It appears there were actually 6 tornadoes in all, including one F2 in Sherman county. The tornadoes basically occurred between 2300z-0030z, with no reports of hail or wind. It looks like these reports are the only tornadoes to occur in Nebraska in the month of January, at least since 1950.
Versus what is typically referred to as a "landspout", it might be a little better to bin these tornadoes as "low topped" or "cold core". It appears they were associated with the northeast quadrant of a cold/nearly stacked low, along an inverted surface trough extending northward through east central Nebraska. The 00z/8th North Platte sounding (not shown below) had a 500 mb temperature around -25 C, with its EL suggesting storm tops of only 23K feet! Surface temperatures were 50 F at the warmest across south central Nebraska, with dewpoints only in the lower-middle 40s F!
Tornado reports for 7 January 1992 (w/ F-scale rating):