2:20 p.m. update: The National Hurricane Center now says there’s an 80 percent chance a (sub)tropical depression or storm will form off the coast of the Carolinas by Friday, a 10 percent increase from earlier this morning. Its morning hurricane hunter aircraft mission clocked 40-45 mph winds north and west of the low pressure center.

“Environmental conditions are favorable for some additional development, and any increase in the organization of the associated thunderstorm activity would result in the formation of a subtropical cyclone,” the Center said in a statement.

Original post from 11:18 a.m.


GFS model forecasts possible Tropical Storm Ana to be lashing the coast near Charleston Saturday night, with sustained winds of around 30 knots or 35 mph (WeatherBell.com)

The first tropical storm or depression of the 2015 Atlantic hurricane season has a 70 percent chance to form in the next 48 hours says the National Hurricane Center. And it’s one that will crawl towards the coast of the Carolinas, producing heavy rain and strong winds.

The system will earn the name Ana if it achieves sustained winds of at least 39 mph. Technically, it will probably be classified as a subtropical storm since it’s likely to have characteristics of both a tropical and mid-latitude weather system.

As much as 2-5 inches of rain is forecast along the North Carolina and South Carolina coasts, where showers have already begun, through Monday. Winds gusts of 35 to 50 mph are likely at the shore as the system draws closer this weekend, or perhaps a bit higher depending on how strong it gets. Some minor flooding and beach erosion are also possible.


Rainfall forecast through Tuesday morning from the National Weather Service (WeatherBell.com)

The part of the coast expected to get the worst of storm spans from roughly Charleston to Wilmington, including the Myrtle Beach area. It won’t be a good beach or golfing weekend, to say the least.

Early this morning, a low pressure system – mainly non-tropical in nature – was centered about 230 miles south-southeast of the South Carolina-North Carolina border. It has become better organized over the last day and, while somewhat asymmetric (with most of the thunderstorm activity on its west side), shows signs of improved structure.


Visible satellite image of disturbance that may turn into Tropical Storm Ana (NASA)

Offshore water temperatures around 79 degrees mean the system has a reasonable chance to continue intensifying and acquire some tropical characteristics.

Hurricane hunter aircraft are currently investigating the system to get a better handle on its intensity.

As it’s unlikely this storm will become anything stronger than a moderate tropical storm, it is not expected to pose dire threats to life and property. But it could surely prove disruptive in coastal North and South Carolina, where it’s forecast to hover just offshore through Saturday before perhaps crossing the coastline Sunday near the North and South Carolina border based on the latest track forecasts.


Model track forecasts for possible Tropical Storm Ana (UCAR)

As the system will likely in a weakening mode once it nears shore and comes inland, its rain and wind probably won’t extend too far outside the coastal plain – with increasingly scattered showers farther inland.

By Sunday or Monday, models suggest the system will lift off to the northeast, but – by then – may be moisture-depleted. A little of its moisture may get drawn to the north over the weekend and Monday, increasing humidity and perhaps introducing slight shower chances in places like Richmond and Washington, D.C.

If this system gets named prior to May 9, it will be the earliest named storm since April 20, 2003 – a storm also named Ana. The last storm to get named in May was Beryl 2012, and bore a close resemblance to this year’s system.