Tropical system may develop

Published 8:46 am Wednesday, June 5, 2013

The 2013 Atlantic hurricane season is less than a week old and action is already under way.

An area of disturbed weather hovering near Yucatan, Mexico on Tuesday will track along at least part of the Atlantic Seaboard after affecting Florida in the coming days.

AccuWeather.com meteorologists expect the system to produce a swath of heavy rain from parts of the Florida Peninsula into portions of the mainland South this week.

Depending on the track of the system, a dose of heavy rain will fall on part of the mid-Atlantic coast, to include eastern North Carolina, and eastern New England toward the weekend. Forecast models show the rain arriving in the RC area by Friday.

Flooding is a concern in the southeastern corner of the nation, where slow movement of the Gulf system is likely.

Downpours could affect ground and air travel and lead to urban flooding problems along the heavily populated I-95 corridor Friday and Saturday.

Drenching showers and locally gusty thunderstorms were affecting western Cuba, the Keys, South Florida and the eastern coastline of Yucatan, Mexico, Tuesday midday. Cabo de San Antonio, on the western tip of Cuba, has received nearly 8 inches of rain in the past three days. During the same period, Marathon, in the Florida Keys, has received nearly 5.50 inches of rain.

Rainfall will gradually propagate northeastward over the next couple of days impacting more of Florida.

According to Tropical Weather Expert Dan Kottlowski, “There will be a window of opportunity for the system to develop tropically Wednesday into Thursday as it begins to drift northeastward.”

Kottlowski stated that strong upper atmospheric winds, which are currently hindering development, could drop off enough to allow more of a circulation near the surface of the eastern Gulf of Mexico.

Tropical systems are storms that inhabit the lowest part of the atmosphere. Since they are warm weather (warm core) storms, they can strengthen over warm water and tend to weaken over land or cold water. Strong winds near the top of the storm can also prevent development or tear a tropical storm or hurricane apart.

Indications are that steering winds will guide the system, whether it has fully developed tropically or not, on a general northeastward path during the second half of the week into the weekend.

The first name on the list of tropical storms and hurricanes for the Atlantic Basin 2013 season is “Andrea.”

While the exact path will depend on how much development occurs, rainfall along parts of the Atlantic Seaboard from Florida to the coastal Carolinas and eastern New England could be enhanced as the system moves along.

“It is possible this system never has enough time to become a well-organized tropical storm or hurricane,” Kottlowski said.

The first stage of development of a warm core would be a tropical depression. However, even if the system were to reach that phase, it does not guarantee that a tropical storm or hurricane would follow.

Even weak tropical or sub-tropical systems can bring tremendous rainfall, on the order of several inches or more. Weak systems can also bring locally severe thunderstorms and dangerous surf conditions.

Over the weekend in the East, the Gulf system could interact with another storm system coming in from the Plains. That system over the central part of the nation will bring another round of severe weather to storm-weary residents in Oklahoma and surrounding states into Wednesday.

The heaviest rain is forecast to fall mainly east of the track of the Gulf storm system.

While a zone with little rainfall can occur in between both the Gulf and Plains systems during Friday into Saturday, some areas along the Atlantic coast could receive 3 inches or more with a zone of 1 to 3 inches possible centered over the Appalachians. If both systems were to merge or the Gulf system were to track farther west, heavy rain could fill in from Washington, D.C. to Philadelphia, New York City and the Appalachians.

According to Expert Senior Meteorologist Henry Margusity, “The Gulf system is likely to pick up forward speed later in the week and over the weekend, which should work to shorten the duration of the rainfall and could lessen problems caused by flooding farther north.”

As long as the Gulf system remains weak and picks up forward speed, few or no problems related to coastal flooding would occur along the Atlantic Seaboard.

Most areas could handle a dose of drenching rain without widespread stream or river flooding, as long as the rain does not continue for days on end.