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“Just in general, we absorbed a lot of rain over multiple days,” said NWS Meteorologist Clay Cheney. “And so the area became really primed and conducive to flash flooding.” As the storm drew closer, the NWS began to update its messaging. First, it moved the start time for its Flash Flood Watch up earlier to begin at midnight Aug. 17. As Tuesday unfolded, it published updates on its social media accounts, and at 3:12 p.m. — half an hour before the East Fork gauge reached flood stage at 3:45 p.m. — a Flash Flood Warning was issued. Unlike the Flash Flood Watch alert, the Flash Flood Warning resulted in alerts sent to cell phones in the affected area. Locally, Haywood County Emergency Services had also been working to communicate warnings to local residents, informing them of the danger via social media posts and Haywood Alerts messages sent directly as text messages and phone calls to those who had signed up for the service. The first Haywood Alerts message went out around 2:20 p.m. Aug. 16, alerting users of the Flash Flood Watch. Subsequent alerts went out at 3:12, 4:09 and 4:25 p.m. Aug. 17.
CHALLENGING TERRAIN
September 15-21, 2021
Homes throughout the Cruso area were left destroyed after the floodwaters receded. Scott McLeod photo
‘And then it was too late’ Flood warning timeline reveals challenges of mountain forecasting
BY HOLLY KAYS STAFF WRITER n the afternoon of Tuesday, Aug. 17, Rob Young was watching the rain fall. He watched it first through the windows of his office at Western Carolina University and then later at his home in Webster — and, continuously, on his computer screen, where ever-changing river depths were displayed through the state’s Flood Inundation Mapping and Alert Network, or FIMAN. “At one point I was saying, ‘This is going to be more of a nonevent than I thought,’” he said in an interview Sept. 3, when bright sunshine had replaced the streaming skies of Tropical Storm Fred. “Then all of a sudden I started hearing houses are going down the river in Cruso.” The FIMAN site features a map marking every river gauge in North Carolina, with a color-coded circle indicating its current level — green denotes a normal reading, with yellow, orange, red and purple marking pro8 gressive levels of danger. A ring around the
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interior circle indicates the river’s forecasted peak condition. As Young watched the map Aug. 17, he waited for the outer rings to change color. “It never happened until the gauge was reporting a flood,” he said. “And then it was too late.” As director of Western Carolina University’s Program for the Study of Developed Shorelines, Young has a professional interest in water, and the ways it can change even the most longstanding human settlements. He studies hurricanes and wetlands, and how science can inform management and policy in these vulnerable places. The impact of Tropical Storm Fred shocked him, as did the suddenness with which it arrived. After the storm passed, he started asking what the National Weather Service knew, what local emergency managers knew and when they knew it. Had somebody messed up? Could this loss of life and property have somehow been averted? But no, he concluded — the devastation in Haywood County was not the result of cumbersome bureaucracy or incompetent leadership. Rather, it was the result of the immense difficulty of accurately predicting mountain weather, of the inherent danger of living in a floodplain and of an unprecedented load of rain.
“I’m not convinced we could have done much of a better job with a flash flood like this that happens so incredibly quickly,” he said.
EVOLVING PREDICTIONS Meteorologists at the National Weather Service Forecast Center in GreenvilleSpartanburg had been watching Tropical Storm Fred for days prior to its Aug. 17 arrival in Haywood County, posting regular updates on the storm’s projected path and impacts to its carefully curated social media pages. At 2:20 p.m. on Monday, Aug. 16, those projections led the NWS to issue a Flash Flood Watch beginning Tuesday morning for a 31-county area, which included the entire far western region of North Carolina. Rainfall amounts could vary widely, the alert stated, ranging from 2-3 inches in piedmont areas to 8-10 inches in upslope mountain areas. The notification went out via mass market media, the National Oceanic and Atmospheric Administration weather radio and NWS official Twitter accounts. That rain would come at a time when soils were already saturated. On Sunday, Aug. 15, a river gauge a mile past Jukebox Junction on the East Fork Pigeon River had peaked at 7.28 feet, not far below the flood stage threshold of 8.5 feet.
Predicting the weather isn’t easy, and predicting mountain weather — especially extremely localized but extremely intense outbursts — is doubly difficult. On a broad level, said Senior Service Hydrologist Joshua Palmer, the NWS was expecting heavy, potentially dangerous rainfall from Tropical Storm Fred, and that’s exactly what happened. “The challenge is — and this is where the state of the science comes into play — can we provide the Cruso residents a forecast the day or two in advance that says, ‘You guys are going to get 8.5 inches of rain between 10 a.m. and 5 p.m. on Tuesday, Aug. 17?” said Palmer. “And we’re just unfortunately not there yet.” There was no warning specific to the Cruso area until the river was rising in the Cruso area such that, for many people, it was already impossible to leave. But that’s merely a reflection of current forecasting capabilities, not a reflection of missed cues or overlooked data on the part of the forecasters, said Palmer. Flash flood watches don’t happen too often — there have been three this year for Haywood County — so when they’re issued it’s important to take them seriously. “When that flash flood watch goes out and you’re in a campground setting and you’re next to a river, that’s a decision that has to be made as to whether there’s a risk there that you could experience flooding,” Palmer said. While “being wrong is part of the job,” Palmer said, when it comes to weather prediction error comes at a price. If a severe weather watch is issued and nothing happens, people who received the alert might pay less attention the next time. For the same reason, forecasters have to avoid giving a prediction that’s too specific for the science to support it with reasonable certainty. Especially in the mountains, the outcome for a local area depends on exactly where the heaviest rain is located, and there-
