Besides SN 2017eaw in NGC 6946 there are currently a few other supernovae visible from northern areas in telescopes of 17.5-inch or possibly less.
SN 2017egm in NGC 3191 is superluminous (SNSL-I) or hypernova in NGC 3191 in Ursa Major. I viewed it last night (June 18) and estimated it around magnitude 14.5. At a glance the supernova/galaxy combination appeared as a fuzzy, but odd looking star. With averted vision the supernova stood out east of center. See http://www.astronome...org/?read=10498 for more information.
SN 2017ein in NGC 3938 is a peculiar Type Ic as it only reached around magnitude 15.1. It is currently fading though. It lies in Ursa Major.
SN 2017erp which is a normal Type Ia in NGC 5861 in Libra. It’s a bit south, but sufficiently high from my latitude of 37 degrees north. It was an easy starhop from Beta Librae. On the night of June 18 I estimated it to be around 14.3-14.4 (though an image I took later had it closer to 14.7V). It is currently on the rise and may reach magnitude 13.2. Also viewed the galaxies NGC 5858, IC 1091, and NGC 5872 in the area. Of these, NGC 5861 was by far the largest.
MASTER OT J132501.00+431846.1 was initially thought to be a supernova near NGC 5145, but its quick fading is more indicative of a dwarf nova in our galaxy. It was about magnitude 14.5 a few nights ago, but may be too faint now to be detected in anything but large apertures. Thus far there has not been a spectrum to my knowledge to determine its nature.