Baltimore gets the first snow of the eason as school's in the area are canceled and up to three inches of snow could accumulate. (Kenneth K. Lam/Baltimore Sun)
On an unexpectedly snowy day, Baltimore unofficially set a record for its wettest year in the books, going back to 1871.
As of 5 p.m., enough snow, ice and rain had fallen at Baltimore-Washington International Thurgood Marshall Airport to surpass an annual precipitation record of 62.66 inches, set in 2003.
The heaviest snow was reported in northern Baltimore County, western Howard County and across Carroll County, where a winter storm warning is in effect until early Friday morning. Baltimore City, eastern Howard and southern parts of Baltimore and Harford counties were under a winter weather advisory.
By early afternoon, the National Weather Service’s snowfall reports included 5 inches in Westminster and Parkton, 4.5 inches in Norrisville, 2.8 inches in Bel Air, 2.5 inches in Perry Hall, 2 inches in Columbia and 1.7 inches at Baltimore-Washington International Thurgood Marshall Airport.
Several Baltimore-area schools closed Thursday, including public school systems in Baltimore County, Carroll County, Harford County and Howard County. The Maryland Zoo also closed.
The precipitation turned to mostly rain along the I-95 corridor by the afternoon.
Still, slick conditions were complicating travel, particularly to the west and southwest of Baltimore.
Maryland State Police said they responded to nearly 100 crashes across the state between 6 a.m. and 10 a.m. Thursday, and urged people to drive cautiously throughout the day. State Highway Administration spokesman John Schofield said the agency had 1,400 pieces of equipment treating major roads statewide.
“Everyone certainly should allow for the extra time and check traffic conditions because there’s going to be some dangerous conditions,” weather service meteorologist Chris Strong said.
In Western Maryland, winter storm warnings were in effect through late Thursday. Up to 6 inches of snow and a quarter of an inch of ice are expected there.
Temperatures remained stubbornly close to the freezing mark across Central Maryland into Thursday afternoon, helping to produce more snow than many expected. Weather service meteorologist Jason Witt said a high pressure system off the coast of Maine was steering a steady stream of cold air from eastern Canada into the region.
He said it’s unusual for those conditions to come together and produce significant snow in the mid-Atlantic in November.
“This was one of those rarities in November where cold air happened to be in place, and it wasn’t going anywhere fast,” Witt said.
Based on the snowfall at BWI, Thursday’s accumulations were the region’s biggest in November since 1989, and its earliest measurable snowfall since 1996.
Temperatures began rising above freezing along I-95 in the afternoon, causing precipitation to turn to sleet and snow.
The type of precipitation that falls depends not just on how cold it is close to the ground, but the temperature of air higher up in the atmosphere. A warm layer aloft can cause precipitation to fall as rain until it reaches colder air close to the ground, turning it into sleet or freezing rain.
Multiple precipitation types are expected across the area in association with tomorrow's storm. Here's some insight into how snow, sleet, freezing rain and rain form. pic.twitter.com/6uuR41m8mU
Eventually, warmer air is forecast to move in overhead and turn precipitation to a cold rain that could last into early Friday. Some snow and sleet showers are possible into early Friday morning, and higher elevations along the Mason-Dixon Line may not see any change-over from snow.
A flood watch in effect along and east of I-95 was canceled early Thursday afternoon as fears of heavy rain passed. Still, as much as an inch of rain is possible overnight, forecasters said.
That suggests the region could push the annual precipitation record significantly higher, with more than six weeks left to go until 2019 arrives.
Temperatures Friday are forecast to rebound into the 40s, and little to no precipitation is expected in Maryland, aside from possible lingering showers in the northeast corner of the state, Strong said.
Wintry precipitation is not uncommon in November. At some point over the past 127 years, at least a trace of snowfall has been recorded in Baltimore on every date this month. The most recent November snowfall here fell Nov. 26, 2014, when 0.3 of an inch accumulated.