Polar vortex threatens to disrupt Iowa caucuses

• Iowa is under a winter storm warning as 6–12 inches of snow are expected across its central and southeastern regions through Tuesday, according to the National Weather Service.
• The run-up to the caucuses coincides with one of the most active periods of winter weather in recent memory, Axios extreme weather expert Andrew Freedman reports.
• The snow is expected to be followed by a polar vortex that lingers through caucus day, with single-digit temperatures for the highs and below-zero overnight lows.

What's happening: The campaigns of former UN ambassador Nikki Haley and former President Trump have both already canceled Iowa events due to weather and travel issues.

• Vivek Ramaswamy will drive to his campaign events this week rather than his typical private plane rides.
• Blowing snow with winds gusting as high as 40 mph are expected Tuesday, reducing visibility.

Zoom in: More frigid temperatures next week could dampen caucus turnout, especially for Trump supporters who assume he's already ahead, local Democratic political consultant Jeff Link tells Axios.

• Poor weather is most likely to negatively impact turnout among older Iowans, said Steffen Schmidt, a political science professor at Iowa State.
• That could disproportionately affect Trump too, Link says, as the former president's supporters likely skew older than voters for Haley and Ron DeSantis.

Zoom out: Iowa's winter caucuses are no stranger to weather disruptions, Schmidt says.

• "Weather is the No. 1 caucus turnout problem."

Axios' Sophia Cai contributed reporting.