Why Florence is so unusual — and so dangerous

Hurricane Florence is a highly unusual storm, not just because of its intensity and size, but also the journey it's taking toward the Carolina coastline.

The big picture: As this historical track map shows, few other major hurricanes have hit North Carolina — and none has followed as bizarre a path as Florence is expected to take.

The details: The storm is approaching the coast at a 90-degree angle, moving southeast to northwest, which is unusual. And because of a collapse in the atmospheric steering currents, Florence is going to be set adrift. It may slowly spin southwest, parallel to the North Carolina and South Carolina coasts. Eventually, it may visit Georgia, too.

The implications: This track will maximize the storm surge flooding along the North Carolina coast, with the National Hurricane Center projecting a maximum surge of 9 to 13 feet between Cape Fear and Cape Lookout, N.C.

• Parts of South Carolina will first see strong offshore winds as the center of the storm moves to the north.
• Then, perhaps suddenly, the flow will turn onshore, with floodwaters rushing in — trapping anyone who had gone near the coast to see the tide pushed out to sea in the storm's early stages.
• The track will also ensure that this hurricane dumps potentially "catastrophic" amounts of rain on inland areas, with upwards of 3 feet forecast to fall.

The bottom line: Every hurricane presents its own hazards. Few, however, move as strangely as Florence will, while at the same time being as large and powerful. This presents communication challenges in convincing people to leave threatened areas, since they may not be used to dealing with a nearly stalled-out hurricane or one that backslides from northeast to southwest.