March 16 (UPI) — Even before a round of mid-May blizzards started blanketing an area stretching from South Dakota to northern Michigan on Saturday, a partial government shutdown already was making air travel miserable for Americans.

Extreme winter weather snarled all manner of transportation across the Midwest, while airports in Atlanta, Charlotte and elsewhere on the East Coast were slowed by pounding rain, on top of an increasing number of TSA employees either calling out sick or quitting their jobs because they are not getting paid.

As of early evening on Monday, there were 21,549 total flights delayed in the United States and 5,159 flights that were canceled, Flight Aware reported.

The Department of Homeland Security, which is home to the Transportation Security Administration, has not been funded since Jan. 30 amid a debate in Congress over funding the Department of Homeland Security, of which TSA is a part.

Democrats and Republicans in Congress disagree on adding guardrails for DHS agencies involved with immigration amid a crackdown by the Trump administration, which has left TSA unfunded.

The nation’s air traffic controllers, customs agents and TSA agents missed their first paycheck over the weekend, which has led to hundreds of TSA employees quitting their jobs, the New York Post reported.

The partial shutdown already had affected security and other services at airports, leading to long lines and advice that travellers arrive at the airport even earlier because of how backed up they have been.

On Sunday afternoon, as airports, travellers and millions at home prepared for winter weather to roll through overnight, the trade association Airlines for America, which represents both passenger and cargo airlines, sent an open letter to Congress pleading for them to fund TSA on predictions of what is already happening.

The CEOs, which include the leaders of the biggest U.S. passenger airlines, as well as FedEx and UPS, said that without funding TSA they expect travel issues during spring break, the World Cup and other national travel dates to be as chaotic as they were last year during the longest government shutdown in history.

Making matters worse has been a wide range of extreme weather across the country, from steady showers and a tornado watch shutting down Charlotte Douglas International Airport several times this morning — with the same occurring at major airports in Atlanta, Newark, Washington, D.C., Chicago, Detroit and Minneapolis, the Charlotte Observer reported.

The weather is not expected to let up, either, with the National Weather Service predicting that while the Midwest will get a bit of a break, severe thunderstorms with damaging winds and some tornadoes — as of early afternoon more than 34 million people were under tornado watches between Florida and New Jersey — expected later into the evening.