BETHLEHEM, Pa. — The National Weather Service is warning of the potential for stormy weather again this weekend, even as cleanup and restoration efforts from this week's tempest continued Friday morning.
The ferocious storms that barreled through the Lehigh Valley region Wednesday resulted in a trail of significant wind damage and knocked out power to hundreds of thousands of utility customers.
The Storm Prediction Center has the area at a marginal risk (1 out of 5) of severe weather on Saturday, and a slight risk (2 out of 5) on Sunday, though the latest model guidance continues to show differences in timing and coverage of storms.
2:31am CDT #SPC Day3 Outlook Slight Risk: from eastern MT into western ND and also from the Mid Atlantic into southern/eastern New England https://t.co/K89lXjsUbi pic.twitter.com/cP9ZzH69wD
— NWS Storm Prediction Center (@NWSSPC) June 28, 2024
Wednesday’s event
One of the hardest-hit areas in the region on Wednesday was in Carbon County, where the National Weather Service said the Lake Harmony area in Kidder Township was blasted by hurricane-force winds during a downburst event.
The destructive winds topped out around 100 to 110 mph, the weather service said, snapping and uprooting trees and causing damage to residences, sheds and other structures.
Downbursts are powerful winds that descend from a thunderstorm and spread out quickly once they hit the ground.
Here is additional information on the Kidder Township Downburst. Our full preliminary report is available here: https://t.co/20miA0SMr0 pic.twitter.com/VSwWN7s0or
— NWS Mount Holly (@NWS_MountHolly) June 27, 2024
That was the case in Kidder Township, where winds caused damage similar to an EF1 (86-110 mph winds) tornado.
The path length of the downburst was measured at 0.9 of a mile, with a width of 350 yards, according to a damage survey conducted by the NWS, Carbon County Emergency Management and the Lake Harmony Fire Company.
Even in the Lehigh Valley, widespread wind damage was misinterpreted as tornado damage.
However, straight line winds and downbursts are a separate phenomenon, with the latter usually holding a large core of hail and rain that can fall rapidly toward the ground.
“When the downdraft hits the ground, much like a stream of water coming out of a faucet and hitting the sink, it spreads out rapidly in all directions and becomes known as a downburst,” according to the weather service.
What’s ahead for the weekend?
The SPC said scattered damaging winds and a couple tornadoes are possible Saturday from parts of Ohio into northern West Virginia, central and western Pennsylvania and western New York.
But the Lehigh Valley shouldn’t worry too much, EPAWA meteorologist Bobby Martrich said.
“I don’t think this is going to be something that’s going to be affecting our eastern areas on Saturday, although you will be mostly cloudy,” Martrich said in his latest video update, highlighting that central Pennsylvania counties “will have a little bit to deal with.”
“That’s kind of the dividing line here,” Martrich said, pointing to places such as Williamsport, Lock Haven, Selinsgrove and surrounding areas that should be on guard.
Martrich said, if anything, the Lehigh Valley could see "garden variety" storms Saturday.
But the area will have to stay alert Sunday, with timing and placement on any storms still to-be-determined.
High temperatures are expected to be in the upper 80s to low 90s for much of the region, with surface dew points in the 70s.
“We will have to see if these can mix out some during peak heating,” the latest NWS forecast discussion said.
The combination of temperatures and dew points will yield heat indices Sunday afternoon well into the 90s, with some areas around 100 degrees.
While showers and thunderstorms are forecast to develop, the bulk of the activity could be along and south/east of the Intersate 95 corridor, but folks in the Lehigh Valley should pay attention.
“Given the heat and high humidity in place, some storms could become locally severe,” the weather service said.
