The prospect of water pushing into homes and businesses weighs heavily on the minds of Tampa Bay residents ahead of storms.
The area has not had a direct hit from a hurricane in over a century, yet multiple storms have managed to flood areas such as coastal Shore Acres in St. Petersburg or more inland homes along the Alafia River in Riverview.
While guidance from the National Hurricane Center and emergency managers is vital in assessing personal risk, it’s helpful to have a few extra tools in the belt. One of those is watching real-time and future water levels.
An online dashboard from the National Oceanic and Atmospheric Administration provides data on tide gauges across portions of coastal Tampa Bay. Additionally, another resource from the National Water Prediction Service shows where river flooding is possible.
The information, while far from the only piece in the larger puzzle that is hurricane preparation, gives residents another way to evaluate their risk.
We’ve gathered together what to know about rising water and how to access the data surrounding it.
What to know about tides
Tides are influenced by the sun and moon, according to the National Oceanic and Atmospheric Administration. When the tallest part of a wave reaches an area, that’s high tide. The opposite, the lowest, is low tide.
The difference in these heights is called a tidal range.
Weather patterns can also influence tides. Strong wind and rain can lead to higher-than-expected tides, said Virginia Dentler, an oceanographer for the National Oceanic and Atmospheric Administration.
Tampa Bay tends to see its highest tides of the year around late summer and early fall — coincidentally around peak hurricane season. Around this time, water levels grow by about 8 or 9 inches from what is typically recorded in winter and spring.
“When you have warmer waters, ocean water expands, and so it increases in elevation along the coast,” Gregory Dusek, a senior scientist at the National Oceanic and Atmospheric Administration, previously told the Tampa Bay Times.
What about ‘king tides’?
A “king tide” is a colloquial term that refers to higher-than-normal tides. The flooding these high tides can cause has a few names: king tide flooding, nuisance flooding or sunny day flooding.
A king tide occurs when two ingredients come together: When the moon is closest to the Earth, combined with a new or full moon.
In Tampa Bay, there are just a few feet of difference between low and high tides — less than in other coastal parts of the country. That means whatever weather occurs that day will play a more important role in determining if a high tide will cause flooding here.
Flooding can also occur without a weather system, though it’s less common.
Dusek estimates Tampa Bay sees king tides about four or five times a year.
One occurred while Hurricane Idalia was skirting the coast of Tampa Bay in 2023. Idalia scraped the coast just hours before a king tide — but had it arrived about six hours later, Idalia’s storm surge likely would have been about 2 feet higher.
Where to find tide data
The National Oceanic and Atmospheric Administration has a plethora of tidal stations across the country. In Tampa Bay, a number of those sites are concentrated along the coastal waters of Pinellas and Hillsborough counties.
Because Tampa Bay has a port system, there are more tidal gauges in the surrounding waters, Dentler said. However, more-northern areas of Tampa Bay, like Pasco County and beyond, are without tidal gauges.
Dentler said tide stations are typically added onto preexisting structures, like Pier 60 on Clearwater Beach.
When a storm is incoming, Dentler suggests looking to the National Oceanic and Atmospheric Administration’s Coastal Inundation Dashboard.
“It’s our real-time product,” Dentler said.
Pinpoints on a map of the country show where tide stations are located. Once a user clicks on their desired location, that station’s observed water levels pop up.
All stations give real-time water level data and will show when minor flooding (in yellow), moderate flooding (in red) and major flooding (in pink) is possible.
The lines on the graph depict three possible water levels: Predicted water levels, observed water levels and forecasted water levels.
The dark blue line shows water level predictions oceanographers made a year in advance. The red line shows where water levels currently are. The light blue line shows the forecast guidance, which inputs external weather forces such as high winds.
The forecast guidance line is the best bet in knowing how high water levels may reach during a storm, Dentler said.
All stations have different heights at which flooding can occur. In St. Petersburg, for example, minor flooding can happen at a little less than 2½ feet.
The highest water levels recorded were all during storms. Two out of the top 10 highest water levels occurred in 2023, one during Hurricane Idalia and one during a December storm that flooded local streets.
Water levels from Hurricane Idalia are the second highest in the St. Petersburg station’s recorded history — water reached 3.85 feet above the average height of the highest tide recorded each day.
Where to find river water levels
Just like coastal areas, inland residents of Florida are no strangers to flooding.
Hurricane Ian crawled across the state in 2022, dumping up to 20 inches of rain in some areas and flooding rivers.
The Peace River broke a century-old record a few days after Ian’s landfall when it reached nearly 24 feet — more than 3 feet higher than the record set in 1912, according to the Southwest Florida Water Management District.
The National Water Prediction Service has another tool that identifies water levels in rivers across the country. If you zoom in on Florida, you’ll find little dots lighting up the entire state.
Each dot color corresponds with the stage of flooding: Green (no flooding), yellow (action), orange (minor flooding), red (moderate flooding) and purple (major flooding).
Similar to tidal gauges, each river has different height levels at which flooding can occur.
Take the Suwanee River at Manatee Springs, for example. The river, considered to be in a flood stage at 7 feet, had minor flooding in late April when water levels reached nearly 8 feet.
The blue line shows observed water levels, while the dotted purple line shows the water level forecast.
Should the National Weather Service place an area under a flood warning, there will be a tab under the specific river gauge laying out hazards, along with further flooding details.
A recap of websites
- To find high tides and low tides: Tidesandcurrents.noaa.gov.
- To find the Coastal Inundation Dashboard: Tidesandcurrents.noaa.gov/inundationdb.
- To find river gauges: Water.noaa.gov.
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