Maui County officials continue to closely monitor a wildfire on Crater Road near Haleakala that began Wednesday night and has engulfed approximately 550 acres.

The fire was 70% contained at 355 acres by early this afternoon, but expanded later in the day to the point that the Maui Fire Department said at 8 p.m. tonight that a fire containment percentage was difficult to estimate. MFD said that strong, swirling wind during the afternoon caused fire spotting, which sparked fire outside of the control lines. MFD said fire in a eucalyptus grove on the mauka flank has been problematic. MFD said that as of 8 p.m. the fire’s progress had been stopped on the south side and that the eucalyptus trees were still burning on the east (mauka) side but at a slow pace.

The timing of the fire is close to the one-year mark of the Aug. 8 Lahaina wildfires, the deadliest in the U.S. in over a century. That fire killed least 102 people, burned nearly 3,000 acres and destroyed or left uninhabitable some 3,900 structures, most of them homes, many of which housed multiple families.

No injuries or structural damage have been reported from this latest fire, which is at an elevation of about 7,000 feet.

Initially estimated at 300 acres, the fire grew to approximately 500 acres by this afternoon, according to the MFD.

By this afternoon the Maui Emergency Management Agency reported that strong, swirling wind had caused fire spotting outside the control lines.

Although no evacuation orders have been issued for the Haleakala Crater Road fire, MEMA sent out an emergency advisory this afternoon urging residents above Kekaulike and Haleakala highways between Upper Kimo and Waipoli roads to prepare for potential evacuation.

MEMA stated that a follow-up message for evacuations will be issued if necessary, and urged residents to monitor radio, TV and mobile devices for official information.

“Due to a change in the behavior of the fire in the Upper Kula area, we urge all residents to prepare for a potential evacuation. The safety of our community is our top priority, and we need your cooperation to ensure everyone’s well-­being. This is just an advisory message; a follow-up message for evacuations will be provided if deemed necessary,” MEMA announced today in an alert.

In response to the fires, three to five helicopters, five to six bulldozers, 18 MFD firefighters, 30 state Department of Land and Natural Resources Division of Forestry and Wildlife personnel, 17 National Park Service hand crew members and others have been deployed.

This afternoon DLNR closed Polipoli Spring State Recreational Area, the Kula Forest Reserve and all Na Hele Trails in the reserve until further notice.

Crater Road will be closed through this morning after conditions are reassessed. Haleakala National Park remains closed until further notice.