Re: [Phys-L] interacting hurricanes

[bnorwood111@gmail.com]

Hi Phys-L Hurricaners

Might a pair of Dremel, variable-speed Mototools, driving 1/4 inch diameter brushes, work in a ripple tank to model colliding hurricanes?

Bill Norwood
Retired from Physics Dept, U of MD at College Park

Sent from my iPhone

> On Aug 22, 2020, at 8:43 PM, Brian Whatcott <betwys1@sbcglobal.net> wrote:
>
> Uh-oh - someone forecasting weather effects who does not have access to the  several hi-$ systems in Europe and the US modeling short-term weather. With the results destined to show up before we all forget too  <g>
> Brian W
>    On Saturday, August 22, 2020, 06:59:15 PM CDT, John Denker via Phys-l <phys-l@mail.phys-l.org> wrote:  
>
> Hi Folks --
>
> I suppose you've seen the forecast that calls for two hurricanes
> (Laura and Marco) in the Gulf of Mexico at the same time.
>
> Based on what I know about vortexes,
>   https://www.feynmanlectures.caltech.edu/II_40.html
>
> I'm starting to suspect all the forecasts are off. I expect
> each hurricane to get caught up in the velocity-field of the other,
> to a much greater extent than what I've seen in any forecast tracks
> so far.  They should tend to orbit around each other.  Meteorologists
> even have a name for this:
>   https://www.usatoday.com/story/news/nation/2020/08/22/tropical-storms-laura-marco-collide-fujiwhara-effect-explained/3410073001/
>
> I find it hard to imagine that anybody could build a forecast model
> that didn't take this into account, automatically, as a natural
> consequence of modeling the physics ... so probably there's something
> fundamental that I'm not understanding.
>
> Order-of-magnitude check:  For a category-1 hurricane, tropical-storm
> winds (39 mph or greater) typically extend 125 miles from the center.
> The speed scales like 1/r, so I would expect 20 mph or (!) greater
> 250 miles from the center.  That's nontrivial compared to the current
> forecast of forward motion (13 mph toward the northwest).
>
> They might not get close to each other, but if they do, it's gonna be
> innnnteresting.
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