As a “potentially historic” winter storm impacts the region, the precipitation Sunday morning and early afternoon in the Lehigh Valley was mostly rain or light snow that melted on contact with the ground.
Don’t let that fool you, things are expected to take a sudden turn by late afternoon. That’s when colder air will begin to infiltrate the area, and the precipitation will change to snow fairly quickly, forecasters say.
Live updates: Major snow storm sets sights on Lehigh Valley
While the snow may be light at first, it will significantly pick up in intensity after dusk and continuing through the overnight hours, according to Eric Hoeflich, a meteorologist with the National Weather Service forecast office in Mount Holly, New Jersey.
“Things could change, but right now we’re expecting around a foot of snow up that way (in the Lehigh Valley),” Hoeflich said in a Sunday morning conversation with a Morning Call reporter. “We’re already seeing some snow at Allentown being reported. That’s probably light snow and barely accumulating if at all. It will really pick up this evening into the overnight hours.”
As for the specific timing, a chart in the weather service’s storm briefing shows the chance of hourly snowfall rates greater than 1 inch. For the Lehigh Valley, at 7 p.m. there is a 20% chance of that high snowfall rate occurring, but by 10 p.m. the probability jumps to 65%. It will remain that high until around 4 a.m. Monday By 7 a.m., the chances drop to 30%.
This chart shows the chances of hourly snowfall greater than 1 inch from a major winter storm impacting the region. (NWS Mount Holly)
In New Jersey and the Philadelphia region, which are expected to bear the brunt of the coastal storm, the odds of those high snowfall rates are near 90% during the overnight hours.
“The heaviest [should] end probably about 7 a.m. or so, but we could still see some snow showers continuing even through midday,” Hoeflich said.
He added there is a sharp cutoff in snow totals expected just to the west of the Lehigh Valley, meaning totals could still shift if the storm track moves. As of Sunday morning, the weather service projected the Lehigh Valley to get between 10 and 20 inches of snow; however, some forecast models midday Sunday were suggesting slightly lower totals.
During the worst of the storm Sunday night into Monday morning, snowfall rates could exceed 2 inches per hour in some areas. Snow covered roads along with reduced visibility from blowing snow will make travel difficult if not impossible, forecasters said.
https://www.mcall.com/2026/02/22/allentown-weather-when-will-heavy-snow-begin-forecast/
