The 2021 Atlantic Hurricane Season runs through November 30, and the U.S. Geological Survey is prepared to provide science that can help guide efforts to protect lives and property if a major storm makes landfall this season.
Forecasters are calling for an above average hurricane season this year. In comparison to the 2020 hurricane season – the busiest on record with 30 named storms of which 12 made landfall in the U.S, experts do not believe the 2021 season will be as active. This year, there is a 60% chance of an above average season and a 30% chance of a near-normal season according to the National Oceanic and Atmospheric Administration Climate Prediction Center’s 2021 hurricane season forecast. An average hurricane season produces 14 named storms with winds of 39 miles per hour or higher, and includes seven hurricanes, three of which are major hurricanes with winds of 111 miles per hour or higher. This year the NOAA forecast calls for 13 to 20 named storms, of which six to 10 could become hurricanes, with three to five of those being major hurricanes.
Tropical storms, hurricanes and other large coastal storms can impact seaside and inland communities and ecosystems with high winds, storm surge, erosion and flooding. These forces can destroy buildings, roads and bridges and reshape the nation’s coastline.
When a major storm threatens to make landfall in the U.S. or its territories, the USGS provides comprehensive scientific capabilities and information that decision-makers, emergency responders and communities can use to help them prepare, cope with and recover from a storm. This includes the USGS’s ability to forecast coastal change; track storm surge, river and stream levels and flow; capture high-resolution ground elevation and topographic data; create detailed maps that can be used by disaster teams responding in the aftermath of storms; measure coastal and inland flooding across entire regions; and determine the extent floodwaters may have spread non-native species.
Forecasting Coastal Change as a Hurricane Approaches
Before a storm’s expected landfall, USGS coastal change experts forecast how a storm may reshape the coastline using a sophisticated system they developed called the Total Water Level and Coastal Change Forecast model. The model provides detailed forecasts of a strong storm’s likely effects on sandy beaches along the Atlantic and Gulf coasts.
Working with the National Weather Service, the USGS coastal hazards storm team updates forecasts–which are publicly available on the Total Water Level and Coastal Change Forecast Viewer–several times a day using real-time water levels from the National Weather Service’s Nearshore Wave Prediction System along with the USGS’s detailed data on the shape and elevation of the beach. The coverage area of the viewer was recently expanded and now displays forecasts from the coast from Texas to Maine, almost 3,000 miles.
Additional forecasts are made when named storms approach stretches of sandy coastline with the Coastal Change Hazard Forecast model. This model estimates the timing and height of water levels at the shoreline as well as where protective coastal sand dunes are likely to be eroded at their bases or overtopped by storm waves and where coastal areas behind the dunes could be inundated by seawater. NOAA will use the predictions to help inform forecasters at the National Hurricane Center.
These forecasts can help emergency managers make critical decisions before a major storm strikes, including which areas to evacuate, which roads to use and where to position storm cleanup equipment. The forecasts typically begin 72 hours before a storm is expected to make landfall, are updated based on the latest forecasts from the National Hurricane Center and are available at the USGS Coastal Change Hazards Portal.
For this year’s hurricane season, the coastal storm team is also testing new instruments as part of a pilot program that will monitor and measure wave heights and storm tides for any coastal storms that approach the Tampa Bay area.
“The pilot test site will include a series of scientific instruments under water, floating on the water, on shore and all tied into our beach camera system we currently use to assess the accuracy of our Total Water Level and Coastal Change Forecast,” said oceanographer Kara Doran, USGS Coastal Change Hazards Storm Team leader.