US: Hurricane Sally makes landfall in Gulf Shores (Alabama) September 16 /update 4

Event

Hurricane Sally strengthened to a Category 2 hurricane on Wednesday, September 16, and made landfall near Gulf Shores (Alabama) at 04:45 (local time). According to the National Hurricane Center (NHC)'s 09:00 (CDT) advisory update, Sally is located approximately 30km (20 mi) west of Pensacola (Florida).

The NHC has issued the following watches and warnings:

• A hurricane warning is in effect for Mississippi/Alabama border to the Okaloosa/Walton county line (Florida)
• A storm surge warning is in effect for Dauphin Island (Alabama) to the Walton/Bay county line (Florida)
• A tropical storm warning is in effect east of the Okaloosa/Walton county line to Indian Pass (Florida)
• A tropical storm warning is in effect for the Mississippi/Alabama border to the Mouth of the Pearl River
  

The NHC reports that the storm is currently moving north-northeast at 7 kph (4 mph), sustaining winds of up to 140 kph (85 mph). The NHC's 07:00 (CDT) advisory stated the storm is tracking north-northeastward to northeastward later on Wednesday, followed by a faster northeastward motion on Thursday, September 17. The center is expected to move across the extreme western Florida Panhandle and south-eastern Alabama through early Thursday and move over central Georgia on Thursday afternoon through Thursday night. Hurricane-force winds have been spreading inland over southeastern Alabama and the western portion of the Florida Panhandle. Catastrophic and life-threatening flooding is likely along portions of the northern Gulf Coast. Hurricane-force winds extend outward up to 65km (40 mi) from the center and tropical-storm-force winds extend outward up to 205 km (125 mi). The storm is expected to weaken into a tropical storm as it tracks inland on Wednesday.

The NHC has warned that historic and catastrophic flooding is unfolding along and just inland of the coast from west of Tallahassee (Florida) to Mobile Bay (Alabama). In addition, widespread moderate to major river flooding is forecast. Significant flash and urban flooding, as well as widespread minor to moderate river flooding, is likely across inland portions Alabama and into central Georgia. Widespread flash and urban flooding are possible, as well as widespread minor to moderate river flooding, across western southern Carolina into western and central North Carolina. Scattered flash and urban flooding are possible, as well as scattered minor river flooding in southeast Virginia. Sally is expected to produce up to 508 mm (20in) of rainfall, with localized higher amounts possible along and just inland of the central Gulf Coast from west of Tallahassee to Mobile Bay of up to 889 mm (35 in). The governors of Alabama, Florida, and Mississippi have declared states of emergency. Many areas remain under mandatory evacuation orders. Beaches and highways have been swamped in Mississippi and low-lying properties in Louisiana covered by the rising water. More than 200,000 homes and businesses in Alabama and Florida reported power cuts by Wednesday morning. As the storm is moving extremely slowly, the rains are expected to linger.

Wind damage, widespread flooding, and dangerous sea conditions are expected during the passing of the storm, and significant disruptions to transportation, business, and utilities are likely in the coming days. 

Context

The Atlantic hurricane season runs from late May through to the end of November, with activity typically peaking in late August and early September. Numerous tropical storms form in the Atlantic Ocean during this period, with most affecting the Caribbean, the Gulf of Mexico, and the east coast of the United States. Although communities in the region are generally well prepared for adverse weather conditions during the hurricane season, severe storms bring a significant risk of flooding and infrastructural damage.

Organized tropical activity tends to peak in August and September. Storms tend to flood sections of highways and cause dirt-based roads to become temporarily impassable. More organized systems, depending on intensity, can prove catastrophic in terms of tidal surge, wind damage, flooding, and mudslides.

Advice

Those in the above areas are advised to monitor local weather reports, avoid areas directly affected by flooding, confirm road conditions before setting out, and adhere to instructions issued by local authorities.