Flood watch until 11 p.m. Thursday, and watch out for those trees

A potent and complex spring storm was forecast to wring out one to perhaps three inches of rain across the region Thursday, threatening flood-prone areas, power lines, and millions of innocent blossoms. Not to mention putting in peril the drought watches on both sides of the river.

Philadelphia International Airport reported Thursday morning that some flights had been cancelled and others were delayed as the FAA ordered some flights headed to Philadelphia to wait on the ground.

In light of other recent rains and saturated soils, the National Weather Service hoisted a flash-flood watch for the entire region from 8 a.m. to 11 p.m. The Storm Prediction Center in Oklahoma also placed the area in a "marginal" risk zone for "severe" weather, meaning wind gusts approaching 60 mph.

The chances for fireworks are greater south and east of the city, and a wind advisory was in effect for New Jersey's coastal counties.

Given the boggy soils, of some concern to utility officials was the fact that winds were forecast to blow from the east.

"Trees aren't used to that," said Peco spokesman Ben Armstrong.  Since trees and branches are accustomed to bending with prevailing westerlies, a so-called counter wind can be challenging, especially to white pines and other varieties with shallow roots.

Armstrong said Peco will have extra crews on hand Thursday.

The rains could well claim one victim: the drought watch imposed on all eight counties by the New Jersey and Pennsylvania Departments of Environmental Protection.

Despite the rains of the last few days, precipitation has been running about 80 percent of normal during the last six months, a departure from the trend of recent years, which generally have been quite wet.

The region has been blessedly free of major riverine flooding, and waterways aren't exactly brimming, according to the U.S. Geological Survey.

The Delaware River is forecast to crest at 16.3 feet at Trenton during the weekend after the fresh rainwater works its way downstream. Flood stage is 22 feet.

The river hasn't sloshed over in more than three years, and that time was the result of an ice jam, said Ray Kruzdlo, the National Weather Service hydrologist in Mount Holly. The last rain event that sent the river above flood stage was Tropical Storm Lee back in 2011.

The Schuylkill has been jumpier, as the folks who use Kelly Drive or live along the banks in West Norriton, Montgomery County, well know. The river is projected to reach 11.5 feet; flood stage is 13.

But West Norriton won't be taking chances, said Jason Bobst, the township manager, and officials are staying in touch with the frequently flooded residents along the river.

"This isn't the first time we've gone through something like this," said Bobst. "We'll play it by ear.

"Hopefully we'll get a little wet, and that will be about it."