Marylanders should see the sun return by Wednesday afternoon, ending a siege of freezing rain and rain that slicked many streets and sidewalks, touched off a flurry of road accidents Tuesday, and closed or delayed school for hundreds of thousands of students.
All that resulted from only a light icing early Tuesday. Forecasters said more icing was expected overnight into Wednesday, but rising temperatures should bring that to a halt before daybreak.
"Most of the freezing rain will start at the onset of the [rain] shield that moves in after midnight. Then it's going to change to plain rain as a combination of southeast surface winds and east surface winds bring slightly warmer air," said Steve Zubrick, science and operations officer at the National Weather Service forecast office in Sterling, Va.
"This is not the classic situation to get really good ice accretion rates. … We just have no good source of cold air," he said.
As much as a quarter- to a half-inch of rain was predicted to fall overnight.
The center of the massive storm was still moving east out of the Plains and across the upper Midwest on Tuesday, delivering heavy snow and bringing transportation hubs to a crawl from Oklahoma to Chicago, where up to two feet were predicted.
The storm was forecast to reach the Ohio Valley early Wednesday. Then its energy was expected to jump to a new low forming off the New Jersey coast.
From there, the storm will race off to the northeast, ending the precipitation in the Mid-Atlantic states, forecasters said. The region could then begin to see some sunshine.
Wednesday morning should find communities along the Pennsylvania line in the low- to mid-30s. Between Baltimore and Washington, thermometers should be in the mid-30s, with Southern Maryland near 40 degrees.
"Whatever the freezing rain does, it's going to melt during the day, because we're forecasting highs for [Baltimore] in the upper 40s," Zubrick said. "Then a cold front comes through."
Temperatures will drop back below freezing Thursday morning. "So any water left standing will freeze," he said.
The next winter storm system could arrive by Friday night, with rain and snow forecast for Saturday.
Tuesday's ice storm turned out to be far less troublesome than the forecasts on Monday seemed to suggest. BGE, which had prepared for another round of outages, had nothing out of the ordinary.
Most main roads were salted and passable. Slippery spots remained, however.
Between midnight and 9:30 a.m. Tuesday, Howard County police said there were 18 accidents, 13 of which were fender-benders with no injuries. No one was killed in the others, which included two on I-70 near the Patapsco River bridge. Three other vehicles slid off the road into ditches or a tree, but without serious injuries to occupants, Howard police said.
Other crashes were reported along Interstate 81 in Washington County, but they were not serious, said State Highway Administration spokesman Charlie Gischlar.
The icing was enough to get the attention of school officials. Most area public school districts, like the city, decided to start classes later than usual. Some, like Baltimore County, closed altogether.
Zubrick said Marylanders may have looked at ice forecast maps predicting a quarter-inch of ice by Wednesday morning and taken that to represent what was due overnight Monday into Tuesday. In fact, only light icing had been expected Tuesday morning.
"I thought it went pretty much as planned," he said.
Not so much Tuesday night into Wednesday. Thanks to an influx of warmer air, the two-day icing potential "is not as great as we were originally expecting. … The model guidance [Tuesday] is suggesting warmer temperatures than what it was suggesting [Monday]," Zubrick said.
Temperatures in Garrett County Tuesday climbed into the mid-40s. Cold air "damming" east of the mountains, however, held temperatures 10 degrees colder along the Pennsylvania border. That's where the icing potential remained a concern Tuesday night.
"From eastern Washington County across Frederick, Carroll and Baltimore to Harford, that area has the potential for seeing the most icing due to freezing rain," Zubrick said.
But by midnight, heavier precipitation and an influx of warmer air was forecast to turn even that freezing rain to all rain.
By Friday night, forecasters will be watching another coastal low. But they say there does not appear to be enough cold air available to produce serious snow for the Mid-Atlantic. For now, they're predicting a rain/snow mix.
Baltimore Sun reporters Liz Kay and Larry Carson contributed to this article.