Wake County Hazard Mitigation Plan - Adopted 10-21-2024

SECTION 4: RISK ASSESSMENT

were underwater for days, even weeks in some areas. Thousands of homes were lost. Crop damage was extensive. The infrastructure of the eastern counties, mainly roads, bridges, water plants, etc., was heavily damaged. By the end of 1999, $1.5 billion had already been spent, with estimates that the cost would reach $3-4 billion. The counties within the Raleigh county warning area probably sustained more than half of the state total. Even worse, was the loss of life, mainly due to flooding. Many Carolinians did not heed the call to evacuate and many more drove into flooded streams and rivers. In the central part of the state, 21 people lost their lives. Also, the loss of livestock was significant, mainly swine and poultry. Tropical Storm Ernesto (2006) – Tropical Storm Ernesto produced high winds county wide. There were numerous reports form emergency officials of downed trees and large tree limbs. Tropical Storm Hermine (2016) – Tropical Storm Hermine produced heavy rain across portions of central North Carolina. However, due to dry antecedent conditions, no flooding occurred despite rainfall amounts of up to 3 to 5 inches across southeastern portions of central North Carolina. Given the rain and gusty winds associated with Hermine there were numerous reports of trees down and wind damage and resultant power outages. A large tree fell through the roof of a house near New Hill. Tropical Storm Michael (2018) - Tropical Storm Michael moved through North Carolina on Thursday, October 11th. Michael brought heavy rain and strong damaging winds to central North Carolina. While heavy rainfall of 3 to 6 inches produced minor flash flooding across the area, it was high wind gusts of 40 to 60 mph that caused the biggest problems, knocking down score of trees, leading to blocked roadways and thousands without power. Hurricane Isaias (2020) - Hurricane Isaias made landfall in southeast North Carolina, then moved north through coastal North Carolina. Significant rain fell across the Coastal Plain, Sandhills and eastern Piedmont of North Carolina as Isaias moved northward through the state along with gusty winds up to 50 to 60 miles per hour. Isaias produced two to five inches of rain across much of eastern NC, resulting in flash flooding, as well as minor flooding along the Neuse River. Hurricane Ian (2022) - Hurricane Ian made landfall along the South Carolina coast near Georgetown during the early afternoon hours of September 30, 2022. Widespread wind gusts over tropical storm force and heavy rainfall occurred across much of central North Carolina through the afternoon and evening hours. There were numerous reports of wind damage and power outages as a result of the storm. PROBABILITY OF FUTURE OCCURRENCE

Probability: 3 – Likely

In the 27-year period from 1996 through 2023, 13 hurricanes and tropical storms have impacted the Wake County area, which equates to a 48 percent annual probability of hurricane winds impacting the county. This probability does not account for impacts from hurricane rains, which may also be severe. An additional 12 storms passed within 50 miles of Wake County during this period; these storms did not have significant wind impacts but may have brought heavy rains. CLIMATE CHANGE One of the primary factors contributing to the origin and growth of tropical storm and hurricanes systems is water temperature. Per the Intergovernmental Panel on Climate Change Sixth Assessment Report (IPCC AR6), tropical cyclone rainfall rates and intensities are projected to increase globally. Tropical cyclones that reach very intense levels (Category 4 and 5) are projected to increase due to global warming and high levels of atmospheric moisture content. According to the Fifth National Climate Assessment, between the years 2000 and 2021, 38 tropical cyclones caused over $1 trillion in losses and 6,200 deaths. While damages to coastal communities are expected to increase, with significant damages occurring where tropical cyclones make landfall, it is unclear how impacts and damages may change inland. It is also unclear whether these changes can be attributed to climate change as there are uncertainties and

Wake County, NC Multi-Jurisdictional Hazard Mitigation Plan

WSP June 2024 Page 164

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