Forecasters are watching a potential tropical system that may skirt the U.S. East Coast this week, brushing past major Northeastern cities in time for the Fourth of July holiday.
The collection of thunderstorms now about 140 miles east- northeast of Melbourne, Florida, has an 80 percent chance of becoming tropical depression or storm within five days, said the U.S. National Hurricane Center in Miami.
The storm’s East Coast impact for the holiday will depend on the timing of a cold front that’s expected to sweep into the area later this week, said Rob Carolan, owner of Hometown Forecast Services Inc. in Nashua, New Hampshire.
“If you are in New York City, you should be fine, but if you are in southern New England, it could ruin your Friday,” Carolan said.
Across the U.S., June is ending with incidents of severe weather. Along the Mississippi River in Minnesota, Iowa and Illinois, waters have risen to major flood stage and more rain is on the way.
The Mississippi River gauge at Burlington, Iowa, is at 18.75 feet (5.7 meters), almost a foot above major flood stage, and the water is expected to reach 19.5 feet by next week, according to the National Weather Service in Davenport, Iowa.
Carolan said the area is expected to get more rain today and there is a chance of severe thunderstorms that can bring hail, high wind and tornadoes.
The U.S. Storm Prediction Center said there is a moderate chance severe storms will develop today across Iowa, Missouri and Illinois, an area home to about 6.4 million people.
In the Pacific, the National Hurricane Center is also tracking Tropical Storm Douglas, which isn’t a threat to land, and a potential storm off the coast of Mexico.
The system in the Atlantic may bring rain to North Carolina by the middle of the week.
While Atlantic sea surface temperatures are higher than normal below South Carolina, they are lower than normal in the waters around the Northeast, Carolan said. Tropical systems need warm water to strengthen and organize.
Carolan said the system will probably block a New England cold front from moving out to sea, which will mean rain for Massachusetts, parts of Connecticut and Rhode Island.
In addition, the storm may cause heavy surf and rip currents to form along the beaches of Long Island, Rhode Island and Cape Cod in Massachusetts, he said.
“The Fourth being a big beach weekend, there could be some issues with rip currents,” Carolan said.