On September 16th, 1999, Hurricane Floyd made landfall in southern North Carolina with wind speeds of 105 miles per hour (mph). This hurricane brought devastating rainfall and flooding to an area of the United States that was already in disarray from Hurricane Dennis, which impacted the same area just weeks prior. Although the GOES-16 satellite technology we use today was not in place at the time, tools that allowed meteorologists to monitor this tropical cyclone still existed. Below shows a general overview of the path this cyclone took (Fig. 1).
Figure 1: Map showing the track Hurricane Floyd took during its lifespan. Deeper yellow and orange colors indicate a higher category on the Saffir-Simpson Hurricane Scale. (Source: NOAA)
As seen in the figure above, Hurricane Floyd actually reached category 4 on the Saffir-Simpson scale two separate times, the first on September 13th while north of Hispaniola, and the second on September 15th while north of the Bahamas. Hurricane Floyd reached a peak pressure of 921 millibars on September 13th, and a satellite view of the cyclone during this time can be seen below (Fig 2.).
Figure 2: Satellite view of Hurricane Floyd from 13 September 1999 at 1415Z, while at peak intensity of 921mb. (Source: NOAA)
Fortunately for the eastern United States, Floyd would weaken to a category 2 hurricane before making landfall. One perspective of this can be seen in the figure below, which shows that the cyclone weakened prior to making landfall in North Carolina (Fig. 3). This can be seen through the destruction of the eye closer to landfall, as well as a weakening of the structure of the cyclone in general.
Figure 3: Infrared satellite view of Hurricane Floyd as it moved north along the east coast of the United States and made landfall in North Carolina. Deeper red colors indicate thicker clouds.
As stated previously, Floyd brought excessive precipitation to the eastern United States, amplified by the storm’s interaction with a cold frontal boundary. A large portion of North Carolina received upwards of 15 inches of rain, which, when combined with up to 10 feet of storm surge in some areas, led to widespread flooding in the region. Hurricane Floyd caused 51 fatalities in North Carolina alone, most of which were a result of said flooding.
Figure 4: Radar reflectivity loop from 15-16 September 1999. Yellow and orange colors indicate higher rates of precipitation.
Figure 4 above shows how widespread the precipitation created by this system was. Due to Hurricane Dennis just weeks earlier, the soil in a lot of these areas was already saturated with water. This made the flooding even worse, as there was nowhere for the excess water to go. As seen below in Fig. 5, several rivers across the state overflowed and caused even more flooding issues. Some rivers even exceeded 500-year flooding levels as a result of Floyd.
Figure 5: Aerial views of the same region of North Carolina, before and after Hurricane Dennis/Floyd. This shows the flooding of rivers across the state caused by these storms. (Source: NOAA)