President Donald Trump on Monday mocked climate scientists as he jokingly pleaded for global warming to “come back fast, we need you!” while warning the Midwest of impending freezing temperatures.

“In the beautiful Midwest, windchill temperatures are reaching minus 60 degrees, the coldest ever recorded. In coming days, expected to get even colder,” Trump tweeted Monday evening. “People can’t last outside even for minutes. What the hell is going on with Global Warming? Please come back fast, we need you!”

It was not the first instance where the president mocked global warming. Amid freezing temperatures last year, Trump tweeted: “Brutal and Extended Cold Blast could shatter ALL RECORDS – Whatever happened to Global Warming?”

Trump’s Monday tweet comes ahead of winter storms that are expected to hit the Upper Midwest and part of the Deep South and Northeast by midweek, making travel conditions treacherous.

On Tuesday, more than 1,000 flights were canceled or delayed in anticipation of the dangerous conditions.

The National Weather Service’s Weather Prediction Center said that parts of southeastern Minnesota and Wisconsin could see over a foot of snow. The winter storm will then bring upwards of a foot of snow to Michigan before targeting the Northeast overnight Monday into Tuesday.

Rain and snow will develop along an arctic front associated with the storm over parts of the Ohio Valley stretching into the Lower Mississippi Valley on Monday, according to the NWS.

The snow and rain will move eastward by Tuesday afternoon, affecting cities such as Birmingham, Atlanta and Nashville.

“A dangerous week of cold air and travel conditions are coming up,” Fox News Senior Meteorologist Janice Dean said Monday. “Snow and ice will coat even the Deep South Tuesday through Wednesday, which will make travel incredibly difficult and possibly crippling.”

Winter storm warnings and advisories were posted stretching from Mississippi stretching up through Tennessee into West Virginia.

The storm system is associated with an arctic front that is responsible for a cold air outbreak associated with the polar vortex that will bring bone-chilling cold to the Midwest.

Temperatures on Wednesday could fall to 30 degrees below zero, and could feel as cold as 60 degrees below zero because of the wind chill.

“Some of the coldest air in decades will pour in across the Northern Plains, Midwest and Great Lakes with windchills in the negative 40- to negative 50-degree range and air temperatures below zero for several days,” Dean said. “This will be dangerous and potentially deadly for these regions, and people need to stay inside.”