Key Debby Headlines
- Status: Tropical Storm Debby made a second landfall early Thursday morning around 2 a.m. EDT near Bulls Bay, South Carolina. Debby is moving slowly inland over South Carolina and currently maintains tropical storm strength, with maximum sustained winds of 45 mph.
- Significant Rainfall Amounts and Flooding Impacts: Debby brought heavy rainfall and flash flooding throughout Florida, southeastern Georgia, and parts of the Carolinas. Potentially historic rainfall totals are expected in eastern South Carolina by the time Debby has cleared the area, with isolated totals of 25 inches possible.
- Forecast: Debby is forecast to continue weakening as the center moves further inland. Debby will take a turn to the north and then northeast by Friday, moving across the Mid-Atlantic and Northeast through the weekend. Heavy rainfall is likely to result in additional flooding, with the highest flash flood risk in central North Carolina and Virginia through Friday, and for central and northeast Pennsylvania, central and northern New York, and much of Vermont through Saturday.
Rainfall Recap
Since Saturday, August 3, Debby has brought more than 1.5 feet of rain throughout parts of Florida, with the highest preliminary totals near Lake City, Florida, amounting to 19.67 inches. Southeast Georgia saw just under a foot of rain, with the Claxton Evens County Airport recording 11.46 inches. The Charleston region of South Carolina has seen between 10-15 inches of rain through Thursday morning, with another 4-8 inches expected in the Carolinas throughout the rest of the week.
According to NOAA river gauges, the Manatee River at Rye Bridge in Florida entered major flood stage early on August 5 and crested to a record 20.12 feet. The previous record was set July 21, 1962, at 20.00 feet. As of Wednesday morning, water levels have dipped into the moderate stage and are forecasted to drop below flood stage by Thursday evening. Monitoring the excess water on the Manatee River remains crucial, as river flooding earlier this year caused the city of Bradenton’s sewer system to overflow. Sewer overflow and environmental damage remains a lingering liability for the river.
Widespread Impacts from Hurricane Debby
Flood damage assessments have just begun in some areas hit by the storm. In the Big Bend of Florida, many are still recovering from last year’s Hurricane Idalia, which led to 12 deaths and over USD 3 billion in damage. Hurricane Florence in 2018, also a large and very slow-moving hurricane that made landfall as a Category 1 storm, produced similar record-high inland flood damages in the Carolinas (table below).
- In Florida, damaging hurricane-force winds, storm surge and intense rainfall caused extensive flooding and wind damage. A state of emergency was declared for 61 counties, and the Florida National Guard was activated. At least 5 fatalities were reported after Debby hit the state. At its peak, more than 350,000 homes and businesses were without power, with 33,000 still without power as of August 7. Thousands of coastal residents were ordered to evacuate, and numerous flights were canceled or delayed across major airports including Tampa, Fort Lauderdale, Orlando and Miami.
- In Georgia, the coastal city of Savannah experienced widespread flooding, leading to a curfew and the closure of the Port of Savannah. During the peak of this event, a maximum of 122,500 customers were without power. A fatality was reported in Moultrie, and Valdosta saw downed trees and power lines. Emergency shelters operated while schools and universities suspended operations.
- South Carolina also declared a state of emergency, with 12,000 customers without power on August 7. Charleston and Myrtle Beach airports saw more than 100 flight cancellations, and a suspected tornado caused structural damage on Edisto Beach. A curfew was imposed in downtown Charleston, as Debby’s rain continued to pour on the coastal city.
- In North Carolina, a state of emergency was declared on August 5, with Debby’s forecast impact. The state continues to address the extensive infrastructure damage and power outages caused by the rainfall persisting through Thursday, August 8. Multiple tornadoes have been reported across the state.
- Multiple tornadoes have been confirmed by the National Weather Service in Florida, South Carolina and North Carolina as a result of Debby.
Implication on NFIP Take-Up Rates
With the main goals being to provide flood insurance to help people recover from flooding and to reduce the nation's overall flood risk, the National Flood Insurance Program (NFIP) offers flood insurance policies to property owners, renters and businesses in participating communities.
Across western and north central Florida and the southeastern US coastline, there is significant variation in the take-up rates of NFIP flood policies. Coastal counties generally have higher take-up rates due to the risk of storm surge; however, only Monroe County, Florida, has a take-up rate greater than 50%. Hurricane Debby’s landfall location in Taylor County in the Big Bend region shows a take-up rate of just 5%, which is well below the Florida state average of 12%.
In the figure below, the flood footprint in red, as analyzed by KatRisk, highlights the extensive impact of both coastal and inland flooding caused by Hurricane Debby. The shaded areas represent county take-up rates of NFIP policies relative to the total number of housing units. Northern and central Florida, along with the inland counties of Georgia and the Carolinas, are areas of highest concern for uninsured losses, with NFIP take-up rates of less than 5%.
Forecast Details
Debby has begun to increase its forward motion, now moving generally northward at 7 mph. Large-scale steering features will soon accelerate Debby to the northeast moving the storm over the Mid-Atlantic and Northeast US Friday and into the weekend. Along the forecast track, Debby is expected to bring heavy rainfall and gusty winds to impacted regions.
Flash flooding risk is present throughout the Southeast and Mid-Atlantic through Friday, and much of the Northeast through Saturday morning. Debby is forecast to merge with a frontal system and become extratropical over the Northeast on Friday; the NHC best forecast tracks the center of Debby over Atlantic Canada this weekend and clearing land by Monday before fully dissipating.
This will be the last report issued for former Hurricane Debby and its remnants.
Additional links of interest:
- US National Hurricane Center
- NOAA Storm Surge Data
- NWS Tampa
- NWS Charleston
- US National Weather Service
- USGS Flood Event Viewer