Rising tensions, not-so-veiled threats and a fever of rumors have set the stage for a looming weekend rally in downtown Portland.

As many as 1,000 clashing demonstrators are expected to converge at Tom McCall Waterfront Park and surrounding areas for an unpermitted protest and counter-protest beginning at 10 a.m. Saturday, Aug. 17.

In the buildup, city and law enforcement leaders embarked on a media blitz of podcasts, interviews, opinion columns and online videos, each harmonizing on a single refrain: violence is not welcome in the Rose City.

"Extremists from across the political spectrum have used our city, our home, to commit acts of violence," Mayor Ted Wheeler said. "This is why I continue to empower and direct the Portland Police Bureau to use whatever means necessary — and amass whatever resources necessary — to ensure public safety and to uphold the law."

A message to anyone who plans on using Portland on August 17th to commit violence and spread hate:

We.
Don't.
Want.
You.
Here.

Stop using our beautiful city and our home to spread fear and disrupt our lives. https://t.co/CtkoxMz6rQ

— Mayor Ted Wheeler (@tedwheeler) August 7, 2019

Police Chief Danielle Outlaw issued a preemptive warning as early as Aug. 2, noting that some prospective attendees were publicly expressing "criminal intentions."

"We're being thrust into this political show," she said. "I want to reassure our community that we have their best interests at heart. And we're doing what we can to assure that our city is safe for all of us."

Members of the City Council and a large coalition of allies from organized labor, religion, civil rights, sports, business and the community at large announced a gathering in Pioneer Courthouse Square at 10 a.m., Wednesday, Aug. 14, for a peace vigil.

The conservative rally, "End Domestic Terrorism," is being organized by Joe Biggs, a Florida veteran who gained notoriety while working for the conspiracy-pedaling site InfoWars. Local liberal counter-protesters — including some who call themselves anti-fascists or antifa — have vowed to challenge that rally.

"We call on the community to defend itself, as it has countless times before," Rose City Antifa wrote online.

The Proud Boys, a men-only fraternity whose members label themselves "Western Chauvinists," also are mobilizing. A leader of the group, Enrique Tarrio, said in a statement that groups of "deranged and unstable" antifa have "run amok for far too long."

"Their days of operating with impunity are over," Tarrio promised.

The tension has increased since a spate of mass shootings across the nation. A 21-year-old armed man, Thomas Bartram, who was briefly detained outside a vigil in El Paso, where 22 people died, later told NBC News he was headed to Portland.

And with the planned brawl a chance to relitigate three years' worth of conflict — most recently the June 29 protest that left the conservative writer Andy Ngo bloodied — it's anyone's guess what acts will ultimately unfold on Saturday.

Portland's crystal ball, much like the City of Roses, remains overcast.