Hurricane Isaias Unlikely to Cause Widespread Atlantic Beach Erosion

USGS coastal change experts predict that storm waves kicked up by the Category 1 hurricane are likely to cause some erosion at the base of the dunes along about 11 percent of coastal beaches between Florida and Virginia. However, only about one percent of beaches in the region are likely to have waves overwashing the dunes, and inundation - the most severe type of beach erosion -  is not predicted anywhere in the region. This prediction, based on forecasts from the National Hurricane Center, can help local emergency management officials make decisions about which areas to evacuate, where and when to close coastal roads, and where to position clean-up equipment in advance of the storm.

A map of the coastal change forecasts for Hurricane Isaias is at  https://marine.usgs.gov/coastalchangehazardsportal/ui/alias/isaias2020. The maps have three strips, side by side. The strip closest to the coast shows the likelihood of erosion at the base of the dunes. The middle strip shows the likelihood of dune overwash, and the outer (seaward) strip is the likelihood of the most serious impact, inundation. Each strip is color-coded, with the brightest red segments showing a 90% or greater probability of that effect occurring, and white segments showing a probability of 10% or less.

The latest coastal change forecast is at https://marine.usgs.gov/coastalchangehazardsportal/ui/alias/isaias2020 It will be updated as the hurricane center’s forecasts change.