According to the National Weather Service office in Mount Holly, New Jersey, “Rip currents can sweep even the best swimmers away from shore into deeper water,” This is especially pertinent as Tropical Storm Imelda and Hurricane Humberto continue to move through the western Atlantic, which is setting the stage for a prolonged period of dangerous surf conditions, strong rip currents, and flooding.
Neither storm is forecasted to make landfall, yet the effects from both will be felt for hundreds of miles along the Eastern Seaboard. The storm that will come closest to the U.S. is Imelda, while Humberto will stay further offshore, yet both will large swells of 7–12 feet in some spots as a result of the constant flow of onshore winds. When these waves hit the shore, they will create powerful breaking waves as well as rip currents that may be stronger than the strongest swimmers.
Early in the week, the conditions are expected to be worst along the Florida coastline through the Carolinas, and then the area at risk is expected to shift northwards towards New England. By mid-week, the area at risk is expected to be stuck for some days. The reason distant effects of storms can be experienced even on bright days can be attributed to the science of how wave energy behaves over large distances. When this wave energy reaches the coastline features of jetties and reefs, it forces water through tight channels, racing it back out to the ocean.
For beachgoers, however, the hazard is found in the seemingly calm area of rip currents. As coastal physical oceanographer Chris Houser says, “You might actually think that the calm water is safest. It’s probably a rip current.” Lifeguards and local authorities are warning beachgoers to avoid unprotected beaches and rip current areas that are marked as dangers. This warning was emphasized by the Volusia County Sheriff’s Office in Florida after a 51-year-old man drowned when he was swept away from shore by a rip current.
Mariners and small boaters are also on alert. Small Craft Advisories extend to the same area as High Surf Advisories, warning of rough surf and strong winds that can rapidly sink smaller craft. The dangers posed by these waves and the flow are not limited to the surface; Coastal Flood Warnings have been issued for coastal areas that will be impacted by the same waves and flow that will cause the coastal flooding. Of particular note is the Outer Banks region of North Carolina.
Rising water along the coast due to these storms will primarily be facilitated by both the action of waves and storm surge-like phenomena, even if the storm doesn’t make landfall. Looking at the mechanics of coastal flooding, one would understand that both the mean sea-level rise due to strong winds and the action of waves can contribute towards an increase of water levels along the coast. Moreover, if the coast has broad shallow banks, like those along the Atlantic coast, then the action of waves and strong winds can significantly enhance the risk of flooding.
The risks of rip currents are expected to continue at a high level for all areas along the East Coast from Florida’s Gold Coast to Maine throughout most of the week, according to the National Weather Service. Even as the size of waves decreases, a changed underwater environment from the recent storms may continue to contribute to such dangers for several days after a storm passes by, as Greg Dusek, a NOAA spokesperson, explains: The risk is still there even if it looks inviting at the beach.
For individuals caught in a rip current, current safety guidelines now recommend the new “flip, float, follow” technique: flipping onto their back to keep their head above water, floating to conserve energy, and following the current until it dissipates, signaling for assistance when feasible. This technique lowers the risk of energy exhaustion and raises survival odds until assistance can be made available.
Given the potential for 17 to 25 named storms and 8 to 13 hurricanes in the Atlantic Basin, according to the seasonal forecast issued by NOAA, the region is reminded to exercise caution. High levels of hurricane activity, due to the warming waters and La Niña, lead to the potential for the shore to experience life-threatening conditions, even when the storms are well out to sea. “Severe weather and emergencies can happen at any moment, which is why individuals and communities need to be prepared today.” says NOAA Administrator Rick Spinrad.
For people living along the Eastern Seaboard, as well as beachgoers and those out at sea, being prepared for these storms means more than just following the path of the storms and waiting for the storms to make landfall. It also means being aware of the unseen dangers posed by the ocean. This will be tested as Imelda and Humberto move their powers towards the coast, and what used to be familiar beaches turn into danger zones.
