The busiest travel period of the year is underway as hundreds of flights are already delayed setting up for what could be a "perfect storm" of disruptions over the Independence Day holiday weekend. 

As of 1440 ET, FlightAware, a flight tracking company, reports 680 flights are delayed and 28 canceled. The number has been steadily increasing Friday as air travel demand soars amid pilot and crew shortages causing flight disruptions. Most of the delays are at airports across the Northeast, including New York City and Washington--Baltimore metropolitan regions. 

"We're now going into the Independence Day Holiday weekend and are concerned that our customers' plans will be disrupted once again," Captain Jason Ambrosi, Chairman of the Delta Master Executive Council (MEC), a unit of the Air Line Pilots Association, said in a statement. 

Ambrosi continued: "The perfect storm is occurring. Demand is back, and pilots are flying record amounts of overtime but are still seeing our customers being stranded and their holiday plans ruined."

Hundreds of off-duty pilots picketed Delta Airlines at airports this week. Pilots are stressed as flight delays and cancelations result in record amounts of overtime this year. 

Earlier this week, Transportation Secretary Pete Buttigieg told NBC Nightly News's Lester Holt, "there are going to be challenges" this holiday weekend. 

"There's no quick fix" to the mess in the air, United Airlines CEO Scott Kirby recently said, adding the industry is short 12,000 pilots. 

Besides labor shortage, airline industry group Airlines for America, which represents the country's largest airlines (American Airlines, Delta, United, Southwest, JetBlue, and Alaska Airlines, as well as shippers FedEx and UPS), blamed the Federal Aviation Administration's own understaffing for "crippling" East Coast air traffic. This looks like finger-pointing to us. 

Buttigieg warned last month that airlines face federal government action-- presumably fines -- over mounting flight cancellations and delays. 

This weekend will be nothing short of a disaster if the trend of delays and cancelations continues.