As a hurricane approaches land, the storm tide it produces is one of the most serious hurricane threats to people and infrastructure. Storm tide is ocean water that’s pushed onshore by a tropical storm or hurricane’s strong sustained winds, combined with the changes in water elevation caused by tidal cycles. Storm tide can cause water levels to rise and flood large areas very quickly and poses a major risk for drowning.  

Before a storm makes landfall, the USGS may deploy scientific instruments called storm-tide sensors. These specialized instruments help determine the severity of a storm by recording data on storm tides, waves and coastal flooding. USGS and National Oceanic and Atmospheric Administration scientists use this information to improve forecast models. The data may also help relief efforts by the Federal Emergency Management Agency and other federal, state and local agencies by pinpointing the areas hardest hit by storm-tide flooding. 

Once it’s determined a hurricane or tropical storm will likely strike the U.S., USGS experts, often in discussion with the National Hurricane Center and FEMA, will decide whether and where to deploy storm-tide sensors. If deployed, USGS crews will attach the sensors to sturdy coastal infrastructure like bridges and piers that are less likely to be washed away by strong waves. Once conditions allow scientists to return to the field, crews collect the sensors so the data they recorded can be downloaded.

The value of storm-tide sensor information continues long after a storm passes. Engineers use it to design structures to better withstand floods and assess how well dunes and wetlands reduce storm damage. It can also help inform land-use practices and building codes that can lead to more resilient coastal communities.

This year, the USGS is continuing a pilot program to develop methods to deliver storm-tide sensor data faster than current methods permit. This includes storm-tide sensors that can be permanently installed, cutting down sensor deployment times, and sensors that can transmit, allowing the data to be available within hours instead of days.

Come back next week to learn about coastal change and how alterations to shorelines can affect coastal flooding, and how USGS works to forecast coastal changes before storms make landfall.

* Editor's note: The GIF at the top of the story shows the devastating effects Hurricane Michael's storm tide and strong winds had on Mexico Beach, Florida, when Michael made landfall as a Category 5 hurricane October 10, 2018. Images courtesy of NOAA.

In case you missed it, here's a link to the other posts in this series:

• Introduction to a Six-Part Series Highlighting USGS Hurricane Science

• Changes to the coastline can affect where, and how severely flooding occurs
• Hurricanes may pose a threat to people along the coasts and far inland
• Hurricanes can spread invasive species if they survive the ride
• Determining how high flood waters reached helps communities prepare for future floods
• Maps and imagery for hurricane response