WTUS82 KCHS 070003 HLSCHS GAZ087-088-099>101-114>119-137>141-SCZ040-042>045-047>052-070815- Tropical Storm Debby Local Statement Intermediate Advisory Number 18A National Weather Service Charleston SC AL042024 803 PM EDT Tue Aug 6 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 Tropical Storm Warning is in effect for Beaufort, Charleston, Coastal Bryan, Coastal Chatham, Coastal Colleton, Coastal Jasper, Coastal Liberty, Coastal McIntosh, Dorchester, Effingham, Hampton, Inland Berkeley, Inland Bryan, Inland Chatham, Inland Colleton, Inland Jasper, Inland Liberty, Inland McIntosh, and Tidal Berkeley * STORM INFORMATION: - About 80 miles south-southwest of Charleston SC or about 30 miles east-southeast of Savannah GA - 31.8N 80.6W - Storm Intensity 40 mph - Movement East-northeast or 75 degrees at 3 mph SITUATION OVERVIEW ------------------ Potentially historic rainfall totals will likely produce areas of catastrophic flooding through at least Thursday. Additional rainfall amounts of 6 to 8 inches is forecast over southeast South Carolina with 2 to 4 inches across southeast Georgia. This will likely result in unprecedented flooding in some areas. THIS IS A POTENTIALLY SIGNIFICANT AND LIFE THREATENING EVENT. Tropical Storm Debby is forecast to move offshore the Georgia coast and over the Atlantic later today and tonight. Debby will then meander nearby before making landfall along the South Carolina coast Thursday morning. This slow motion will result in a prolonged period of significant impact across the area. Tropical storm force wind combined with saturated soil should result in downed trees and power lines. Additionally, there will likely be an extended period of major flooding along larger main stem rivers that continues well after Debby moves away from the region. POTENTIAL IMPACTS ----------------- * 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. * WIND: Protect against dangerous wind having possible significant impacts across southeast South Carolina and southeast Georgia. Potential impacts in this area include: - Some damage to roofing and siding materials, along with damage to porches, awnings, carports, and sheds. A few buildings experiencing window, door, and garage door failures. Mobile homes damaged, especially if unanchored. Unsecured lightweight objects become dangerous projectiles. - Several large trees snapped or uprooted, but with greater numbers in places where trees are shallow rooted. - Some roads impassable from large debris, and more within urban or heavily wooded places. A few bridges and access routes impassable. - Travel by vehicle or on foot increasingly difficult. Danger of death or injury from falling objects such as trees or electric wires outside. - Scattered power and communications outages, but more prevalent in areas with above ground lines, which could persist for hours or days. - Some poorly secured small craft could break loose from their moorings. * TORNADOES: Protect against a dangerous tornado event having possible significant impacts across portions of the Charleston Tri-county. 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. Elsewhere across southeast South Carolina and southeast Georgia, little to no impact is anticipated. * OTHER COASTAL HAZARDS: Significant beach erosion and a high risk of powerful and dangerous rip currents can be expected this week. PRECAUTIONARY/PREPAREDNESS ACTIONS ---------------------------------- * EVACUATIONS: Follow the advice of local officials. * OTHER PREPAREDNESS INFORMATION: Rapidly rising flood waters are deadly. If you are in a flood-prone area, consider moving to higher ground. Never drive through a flooded roadway. Remember, turn around don't drown! Closely monitor weather.gov, NOAA Weather radio or local news outlets for official storm information. Be ready to adapt to possible changes to the forecast. Ensure you have multiple ways to receive weather warnings. * 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 12 AM EDT, or sooner if conditions warrant. $$