Vice President Joe Biden to Attend Memorial for Granite Mountain Hotshots

Crews battling the Arizona wildfire that killed 19 firefighters made significant progress Thursday, moving within sight of fully corralling the blaze, authorities announced.

Despite still gusty winds and temperatures in the 90s, the Yarnell Hill Fire near Prescott was 80 percent contained as of Thursday evening, according to Inciweb, a federal website that disseminates information from agencies like the U.S. Forest Service and Bureau of Land Management. That's a significant upgrade from earlier in the day, when it was 45 percent contained.

"Praise the Lord!" wrote one person on an official Facebook page dedicated to the fire.

The Yavapai County Sheriff's Department has lifted an evacuation order for residents of Peeples Valley, according to Inciweb. Those in the community of Yarnell, which is about 75 miles northwest of Phoenix, still face a mandatory evacuation order.

On average, workers are putting in 13- or 14-hour shifts but are able to sleep, shower and eat when they need to, U.S. Forest Service spokeswoman Suzanne Flory had said. "We're very safety conscious and we're very careful about not overstressing or overworking anybody and making sure they get that rest that they need."

There are four helicopters battling the blaze, she told reporters.

Temperatures reached into the 90s on Thursday, with winds gusting in excess of 20 mph. It should get a little cooler in the coming days, with the thermostat peaking in the 80s and winds expected to be a little calmer.

There's also a chance of showers and thunderstorms for the coming week, at least.

Rain would be welcome in many ways, though thunderstorms also bring the possibility of lightning that could spark more fires. And wet conditions could also hamper efforts because people could get stuck in mud, explained National Weather Service meteorologist Jim Wallman.

The Maricopa County medical examiner's office performed autopsies and said Thursday that the causes of death for all 19 were "fire-related injuries." The manners of death were described for each as an "accident."

Plans to remember the 19 firefighters include a memorial service scheduled for Tuesday. Vice President Joe Biden will attend the service in Arizona, a senior administration official told CNN on Friday.

On Wednesday nearly 600 firefighters and support workers assigned to the fire took a brief break from their hard work to observe a moment of silence in honor of the 19 members of the Granite Mountain Hotshots, who died Sunday when the fire took a sudden, unexpected turn.

The pause coincided with the movement of a convoy of vehicles driven to the fire by the Granite Mountain team. The vehicles are being returned to Prescott, where they were based.

To start Wednesday's moment of silence, a loud alert tone sounded on firefighters' radios and an unidentified fire team commander announced, "As the crew carriers for the Granite Mountain hot shots leaves the Yarnell Hills fire and begin their journey home, all personnel in the incident will observe an operational pause, in observance of our fallen comrades."

The first official service to remember the lost firefighters will be held Tuesday in Prescott Valley. A ceremony is expected to begin at 11 a.m. local time at Tim's Toyota Center, according to CNN affiliate KPHO. The bodies are being guarded by members of the Phoenix Fire Honor Guard at the medical examiner's office in downtown Phoenix, the affiliate reported Thursday.

CNN's Jackie Castillo and Lesa Jansen contributed to this report.