Five states across the Plains and Midwest were under blizzard watches and warnings early Monday, as a sprawling winter storm threatened to snarl travel and dump up to 18 inches of snow.
Although the largest snow totals were expected in rural areas, cities such as Denver, Omaha, Des Moines and Green Bay could get between 6 inches and a foot of snow through Wednesday, forecasters said.
Flight delays and cancellations could hit airports in Denver, Minneapolis and even Chicago, according to The Weather Channel.
The storm was not likely to affect the majority of caucusing Iowans, however, since the system wasn't forecast to reach the majority of the Hawkeye State until Tuesday.
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"The southwest corner of Iowa is most likely where the caucuses will be affected by light snow, but the storm should not impact most places," Weather Channel Lead Meteorologist Kevin Roth told NBC News.
The storm is expected to move eastward through Kansas, Nebraska and South Dakota, later Monday, before intensifying Tuesday as it reaches Iowa, Minnesota, Wisconsin and Michigan.
Parts of Nebraska, Kansas and Iowa could get up to 18 inches of snow by the time the storm moves into the northeast and turns to mostly rain on Wednesday.
The system has already moved through southern California, where a woman was killed when high winds uprooted a tree and crushed her car and 80,000 homes and businesses were left without power. Blizzard warnings in effect for parts of California and Nevada were lifted early Monday.
In the Californian mountains, 16 inches of snow was reported at Mammoth Mountain Ski Area through Sunday afternoon. This snow had shifted into parts of Nevada, Utah and Colorado early Monday, where it was already "snowing pretty good" at 6 a.m. ET, according to Roth.
This article first appeared on NBCNews.com.