Having already discussed every influencing factor and possible outcome during the excruciating lead-up to March 4, the day itself is turning out to be fairly quiet. What's a primary junkie to do? Watch the March 4 Primary Weathercast! Ohio and Vermont are being ravaged by a wintry mix, while Rhode Island is bracing against thunderstorms and heavy rain. (Texas is sunny and warm coming out of storms and tornadoes that plagued the area for the last few days, so weather won't be much of a factor there.)
In Ohio, the northern Cleveland region will be getting the worst of the snow and ice, which might have helped Clinton by knocking down turnout in the strongly Obama-leaning 11th Congressional District. However, heavy rain and flood warnings across the south mean equally miserable voting experiences for most Ohioans, including those in the pro-Hillary southeast.
This means lower turnout across all three northeast states, which taken together should aid Obama. Hillary is counting on her base, especially in Ohio, but the rank and file may stay home when faced with "severe storms" and "flood warnings." And, to generalize wildly, the old tend to be a less hardy lot than the young. Also, Clinton has received an advantage from last-minute voters in the past, and those late deciders are less likely to brave the gale. (More committed voters have been taking advantage of early voting laws in Ohio and Texas, and will be staying inside their warm and comfy homes). Obama is largely relying on highly motivated voting blocs (wealthier, educated voters and students) who have turned out heavily for him in inclement weather elsewhere. Wintry mix breaks for Obama!
Update: While icy roads in northern Ohio haven't caused poll closings as of yet, flood zones in eastern Ohio have started extending voting due to the weather, which could offset some losses for Hillary.