Hurricanes don’t just set up anywhere. We’re not going to see them up near Iceland or Alaska. They form in warm water… and at this time of year, the water in the Atlantic is at it’s hottest.
Believe it or not, what will impact millions in the US, started off as a tiny wave off the coast of Africa… we call this a tropical wave. It’s a disturbance in the atmosphere.Which is the first ingredient for a hurricane…The second ingredient is, like mentioned before, warm water. It has to be at least 80 degrees at least 150 feet deep or deeper. We also need warm, moist air to rise and cause convection… this is the thunderstorm activity. This is why you see tropical disturbances as clusters of storms.
We also need low wind shear which is the change of wind speed with height. For a hurricane to form and stay alive, it doesn’t need erratic wind like a severe thunderstorm does. In fact, wind shear will break up a hurricane. With low wind shear, the cluster of storms will begin to form a hurricane.
The two things on this list that have kept Florence alive are the warm water and the lack of wind shear. The water under Hurricane Florence right now is roughly 84 degrees… and there’s virtually no wind shear… leaving Florence free to grow and intensify.
What determines the path of a hurricane are the steering winds. Our set-up isn’t favorable for the Eastern Seaboard. By the end of the week, two areas of high pressure will potentially stall Florence over land for days. In isolated locations, there could be over 30″ of rain.
Here is the brand new projection. We are still slated for a Thursday night or Friday morning landfall with over 120 mph wind and up to a 12 foot storm surge… and we haven’t even talked about the size… it’s well over 400 miles wide. To put it in perspective, that’s larger than the state of North Dakota.