This weekend I tweeted my concern about the potential impacts of Hurricane Florence later this week. Some guy chastised me for fear-mongering. I dismissed that as just typical Twitter posturing. I have spent my entire career as a meteorologist, at NASA and now as a University of Georgia professor, trying to combat weather hype and "social media-rology." If I say that I am worried about a storm with that level of aggressiveness, it looks to be a serious situation. I just told my family to alert people they know about Florence. Here are three reasons why I am so concerned.
It is rapidly intensifying. After a brief stint as a tropical storm, Hurricane Florence is now undergoing rapid intensification. By the time you read this, I would not be surprised if it is back up to a major hurricane classification (category 3 or higher). It is moving into an environment with less wind shear and very warm ocean waters. Meteorologist Jonathan Erdman of weather.com tweeted out,
With an increase in maximum sustained winds of 35 mph over the past 24 hours ending 5am ET, #Florence is now "rapidly intensifying", per the criterion (at least 35 mph in 24 hours), for the second time in its time as a #tropical cyclone.
This was expected and is one of the most worrisome aspects of Florence. It is expected to be a major hurricane (Category 4-5 storm) at landfall. As of right now, the projected landfall area is the southern North Carolinas coast. One thing to notice on the map below is that the forecast periods are entering the more narrow part of the "cone of uncertainty." Weather Channel meteorologist and tropical expert Dr. Matt Sitkowski noted, "the goal posts narrowing." However, tropical meteorologist Ryan Maue of Weathermodels.com posted a set of tweets that should keep residents of South Carolina and North Carolina on alert,
The landfall location of Hurricane #Florence is still uncertain to 100-200 miles. Complicating will be very SLOW movement Thurs-Fri exacerbating extreme rainfall. GFS (American) model (reliable thru 5-days) is a rightward solution over NC......The leftward solution from the most reliable ECMWF model for Hurricane
#Florence is centered just south of SC|NC border. The actual landfall point will matter but large size of storm means coast from Charleston, SC to NC Outer Banks should prepare for hurricane conditions.
It is dangerous to think that impacts are just at the point of landfall. It is important to remember to not just focus on the "point" of landfall. I have been using the hashtag #NotADot on social media to convey that storms like this are not just a "dot" on the map. Yes, the strongest winds, surge and thunderstorms will be near the eyewall of Hurricane Florence, but with a storm of this magnitude, numerous impacts from storm surge, rainfall, potential tornadoes, and falling trees will have broad reach. As I have written in the past, it is important to remember that the worst impacts of a landfalling hurricane are often to the right of the center. However, this does not mean conditions elsewhere around the storm are not bad. We are speaking in relative terms so do not let your guard down.
Rainfall and secondary impacts. With Florence, I expect impacts near the storm and throughout the South Atlantic to Mid-Atlantic regions. To give you an example of the extended concerns, my friend Marlo Wilson is an urban planner in the Washington DC metropolitan area. She messaged me,
We are already having flooding issues over in Alexandria (Virginia). It is going to be a long week.
The graphic below is frankly one of the scariest aspects of Hurricane Florence and has me feeling similar to how I felt with Hurricane Harvey last year. NOAA's Weather Prediction Center is projected 15 to 20 inches of rainfall for some parts of the area. Much of this area already has saturated soil. This means an inland flooding threat, which can often be potentially deadly in the short and long term. It also means the potential for falling trees, a hidden danger often associated with landfalling storms. In Hurricane Sandy, 19% of the 106 deaths were from falling trees. Other reasons, from the analysis at this link, for fatalities in that storm include drowning (37%), falls (11%), carbon monoxide (8%), illness (6%), fire (5%), auto accident (4%), and other (10%). As we have learned with Hurricane Maria or Harvey, fatalities can be immediate or over time with storms of this magnitude. By the way, if the storm stalls as some models project, the aforementioned rainfall totals could be a "low" estimate.
This is sadly shaping up as one of those scenarios that has a pit in my stomach. I felt this way before Harvey and Maria. The National Hurricane Center agrees. There recent public advisory graphic starts with "there is an increasing risk of life-threatening impacts from Florence." This is not fear mongering it is urgency for people to prepare.
