Fred highlights challenges in forecasting, importance of preparedness

Sep. 24—On Sunday, Aug. 15, local and national agencies had their eyes on Haywood County.

The team at the National Weather Service Greenville-Spartanburg knew that rains from Tropical Storm Fred would dump rain on Western North Carolina, so they put together short briefing pages to outline the risk for flash floods. The briefs went out to their local partners, including Haywood County Emergency Services.

As the threat for flooding ramped up, the briefing page became a briefing package. Then, the NWS transitioned to live webinar to keep local agencies and authorities informed minute-by-minute, says Trisha Palmer, warning coordination meteorologist at NWS Greenville-Spartanburg.

Meanwhile, in Haywood County, Emergency Services was putting together teams of rescuers and mutual aid groups across the state. They knew Fred would be a major event, but no one predicted the full devastation.

It's been more than a month since Fred hit and many wonder: what happened?

Making sense of it

Haywood County Emergency Services and the NWS started sending out alerts and posting flash flood watches on social media Monday, Aug. 16.

But when Fred finally reached Haywood County, it lingered over a crest on the Blue Ridge Parkway, pouring rain down into the East Fork of the Pigeon River.

At 3:15 p.m. Haywood County upgraded the flash flood watch to a flash flood warning. In the span of an hour-and-a-half, from 3:15 p.m. to 4:45 p.m., on Aug. 17, the river nearly doubled, rising from 6.5 feet to 12 feet. Compare that to an earlier reading the same day, when the river was at a mere 1.9 feet.

By the time the river peaked at 16.2 feet just an hour later, around 5:45 p.m., it was too late for many people to evacuate or secure their belongings. The damage had been done. Entire houses washed away. Six people were left dead. Dozens were, and many remain, displaced.

Turns out, science and technology can only go so far when you're dealing with extreme weather events in rural or mountainous areas.

More data needed?

Some people reported not receiving any alerts about the flooding, or receiving the alerts too late. This could come down to a few issues: forecasting in mountain areas, emergency alert methods and outreach.

Although the potential for flash flooding was known, variations in elevation can impact what data is available to forecasters. Palmer says that NWS makes predictions based on multiple factors they call a "total observation concept." This includes radar, satellite imagery, stream and rain gages, as well as reported data from citizens and trained spotters.

Rain and stream gages are some of the most valuable tools when it comes to predicting weather, says Palmer. Most of these gages are monitored by the U.S. Geological Survey and take interval readings of rainfall and stream and river depth. But, they're positioned to give localized data — they don't always tell the full story.

Bill Hazell, field office chief at the USGS South Atlantic Water Science Center at Asheville, says the closest rain gage to the storm cell that lingered over the parkway is in Cruso, at the East Fork of the Pigeon River. However, rain collected in a steep basin along the Blue Ridge Parkway, between Haywood and Transylvania counties before it rushed into the river.

If there is only one stream gage in a certain area, the USGS and forecasters have to use that data. Some wonder if more stream gages are needed, and if it could be helpful in preventing such flood damage. For example, having gages located at headwaters where rivers and streams originate could be helpful in buying the NWS and Haywood Emergency Services more time to evaluate data and decide when to send out alerts.

Hazell says that for his team having more data points could be a big help, but it's not always as easy as simply adding an additional rain or stream gage.

"From our standpoint, you can never have too many data points," Hazell said. "More gages would help, but you need someone who can pay attention and can analyze them."

Hazell said it's important to have context for data. You can't just monitor the gage, you have to look at patterns and previous data to determine at what level of rain or what river reading people would need to begin evacuating.

Zack Koonce, Haywood County Emergency Services officer, echoes this sentiment. He says it's not easy to just add an extra gage with all the local and federal agencies that the USGS would have to work with. These include the N.C. Department of Transportation, U.S. Forest Service and N.C. Emergency Management.

But, even without adding in more rain or stream gages, Hazell says that the USGS is working to improve communications. One solution they're trying is to increase the frequency of transmitting gage data to local agencies. Right now, the gages take readings every 15 minutes. Every hour, the four readings for the hour are relayed to a network of agencies, including the NWS and Haywood Emergency Services. During extreme events, the USGS does have the ability to take readings every five minutes and transmit data every 15 minutes, but that also takes manpower. However, it's something the agency is working toward doing more regularly.

But perhaps the biggest challenge of all is simply reaching people who may be affected by the weather events.

'Prepare, prepare, prepare'

Haywood County Emergency Services has one option for pushing alerts to residents, wireless emergency alerts (WEA). Haywood County is the local alerting authority, so they have the capability to push out notifications to anyone in a district area. These are the alerts that are involuntary, like an Amber Alert for missing children — unless you turn them off. The other alerts go to those who sign up through a contracted agency called Everbridge. Most of the alerts that went out on Aug. 17 were to residents who had signed up for them.

On the other hand, the NWS is able to issue alerts through cable TV via the Emergency Alert System (EAS). But Palmer acknowledges that fewer and fewer people have cable TV, so this isn't the most effective way to reach people.

Haywood County Emergency Services Public Information Officer Allison Richmond says the department does plan to conduct more outreach and education regarding these alerts and how to sign up for them, as well as what they mean. But she says there will always be people who are difficult to reach.

The ultimate goal for Koonce and the others at Haywood Emergency Services is reducing vulnerability for people living in flood zones. This is a challenge in itself — Western North Carolina has hundreds of watersheds that can be prone to flooding.

Until then, weather preparedness is somewhat of an individual responsibility, says Palmer. It's not easy, but it's necessary for people who live in flood zones to figure out the best method to closely monitor available data and warnings.

"I can't go knock on your door," Palmer said. "It's really important that people have ways to receive warnings."

Hazell also says this is important, and that people are ready to evacuate as soon as they need to.

Palmer recommends having multiple ways to receive warnings: cell phone alerts, social media alerts, even a dedicated weather alert radio. It's not convenient but it could save lives.

At the end of the day, Palmer says the most important thing to do is: "Prepare, prepare, prepare."

List of resources:

Sign up for Haywood County emergency alerts: member.everbridge.net/453003085616422/login

Community Collaborative Rain, Hail and Snow Network (CoCoRaHS): www.cocorahs.org

North Carolina Streamflow via USGS South Atlantic: waterdata.usgs.gov/nc/nwis/current/?type=flow&group_key=basin_cd