(CNN) -- Canadian police and military teams were working Tuesday afternoon to rescue about 300 people stranded after what a local official termed the most brutal storm to hit the Ontario region in 25 years.
Some people had been stuck in their vehicles for more than 24 hours following blinding snow that piled up so high it made it almost impossible to open vehicle doors.
"You really felt almost despair," said Brandon Junkin, who spent nearly 24 hours stranded before being rescued Tuesday afternoon after he heard a helicopter hovering over his immobilized truck. He had run out of gas and was without anything other than a blanket to help him through the ordeal.
Ontario Provincial Police initially reported about 360 vehicles and about 300 people had been stranded near Sarnia, Ontario, on Highway 402 -- a major thoroughfare linking the U.S.-Canada border to London, Ontario.
Some of those people have since been rescued, but Sarnia Mayor Mike Bradley said it could be 24 hours before everyone is taken to safety.
The Canadian military assigned a CC-130 Hercules airplane and two CH-146 Griffons helicopters to the search and rescue effort, which also includes snowmobiles and four-wheel-drive vehicles from the provincial police.
Bradley said truckers stranded by the storm have invited some motorists to shelter with them in their rigs, and nearby residents have also opened their homes to stranded motorists.
He reiterated police warnings not to travel through the region.
"This is probably the most brutal storm we have had in 25 years," he said.
Meanwhile, wintry weather continued its assault Tuesday on the Eastern United States with another hard freeze on tap for the deep South and as much as two more feet of snow in portions of New York and Pennsylvania.
Even northwest Indiana, already buried under as much as two feet of snow and the site of numerous motorist strandings Sunday and Monday, was expected to get another taste of blinding lake effect snow on Tuesday, according to the National Weather Service.
And temperatures will only get colder, CNN meteorologist Jennifer Delgado said.
Cold arctic air is expected to cover the eastern United States through Tuesday, according to Delgado. Florida is expected to shiver through wind chills ranging from 5 to 23 degrees.
While the bulk of the storm that blanketed much of the upper Midwest in snow over the weekend has moved on to Canada, the National Weather Service said portions of upstate New York were expected to get as much as two feet of lake effect snow through Wednesday morning. The heaviest accumulations were expected Tuesday afternoon and evening.
Lake effect snow happens when cold air passes over warmer lake waters, picking up moisture that freezes and falls as snow.
As much as 16 inches of lake effect snow is on tap for parts of northwest Pennsylvania, as well.
Northwest Indiana, where dozens of motorists were stranded Sunday and Monday after a storm that dumped more than two feet of snow in parts of LaPorte County and surrounding areas, was expected to get a few more inches of blowing, drifting lake effect snow, according to the National Weather Service.
That would continue to make travel in the region difficult.
In Florida, where much of the state was under a hard freeze watch for Tuesday night, citrus growers remained cautiously optimistic that the state's valuable citrus crop would survive yet another night of frosty cold.
Although temperatures were forecast to fall into the mid-20s in the southern part of the state and as low as the teens in inland portions of northern Florida, winds were forecast to be light -- a good sign for growers, said Andrew Meadows, a spokesman for Florida Citrus Mutual, a trade association.
"Our fingers are crossed for tonight but the good thing is there's not going to be any wind, which is prefect for irrigation," he said.
Constantly spritzing citrus trees with water can help prevent frost damage. Windy conditions make that work harder, according to the association.
The crop has so far escaped major damage, Meadows said.
By the way, in case you were thinking Wednesday might be better, probably not.
The National Weather Service says that a low pressure system will draw warm moist air from the Gulf of Mexico up into Kentucky and Tennessee, introducing the threat of freezing rain that could coat roads, trees and power lines.