BETHLEHEM, Pa. — A powerful storm will develop along the coast this weekend, forecasters warn, bringing heavy rain to the Lehigh Valley and causing flooding in some areas.
A flood watch is in effect from Sunday evening through Monday afternoon, with excessive runoff potentially resulting in flooding of rivers, creeks, streams and other low-lying and flood-prone locations, the National Weather Service said.
Flooding is expected in poor drainage and urban areas, with rainfall totals of 1.5 to 3.0 inches forecast to fall Sunday into Monday.
The heaviest rain is expected overnight Sunday night, with intense rainfall rates possible that would enhance the flooding in some areas.
The Weather Prediction Center has placed the Lehigh Valley at a "slight" risk of excessive rainfall, meaning there’s a 15% chance of rainfall exceeding flash flood guidance within 25 miles of any given point in the risk area.
Winds could gust to 35 mph through much of the area early Monday, with peak gusts near 50 mph along the coast, where a wind advisory has been issued.
Lehigh Valley storm timeline
While pockets of light rain or drizzle could occur early Sunday for parts of the region, forecasters say the bulk of the precipitation will arrive later in the day.
According to EPAWA meteorologist Bobby Martrich, the “Classic Miller-A type system” typically associated with strong winter storms will bring us rain from start to finish. Here’s a breakdown of what’s expected:
EPAWA's 12/16-17 weekend forecast, covering:
— Bobby Martrich | EPAWA (@epawawx) December 16, 2023
■ One more dry and tranquil day on Saturday
■ Breakdown of the coastal storm expectations
■ Snow showers with an upper level low behind?https://t.co/dd33ekPEGX
- Mid-to-late afternoon Sunday: Showery activity breaks out across the area
- Through Sunday night: Showers continue, becoming steadier closer to midnight
- After midnight/early Monday: “That’s when we really kick it into gear,” Martrich said. Rain will be heavy at times into early Monday.
- Monday morning through afternoon: “I still think once we get into the afternoon hours, we’re done,” Martrich said. “We should be done before noon with any precipitation.”
Post-storm holiday temperature outlook
According to the weather service, we should have a cold Tuesday into Wednesday, followed by moderate temperatures with dry weather through the time frame.
Daytime high temperatures are currently forecast to be near or below average Wednesday, then closer to average Thursday into Friday.
Temperatures through next weekend and into Christmas Day should be in the upper 40s to near 50 degrees.
