The latest from the NHC tonight indicates that Karl has begun strengthening. The strong upper level winds and dry air are slowly giving way to more favorable conditions. This means that Karl is likely on its way to becoming a hurricane and probably a strong one.
Fortunately for the East Coast of the U.S. the steering pattern is such that Karl is almost certainly going to be turning away and back out to sea before the weekend. The only area that might see some effects is Bermuda and it’s too soon to know how close Karl will pass to the region. Obviously, interests in Bermuda should be watching the progress of Karl closely over the next few days.
I expect Karl to become a major hurricane which is higher than the official forecast right now. It looks “good” in the global model fields which tells me that it will likely be a very intense hurricane once it makes the turn and away from the U.S. and hopefully Bermuda.
A strong hurricane will do two things: boost the ACE score and send swells towards the coastal areas of parts of the western Atlantic Basin.
The ACE score doesn’t matter much to the lay person but in science, it’s important. It tells us much more about the quality of the storms and hurricanes that form. The higher the wind speed is the more ACE points a single storm or hurricane achieves. I suspect that Karl could add 20 to 30 ACE points when all is said and done. This will help to show that the 2016 hurricane season was more intense than the past few which is precisely what most forecasting entities were predicting. A bunch of weak, short-lived storms is usually a sign of a struggling weather pattern. We’ve already had a cat-3 hurricane occur with Gaston a few weeks back. Assuming Karl attains that status, it will boost the seasonal ACE quite a bit.
As for the surf community? Karl will help to give you a boost as well. I don’t know the specifics on it just yet since we need to wait and see how strong Karl actually gets but I think we’ll see a period of decent swells hitting the shores from Bermuda to Puerto Rico, the Bahamas and eventually the U.S. coastline. While this is inviting to skilled surfers, keep in mind that breaking waves have a lot of energy associated with them and weak swimmers will need to be careful. I’ll talk more about this potential hazard in the coming days as Karl strengthens.
M. Sudduth 11:05 PM ET Sept 19