A large winter storm is headed into Iowa. For the most part, it will arrive after caucuses have ended. But some of it will hit just about at caucus time.

Council Bluffs, on the southwestern edge of the state, has a 35-50 percent chance of seeing snow between 4 p.m. and 7 .p.m on Monday. The percentage of precipitation gets much higher after 7 p.m., and around then it also gets very windy (15 mph) and any rain will shift to snow.

There's a blizzard watch in effect starting at 6 p.m. — an hour before the caucuses.

A hundred miles further north, in Sioux City, the snow will start probably after 7 p.m. — though maybe beforehand, and it might be rainy early on.

In Des Moines and Ames, in the middle of the state, there's only a 15 percent chance of precipitation before 7 p.m., but it's likely to hit in the 7 o'clock hour. Further east, in Cedar Rapids and Dubuque, the storm won't hit until later in the evening.

So how will this affect turnout?

In the eastern part of the state, not much.

Otherwise, in a couple of ways.

First, it's possible that bad weather — cold rain, wind and snow — will hit before the caucuses, pushing people to stay home.

Second, even if the storm arrives when forecasted, people who don't want to drive home from the caucuses in a blizzard will stay home.

In sum: Expect the weather to exert a modest downward push on turnout.

Timothy P. Carney, the Washington Examiner's senior political columnist, can be contacted at tcarney@washingtonexaminer.com. His column appears Tuesday and Thursday nights on washingtonexaminer.com.