BETHLEHEM, Pa. — The first snowfall of the season could overperform in the Lehigh Valley, one forecaster says.
Meteorologist Bobby Martrich of EPAWA Weather Consulting highlighted the area as one to watch, thanks to the setup of a “thermal gradient” or baroclinic boundary as the storm moves through.
“This is the boundary that separates the colder air with this snow on the north and the warmer air pushing in from the south,” Martrich said in his latest video update.
“In between here you get this boundary. And along there you ever hear somebody say that you have to … smell the rain to get the heaviest snow? Well this is an example of that.”
Martrich said around 8 a.m. Tuesday that we could see "basically an area of more intense lift closer to that boundary."
In his video, Martrich circled an area that included the Lehigh Valley as one that could see enhanced snowfall rates, particularly during the mid-to-late morning hours.
“If there’s going to be surprises today, it’s going to be right in here,” he said. “That’s your surprise area.”
Winter weather advisory
The Lehigh Valley remains under a winter weather advisory in effect until 1 p.m.
While expected accumulations have fallen compared with initial outlooks, the National Weather Service said the probability for plowable snow — 2 inches or more — remains high in the Poconos and areas along and north of Interstate 78.
“As you head well south and east of I-78, the potential for plowable snow quickly decreases to near 0% for the I-95 corridor,” the latest forecast discussion said.
The latest NWS forecast includes snowfall amounts of a few tenths of an inch for the very northwest portion of the I-95 corridor, up to an inch for areas just northwest of there, and in the 1- to 3-inch range for the I-78 corridor.
Areas across the Pocono Plateau have potential for snowfall in the 3- to 6-inch range, the weather service said.
A transition from snow to rain is expected, during which some sleet and freezing rain also is possible.
“There is now the potential for a light accumulation of ice from freezing rain in the transition zone northwest of the I-95 corridor. The ice accumulation looks to be a light glaze,” the weather service said.
The state Department of Transportation has implemented restrictions on certain vehicles during the storm, which will be communicated via variable message boards, the 511PA traveler information website and smartphone apps.
Restrictions will be lifted as quickly as possible when conditions are safe, PennDOT said in a release Monday.
Restrictions can be changed based on conditions on the roadways, and reports from first responders, law enforcement and PennDOT personnel.
