Know Your Zone is a public education campaign to inform the citizens and visitors of Horry County of the hurricane evacuation zones and their vulnerability to storm surge. The zones are broken down into 3 categories.
Evacuation areas for ZONE A includes all areas east of US Business 17 up to the intersection with US 17 as well as all areas east of US 17 to the northern county line. It’s important to remember that Zone A also includes all flood prone areas along the Waccamaw River and the Great and Little Pee Dee Rivers, as well as all mobile home residents within Horry County.
Evacuation areas for ZONE B include includes all areas South of Hwy 707 and Longwood Drive. All areas in Longwood Plantation to the Waccamaw River. All areas east of US 17 Bypass to US 17 as well as all areas east of US 17 to the northern county line.
Evacuation areas for ZONE C include Areas between Hwy 701 and Hwy 544. Areas south of Brown's Chapel Avenue and Hwy 814. All areas east of Hwy 31 (Carolina Bays Parkway) to Hwy 90 and all areas east of Hwy 90 to US 17 to the northern county line.
The Saffir-Simpson Hurricane scale is a five category scale used to generally describe the strength of a hurricane and the damage that can be expected. Storm surge expected with each category used to be included in the scale, however, that was removed in 2009. The reason? All too often, the values of storm surge did not match the category. Today, the categories only refer to wind and the related damage.
Category 1 storms have winds of 74 to 95 mph. They usually cause no significant structural damage to most well-constructed permanent structures; however, they can topple un-anchored mobile homes, as well as uproot or snap weak trees. Poorly attached roof shingles or tiles can blow off. Coastal flooding and pier damage are often associated with Category 1 storms. Power outages are typically widespread to extensive, sometimes lasting several days. Even though it is the least intense type of hurricane, they can still produce widespread damage and can be life-threatening storms.
Storms of Category 2 intensity pack winds of 96 to 110 mph and often damage roofing material and inflict damage upon poorly constructed doors and windows. Poorly constructed signs and piers can receive considerable damage and many trees are uprooted or snapped. Mobile homes, whether anchored or not, are typically damaged and sometimes destroyed, and many manufactured homes also suffer structural damage. Small craft in unprotected anchorages may break their moorings. Extensive to near-total power outages and scattered losses of water are likely, possibly lasting many days.
Category 3 hurricanes produce winds of 111 to 129 mph. These storms cause structural damage to small residences and utility buildings, particularly those of wood frame or manufactured. Buildings that lack a solid foundation, such as mobile homes, are usually destroyed, and some roofs are peeled off. Manufactured homes usually sustain severe and irreparable damage. A large number of trees are uprooted or snapped, isolating many areas. Near-total to total power loss is likely for up to several weeks and water will likely also be lost or contaminated.
Category 4 hurricanes are devastating with winds of 130 to 155 mph. They tend to produce more extensive damage to home and businesses, with some complete structural failure. Heavy, irreparable damage and near complete destruction of gas station canopies and other wide span overhang type structures are common. Most trees, except for the heartiest, are uprooted or snapped, isolating most areas. Total and long-lived power and water losses are to be expected, possibly for many weeks.
Category 5 is the highest category of the Saffir–Simpson scale and has winds over 156 mph. These storms cause complete roof failure on many residences and industrial buildings, and some complete building failures. Very heavy and irreparable damage to many wood frame structures and total destruction to mobile/manufactured homes is widespread. Only a few types of structures are capable of surviving intact, and only if located at least 3 to 5 miles inland. Virtually all trees are uprooted or snapped and some may be debarked, isolating most affected communities. Total and extremely long-lived power outages and water losses are to be expected, possibly for up to several months.
Think of hurricanes as giant engines that use warm, moist air and water as fuel. That is why they form only over warm ocean waters where the water temperatures is 80 degrees or more. The warm, moist air over the ocean rises upward from near the surface. Because this air moves up and away from the surface, there is less air left near the surface. This creates an area of low pressure. Air from surrounding areas pushes into the low pressure area. Then that "new" air becomes warm and moist and rises, too. As the warm air continues to rise, the surrounding air swirls in to take its place. As the warmed, moist air rises and cools off, the water in the air forms clouds and storms. The whole system of storms and wind spins and grows, fed by the ocean's heat and water evaporating from the surface. As winds circulating into the system reach 30 mph, it is classified as a Tropical Depression. Once they reach 40 mph, it is classified as a Tropical Storm and is given a name. As the storm system rotates faster and faster and winds reach 74 mph, it is classified as a hurricane. This is when an eye forms in the center. It is very calm and clear in the eye, with very low air pressure. Hurricanes weaken when they hit land, because they are no longer being "fed" by the energy from the warm ocean waters. However, they often move far inland, dumping flooding rain and causing wind damage before they die out completely.
Most homes can withstand hurricane force winds, but will need some protection from strong winds. Entry points like doors and windows are the weakest and most vulnerable parts of your home during a major storm. Boarding up windows with storm shutters or plywood greatly reduces the likelihood of shattering. Although some people opt for taping windows, experts advise against this method, which provides only a false sense of security and the opportunity for larger, deadlier pieces of glass to enter a home. Outdoor objects surrounding your home can become airborne missiles when swept up by a hurricane’s strong winds, potentially damaging you or your neighbors’ properties. Bring all outdoor furniture, plants, toys and other objects inside or make sure they are tightly secured. Knowing exactly what items are in your home is critical to post-storm recovery in the event that your home or belongings are damaged. It’s as simple as snapping cell phone photos of the contents in each of your home’s rooms.
Evacuations are ONLY issued for areas vulnerable to flooding from storm surge or areas vulnerable to fresh water flooding. Residents of weak structures or mobile homes may also be sometimes asked to evacuate. If your home is outside of an evacuation zone, you should stay put and ride the hurricane out. Most homes are built to withstand hurricane force winds. While some minor damage to siding, shingles, windows and an doors is possible, surviving a storm in most homes is simple with basic precautions. Evacuating when you don’t need to unnecessarily clogs roadways and evacuation routes, puts an added strain on evacuation shelters and takes up much needed room at hotels outside of the evacuation zone.