Fred’s remnants set up a week of wet weather
Flash flood watch for Lehigh Valley may be needed, forecasters say
With the Atlantic hurricane season now in full swing, what’s left of Tropical Storm Fred later this week will become the first round of tropical moisture to wash over the Lehigh Valley since the remnants of Zeta last fall.
Early Monday, the National Hurricane Center said Fred had peak sustained winds of 50 mph as it drew closer to landfall in the Gulf. While it’s not the strongest storm, it does represent a heavy rain threat for the Southeast and, later in the week, for the Lehigh Valley.
The Weather Prediction Center said Fred could contribute to flash flood risks over the next three days from moisture sweeping across the Florida Panhandle and southern Alabama. From there, the storm is forecast to turn northeast through the Tennessee Valley and southern Appalachians.
The Lehigh Valley and the rest of the region will see unsettled weather all week, according to the National Weather Service in Mount Holly, with a “deep layer southerly flow drawing abundant moisture northward.”
That means showers with embedded thunderstorms will become more widespread across the region, though it may prove difficult for meteorologists to track thestorm’scenterasitmovesnorth.
Forecasters put the Lehigh Valley at a slight risk of excessive rainfall on Tuesday. Meteorologists say the forecast looks “quite tropical” as the southerly flow starts to tap into some of the moisture from Fred.
Tuesday night, remnants of Fred will be near the Kentucky/ Ohio/ West Virginia border heading northeast toward central Pennsylvania.
“Several subtle waves out ahead of Fred will provide the impetus for the chance of precipitation Tuesday night into Wednesday morning,” the weather service said in its morning forecast discussion. The remnants of the storm will be riding a “channel” on Wednesday, with the greatest potential for heavy rainfall over eastern PA, or closer to where the remnants of Fred are expected to pass over.
“These multiple rounds of heavy rain Wednesday into Thursday could result in flash flooding,” the weather service said. “A flash flood watch will likely be needed at some point for portions of the area this week.”
Models favor rounds of showers and thunderstorms through late week, and possibly into the weekend.
More than eight inches of the area’s rainfall was attributed to tropical systems in 2020. That included the remnants of Fay, which washed over the region in July, and the punch of Tropical Storm Isaias in August. In early October came the leftovers of Tropical Storm Delta, and later in the month Zeta triggered warnings for heavy rain, flooding and snow.