BETHLEHEM, Pa. — Lehigh and Northampton counties are expected to see slippery conditions tonight as mixed precipitation moves through the area.
The National Weather Service forecasts rain and snow will begin after 5 p.m. Sunday, later turning to freezing rain, rain, sleet and snow around midnight through 2 a.m.
"Slow down and use caution when driving."National Weather Service winter weather advisory
The NWS issued a winter weather advisory to Lehigh and Northampton counties from 7 p.m. Sunday to 3 a.m. Monday warning of "slippery road conditions."
The advisory urges drivers to "slow down and use caution when driving."
Monroe and Carbon counties are under the same warning for an extended time, with "total snow and sleet accumulations between 1 and 4 inches and ice accumulations less than one tenth of an inch."
But the NWS expects the Lehigh Valley will only see snow and sleet accumulations "up to one inch" and a "light glaze" of ice.
"Near and southeast of I-95, this should just be rain, though a little snow or sleet right at the onset can't be ruled out," an area forecast discussion from the NWS says.
"Further northwest, snow may occur long enough to produce a modest accumulation across the I-78 corridor, but then temps should warm and we end up with mostly rain after midnight."
Freezing rain to the
The discussion also says there might be periods of freezing rain south of the existing advisories.
EPAWA meteorologist Bobby Martrich said a "cold air damming event" is what will bring snow to parts of the region tonight in his Sunday, Dec. 15, weather update.
Martrich shared a snow map that puts areas of the Lehigh Valley in sections labeled as "B" and "C."
The map legend defines area "B" as having a "mix of snow/sleet/freezing rain Sunday evening, changes into rain overnight." The precipitation breakdown for area "C" — which includes the northern most parts of Lehigh and Northampton Counties — likely will see that "snow initially mixes with sleet and freezing rain, then to rain."
"Overall this is a light quantitative system, as terms of total liquid equivalent, and it shouldn't do too much," Martrich said.
