I would like to call attention to the passage of the earth through the plane of comet Hyakutake's orbit about March 28.43 UT. This is illustrated on my ephemeris, accessable via my home page URL shown below.
The inclination of the tail to the plane of the sky changes very rapidly (~6 degrees per day) and may lead to a dramatic sharpening/brightening just after closest earth approach. The comet will still be visible in a dark sky after moonset at this time.
Comet 1996 B2 Hyakutake Home Page