A Flash Flood Warning is in effect right now for Bergen County and Atlantic County in New Jersey, covering the window from 5:39 PM EDT to 7:45 PM EDT on Wednesday, August 20, 2026. The warning was issued by the National Weather Service offices in Upton, NY and Mount Holly, NJ and reflects active, dangerous flooding conditions driven by heavy rainfall producing excessive runoff across the region.
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This is not a watch or an advisory. A Flash Flood Warning means flooding is occurring or is imminent. Residents and drivers in both counties should treat the roads and drainage areas as hazardous until the warning expires at 7:45 PM EDT.
What the National Weather Service Is Telling You to Do Right Now
The National Weather Service instruction is direct and unambiguous: turn around, don’t drown when you encounter a flooded road. That phrase is not a slogan. It reflects where flood fatalities actually happen. According to the official NWS alert, most flood deaths occur in vehicles, not in homes, not in fields, not in open water. The road in front of you is where the risk concentrates.
The warning specifically calls out the following flood-prone locations and conditions to avoid:
- Urban areas experiencing excessive runoff from heavy rainfall
- Highways, streets, and underpasses
- Other drainage areas and low-lying spots
The NWS instruction is unambiguous on the driving question: do not drive on flooded roads. There is no depth of water that is clearly safe to cross in a moving vehicle. Six inches of moving water can knock a person down. Twelve inches can carry away a small car. The water on a flooded road does not advertise how deep it is or how fast it is moving beneath the surface.
The guidance also tells you to be aware of your surroundings. That applies whether you are on foot, in a parking lot, near a drainage channel, or navigating an underpass. Low-lying areas that seem passable at the start of a storm can fill faster than a driver expects. If you are already out and you reach a flooded stretch of road, the NWS instruction is not to assess it and decide. It is to turn around.
If you are at home in Bergen or Atlantic County during this warning window, the safest decision is to stay there. If you had plans that require driving between now and 7:45 PM EDT on August 20, 2026, postpone them if you can. The warning expires in a matter of hours.
Why This Warning Matters Beyond Tonight
Flash flood events like this one are short and intense, but they expose a gap in how most households prepare: the car. Families often have a go-bag, extra water, and a battery radio at home, but no habit or plan for what to do when a driver encounters flooded roads unexpectedly. Preparedness for flash floods is mostly a behavioral decision made in the moment, under stress, with poor visibility. Building that decision in advance, before you are sitting at the edge of a flooded street trying to judge the depth, is exactly the kind of planning that USRiskRadar covers year-round. Flash flooding is a recurring hazard across New Jersey and much of the eastern United States, and the same “turn around, don’t drown” principle the NWS applies tonight is the one that applies every time standing water appears across a road, regardless of season or storm type.
Monitor updates from the National Weather Service Mount Holly, NJ office at weather.gov for any extensions or changes to this warning before 7:45 PM EDT on August 20, 2026.
For the fundamentals that apply beyond this specific alert, see our Flood Preparedness guide.
Source: National Weather Service (NWS Upton NY, NWS Mount Holly NJ). Active alert data retrieved 2026-08-20 22:00 UTC via api.weather.gov.
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