BETHLEHEM, Pa. — After a period of cool and quiet weather in the Lehigh Valley, forecasters say the upcoming weekend could bring a real sense of déjà vu to area residents.
Another impactful storm is expected to move up the coast, bringing heavy rain and gusty winds to the region — and expected precipitation totals are rising.
"Rainfall totals look to be in the 1.5-3.0 inch range, with the upper range perhaps limited some on any faster northward movement of the storm," the National Weather Service said in its latest forecast discussion Friday.
It comes after a coastal system dumped record-setting rain on the area last weekend.
"Rainfall totals look to be in the 1.5-3.0 inch range, with the upper range perhaps limited some on any faster northward movement of the storm."The latest National Weather Service discussion
According to the weather service, 1.59 inches of rain fell last Sunday, besting the record of 1.40 inches for the date set in 1969.
Overall, 2.04 inches of rain fell at the airport for the duration of the storm — followed by a trace of snow.
While this weekend’s storm doesn’t look to have a wintry element, it’s likely to leave the area even more waterlogged.
"The cold air will not catch up to this before the precipitation starts and ends, so it will start and end as rain across the entire region," EPAWA meteorologist Bobby Martrich said in his latest video forecast.
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
The big question is: what do flooding risks look like?
The setup and timing
The looming storm is expected to evolve from a system emerging from the Rockies that will quickly dip South.
It’s expected to fetch moisture from the Gulf before merging with another storm that rides up the coast on Sunday and Monday.
“[Expect] just showery stuff early on," Martrich said, putting the arrival time of precipitation as somewhere between 4 to 8 p.m. Sunday before the rain turns steady.
"The mid-to-late afternoon period you could have some showers starting to work in, just kind of light and spotty, and then we have steadier rain coming during the evening hours."
Mirroring last week’s storm, the bulk of the precipitation looks like it will come overnight Sunday into Monday, Martrich said.
“It's [targeting] pretty much the same areas that got hit a week before,” he said.
Flooding risks
There remains some question as to the exact track and intensity of the storm, but the weather service said, "There is a flooding risk and this will be enhanced especially if much of the heavier rain falls in a shorter period of time. We will need to watch some of our creeks and streams, especially the quicker responding ones."
Forecasters said the consensus of the guidance brings the storm across our area, along the coastal plain or just offshore.
"This track would tend to maximize the rainfall and also winds. The specific outcome will ultimately depend on the exact track of the surface low and its intensity," the forecast discussion said.
"A surge of warmer air will work its way northward in advance of the surface low, and this should result in mild temperatures Sunday with temperatures possibly rising some more Sunday night."