The USGS’ network of storm tide sensors along portions of the U.S. Atlantic and Gulf coasts can record water level and barometric pressure every 30 seconds to document storm surge crests, or waves of water, as they make landfall. Anticipating a storm’s path and intensity, USGS scientists often deploy storm tide sensors at other places along the coast just hours or days before a hurricane’s expected landfall. The sensors are housed in steel pipes a few inches wide and about a foot long. Working quickly, and often in severe weather, field crews install them on bridges, piers and other structures that have a good chance of surviving a hurricane’s storm surge. 

The teams are also deploying barometric pressure sensors, one within ten miles of every storm tide sensor; the two devices work together to correlate the storm’s intensity with wave heights. The crews also plan to deploy five clusters of wave height sensors on boardwalks in Flagler, Volusia, Brevard, St. Lucie and Palm Beach counties. By recording wave heights along a line running from the beach to the dune peak and behind the dune, these transects help create a detailed picture of wave action.

Adding Temporary Streamgages to Track Dorian

The USGS Streamgaging Network operates scientific instruments that record water levels and other key pieces of information on rivers and streams throughout the nation, with the support of local, state, and federal agencies. During storms and floods the USGS uses this nationwide network to provide near-real-time data about water levels to the National Weather Service, Federal Emergency Management Agency, the U.S. Army Corps of Engineers, and others. 

When a major hurricane is expected to make a U.S. landfall, the USGS augments the network by installing special streamgages called rapid deployment gauges, or RDGs, in areas where flooding is likely, but no permanent streamgage exists. RDGs measure water levels and local weather data in areas susceptible to storm-tide flooding and transmit that information by satellite in near-real time for flood forecasting and emergency response. The public can see the information in near-real time by clicking on the RDG symbol in the Flood Event Viewer.

Field crews have installed eight RDGs in Florida. They plan to install 12 RDGs in Georgia, completing the work in advance of Hurricane Dorian’s winds, rain and storm waves. If flooding does occur, USGS field crews will make real-time streamflow measurements to verify the streamgages’ readings. After the storm passes, the crews will quickly replace any storm-damaged or lost gauges. During and right after hurricane flooding, these records help FEMA target emergency relief to the hardest-hit areas.