Introduction
If you live near the coast, you’ve likely seen the phrase long before: “A Coastal Flood Advisory is now in effect.” But what does that mean? Why do you feel like it’s happening more often these days?
In 2025, coastal flooding is more of a realized state than an “if,” in the case of the United States. In states such as Florida, North Carolina, and New Jersey, climate change has created rising sea levels, stronger storms, and “king tides,” all happening in low-elevated land at once.
A Coastal Flood Advisory is issued by the National Weather Service (NWS) to alert people of an advisory, as weather, tides, and winds may be pushing seawater onto roads, buildings, parking lots, and into communities. It is not a coastal flood warning in the sense of a coastal flood, and it is serious.
Let’s dive into what that means for you, what it does to you, and what you can do to protect your home and yourself.
What Is a Coastal Flood Advisory?
A Coastal Flood Advisory is a public advisory issued by the National Weather Service (NWS) to inform coastal communities of the threat of minor to moderate flooding from increased high tides, storm surge, or strong onshore winds.
Advisories will be issued by the NWS, typically a few hours before the expected highest tide of the year. These advisories are associated with the Atlantic Coast and Gulf Coast, but especially some regions of the Pacific Northwest as well.
Important Facts to Provide Context
- Issuing Agency: National Weather Service (NWS)
- Impact: Minor to moderate flooding (not life-threatening flooding, but possible property damage)
- Typical Duration: 6 to 12 hours in duration, typical
- Common Causes: High tide + strong winds + low pressure systems
For example, in early October 2025, Jake experienced approximately ankle-deep flooding on downtown streets in Charleston, South Carolina, due to nearly 7.5 feet above normal high tide levels, which caused a Coastal Flood Advisory to be issued.
Why Coastal Flood Advisories Are Increasing
Over the last decade, coastal flood advisories have increased substantially in the U.S. The National Oceanic and Atmospheric Administration (NOAA) reports that coastal flooding has risen to about four times the historical rate of flooding prior to the 1960s. Cities such as Miami, Annapolis, and Norfolk are now experiencing “sunny-day floods,” which are floods occurring during typical rainfall events.
Climate Change and Rising Sea Levels
Sea levels are rising at an average rate of 0.13 inches a year, with some sections of the U.S. being higher. To a certain extent, the tides are already compromising existing infrastructure (pushing further inland).
Stronger Storm Systems
Hurricanes, nor’easters, and tropical storms are creating conditions of heavier rainfall and wind-driven surge forces that push seawater inland.
The “King Tides” Effect
Aligned with the new or full moon, the moon and sun’s gravitational pull creates peak tides, which can promote coastal flooding with no storms.
How to Stay Safe During a Coastal Flood Advisory
Even minimal flooding can impact your day—obstructing traffic, delaying vehicles, or damaging your property. Here are ways to stay safe and reduce your risk while an advisory is in place.
1. Don’t drive through floodwater.
Just six inches of flowing water can knock someone down, and 1 foot of moving water can float a small vehicle. If you observe the roadway is covered with water, make sure you turn around, as it’s tough to tell if it is 1 or 6 inches deep.
2. Safeguard your residence.
Moving patio furniture, trash cans, valuables, and everything else outside to higher ground.
Check sump pumps, ditches, and drains ahead of high tide.
If you reside in a flood-prone area, think about surrounding doors in sandbags.
3. Keep updated.
Follow the NWS app or NOAA Weather Radio to keep current.
Local emergency management agencies regularly post tide forecasts and road closures on social media.
4. Prepare an emergency bag.
Should flooding develop, think about gathering containers with essentials, including:
Flashlight/container and batteries
Bottled water and non-perishables
First-aid kit
Documents in waterproof container.
Expert Insight
Dr. Kim Jenkins, a specialist in coastal resilience at the University of Florida, states that “Coastal flood advisories provide essentially early smoke alarms for flooding and give residents time to prepare and take action before conditions become dangerous. The only mistake would be for people to ignore it as if it is not a big deal, but repeated saltwater flooding can damage vehicles, roadways, and even the foundations of houses.”
Her recommendation? Treat each advisory as a cue to prepare, rather than panic.
Real-Life Example: Miami’s “Sunny-Day Floods”
Residents of Miami Beach, Florida, are no strangers to the unusual sight of flooded streets on sunny afternoons. In 2024 and 2025, during king tides, saltwater bubbled up through storm drains and left portions of Alton Road underwater.
The city has built pump stations and higher roads, but local officials say that flood advisories are now issued dozens of times per year—a sign that this is the new reality for many coastal areas.
FAQs About Coastal Flood Advisories
Q1: How is a coastal flood advisory different than a flood warning?
A1: A Coastal Flood Advisory informs individuals that minor flooding is likely, whereas a Flood Warning informs individuals that significant flooding is possible that poses a danger to life and/or property.
Q2: What is a baseline number of advisories?
A2: It depends on the geography. A coastal municipality such as Charleston or Miami may have 20-40 advisories in a year. If you are several miles further inland, you may have zero advisories.
Q3: Is my home in danger when there is a coastal flood advisory?
A3: Not necessarily (probably not), but you could experience flooding on low-lying streets, beaches, and parking lots in your area. You can check to see if there is a flood map for your locality (it’s usually something you can find by doing a local search on flooding, and it should either show you’re at an elevation above sea level or not).
Q4. Can it flood with no rain?
A4: Yes—this is called tidal flooding or “sunny-day flooding.” Tidal flooding happens when the tide comes in high enough to force seawater to push in. Tidal flooding does not happen due to rain.
Q5: How do you ensure all of your 1,500+ staff nationally are receiving these advisories?
A5: Visit the National Weather Service website or download the NWS mobile app for real-time alerts and tide predictions.
Conclusion
While Coastal Flood Advisories may appear trite, they serve as a necessary preliminary notification that things are changing in our environment—quite literally. As sea levels continue to rise and storm events occur more frequently, Coastal Flood Advisories will continue to play an important role for the safety and security of coastal societies.
For anyone who lives along the coast, every advisory should be adhered to—so keep aware, prepare early, but never discount a tide!
For when the ocean decides to column us doorstep—even for a short duration—it is always easier to be prepared than unprepared!
