Severe Thunder, Large Hail, Heavy Winds Possible In Eastern PA

After a few days of balmy spring weather, which came on the heels of a mini-heat wave, the weather forecast in southeastern Pennsylvania has taken a turn for the bizarre.

In addition to heavy thunderstorms, "severe hail" is possible in the region, as a hazardous weather outlook was issued by the National Weather Service.

Thunderstorms and rain hit the Philadelphia area early Thursday, and rain is possible on and off throughout the day. The thunderstorm severity was categorized as "enhanced" for the five-county area.

Tornado activity was in central Chester County Thursday night, with a tornado warning being issued from 11 p.m. to 11:30 p.m. See details here.

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The bulk of the worst storms could hit just when people are driving home, or starting their Memorial Day weekend vacation: between 4 and 9 p.m. (story continues below photo).

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Here is what to expect:

• Thunderstorms, some of them severe, will impact the area this afternoon into this evening.
• There could be two rounds of storms. The first in the mid to late afternoon, and a second round during the evening.
• Any severe storms will be capable of producing damaging wind gusts, leading to scattered downed trees and power outages. A few storms may also produce large hail.
• An isolated tornado is also possible. While damaging straight-line winds will be a more widespread concern, should any tornadoes form, localized damage would occur.
• Flooding is not expected to be a widespread concern. However, any thunderstorms may produce brief heavy rainfall, and localized flash flooding is possible especially in urban areas.
• Today is likely to be a busy travel day due to the upcoming holiday weekend. The highest storm threat will occur during and after the evening rush hour. Those traveling should be aware of this risk (story continues below photo).

Severe thunderstorms will continue to track from eastern Ohio into western parts of New York and Pennsylvania before spreading over New Jersey and the rest of New York state and the mid-Atlantic into Thursday evening, according to AccuWeather.

"Some of these storms may produce flooding in low-lying and poor drainage areas," AccuWeather Meteorologist Alyson Hoegg said in a release.

AccuWeather meteorologists say they are also concerned that the storms can produce hail and damaging winds. Trees with a weakened root structure from recent rainfall will be more susceptible to being downed by thunderstorm winds, even if gusts are below 58 mph. "There can also be an isolated tornado," Hoegg said.

The storms may lead to times of reduced visibility along sections of interstates at a time when many people may be getting a jump start on holiday travel, according to AccuWeather.

"Everyone starting their holiday weekend early should keep an eye to the sky as these storms could lead to slower travel and delays at airports," Hoegg said

Here is the forecast:

• Thursday: A chance of showers and thunderstorms. Some storms could be severe, with large hail and damaging winds. Mostly cloudy, with a high near 80. Southwest wind around 11 mph. Chance of precipitation is 50%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
• Thursday night: Showers and thunderstorms likely, mainly before 1am. Some storms could be severe, with large hail and damaging winds. Mostly cloudy, then gradually becoming mostly clear, with a low around 64. Southwest wind around 10 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
• Friday:Sunny, with a high near 80. Northwest wind around 14 mph, with gusts as high as 26 mph.
• Friday night: Mostly clear, with a low around 58. North wind 8 to 13 mph becoming light northeast after midnight.
• Saturday: Mostly sunny, with a high near 79. Southeast wind 5 to 8 mph.
• Saturday night: A chance of showers and thunderstorms before 2am, then a slight chance of showers. Mostly cloudy, with a low around 64. Chance of precipitation is 30%.
• Sunday: Mostly sunny, with a high near 89.

With reporting from Patch correspondent Tom Davis.