectivity value isn't necessarily going to get larger. In fact, if hailstones are dry - they can be very large and only have a weak radar reflectivity signal. Normally, the larger the reflectors (precipitation particles, for example hailstones or raindrops), the larger the power return to the radar - which shows up as a higher reflectivity on the display (mets call this the Rayleigh scattering regime). But, once the particles get larger than a few centimeters in diameter (assuming the typical weather service radar wavelength), this behavior is no longer true - and instead the power return can become irregular and unreliably related to the size of the particles (mets call this the Mei scattering regime). Also, the strength of the radar return is related to the wetness of the particle - as the more ice a particle has, the lower the return power to the radar. Hail often has the strongest radar return when there is lots of relatively small hail that is partially melted, giving it a water coating, and an effective size of around 1 cm or so.

Glen

 

[Mike Hollingshead]

I remember a storm dropping south in sc SD in 2001 or 2002 that had this amazing high dbz core being "pulled" around the hook. Maybe the largest, nastiest looking hook/core/storm combo I've seen on radar. Dean Cosgrove was chasing it and would remember the date I bet. An amazing storm for sure anyway.....sigh....