Tropical Storm Ana Recap

Jon Erdman
Published: May 11,2015



 

Highlights

• Ana made landfall as a tropical storm between Myrtle Beach, South Carolina and North Myrtle Beach, South Carolina at 6:00 a.m. EDT on Sunday.
• The National Hurricane Center downgraded Ana to a tropical depression at 2 p.m. EDT on Sunday.
• According to hurricane specialist Michael Lowry of The Weather Channel, Ana is the second earliest landfalling tropical storm on record in the Atlantic. 
• Pockets of rain lingered in eastern North Carolina, southeast Virginia and the southern Delmarva peninsula through Monday.
• On Monday evening, a waterspout may have come ashore and caused damage as a tornado in Dare County, North Carolina.

(MORE: Ana's Impacts in the Carolinas)

Ana History

Ana originally formed as a subtropical storm off the coast of the Carolinas late Thursday night. For more on what a "subtropical" cyclone is, scroll down the page a bit.
Early Saturday morning, the National Hurricane Center said that Ana had made a complete transition from a subtropical storm to a full tropical storm. This was based on the fact that shower and thunderstorm activity was now more collocated with the center of circulation, which is a characteristic of tropical storms.

The west end of Ocean Isle Beach, North Carolina experienced flooding from Tropical Storm Ana on May 10, 2015.
(Greg Agee/Facebook)

Ana finally made landfall between Myrtle Beach and North Myrtle Beach in South Carolina at 6:00 a.m. EDT on Sunday. The National Hurricane Center downgraded Ana to a tropical depression at 2 p.m. EDT on Sunday.
Some locations in northeast South Carolina and eastern North Carolina picked up over 4 inches of rain, including:
- Kinston, North Carolina: 6.7 inches
- Southport, North Carolina: 6.39 inches
- North Myrtle Beach, South Carolina: 6.16 inches
A wind gust to 60 mph was reported at a buoy south-southeast of Cape Fear, North Carolina on Saturday evening.
On the coast, winds have gusted up to 59 mph near Southport, North Carolina, and up to 55 mph at the Ocean Crest Pier on Oak Island in North Carolina.
In South Carolina, a peak wind gust of 50 mph was measured in North Myrtle Beach early Sunday morning.
These persistent onshore winds lead to significant beach erosion in North Myrtle Beach and Kure Beach, North Carolina.

What a Subtropical Storm Is

The low started out not as a typical low-pressure system with fronts you may see over, say, the Plains states. Nor was it a tropical depression or storm like you see in the Atlantic or Pacific Oceans in summer.  It was a combination of those, called a subtropical cyclone.
Our friends at Weather Underground have a full explanation of subtropical cyclones. Basically, a subtropical depression or storm exhibits features of both tropical and non-tropical systems, with a broad wind field, no cold or warm fronts, and generally low-topped thunderstorms spaced some distance from the center.
Subtropical cyclones typically are associated with upper-level lows and have colder temperatures aloft, whereas tropical cyclones are fully warm-core, and upper-level high-pressure systems overhead help facilitate their intensification.
Because of this hybrid nature, the National Hurricane Center still issues advisories and forecasts (i.e. projected path) for subtropical depressions and storms and assigns a number or name much like a regular tropical depression or tropical storm.
Occasionally, if thunderstorms cluster close enough and persist near the center, latent heat given off aloft from the thunderstorms can warm the air enough to make the storm a fully tropical storm. As mentioned before, this is the case with Ana.

Tracks of May named tropical cyclones near the Southeast U.S. coast from 2007-2014.

This Has Happened Before Recently

Some recent Atlantic hurricane seasons have jumped the June 1 starting gun.
(MORE: When Hurricane Season Starts Early)
Most recently, in May 2012, a pair of tropical storms, Alberto and Beryl, both formed off the coast of the Carolinas, Georgia and north Florida.
Beryl washed out the Memorial Day weekend, and was the strongest tropical cyclone to make a U.S. landfall before June 1 on record, with 70 mph maximum sustained winds.
In fact, Beryl made the transition from a subtropical to tropical storm prior to landfall, exhibiting an eye and eyewall on radar, according to Ostro.
Five years earlier, a cut-off low-pressure system off the Southeast coast morphed into Subtropical Storm Andrea. Before officially gaining the subtropical designation, the wrapped-up low was responsible for a 2-3 foot storm surge in St. Johns and Flagler Counties in Florida. A surfer and four crew members of a sailing vessel lost their lives in high surf from Andrea.
There was even an Atlantic tropical storm in late April 2003, ironically also named Ana.
Since 1950, eight subtropical depressions or storms have formed before May 7th, according to Dr. Matt Sitkowski, science and weather content coordinator.
In all, there have been 39 Atlantic tropical or subtropical cyclones that have formed before June 1 since 1851, according to hurricane specialist Michael Lowry. Thus, you can expect one of these pre-June 1 systems once every four years, or so, on average.
More importantly, there's no link between an early start and an active season. Lowry says only 38 percent of early-starting Atlantic hurricane seasons ended up with above-average numbers of named storms.
Meteorologist Chris Dolce contributed to this report.

MORE: Hurricane Strikes By County, Parish