This about as good a hail spike you’ll see anywhere, let alone the Northeast. No surprise given the close proximity to radar and reports of 2” – 2.75” hail. For the NTDA detection, both the azshear and divshear values are in the “high” category. The probability was 40%. The NMDA detection extended only up to the 1.3 degree slice. The 1.8 cuts are shown to the right above. It’s asking a lot of any algorithm to make sense of velocity data in cases such as these, which is a good reminder in general when dealing with hail spikes, non-uniform beam filling, etc.

Looking below at another time (1817 UTC), it’s interesting to compare ProbTor with NTDA probabilities. Agreement between the two in terms of placement has been consistently good. There have been many times where the probabilities are similar, which is very surprising given that ProbTor is looking at coarser gridded azimuthal shear (1km?) as opposed to native resolution used by NTDA. Probably a coincidence. This is more the exception than the rule; most of the time NTDA is giving greater probabilities as one might expect.

-marfafront