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Tropics_Dude83 wrote:A look at Hebert's box will show that storms that cross 20 N at 60 W almost invariably strike the U.S. somewhere. That is a key benchmark. Indeed, I believe a storm crossing at 20 N and 60 W or below has never not hit the US. It's the Hebert theory.
Tropics_Dude83 wrote:Stormcenter wrote:I believe that's a pretty safe bet right now.gatorcane wrote:12Z ECMWF recurves it east of CONUS. That track looks just about what I would forecast for this thing.
Stormcenter, what is your basis for this belief? What models have you looked at? When you look at the upper level air flow charts, model data, projected track so far, and the synoptics, please do elucidate me as to why it is a safe bet that this recurves. Also, it appears to me that you take the most conservative approach imaginable to any system that forms at any time regardless of the circumstances.
A look at Hebert's box will show that storms that cross 20 N at 60 W almost invariably strike the U.S. somewhere. That is a key benchmark. Indeed, I believe a storm crossing at 20 N and 60 W or below has never not hit the US. It's the Hebert theory.
Some models do indicate a recurve at this point but some do not. I am just wondering what your objective evidence is to state that this is a clear recurve?
tolakram wrote:A look at Hebert's box will show that storms that cross 20 N at 60 W almost invariably strike the U.S. somewhere.
I think you have it backwards. Storms that have hit always go through the box. Big difference.
http://www.hurricanecity.com/hebertbox.htm
The HebertBox was "discovered" in the late 1970s by Paul Hebert (pictured at left). This former nws & nhc forecaster found many major Hurricanes that hit South Florida had to first pass through these boxes.
artist wrote:wxman57 wrote:Wthrman13 wrote:EDIT: I should point out that I still think that the storm's intensity should be classified with respect to the ground-relative wind speed (since that is what we humans who live on the ground and aren't usually moving very fast relative to it care about), and not the storm relative. I just think that the *presence or absence* of a circulation center should be considered relative to the storm motion.
Perhaps I'm not understanding you correctly, but that's how intensity is classified - ground relative. The storm's forward speed isn't a consideration. The plane measure surface wind speeds and that's the intensity.
What about vorticity being a factor in classification? If you have no vorticity and you have straight line winds coming at you that are as great in strength as a TS or Hurricane,
they would be just as damaging, yet are not given warnings such as a TS,etc.,
I don't know if this is what he is thinking of or not, but my own question.
Wthrman13 wrote: Sorry, I wasn't clear. Of course I realize that the winds are reported as ground-relative. My point was that I think that whether or not the system has a closed circulation should be considered in a storm-relative framework, but that the intensity should still be considered (as it is currently) in a ground-relative framework. Does that make sense?
artist wrote:What about vorticity being a factor in classification? If you have no vorticity and you have straight line winds coming at you that are as great in strength as a TS or Hurricane,
they would be just as damaging, yet are not given warnings such as a TS,etc.,
I don't know if this is what he is thinking of or not, but my own question.
ncweatherwizard wrote:artist wrote:wxman57 wrote:
Perhaps I'm not understanding you correctly, but that's how intensity is classified - ground relative. The storm's forward speed isn't a consideration. The plane measure surface wind speeds and that's the intensity.
What about vorticity being a factor in classification? If you have no vorticity and you have straight line winds coming at you that are as great in strength as a TS or Hurricane,
they would be just as damaging, yet are not given warnings such as a TS,etc.,
I don't know if this is what he is thinking of or not, but my own question.
Vorticity is a function of the change in the wind direction and velocity over a linear area. Basically, you need to have a closed low with strong winds to have maximum vorticity. No closed low...then vorticity is too low. So, as a quantity, vorticity isn't really useful for classification.
P.S. Straight line winds of storm force not associated with a tropical cyclone might be handled with gale warnings or storm warnings, or by other statements by local weather offices. But seldom, do I believe, would such a system go completely ignored.
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