Why is lake effect snow so localized? Moisture often times converges in pockets or streaks depending on the weather setup. Check out this great visible satellite photo which shows the streaks of clouds cover and sunny breaks in between. Each streak of cloud cover has bursts of lake effect embedded within it.
BTW, the 850 mB temperatures will be falling to -18 with a lake water temperature of +8 (yes, all in celsuis). You need around a 13 degree temperature difference. Notice that later today, tonight and early tomorrow, temperature differences approach 25! This means heavy bursts of snow IN LOCAL AREAS!
Saturday afternoon radar image...CURRENT NORTHERN OHIO RADAR LOOP HERE