A Flash Flood Warning remains in effect for Trenton, New Jersey, Levittown, Pennsylvania, and Hamilton Square, New Jersey until 3:00 AM EDT, according to the National Weather Service (NWS) Mount Holly office. The warning covers Mercer, Bucks, and parts of Burlington counties, where 3 to 5 inches of rain have already fallen, with additional downpours expected, creating significant flooding risks.
The warning, issued at 10:45 PM EDT, follows reports of rapidly rising water in low-lying areas, including streets, basements, and drainage systems. The NWS has confirmed that flash flooding is occurring or imminent in these regions, with life-threatening conditions possible. Residents are advised to avoid travel, move to higher ground if flooded, and never attempt to walk or drive through floodwaters.
The National Weather Service has also issued a severe thunderstorm warning for the same areas, with wind gusts up to 60 mph and large hail reported in some locations. The combination of heavy rain and storm winds is exacerbating the flooding situation, particularly in urban and suburban areas where drainage systems are overwhelmed.
Which Areas Are Most at Risk?
The warning specifically targets Trenton, NJ, where the Assunpink Creek and other waterways are near or above flood stage. In Levittown, PA, localized flooding has been reported in neighborhoods near the Neshaminy Creek, while Hamilton Square, NJ is experiencing street flooding due to poor drainage. The NWS has stated that additional rainfall of 1 to 2 inches is possible before the warning expires, further increasing flood risks.
According to the NWS Mount Holly advisory, the most dangerous conditions are expected between 11:00 PM EDT and 2:00 AM EDT, when rainfall intensity is forecasted to peak. The warning includes the following counties:
- Mercer County, NJ (Trenton, Hamilton Square)
- Bucks County, PA (Levittown)
- Burlington County, NJ (partial coverage)
What Should Residents Do?
Authorities are urging residents in the warned areas to take immediate precautions:
- Stay indoors and avoid unnecessary travel.
- Move to higher ground if water begins rising around your property.
- Do not walk or drive through floodwaters—just 6 inches of moving water can knock you down, and 12 inches can sweep away a car (NWS flood safety guidelines).
- Check on neighbors, especially the elderly or those with disabilities.
- Monitor local emergency alerts via NOAA Weather Radio or wireless emergency alerts on smartphones.
Emergency management officials in Mercer County have activated their emergency operations center and are coordinating with local police and fire departments to respond to flood-related incidents. In Bucks County, PA, the county’s Office of Emergency Management has issued a statement urging residents to prepare for power outages due to downed trees and wires.
Why Is This Flooding Happening?
The flooding is primarily the result of a slow-moving storm system that has stalled over the region, dumping excessive rainfall over a short period. According to the NWS, the Assunpink Creek in Trenton is currently at 10.5 feet, with a flood stage of 12 feet, but rapid rises are expected to push levels closer to critical thresholds (real-time river data). Similar conditions are affecting smaller streams and urban drainage systems in Levittown and Hamilton Square.
Meteorologists attribute the severity of the storm to a combination of warm, moist air from the Atlantic colliding with a cold front moving through the Northeast. The NWS has classified this as a high-impact weather event, with the potential for secondary flooding in areas already saturated from recent rainfall. Comparatively, similar flash flood warnings were issued in June 2023 for the same region after 7 inches of rain fell in 24 hours, leading to road closures and evacuations (NJ OEM report).
What Happens Next?
The Flash Flood Warning is set to expire at 3:00 AM EDT, but the NWS has indicated that residual flooding may persist into the morning, particularly in urban areas with poor drainage. Residents should expect:
- Continued street flooding in low-lying neighborhoods.
- Possible road closures due to high water or downed debris.
- Slow response times for emergency services as crews prioritize life-threatening situations.
- Water rescue operations in affected areas, with the New Jersey State Police and Pennsylvania State Police assisting local agencies.
After 3:00 AM, the NWS will likely issue a Flood Advisory for areas where water levels remain elevated. Residents should remain vigilant and avoid returning to flooded roads until authorities confirm it is safe. The next update from the NWS is expected by 4:00 AM EDT, with further adjustments based on rainfall and river conditions.
How to Stay Informed
For real-time updates, residents can:
- Monitor the NWS Mount Holly for official warnings.
- Follow local emergency management accounts:
- Mercer County OEM: @MercerCoNJ
- Bucks County OEM: @BucksCoPA
- New Jersey State Police: @NJSP
- Use the FEMA app or NOAA Weather Radio for alerts.
If you encounter flooding, report it to local authorities immediately. For life-threatening situations, call 911. For non-emergency flooding concerns, contact your local emergency management office.
The National Weather Service has shared the following advisory graphic for the Flash Flood Warning:
For additional visual guidance, the NWS has provided a radar loop of the storm system affecting the region:
Residents are also advised to check local news outlets for updates on road closures and evacuation orders. If you are in a flooded area, avoid contact with floodwaters, which may contain hazardous materials or contaminated debris.
Have you experienced flooding in your area? Share your story in the comments below or tag local emergency services with your location for assistance.
