WTUS82 KCHS 060307 HLSCHS GAZ087-088-099>101-114>119-137>141-SCZ040-042>045-047>052-061115- Tropical Storm Debby Local Statement Advisory Number 15 National Weather Service Charleston SC AL042024 1107 PM EDT Mon Aug 5 2024 This product covers southeast South Carolina and southeast Georgia **DEBBY TO BRING POTENTIALLY HISTORIC AND CATASTROPHIC FLOODING TO THE AREA THIS WEEK** NEW INFORMATION --------------- * CHANGES TO WATCHES AND WARNINGS: - None * CURRENT WATCHES AND WARNINGS: - A Storm Surge Warning and Tropical Storm Warning are in effect for Beaufort, Charleston, Coastal Bryan, Coastal Chatham, Coastal Colleton, Coastal Jasper, Coastal Liberty, Coastal McIntosh, and Tidal Berkeley - A Tropical Storm Warning is in effect for Bulloch, Candler, Effingham, Evans, Inland Berkeley, Inland Bryan, Inland Chatham, Inland Jasper, Inland Liberty, Inland McIntosh, Long, and Tattnall * STORM INFORMATION: - About 170 miles southwest of Charleston SC or about 90 miles southwest of Savannah GA - 31.1N 82.1W - Storm Intensity 45 mph - Movement Northeast or 50 degrees at 7 mph SITUATION OVERVIEW ------------------ Potentially historic rainfall amounts will likely produce areas of catastrophic flooding through at least Friday morning. Storm total rainfall amounts of 10 to 20 inches, with local amounts approaching 30 inches, will likely result in unprecedented flooding in some areas. The highest rainfall totals will occur across coastal South Carolina and Georgia, including the Charleston and Savannah metropolitan areas. THIS IS A POTENTIALLY SIGNIFICANT AND LIFE THREATENING EVENT. Tropical Storm Debby is forecast to track slowly across southeast Georgia tonight into Tuesday, before moving off the Southeast coast and over the Atlantic late Tuesday and Wednesday. This slow motion will result in a prolonged period of significant impact across the area. A combination of fresh water flooding and storm surge will produce coastal inundation of 2 to 4 feet along the southeast Georgia and southeast South Carolina coast, especially Tuesday through Thursday. Tropical storm force wind impacts and a few tornadoes are also possible during this time, with highest chances across coastal areas. POTENTIAL IMPACTS ----------------- * WIND: Potential impacts from the main wind event are now unfolding across southeast South Carolina and southeast Georgia. Remain well sheltered from hazardous wind having possible limited impacts. If realized, these impacts include: - Damage to porches, awnings, carports, sheds, and unanchored mobile homes. Unsecured lightweight objects blown about. - Large tree limbs broken off. A few trees snapped or uprooted, but with greater numbers in places where trees are shallow rooted. - Some roads impassable due to debris, particularly within urban or heavily wooded locations. Hazardous driving conditions on bridges and other elevated roadways, especially for high profile vehicles. - Isolated to scattered power and communications outages. * SURGE: Protect against life-threatening surge having possible significant impacts across coastal Georgia and coastal southeast South Carolina. Potential impacts in this area include: - Areas of inundation of saltwater along immediate shorelines and in low-lying spots farther inland near rivers and creeks, with storm surge flooding accentuated by waves. Damage to several buildings, mainly near the coast. - Sections of near-shore escape routes and secondary roads become weakened or washed out, especially in normally vulnerable low spots. - Moderate to major beach erosion with heavy surf breaching dunes. Strong and numerous rip currents. - Minor to moderate damage to marinas, docks, boardwalks, and piers. Several small craft broken away from moorings, especially in unprotected anchorages. Some navigation aids possibly displaced well off station, creating difficult navigation near inlets and waterways. Elsewhere across southeast South Carolina and southeast Georgia, little to no impact is anticipated. * FLOODING RAIN: Protect against life-threatening rainfall flooding having possible devastating impacts across southeast South Carolina and southeast Georgia. Potential impacts include: - Extreme rainfall flooding could prompt widespread rescues. As event unfolds, rescues could become impossible. - Rivers and tributaries could overwhelmingly overflow their banks in many places with deep moving water. Small streams, creeks, canals, and ditches may become raging rivers with strong currents. Flood control systems and barriers could become stressed or overwhelmed. - Flood waters will enter many structures within multiple communities, some structures becoming uninhabitable or washed away. Flood waters could render escape routes impassable. Streets and parking lots become rivers of raging water with underpasses submerged. Driving conditions become impossible and life threatening. Widespread road and bridge closures with most weakened or washed out. - Drinking water and sewer services could be negatively impacted. - Hazardous containers and materials could possibly be present in flood waters. * TORNADOES: Protect against a dangerous tornado event having possible significant impacts across mainly coastal areas of southeast Georgia and southeast South Carolina. Potential impacts include: - Isolated to scattered tornadoes can hinder the execution of emergency plans. - Scattered locations could experience enhanced damage due to tornadoes with a few spots of considerable damage, power loss, and communications failures. - Scattered locations could realize roofs torn off frame houses, mobile homes demolished, boxcars overturned, large trees snapped or uprooted, vehicles tumbled, and small boats tossed about. PRECAUTIONARY/PREPAREDNESS ACTIONS ---------------------------------- * EVACUATIONS: Follow the advice of local officials. * OTHER PREPAREDNESS INFORMATION: If a tornado warning is issued for your area, quickly move to the safest place within your shelter. Protect your head and body. * ADDITIONAL SOURCES OF INFORMATION: - For information on appropriate preparations see ready.gov - For information on creating an emergency plan see getagameplan.org - For additional disaster preparedness information see redcross.org NEXT UPDATE ----------- The next local statement will be issued by the National Weather Service in Charleston SC around 6 AM EDT, or sooner if conditions warrant. $$