Tropical Storm Karen has formed in the Gulf of Mexico and is expected to make landfall along the U.S. Gulf Coast, the National Hurricane Center said Thursday morning.

The tropical storm is located about 65 miles east of the Yucatan Peninsula, moving northwest at 12 mph, with maximum sustained winds of 65 mph, according to an Air Force Reserve Hurricane Hunter aircraft investigation.

“Tropical Storm Karen is forecast to produce heavy rainfall over parts of Western Cuba and the northeastern Yucatan peninsula throughout the next day or so,” said Dr. Tim Doggett, senior principal scientist at catastrophe modeling firm AIR Worldwide.

“Karen is then expected to slightly strengthen over the next 24 hours under moderate shear and could reach hurricane status by Friday [but] weakening is expected before landfall on the U.S. Gulf Coast.”

The majority of single-family residential structures along the U.S. Gulf Coast are of masonry construction, according to AIR. Under weak to moderate hurricane wind speeds, these structures can experience moderate damage to the roof and roof covering, with little damage to masonry walls expected. Damage due to downed trees or from loose building debris such as shingles or roofing tiles may also occur.

The vulnerability of mobile homes and light metal structures is much greater than that of other construction types, and these buildings could experience structural damage, says AIR. However, mobile home exposure accounts for a very small proportion of the overall exposure in the Gulf Coast states.

Engineered structures, such as reinforced concrete and steel buildings, should experience less damage compared to residential wood-frame and masonry structures. These structures may exhibit isolated instances of nonstructural damage, such as that to windows and roof coverings, which could result in damage to contents and internal finishes.

Building vulnerability can change significantly as a result of changes in building code and code enforcement, changes in material and construction practices, and structural aging. Louisiana adopted statewide building codes in 2007, as did five coastal counties in Mississippi (2006) and Mobile and Baldwin Counties in Alabama (2001 and 2007, respectively). AIR expects that newer structures in the regions with updated building codes and improved levels of enforcement will perform better than older structures.

Source: AIR Worldwide