A wet and white Christmas is in the forecast for Butler County and the rest of Western Pennsylvania.

Christmas Eve will be a rainy, windy day with a 100% chance of precipitation and wind gusts reaching 30 mph, according to the National Weather Service.

The forecast calls for 1.5 to 1.8 inches of rainfall from Thursday through 7 a.m. Christmas Day from the North Hills area of Allegheny County to Northwestern Pennsylvania.

“There's going to be a lot of water associated with this,” said Lee Hendricks, a meteorologist for the weather service office in Pittsburgh.

The weather goes downhill after Thursday's daytime high of 48 degrees, dropping to 16 degrees, with the rain turning to snow Thursday night.

“It will turn into snow, and it's going to be quite heavy at times,” Hendricks said.

The NWS has issued a winter weather advisory from 7 p.m. Thursday to 1 p.m. Christmas Day.

“In Butler, total accumulation is 3 to 5 inches. A lot of that will be overnight Christmas Eve and early Christmas morning,” Hendricks said.

A white Christmas is a pretty sure thing.

“I'd say that's a pretty good bet at this point,” Hendricks said about the chances of having snow on the ground Christmas Day.

Scattered snow showers with little or no accumulation are possible Christmas Day. The temperature will remain cold with a high of 21 degrees with wind gusts up to 21 mph under mostly cloudy skies.

Snowfall this month is more than double the normal amount in Western Pennsylvania. As of Wednesday, the region saw 19.1 inches of snow based on measurements taken at Pittsburgh International Airport. Typically, the area gets 8.3 inches of snow in December, Hendricks said.

The outlook is for the weather to improve Saturday and Sunday, when partly sunny skies bring high temperatures of 25 and 38, respectively.

On Wednesday, PennDOT issued an alert to motorists about heavy rain and winter weather on Christmas Eve in Butler and surrounding counties.

PennDOT said its crews usually don't pretreat roads with salt brine when a storm is expected to start as rain, which will wash the brine away.

Roads will not be free of snow while precipitation is falling. With freezing temperatures, roads that look wet may be icy, and drivers should use extra caution, especially when approaching bridges and highway ramps where ice can form, PennDOT said.

PennDOT recommends not driving during winter storms, but people who must be on the road should slow down and drive at a speed that suits road conditions, turn on headlights, increase following distance, use defrosters and wipers, keep windows and mirrors free of snow and ice, and pack an emergency kit.

Motorists can check road conditions by visiting www.511PA.com, which is free and available 24 hours a day. It provides traffic delay warnings, weather forecasts, traffic speed information and access to more than 950 traffic cameras.