Severe thunderstorms swept across parts of the Midwest and the East Coast on Sunday, August 17, 2025, unleashing torrential rainfall that prompted the National Weather Service (NWS) to issue multiple Flash Flood Warnings in New Jersey and Illinois. The dangerous conditions on land were compounded by coastal threats, as Hurricane Erin, a major storm churning in the Atlantic, began to generate life-threatening surf and rip currents along the Eastern Seaboard.
In New Jersey, a Flash Flood Warning was issued for parts of Burlington County on Sunday evening, remaining in effect until 10:15 p.m. The National Weather Service reported that between 0.5 and 1.5 inches of rain had already fallen by 8:12 p.m., with an expected rainfall rate of 1 to 2 inches in just 30 minutes. Earlier in the evening, Essex, Hudson, and Union counties were also under a flash flood warning, which expired ahead of schedule. The storms were accompanied by severe thunderstorm warnings, with radar indicating wind gusts of up to 60 mph and potential hail near Wrightstown. The severe weather was driven by a cold front that is expected to bring significantly cooler temperatures to the state on Monday, with highs struggling to reach the 70s.
Meanwhile, residents in Illinois awoke to similar alerts. A Flash Flood Warning was in effect until 7:15 a.m. Sunday for several counties, including northern Iroquois, northeastern Grundy, Kankakee, southern Kendall, and southwestern Will. The storms followed a day of high heat and humidity, with feel-like temperatures approaching 90 degrees. The weather pattern is expected to remain unsettled, with scattered showers and storms forecast through Tuesday before cooler, drier air arrives midweek.
While Hurricane Erin is not projected to make landfall in the United States, its influence is being felt along the coast. The NWS has warned of a high risk for dangerous rip currents at all New Jersey beaches. Breaking wave heights are forecast to increase from 2-3 feet on Monday to 3-6 feet on Tuesday, creating hazardous swimming conditions that will persist through the middle of the week.
Understanding the Alerts: Watch vs. Warning
In the face of such severe weather, it is crucial for the public to understand the difference between the alerts issued by authorities. According to the National Weather Service, the terminology is designed to communicate specific levels of threat:
- Flood Watch: This means conditions are favorable for flooding to occur. It is a call to “Be Prepared” and stay informed, as flooding is possible but not imminent.
- Flood Advisory: Issued when a weather event may cause nuisance flooding that is not severe enough for a warning but could still pose a threat to life or property if caution is not exercised.
- Flash Flood Warning: This is a more urgent alert meaning a flash flood is imminent or already occurring. This is a signal to “Take Action!” immediately. A flash flood is a sudden, violent flood that can develop in minutes. If you are in a flood-prone area, you must move to higher ground right away.
The Dangers of Floodwaters: Turn Around, Don’t Drown!
Emergency officials consistently emphasize the life-saving message: “Turn Around, Don’t Drown!” Floods are the most common natural disaster in the United States, and according to the Virginia Department of Emergency Management, more than half of all flood-related drownings happen when a vehicle is driven into hazardous floodwater. It takes just six inches of moving water to knock an adult off their feet and only one foot of moving water to sweep away most vehicles. Floodwaters can also conceal washed-out roads, debris, harmful bacteria, and downed power lines that can electrically charge the water. The safest course of action is always to avoid entering floodwaters, whether on foot or in a vehicle.
