This is a collective page of storms that weren't operationally classified as a tropical or subtropical system, but there is considerably uncertainty on their status as a tropical or subtropical cyclone.

1996 Lake Huron Cyclone

Category 1 tropical cyclone (SSHWS)
Counterclockwise vortex
Duration September 11th – September 15th
Peak intensity 120 km/h (75 mph) (1-min)  993 hPa (mbar)

2006 North American Blizzard

Category 1 tropical cyclone (SSHWS)
Counterclockwise vortex
Duration February 11th – February 13th
Peak intensity 130 km/h (80 mph) (1-min)  971 hPa (mbar)

Subtropical Storm "Stephanie" 2016

Tropical storm (SSHWS)
Counterclockwise vortex
Duration Unknown – Unknown
Peak intensity 85 km/h (50 mph) (1-min)  Unknown hPa (mbar)