Freezing rain and sleet fell across the south shore Tuesday afternoon as forecasters continued to warn of dangerous conditions overnight as temperatures drop and roads and bridges ice over.

Officials warned that when temperatures in the New Orleans area dip firmly below freezing, residents would face the most treacherous conditions in what had so far been an uneventful storm.

The worst of the winter storm is expected in the early evening, as freezing rain and sleet blanket both sides of Lake Pontchartrain, said Ken Graham, the meteorologist in charge at the National Weather Service’s Slidell office. That precipitation is expected to freeze on roadways, leading to slick conditions overnight, Graham said.

The storm itself is expected to wrap up with snowfall in the early morning hours, he said.

All that precipitation could stick around for a while since temperatures will remain below freezing for much of the day Wednesday, Graham said. That could mean an additional day of hazardous conditions, he said.

“We’re going to have some frozen roads tomorrow,” he said.

The forecasts prompted many agencies to extend their closures for an additional day, with many government offices and schools planning to reopen on Thursday.

Temperatures are expected to eke their way above freezing for a few hours on Wednesday, though it remains to be seen whether they will remain that high long enough for the ice to evaporate and clear the roadways.

New Orleans began feeling the first real effects of the winter storm blowing into the area Tuesday afternoon, even before any significant rain fell.

Ice and salting operations closed or restricted traffic on area bridges and highway on-ramps as schools and other agencies announced closures would be extended through Wednesday, when the worst road conditions were expected.

The official forecast remains unchanged for now, with expectations that the area would see high amounts of freezing rain, followed by sleet and then snow, through the afternoon and early evening. Officials warned that icy, hazardous conditions are expected throughout the area.

“We’ve always been expecting the heaviest precipitation to be this afternoon through the early evening hours,” said Bob Wagner, meteorologist with the National Weather Service.

New Orleans woke to dreary gray skies Tuesday morning and a chill, crisp air carrying just a hint of the wintry mix expected to fall on the area by later in the day.

City streets were largely empty as schools and government offices and many businesses shut their doors as forecasts predicted sleet and snow would begin falling by the early afternoon.

All flights at Louis Armstrong International Airport were cancelled after 11 a.m.

While there was not much precipitation in the early morning, forecasters still expect potentially hazardous conditions to develop later in the day as freezing rain, sleet and snow pile up. Up to a half inch of ice could accumulate by the evening south of Lake Pontchartrain, with the north shore seeing about a half-inch, said metorologist Tim Erickson with the National Weather Service office in Slidell.

A winter storm warning remains in effect for the entire New Orleans area and extends out to Lafayette and Baton Rouge.

Temperatures on the north shore hovered just above freezing about 9 a.m., while it was a few degrees warmer south of Lake Pontchartrain. Wind chill meant it felt a few degrees colder throughout the area.

Freezing rain is expected on the north shore by early afternoon, followed by sleet and then snow in the evening, Erickson said. The south shore will see the same pattern with a bit of a delay, with rain starting late in the afternoon.

“Once the snow starts, you know that’s the back edge of the entire event,” Erickson said.

About an inch of snow will fall on both sides of the lake, though its not clear yet whether any will accumulate.

More worrying to officials, about a half-inch of ice is expected to accumulate on the south shore over the course of the storm while about a quarter-inch builds up in St. Tammany Parish. While there were no road closures this morning, freezing temperatures overnight will make road conditions hazardous, as streets, particularly bridges and elevated roadways, remain slick through the morning, leaving drivers facing a potentially hazardous commute Wednesday morning.

Relief, in the form of temperatures above freezing that will clear the roadways, isn’t expected until Wednesday afternoon, Erickson said.

“Wherever those icy bridges are they’re going to stay right through Wednesday,” he said.