Flooding, fallen trees close roads around York County

Heavy rains will continue in York and surrounding counties through Wednesday, July 25, according to local weather services.

AccuWeather meteorologist Jake Sojda added that it could persist through Thursday morning.

Rain will be fairly consistent, with a few hours' break between each downpour, he said, and it will keep piling up, causing "significant flooding concerns" by Wednesday.

"Fortunately, the break in downpours has allowed us to catch breaks in water levels rising," county spokesman Mark Walters said Tuesday morning.

The county's Office of Emergency Management activated its Emergency Operations Center to keep watch on water levels, roads and other concerns, Walters said.

It's functioning at level 3 — meaning it requires full staff — which Walters said is standard for monitoring conditions. In more severe cases, the office would call for volunteers, he said.

Walters said the county saw a few minor evacuations because of the weather, including three from a mobile home park in Fairview Township along Yellow Breeches Creek and one in Dover for a medical condition.

According to Met-Ed, 920 customers in the county had power outages as of approximately 11:30 a.m. Tuesday — 471 in York City.

York County is under a flash flood watch through Wednesday evening, according to the National Weather Service.

The weather service said Tuesday morning that up to 8 inches has fallen in York County and parts of Lancaster, Dauphin and Cumberland counties over the past few days, with another 1 to 3 inches expected by early afternoon. It said urban areas and small streams were especially at risk.

More:York County under flood warning through Monday evening

More:Flash flood watch in effect for York County

High-risk areas: The areas getting the heaviest rainfall run through the center third of York County, excluding the southeastern and western areas, and extend through Lancaster, Lebanon and parts of Dauphin counties, continuing north, said National Weather Service meteorologist Michael Colbert.

Sojda described the target region as a bullseye, covering northern Virginia through central Maryland and the Capital Region near Washington, D.C., as well as southcentral and much of eastern Pennsylvania up through the Poconos.

Forecasts predict 6 to 10 inches of rain in this region through Thursday morning — with some areas seeing a weeklong total of more than a foot, Sojda said.

"York County is definitely vulnerable to being on the high side of that," he said of the expected inch count. 

Sojda warns residents living in low-lying areas or near streams and creeks to keep an eye on local emergency management updates from social media to know when water levels are rising and it's necessary to get to higher ground.

Low pressure: The rain is coming from an upper-level area of low pressure to the west, according to Colbert. On the east side of it, a southerly flow over Pennsylvania has brought up a lot of humidity from the Gulf of Mexico, the Atlantic Ocean and other tropical regions, he said.

Thunderstorms began Saturday, and now the system is locked into place, he said.

Sojda said the low-pressure area is sitting over the southeastern part of the country, pulling moisture up from those areas and feeding into the northeastern U.S., "pushed up against higher terrain and wringing it all out."

Though it's more typical for a spring or fall pattern, Colbert said, "things just happen sometimes."

What's more atypical is that the pattern in prolonged, Sojda said. Having this amount of rain for several days is what's causing problems, he said.

Water on the rise: Colbert said the region can expect ongoing flood warnings, as water from small creeks flows downstream to rivers, making water levels rise.

Areas to watch for in the county are along the Codorus and Conewago creeks — tributaries of the Susquehanna River — but Colbert said they are not in any danger of flooding yet. 

On Tuesday, the weather service reported that the Codorus was "already above flood stage," and additional rapid rises were expected on the Conowingo and Little Conowingo creeks, according to a news release.

Farther north, the Swatara Creek, which runs through Hershey and Middletown, is in a minor stage of flooding, Colbert said.

Sojda said the Susquehanna River might reach the minor flood stage by Wednesday or Thursday. He said most of the streams and creeks flowing into the river would also break banks by then.

Avoid driving: Colbert and Sojda both say the best way to stay safe is to avoid driving through flooded streets.

Visibility is limited in those situations, they explained.

While drivers might think a road looks safe, they cannot tell how fast water might be flowing under the surface, Sojda said.

Colbert added that areas of the road surface could dip down, so standing water could be a lot deeper than it appears.

"It's still raining and we cannot stress this strongly enough: do not cross flooded roads!" the York County Planning Commission posted on its Facebook page Tuesday morning.

"Even if you're sure that your vehicle can handle the depth, there's no guarantee the road surface is in place below the water," the post read, citing a collapsed bridge where Watertank Road crosses the the Codorus Creek, near Glenville. 

Walters reminded county residents that 6 inches of fast-moving water can knock over and carry away an adult, 12 inches can carry away a small car and 18-24 inches can carry away an SUV, according to the National Oceanic and Atmospheric Administration.

He said it's best just to avoid driving through affected areas, especially near bodies of water such as the Codorus Creek and Susquhanna River, which are prone to flooding.