According to catastrophe modeling firm AIR Worldwide, Tropical Storm Arlene became the first named storm of the 2011 Atlantic hurricane season early this morning after its winds strengthened overnight. Currently about 115 miles east of Mexico’s east coast city of Tampico, and with winds of about 50 miles per hour, Arlene is expected to increase in intensity to near-hurricane strength before making landfall near Tampico early tomorrow morning.
According to the 11:00 am (EDT) National Hurricane Center (NHC) Public Advisory, Tropical Storm Arlene is moving toward the west-northwest at near eight mph and its tropical storm force winds extend outward up to 140 miles. “The main threat Arlene poses is heavy rain that could bring life-threatening flash floods and mudslides in the mountains inland from Tampico,” said Dr. Tim Doggett, principal scientist, AIR Worldwide. “Heavy rain is also expected in southernmost Texas near Brownsville and along the Rio Grande Valley.”
The Government of Mexico issued a hurricane watch for the northeastern coastal area from Tuxpan north to La Cruz, while a tropical storm warning is in effect from Barra de Nautla northward to Bahia Algodones. The National Weather Service in Brownsville has issued a Coastal Flood Watch for Cameron, Willacy, and Kennedy counties until 7:00 am Friday.
Dr. Doggett continued, “Arlene formed from a persistent disturbance that tracked from the western Caribbean into the Bay of Campeche over the past week. While sea surface temperatures in this region are now warm enough to support the development of hurricanes, moderate wind shear has hindered the strengthening of Arlene over the past several days and, until last night, its circulation remained ill-defined. As this environmental shear weakens during the next twenty-four hours, some further strengthening of Arlene is likely, probably to just below hurricane strength by early Thursday, the time of expected landfall.”
Storm surge from Arlene could raise sea levels up to two to four feet above normal in many areas, and the storm is expected to produce rainfall accumulations of four to eight inches in parts of the Mexican states of Tamaulipas, Veracruz, and eastern San Luis Potosi. Over the inland mountains, as much as 15 inches of rain could fall in isolated areas.
“Heavy bands of rain will also affect southern Texas, beginning as early as Wednesday morning,” commented Dr. Doggett. “Rainfall in the upper Rio Grande Valley will vary between one to three inches, and between two to four inches in the lower Valley. In isolated areas as much as six inches of rain may fall, accompanied by gusting winds as high as 35 mph.”
According to AIR, Insured residential properties in Mexico overwhelmingly are of confined masonry construction, while insured commercial properties are dominated by confined masonry and reinforced masonry construction. Both construction types should fare well against Arlene’s wind speeds; structural damage should be minimal. Poorly constructed homes and commercial structures (agricultural barns, green houses, and similar buildings) may suffer minor damage to roof and wall claddings. Low-rise non-engineered commercial structures and residential dwellings may suffer isolated instances of roof and wall cladding damage.
Source : AIR Worldwide
