Q&A: NWS meteorologist reflects on 5-year anniversary of Hurricane Florence

CHARLOTTE — The following is a Q&A with Steven Pfaff the warning coordination meteorologist for NWS Wilmington, five years after Hurricane Florence made landfall near Wrightsville Beach.

Q: What does a warning coordination meteorologist do?

A: We interface a lot with emergency managers. we work with schools, a lot of other partners … just pretty much trying to get everybody on the same page with what hurricane center products mean. and a big part is public weather safety information.

Q: At what point did you realize that Florence was going to be a very unique storm?

A: It was really interesting from the start when you think about, at least climatologically, the hurricanes and the paths that they have and how we’re impacted by them -- usually it’s coming up from a southerly direction. Usually, these big tropical waves come off the west coast of Africa and then they cross the tropical Atlantic waters and then get toward the Bahamas and start to sweep off toward the northwest and the north towards us but this was the first time going back to the 1850s where we had one come at us from this far north in latitude. So right off the bat, we knew we were dealing with something. We started doing briefings five to seven days out to try to get the public ready and watch mode basically.

Q: What was going on climatologically that made a hurricane form so far north?

A: Oftentimes, we look at where the Bermuda High is. The Bermuda High is a big clockwise spinning gyre that sets up over the Atlantic Ocean during the summertime. It’s based on, you know, the ocean heats at a slower rate than air over land so you get pressure differences just based on the differential in heating. Usually, when the Bermuda High is in its classic sense, it’s a little farther south and the western periphery of that high is just across the Carolinas. This time it was farther to the northeast and got to the north of Florence and what that did was block it from moving northward and as Florence moved towards the west, that area of high pressure just happened to be blocking it from making that northern turn.

Meteorologists Steve Udelson and John Ahrens tracked Florence over its several-day journey across the Carolinas.

Q: In the leadup to the storm, what did you do to try to help the state prepare?

A: What became more and more apparent with each passing day before the arrival of the storm, was that this system was going to slow down considerably and even just an average-moving hurricane moving at 15 mph can bring a lot of heavy rainfall. Now, we’re looking at this thing. Every forecast is creeping slower and slower and slower across southeast North Carolina and northeast South Carolina, so we just had to keep ratcheting up the rainfall amounts.

Floyd was 18-20 inches of rain. We were forecasting over 30 inches of rain with Florence and in some places Doppler radar estimates where we don’t have rain gauges, we had over 40 inches of rain. When you have this monster storm that’s throwing tropical moisture into the area, that flash flood concern is going to be high on our list.

It also brought a prolific number of tornadoes -- that favorable quadrant in the hurricane that the eastern half was focused over our area for over a day. Our office issued 35 tornado warnings. We were able to confirm 18 of them. At one point, it was forecasted to make landfall as a major hurricane on top of that. Luckily for us, it found some dry air that spiraled into the system as it approached the coast so it weakened a little bit, but it just goes to show you, if you just rely on the Saffir-Simpson Scale, the wind part of it, you can still have a catastrophe. You should never hear anybody say it’s only a Category 1.

Q: At one point, it had intensified to be a Category 4 and then it made landfall as a Category 1. Is there a kind of sense that people look at hurricanes like that and underestimate the threat?

A: Yeah, if you catch yourself saying, ‘I’m only going to do x, y or z because it’s Category 1, 2 or 3,’ you’re doomed to fail, at some point. Because you’re going to come across a storm that’s going to produce prolific rainfall like Hurricane Florence did. You’ve got to look at a hurricane in its complete picture with what aspects it can bring to our community. So it’s the storm surge, the wind part, the tornado aspect of it, the heavy rain and flash flooding, the maritime issues, and then of course the river flooding that follows after big storms like Floyd or Florence. Before Hurricane Florence, our rivers were low so I can’t even begin to imagine if we had a lot of rainfall leading up to Florence. How that would have compounded the problems that we had.

Flooded roads in Cheraw, SC after Florence moved through.

We had to deal with messaging challenges before the storm. We’ve never seen a storm come in from this direction. We’ve never had a storm, at least in recent times, crawl to three mph or less in our area bringing this amount of rainfall and painting the picture of what 30-plus inches of rain can do to the public is often very difficult. Most of our fatalities are people out driving around. The weight of their vehicle collapses the road because it’s being undermined by flowing water, or the road is already washed away and they drive right into it and get swept downstream.

We also had significant messaging issues during and after the storm (as it) moved away. Because what do people hear about on social media or wherever their sources are? That Florence has degraded. Florence is now a tropical storm. Florence is now a tropical depression. It gives a sense that everything is returning to normal and the people who evacuated want to get back. Meanwhile, the tornado threat is actually increasing, and the flash flooding threat is increased dramatically. And so we had to combat that aspect of the storm as well.

Q: Moving forward, what kind of lessons can you take away from this hurricane?

A: I think first and foremost is, that just because we haven’t seen it before doesn’t mean we can’t have it. No one would have thought that at this latitude we’d have 40 inches of rainfall. So, that’s where I feel like we’re at our weakest. If we haven’t seen anything in a long time, or have never seen it before, are we going to be as prepared as we can be for it? We were in the unknown at that point. We knew there was going to be incredible flash flooding, catastrophic inundation of people’s homes and lives turned upside-down and we were just concerned that people were heeding the warning especially because at the time of landfall it was just a Category 1, a catastrophic, Category 1 hurricane.

Q: What concerns do you have about potential future storms that could come this way?

A: We can’t ignore our history. We unfortunately have a deep and long history of hurricanes in northeast South Carolina and southeast North Carolina and bad storms along the way. Hurricane Hazel back in 1954. Fran 1996. Hugo 1989 impacting the southeast coast. You can’t ignore that. They’ve happened before. They’ll happen again. Regardless of what that yearly forecast is that comes out at the end of May. It doesn’t matter. All it takes is one storm. Based on that history, we can’t ignore it. We can’t afford to take a year off when it comes to hurricane preparedness. The estimates are for at least a 20% increase in major hurricanes based on how climate change is going to evolve. So we’re seeing more and more category 3s, 4s and 5s out there. We need to be smart when it comes to the flash flood aspect because if you have a warmer atmosphere. It can hold more water, so it’s no surprise just in our area alone we’ve seen at least 7 of the “500-1000″ year floods since 1999.

Q: How does that impact how you’re able to give warnings?

A: The accuracy of the models with the forecasting is getting better which is great. It helps that. It alleviates some of that pressure, but also the planning you never want to plan for something that’s on the low end of impacts. You want to plan for that probable worst-case scenario.

Michelle Alfini

Michelle Alfini, wsoctv.com

Michelle is a climate reporter for Channel 9.