Multiple models of the effects of a warming climate on hurricanes have predicted storms that are not just larger, but slower moving. As with Hurricane Harvey in 2017, Florence seems to be bearing out that prediction. As a consequence, these storms remain active in a small region for a long period, resulting in torrential rains, increased flooding, and potential mudslides.
At the moment, the storm looks as if it could push directly into the Pamlico Sound area, generating disastrous surge levels for cities and towns located well away from the coast.
Looking more closely at areas just off the Sound it’s apparent that towns like New Bern and Greenville are facing serious danger. The red areas in these images represent flooding greater than 9’ above ground level. All the shaded areas show that roads will be impassible and homes and businesses flooded across a large area. All of this is a big reminder that the best place to be is Not There. If you need a more detailed view of the inundation predictions, click here.
This is still just a prediction, but as bad as this image looks it’s less than half the story. Because this is just the surge. It does not include flooding from the intense rain expected as Florence moves over the area. Florence could still turn, driving more water up the Albemarle Sound to the north, or at the Wilmington area to the south. But in any case, the Outer Banks and the Pamlico area look to be in for a heavy pounding. Do Not Try To Ride This One Out. This is not just another East Coast storm.
The latest rainfall predictions call for the same area that is hit most savagely by the winds and surge to also be the center of 20” or more of precipitation.
Note that neither the rainfall nor the windspeed predictions have yet been updated to reflect the scenario under discussion on Wednesday morning that could see Florence’s forward progress halted on Friday and the storm either drift slowly southwest or turn completely south along the coast. Should Florence hug the cost, it could potentially continue to draw energy over an extended period, increasing the potential for more surge, wind, and flooding.
As Ars Technica reports, the forecast on Florence has “gone from bad to worse.”
It really is impossible to say where a "bullseye" will occur in terms of rainfall due to the uncertain storm motion, but coastal areas of the Carolinas likely face the greatest threat. Forecast modeling indicates broad areas may receive 10 to 30 inches of rain, with higher localized totals of 30 to 40 inches over the next week or so.
As dire as the rainfall image above may appear, it’s very likely that it’s an underestimate of what’s coming based on the latest information. Do not take chances with this. Do not expect to be okay “because we were fine last time.” Just leave.