Mother Nature is expected to deliver an unwelcome present on Christmas Day, a powerful wind and rain storm that forecasters say could cause flooding and widespread power outages.

“The primary hazards will be strong winds potentially over 50 mph, heavy rainfall of 1 to 3 inches, areas of dense fog and coastal splash over,” the National Weather Service office in Gray warned in a Tuesday evening tweet. “Power outages are likely where winds gust over 50 mph, especially along the coast. In addition, minor to moderate stream and river flooding will be possible due to the combination of snow melt, warm temperatures, and heavy rainfall.”

The storm will likely begin on Christmas Eve after 6 p.m., said Hunter Tubbs, a meteorologist with the National Weather Service. Although the forecast could change, the weather service on Tuesday issued a high wind watch from 10 p.m. Thursday through 7 p.m. Friday.

Strong southerly winds will develop ahead of a cold front late tomorrow. The front will cross the area Christmas Day bringing heavy rain and very strong winds, especially to the coast. Stay tuned to https://t.co/MQrn8fFInT for the latest forecasts. #MEwx #NHwx pic.twitter.com/vl0huIsei1

— NWS Gray (@NWSGray) December 23, 2020

Portland could get as much as 2 inches of rainfall while areas in central Maine and the White Mountains of New Hampshire could get up to 3 inches. The heavy rain will melt snow and create the potential for flooding in streams, rivers and low-lying areas. The National Weather Service will be tracking water levels in the Saco, Androscoggin and Kennebec rivers, Tubbs said.

Temperatures should be mild on Christmas Day – 50 degrees or higher – but the storm is expected to end abruptly Friday night and temperatures could drop as much as 30 degrees, potentially leaving streets and sidewalks coated with ice, Tubbs said.

“It’s looking like a big storm with a lot of heavy rain. We’re very concerned about flooding,” Tubbs said. “Wind will also be a factor with gusts over 50 mph and up to 60 mph. There’s a pretty solid chance that there will be power outages (on Friday).”

Though Christmas is a day off for most workers, that will not be the case for Central Maine Power line crews and storm center employees, spokeswoman Catharine Hartnett said.

The utility on Tuesday was already enlisting employees to fill its holiday roster in preparation for possible widespread power outages. CMP said it has responded to three major storm-related power outages already this month. High winds from Friday’s storm could blow broken tree limbs onto utility poles and lines, CMP said in a news release Tuesday.

“We have been watching and planning for this storm for several days and are letting all of our own employees know that they will likely be called in to work over the holiday,” David Flanagan, executive board chair of CMP, said in a statement. “We know that customers may be distracted by last minute holiday preparations and we want to be sure they consider the possibility that power may be impacted as they get ready.”

CMP serves approximately 636,000 customers in 346 communities located in central and southern Maine.

Flights in and out of the Portland International Jetport likely will not be adversely impacted by the Christmas Day storm, jetport Director Paul Bradbury said Tuesday evening.

Bradbury said the decision to cancel or divert a flight is left up to individual airlines. His staff will be focused on keeping runways clear for incoming and outgoing planes.

“Winds are always a concern, but we do our best not to close,” Bradbury said.

Passenger boardings on Christmas Day will be significantly lower this year compared to last because of concerns about flying during the COVID-19 pandemic, he said. The jetport has seen fewer than 500 advance passenger bookings for Friday.