A plane of migrants was diverted to PHL. Activists are preparing in case others are sent here on purpose.

When word gets out that a bus of asylum seekers is heading from Texas to Philadelphia, a streamlined phone chain springs into action.

A WhatsApp group that includes various nonprofits sends volunteers to 30th Street Station to meet the buses with hot chocolate, blankets, and coats. A SEPTA bus is at the ready to take migrants to a welcome center in North Philadelphia and Health Department officials are there to address any health emergencies.

» READ MORE: More buses from Texas? Philly ready to welcome immigrants as pandemic bar drops.

Last week, the group learned that Texas Gov. Greg Abbott, the man behind the uncoordinated efforts to send asylum seekers to self-described sanctuary cities, chartered a plane of migrants to Chicago as that city cracked down on his buses. Cathryn Miller-Wilson, executive director of HIAS Pennsylvania, said the group chat immediately began rethinking some of its processes.

“We agreed, OK, we have to put a plan in place so we can meet the planes if they get to Philly,” she said.

On Tuesday, volunteers were almost put to the test.

The Federal Aviation Administration diverted a plane of 180 asylum seekers who were headed from El Paso to John F. Kennedy Airport in New York City. An FAA spokesperson said the plane landed in Philadelphia because of low visibility. In the end, Philly was only a pit stop. A city spokesperson said the Eastern Airlines passengers were picked up by buses headed to New York before 11 p.m. But had they stayed in Philly, the city would have been able to connect the plane’s passengers to shelter and other services.

Miller-Wilson echoed the sentiment.

“We are ready,” she said of anything Abbott throws the city’s way. “We will likely have a meeting to solidify what we will be doing differently for the planes.”

Abbott confirmed to Fox News that he was behind the New York City-bound plane, proof to observers that he is escalating his efforts to funnel migrants to sanctuary cities. Abbott claimed he’d bused more than 82,900 asylum seekers as of Dec. 20 — including 3,400 to Philadelphia — to cities that include Denver, Los Angeles, and Washington.

» READ MORE: In Texas he was offered a choice of three cities. How one immigrant ended up on a bus to Philadelphia.

Many of the arrivals have described monthslong harrowing journeys as they escaped persecution and other dangerous conditions in their home countries. Philly arrivals often quickly link up with family across the region, while others stay at the city-operated welcome center getting legal support from HIAS Pennsylvania, Nationality Services Center, and Catholic Social Services until they have a more permanent home. The city says there are fewer than 40 people at the center now.

After the first bus drop-off in November 2022, Philly advocates quickly worked out a system that streamlines how volunteers work through dozens of newcomers of various ages, many of whom don’t speak English. Still, organizations recognize adding planes to the mix means they’ll have to tweak their initial greeting phase.

Logistical details such as bringing hot beverages and lugging carloads of coats in various sizes need to be worked out with Philadelphia International Airport. They’ll have to figure out airport logistics such as where to keep the SEPTA bus that will take newcomers to the welcome center.

Abbott has maintained that his actions are a necessary relief for border towns in Texas, which he said are being overrun with new arrivals. His office did not respond to a request for comment, but spokesperson Renae Eze told NBC News this month that the governor has no plans of slowing down his efforts even as winter sets in.

“Until President Biden does his job and secures the border, Texas will continue busing migrants to sanctuary cities to provide much-needed relief to our overwhelmed border towns,” Eze said.

Cities including Chicago and New York City have declared states of emergency as they deal with the influx of migrants. Chicago has set hours for when buses can make drop-offs and this month, its City Council approved a bill that allowed for buses caught violating the rules to be impounded. Then the first plane arrived.

On Wednesday, New York City Mayor Eric Adams issued an executive order that requires buses of asylum seekers to give 32 hours’ notice and to drop people off only during set times and at a specified location, or face fines or being impounded. The mayors of New York, Chicago, and Denver have called on Texas to coordinate with them and for federal action.

Miller-Wilson is similarly urging federal lawmakers to help ease the stress felt by some cities by giving them work authorization, which requires a lengthy process to secure.

“New York would not be overwhelmed if people were authorized to work and could support themselves and didn’t have to rely on charity,” she said.