Impact of Helene on the Southern Appalachians
The past 10 days have been rough and sort of unreal around here. I hope all my iNaturalist friends and followers in the Southern Appalachians made it through hurricane Helene relatively unscathed. I got lucky but I'm keenly aware that not everyone in the area fared as well. Who is still out there alive and kicking?
For those unaware, on Thursday night (Sep. 27), hurricane Helene made landfall in Florida and quickly spun northwards dumping unprecedented amounts of rain along the way. It stalled over the Southern Appalachians where it encountered both the mountains and another storm system to the north that had already drenched the area and saturated the ground. The results have been widespread devastation.
(Image credit: NOAA)
We were still teaching classes in person Thursday morning but only half of my students showed up. Afternoon and Friday classes were supposed to be online to leave parking lots empty so the university could prepare for and react to potential flooding. Right after I was done with my last zoom meeting with students on Thursday evening, we had two tornado warnings and that was even before the hurricane arrived in our area. Tornado warnings are very rare here in the mountains, so having two in quick succession was unusual. One of those tornadoes formed just 15 miles from where I live. I spent the evening in the basement, prepping for more rain to come. By morning, the wind was driving the rain horizontally and my power was flickering on and off. Before power went off for good, I managed to get an email out that I likely would not be able to do a zoom meeting that day. The storm left a trail of power outages from Georgia and South Carolina into western North Carolina. Along with power, cell phone towers and internet blacked out as well. Even 10 days later, some areas still don't have power and communications back.
There are a few of these satellite images floating around with a larger area shown. I cropped it to just NC. I don't know what the "before" date is and I'm not entirely sure of the time but found one post claiming the second picture is from Sep. 28, not sure if in the early morning hours or late in the evening. Asheville (the bright cross in the first picture, representing I-40/I-26 intersecting) was basically wiped off the power grid.
Late morning on Sep. 28, my basement started getting wet. I thought for sure the weak points would be the door and windows, but by noon water had started seeping up from the basement floor rather than leaking down from above. Apparently the ground around the house was so saturated at this point that the water just came oozing up through the concrete from below and through the foundation. Fortunately for me, the rain stopped before it could get worse than about an inch of water throughout the basement.
The amount of rain dumped by this storm on top of what the previous had already done was staggering. This figure shows the Annual Exceedance Probabilities (AEPs) for the highest 3-day rainfall period. From what I understand, 1% AEP means rainfall that has a 1 in 100 chance of being equaled or exceeded in any 1 year with an average recurrence interval of 100 years (often referred to as a "100-year flood"). Those are the green areas on the map. The dark blue areas indicate "1000-year flood" or even lower probability of that much rain falling over a 3-day period.
(Source: www.weather.gov)
The result from that much rain has been a series of devastating floods from water run-off and creeks swelling into raging rivers as well as landslides when slopes failed to hold the saturated soil any longer. This map shows the number of landslides in the aftermath of Helene that had been reported by yesterday. The red dots are "flagged" landslides that affected rivers, roads, or other structures such as bridges or buildings. I marked the location of Asheville and Boone, which both have been impacted by this.
(Source: USGS Landslide Dashboard)
As a consequence of the flooding and landslides, infrastructure in the region has all but collapsed. Bridges and buildings washed away in the floods, roads either collapsed or got buried. The Southern Appalachians have always had remote areas that were tricky to get to, but this made them pretty much inaccessible. Search-and-rescue teams had to go out with helicopters to get to people. Folks are out on horseback and with mules to deliver supplies to those stranded in the mountains. It's unreal how one storm basically collapsed everything. Even now, 10 days after the event, the area is still closed to all but essential travel.
(Source: DriveNC.gov)
Even main routes such as interstates I-26 and I-40 have suffered major destruction and it will take months to years to repair. Google maps gives an estimated timeline for closures until March '25 for I-26 and Sep. '25 for I-40 in TN and '28 in NC, but honestly nobody really has a timeline for these repairs yet as the damage is still under assessment.
Some of the smaller roads are completely gone, culverts and bridges ripped away by the currents and entire sections of road slid down the mountain slopes. The Blue Ridge Parkway in NC has suffered catastrophic failures as well. This picture is just one example of many.
What that means basically is that travel in the area is all but impossible at a time that is usually the peak tourist season as people flock to the mountains for the fall colors. Traffic from NC to TN has to go the long way around via Virginia or Georgia for the foreseeable future. Newfound Gap Road (441) through the Smoky Mountains has been reopened as it suffered little damage by comparison, but they have had to close it again at least at night to prevent large trucks from attempting that route. It's a steep and curvy mountain road, not at all suitable for a big rig and there have been multiple accidents already because some people ignore all signage and warnings.
If the roads are in such bad condition, I hate to think about what the trails might look like. Some of the hiking trails south of Asheville were already pretty badly eroded from the last major storm, and this may have made them completely impassable. One third of the Appalachian Trail was closed, and all State Parks in western NC are closed until at least the end of this month to assess the damages.
(Source: https://www.ncparks.gov/closures)
So no power, no cell phones or internet, no travel, no hiking - what impact does this have on iNaturalist observations? This past week was supposed to the our annual BioBlitz at AppState and we were looking forward to welcoming UNC Asheville to the competition. Well, that sort of happened without us. Both campuses closed after the storm wreaked havoc in the area. AppState classes won't meet until at least Oct. 16, and Asheville classes are cancelled through the end of October. Last night's observation tallies from the BioBlitz speak volumes.
This heat map shows observations made in the area of the Southern Appalachians during the week following the hurricane:
By comparison, this is the corresponding time frame (Sun.-Sat. again to account for weekends) last year:
Basically Asheville and Boone, usually observation hot spots in the Southern Appalachians during fall color season, and the Blue Ridge Parkway between them have blinked off the observation map for this year. It will take a while to fix roads and trails to allow people access to these mountains again. As one of the news articles I've read put it: "Mother Nature took back her mountains."