Alberto 1 of only 9 early storms since 1851

The photo above shows some rough water at Breach Inlet Sunday. (WCIV)

BREACH INLET, S.C. (WCIV) -- Tropical Storm Alberto weakened slightly as it continued to linger off the South Carolina Coast Sunday, and as it did, National Weather Service forecasters confirmed it would not likely threaten our area.

But, that didn't keep people from asking how unusual it is for a tropical storm to form off our coast -- two weeks before the official start of hurricane season.

So, here's a glance at the stats.

Ana is actually the earliest tropical storm to form -- April 2003. But, Alberto is only the ninth storm to form from May 10-20 since 1851. That's one storm about every 18 years and 10 days.

In that timeframe, Alberto is the closest to form to the U.S. While it is likely to not touch land, weather experts say it is a good reminder of what should be prepared for in upcoming weeks.

"Now is the time to get your family's plan of action in order in case a bigger more threatening storm approaches our coast," said ABC News 4 meteorologist Dave Williams.

Things didn't look too bad at around 6 p.m. Sunday on the sandy stretch of Breach Inlet between Isle of Palms and Sullivan's Island, the only real threat expected as of that point was a chance of more severe rip currents.

That moderate risk of rip currents is expected to last for a few days.

As for Alberto, as of 7 p.m., models from the National Weather Service showed his path to go further out to sea.