Hello Les,
I've played around with the image-there seems to be at least one other
vertical structure next to the suspect FC,therefore I think these are
most likely hail/snow shafts (a multiple vortex being highly unlikely
in these conditions !).
However-the sounding has a steep nr surface lapse rate and dry air
aloft-a situation known to produce FCs and waterspouts.Are we looking
towards the coast BTW ?
I would report it as a suspect-they may have other sightings.
FWIW my money is that it's a ppn shaft,
regards,
David