Last week, advanced NOAA satellites meticulously tracked Hurricane Debby, a significant weather event that carved a path of destruction across the southeastern and northeastern United States. Debby made its initial impact on Florida’s Big Bend region, near Steinhatchee, before surging up the East Coast. This powerful storm unleashed widespread flooding and damaging winds that reached as far north as New York state, accompanied by numerous destructive tornadoes along its extensive trajectory. Rural villages and hamlets south of the Finger Lakes region experienced some of the most severe flash flooding.
Hurricane Debby’s origins can be traced back to a tropical wave that the National Hurricane Center (NHC) began to monitor on July 26. The system gradually intensified, eventually becoming Tropical Depression Four near Cuba on August 2. By late the following day, as it moved into the southeastern Gulf of Mexico, Debby was officially upgraded to a tropical storm, marking its formal designation and increased intensity.
Alt text: GOES-16 satellite view of Hurricane Debby landfall in Steinhatchee, Florida, showcasing storm position and intensity.
The evening of August 4 saw Hurricane Debby reach Category 1 status on the Saffir-Simpson Hurricane Wind Scale, signaling a further escalation in its strength. The storm made landfall near Steinhatchee, Florida, on the morning of August 5, bringing hurricane-force winds and a significant storm surge to the coastal community. After moving inland across northern Florida and southern Georgia, Debby’s forward motion slowed as it drifted back over the Atlantic Ocean off the coast of South Carolina on August 6.
Around 2 a.m. EDT on August 8, Hurricane Debby made a second landfall near Bulls Bay, South Carolina. Although its sustained winds had decreased to approximately 50 mph at this point, the storm still posed a threat due to heavy rainfall and flooding. Later that same day, as Debby moved east of Charlotte, North Carolina, it was downgraded to a tropical depression, indicating a weakening of its wind intensity but not necessarily its capacity for causing damage from rain. The storm transitioned into a post-tropical cyclone as it continued its northward journey through the Northeast and into Canada, bringing substantial rainfall to southern Quebec and the Maritimes before finally dissipating on August 10.
Alt text: Suomi NPP satellite image capturing post-tropical cyclone Debby over the Northeast, highlighting cloud patterns and geographical reach.
Debby’s most devastating impact stemmed from its torrential rainfall, which triggered widespread flash floods and river flooding across a large swathe of the southeastern U.S., particularly from Florida through the Carolinas. By Friday, August 9, the scope of the storm’s impact was evident as more than 35 million people from South Carolina to Vermont found themselves under flood watches or warnings, bracing for potentially life-threatening conditions. Berkeley County, South Carolina, was particularly hard-hit, recording rainfall amounts as high as 14 inches last week, while Charleston experienced even greater totals, with up to 15 inches of rain.
In addition to the rainfall, Hurricane Debby generated a substantial storm surge along Florida’s Gulf Coast. This surge inundated coastal areas, leading to significant property damage and leaving behind a trail of debris. Amidst the cleanup efforts following the storm surge, an unusual discovery was made by a Tampa Bay resident: a World War II-era message in a bottle, a historic artifact unearthed by the powerful forces of nature.
Alt text: Historic WWII message in a bottle discovered in Tampa Bay after Hurricane Debby, showcasing an unexpected find from storm debris.
Strong winds associated with Debby also played a significant role in the storm’s impact. Trees were toppled, properties were damaged, and power outages became widespread. More than 300,000 customers from Florida to the Carolinas were left without electricity. The power outages extended further north, affecting thousands more in Ohio, Pennsylvania, New York, and across New England, with Vermont experiencing particularly severe disruptions to the power grid.
Furthermore, Hurricane Debby spawned numerous tornadoes across the Southeast. On August 8 alone, at least twelve tornadoes were reported from North Carolina to Pennsylvania, adding another layer of destruction to the storm’s extensive impact.
Hurricane Debby holds a significant place in the 2024 Atlantic hurricane season as the second hurricane to form, following the earlier and highly destructive Hurricane Beryl. Debby’s formation date of August 2 was also notably early in the season. According to hurricane researcher Phil Klotzbach at Colorado State University, the average date for the second Atlantic hurricane to form is typically around August 26, making Debby an unusually early arrival.
Adding to its historical context, Debby’s landfall in Steinhatchee, Florida, marked it as the fourth hurricane to make landfall in Florida during the month of August since the year 2000. The other three hurricanes to make landfall in Florida in August since 2000 were Charley (2004), Katrina (2005), and Idalia (2023), highlighting a pattern of August hurricane activity in the region.
NOAA satellites are indispensable tools for hurricane forecasting and monitoring. They provide critical data on the location, movement, and intensity of these powerful storms. The GOES-16 and GOES-18 geostationary satellites offer continuous surveillance of the entire Atlantic and eastern/central Pacific hurricane basins. This constant monitoring allows for real-time tracking of tropical cyclones and the environmental conditions that contribute to their formation.
By capturing images of storms as frequently as every 30 seconds, these satellites enhance forecasters’ ability to discern cloud feature movements and improve the accuracy of storm center estimations. GOES-16 and GOES-18 also deliver detailed insights into a hurricane’s structural properties, including cloud top cooling, central pressure, and convective structures, as well as specific characteristics of the eye, wind estimates, and lightning activity. This comprehensive information is vital for accurately assessing a storm’s intensity and predicting its future behavior.
Complementing the geostationary satellites, the Joint Polar Satellite System’s (JPSS) polar-orbiting satellites, Suomi-NPP and NOAA-20, gather data over every point on Earth twice daily. These satellites precisely measure sea surface temperatures and atmospheric temperature and moisture, which are crucial for generating storm forecasts several days in advance. Data from JPSS instruments are particularly valuable in helping forecasters predict a hurricane’s path with a lead time of 3 to 7 days, providing crucial time for communities to prepare and respond.
