Monday, August 22, 2016

Advanced Hurricane Links


earth.nullschool.net via Mr. Masters

After this post, I promised to give you more links on hurricanes. Here they are!

One important factor in if a tropical wave will develop into a storm with a closed circulation--and possibly into a dangerous hurricane--is the wind sheer. Here's one map with sheer. Sheer can tear apart a hurricane.

I originally found these U/WI maps through this site, which explains in brief many of the maps you can link in the above UWisc site. The first time I looked at many of them, I thought “what am I looking at?” But the more you look, and the more you go back to explanations, the clearer the maps appear. Those of you who might watch The Weather Channel but have not dug deeply into how hurricanes form will have heard many of these terms: sheer, vorticity, convergence, and divergence. So here is that information which those forecasters look at before summarizing it for the broadcast audience. 

A great map to look at when you want to become a thoughtful amateur forecaster is this one, the depth of the 26C ocean layer. The redder, the deeper. This matters because hurricanes derive energy from hot ocean water, and because as they strengthen, they churn up deeper layers of ocean. If those deeper layers are cold, hurricanes can "turn themselves off" by doing this churning. But if the heat goes deep, they can churn and churn and still get fed. Katrina is a textbook example of one that had a deep 26C isotherm to feed from.

NOAA 22 August 2016


Large-scale weather patterns help determine where hurricanes are likely to develop in any given month. Dr. Masters at Weather Underground revisits the basics of the CCKW (convectively coupled Kelvin wave), MJO (Madden-Julian oscillation), and La Nina/El Nino,  from time to time. Here is a link to his recent post on these. I was particularly happy to see this one because I’d been watching the TIW -- that wavy cold temperature thing off South America in the top image of this post--developing and getting colder, and I had no idea what it was called. I was fairly certain “wavy cold temperature thing” was not the term the pros would use. I’m relieved that now I know: Tropical Instability Wave.

Let's return to the super-cool site earth.nullschool.net. I'm linking you here directly to the No. Atlantic. Watch the winds blow for a moment. (Soothing, isn't it?...except maybe for Floridians.) Now hit "I" on your keyboard. And keep hitting it. What this will do is take you upward through the layers of air, all the way up to the stratosphere. The redder the lines, the faster the wind is blowing.

You’ll notice that if you hunt down more and more links that explain these images and why they're important, you’ll start seeing calculus equations...and I admit, that’s where I stop my researches. If it takes calc to unpeel the next layer of understanding, I’ve learned enough for fiction-writing purposes. This ends up being a good thing, for if I didn’t have some sort of trigger to stop me, I’d do nothing but research and write no novels!

A friend wrote me an email this morning and said, "What, are you psychic? How did you know to post these hurricane links when you did?" No, I'm not psychic! If you watch African weather and do it from year to year, you learn to see them coming a long way off. To someone living in 1888 on the Gulf Coast, your or my ability to forecast hurricanes would seem like magic, wouldn't it?


And yes, there will be a hurricane novel one day to take its place beside my tornado, earthquake, and volcano novels, Storm, Quake, and Erupt. I have many ideas, and a person can only write a handful of books every year.

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