Could Hurricane Matthew make landfall in North Carolina or South Carolina? The model trend Monday pushed the storm's projected path further west: closer to the shoreline and less out-to-sea than earlier runs. Just how close to the coast it gets is still anyone's guess.
As of Monday at 11p et, the National Hurricane Center said Hurricane Matthew remained a Category 4 storm with maximum sustained winds of 145 mph. Winds were gusting to near 175 mph as it approached the southern coast of Haiti. (Remember: The storm's impact will be felt in rainfall and not just wind speed.)
The National Hurricane Center's official forecast - often displayed as the popular "cone of uncertainty" - shifted west Monday as numerous independent model runs pushed the storm's projected path closer to Florida. The storm is expected to travel west after crossing the Bahamas on Wednesday and Thursday. That much everyone seems almost certain.
How far west - and how far north - become the next big questions. By Thursday, Hurricane Matthew is expected to remain a Category 3 storm as it approaches Florida's east coast. Despite our best technology, the exact location of this storm cannot be determined four days out. The best we can determined, using technology, science and metrological expertise, is that the storm will be somewhere between Orlando and several hundred miles off the shore of Melbourne. Everyone from scientist to beachgoers alike wishes we had a better idea.
Simply put: Hurricane Matthew is expected to follow Florida's eastern shoreline north towards Georgia, North Carolina and South Carolina. Coincidentally Hurricane Matthew is expected to curve slightly eastward - just like the natural shoreline - as it heads north. The eye of the storm could make landfall anywhere between Miami and the outer banks of North Carolina - - or it could not make official landfall at all. (Landfall is only considered official when the entire eyewall crosses the shoreline.)
Regardless of where or when the storm makes landfall, the results could be devastating. Even if Hurricane Matthew weakened to a Category two storm, that still means it would have sustained winds of greater than 96 mph. The National Weather Service says a Category 2 storm can cause "extensive damage."
"Well-constructed frame homes could sustain major roof and siding damage. Many shallowly rooted trees will be snapped or uprooted and block numerous roads. Near-total power loss is expected with outages that could last from several days to weeks. "
A stronger storm would mean the effects are only worse.
If you believe the official forecast, Hurricane Matthew could be as strong as a Category 3 storm as it approaches Florida. It's expected to weaken to a Category 2 near the coastline of South Carolina or North Carolina.
Extensive damage is expected wherever the storm comes ashore. That area will suffer from damaging winds and localized flooding.
If the storm heads inland, it will weakened over time - lessening the storm damage potential. It could still take a day or two to lose its hurricane characteristics.
If the storm stays close enough to the shore, it could continue to soak up warm ocean water, a key ingredient to retaining its strength longer. The worst case scenario would be if Hurricane Matthew's eye remained over ocean water but close enough that it's outer bands and hurricane force winds reach coastal communities. In that scenario, Hurricane Matthew would be able to retain its strength as long as possible; bringing hurricane damage along the shoreline for possibly hundreds of miles.
So what determines which direction the storm will move in? Steering currents in the atmosphere.
What does that mean? Remember two basic weather facts: High pressure spins clockwise and low pressure spins counter-clockwise. (If that still doesn't make sense, just picture two fans, each spinning in opposite directions.) Picture the United States east of the Mississippi River - - and place a high pressure over New York City and a low pressure over Chicago. Now spin them. The result are northward traveling winds over Ohio. In that region, winds from both pressure systems are jointly pushing north.
Those winds are going to pull Hurricane Matthew northward like a vacuum. So why is Ohio not preparing for a hurricane? Because these systems, the high pressure over New York and the low pressure over Chicago, are slowly pushing east. As they move east, the vacuum's path moves east (while still pulling north). With that, Hurricane Matthew's northward track moves east creating an overall "northeastern" motion.
Seems simple enough, right? Well to be fair, we oversimplified that. The pressure systems are actually over Chicago or New York - - but the point's the same: other factors in the atmosphere will "steer" Hurricane Matthew. The trick is trying to figure out: A: How strong is the steering, and B: Where and when does it happen?
One last analogy: Think about driving on the highway. When you're traveling on a highway alongside two other cars, you're all traveling at similar but different speeds. The atmosphere is like a highway. Now imagine what happens when you want to change lanes. You have to judge the speed of the other cars: anticipating how fast they are moving and where they will be in 5 seconds, 10 seconds, 15 seconds, etc etc. As the driver, you're anticipating the movement of the other cars. You have a better prediction where those other cars will be in 10 seconds rather than a minute from now. Forecasting is the same: The forecaster is the driver trying to figure out where the cars will be. The only difference is the forecaster is trying to predict lane changes 4-5 days from now. Hence the uncertainty.
Everyone from Miami to Cape Hatteras needs to be prepared. It could be another day or two before we can narrow that down - if at all. It'll be even a few more days before we know if the Mid-Atlantic and Northeast also need to be on high alert.
FEEDBACK: The science expressed here are the words of James Brierton, panelist on The Carolina Weather Group. If you wish to respectfully challenge the science - - or weigh in on the forecast - - you can do so in the comment section below. Your comments may be shared on our weekly Web show.