The sea level did, in fact, rise faster in the southeastern U.S.

For people in the southeastern United States, and especially in Florida, who feel annoying tidal flooding has sneaked up on them in recent years, it turns out to be true. And scientists have a new explanation.

In a paper published online Wednesday, University of Florida researchers calculated that from 2011 to 2015, the sea level along the American coastline south of Cape Hatteras, N.C., rose six times faster than the long-term rate of global increase.

“I said, ‘That’s crazy!’” Andrea Dutton, one of the researchers, recalled saying when a colleague first showed her the figures. “‘You must have done something wrong!’”

But it was correct. During that period of rapid increase, many people in Miami Beach, Fort Lauderdale and other coastal communities started to notice unusual “sunny-day flooding,” a foot or two of salt water inundating their streets at high tide for no apparent reason.

In the paper, published in the journal Geophysical Research Letters, the scientists proposed a mechanism to explain the rapid increase: Two large-scale atmospheric patterns had intersected to push up the water off the Southeast coast, causing a “hot spot” of sea-level rise.

This new mechanism, if it holds up to scientific scrutiny, might ultimately give researchers the ability to predict tidal flooding more accurately and warn communities what to expect months in advance.

William V. Sweet, a sea-level researcher at the National Oceanic and Atmospheric Administration who was not involved in the new work, pointed out that the long-term trend in sea level was a relentless increase, but that much is unknown about the variations that can occur over short periods. “The more we can understand what’s causing those, the more we can be prepared for the next influx of tidal flooding events,” Sweet said.

Many people think the ocean works something like a bathtub, with sea level being the same all the way around. In reality, the ocean is lumpy, with winds, currents and other factors pushing water around to produce substantial variations in sea level from place to place.