Hail Detection and Radar Question And Hail Core Path Question

[STexan]

With GRLevel3 or other radar products that indicates possible/probable hail and an approximate size ... My question is

Is the hail size [estimate] indicated based on perhaps the cell's ceiling height or is it somehow based off the actual reflectivity signature? Or a combination of factors? I guess what I'm asking is how often is there actually hail hitting the ground at the size GRLevel3 stated was possible?

And if the radar hail indications are reasonable accurate, is there a way or place to retrieve "hail shaft path" estimates in a reasonable resolution on a map in the day(s) following a given storm?

Thanks

 

[GPhillips]

Previous thread on the topic

http://www.stormtrack.org/forum/showthread.php?13574-GRevel3-Hail-indicator

The link that Greg gave for the NSSL output has maps that can be overlaid on GoogleEarth. Accuracy of the location of the hail on the ground relative to where it is depicted on the graphic can vary based on shear, distance from the radar, and other factors no doubt.

Article on the algorithm output that is displayed in GR3

http://journals.ametsoc.org/doi/abs/10.1175/1520-0434(1998)013<0286:AEHDAF>2.0.CO;2

From the abstract in the 2nd link, it is described as being based on a "thermally weighted vertical integration of a storm cell’s reflectivity profile", notably reflectivity above the freezing level.

Verification of the gridded output can be found in this article

http://cimms.ou.edu/~smith/pubs/IIPS_2006_Hail.pdf