Meteorologists are keeping an eye on the Caribbean for possible storm development

Clouds at sunset near the islands in the Indigenous Guna Yala Comarca, Panama, in the Caribbean Sea, on Aug. 28, 2023.
(Lusi Acosta/AFP via Getty Images)

From WP by Matthew Cappucci

 
If something materializes, it could be the last hurricane of the 2024 season.

Hurricane season is waning, but it’s not over yet.
Meteorologists are monitoring the western Caribbean for possible storm development toward the end of the month.
The next name on the list is “Patty.”

The forecast is far from set in stone.
While there’s a lot of uncertainty, weather models are highlighting the risk of a pocket of spin that could consolidate into a named storm.
It’s too early to speculate on possible strength or track — especially since there isn’t even a storm yet.
But there’s a chance that this system could end up as the final hurricane churning in the Atlantic before the oceans cool and the calendar flips to 2024.

 

The European model highlights the western Caribbean as a region to watch.
(WeatherBell)

What we’re watching

It’s worth noting that, even if a storm forms, the odds of a U.S.impact are slim.

Only four hurricanes in the past century and a half have struck the Lower 48 during November; records date back to near 1850.

The Atlantic has had a busy season.
The ACE, or Accumulated Cyclone Energy — a metric which gauges how much energy storms churn through to produce strong winds — is running 30 percent above average.

It still falls short of the “hyperactive” season projected by experts, yet it didn’t take a hyperactive season to bring serious impact.

The U.S. was hit by five hurricanes — Beryl, Debby, Francine, Helene and Milton.

Four slammed Florida.
It’s been the third-costliest season on record.
Helene, which caused catastrophic inland flooding across the Carolinas in the Appalachians and foothills, became the deadliest hurricane to make landfall on the U.S. mainland since Katrina.
More than 200 were killed.

Weather models are indicating the potential for a CAG, or Central American Gyre, to form.
That’s a broad zone of weak spin over Central America and the Caribbean.
CAGs usually last between two and five days.
Since the spin is diffuse, the gyres themselves aren’t ordinarily a concern.
They simply bring unsettled weather, with clouds, showers and a few thunderstorms.

But when thunderstorm complexes help consolidate that spin, that’s when it could tighten and organize into a named storm.

Weather models have historically struggled to simulate specifics of CAG evolution.
In other words, they have a difficult time pinpointing where and when a lobe of spin will amalgamate.

That said, the Caribbean is still red hot; oceanic heat content, or hurricane fuel, abounds, and the atmosphere is still plenty supportive for a named storm to form.

When a storm might form

If a storm does organize, it will be right around Halloween.
That’s also when a batch of upward-moving air will move over the Atlantic, making it easier for storms to form.
That will come with something called a Convectively-Coupled Kelvin Wave, or a broad overturning circulation that meanders about the global tropics.
The “enhanced” phase is commonly associated with an uptick in tropical activity.

If something does form in the western Caribbean, it’s too early to know whether it would have any chance of entering the Gulf.

This time of year, storms that form in the Caribbean are more likely to drift west; slipping north or northeast would require an absence of cold fronts or disruptive high-altitude winds.

For now, Jamaica, Central America, Cuba and/or Yucatán Mexico should keep tabs on the western Caribbean.

Sticks, stars : How early charts plotted the way we were

From MSN by Sukanya Datta

If you wanted to know when the bison were returning, and when to expect the next hearty steak, you likely checked the latest cave update, in Ancient Lascaux, France.

For nearly a century, ever since the caves were discovered in 1940, anthropologists have struggled to decode the lines, dots and Y-shaped marks carved into the rock here.

Now, in a study published last year, researchers from Durham University and University College London, analysed 800 such sequences and found that they contained 13 types of marks (sets of lines, dots and Y symbols), in patterns consistent with the 13 months in a lunar year.

Suddenly, the message of the marks became clearer: they could represent the mating, migration and birthing patterns of the deer, bison and horses drawn alongside.

No one likely lived in the Lascaux caves; they were more of an art and information centre. 

And so these marks, made 17,000 to 20,000 years ago, could represent the earliest public data charts in the world.

Go further back, as much as 50,000 years ago, and bones have been found across Africa and parts of Eastern Europe, with notches in them that coincide with the phases of the moon. 

These bones would have acted as a sort of early calendar.

These systems, of knots, notches and dashes, would endure for tens of thousands of years.

As recently as the 15th century, in South America — in the vast but largely isolated Inca civilisation that operated without money and without a script — a system of knotted ropes called quipu were used to track transactions and debt; record census data; and track stocks of royal grain reserves.

We have been visualising data in one way or another, then, since more or less the start of collective living.

Charts came before language. Before trade. Before poetry. Because, before tales of love and heroism, we had to tackle the question of how to track: the new sheep added to a flock, the days left before the wildebeest moved south, the number of people in a kingdom or the number of soldiers lost at war.

What would come later was the qualitative and quantitative analysis, says Venkatesh Rajamanickam, a professor of information graphics and data visualisation at the Industrial Design Centre of the Indian Institute of Technology-Bombay (IIT-B).

“How do festivals make us ‘feel’? What is it like to work in the office versus at home? That came later. But it is only when you record that you can analyse,” he says.

What were some of the earliest charts like?

Take a look.

Stick sea charts; Marshall Islands

(Wikimedia)

For thousands of years, the cluster of about 34 islands and atolls that make up the Marshall Islands used a sort of nautical map to visualise the complex math of tides, currents and ocean swells.

Curved bamboo or pandanus root sticks represented ocean swells; straight twigs stood in for currents and waves; seashells were the islands themselves.

“In a coastal environment, these sticks and shells were a practical choice,” says Rajamanickam. “They could weather rain and seawater, and were easy to carry. The Marshallese would study the charts on land before venturing into the sea.”

Star maps; China

A representation of the Suzhou star chart from the Song Dynasty, China. (Wikimedia)

In Ancient China, star maps were painted and etched onto the ceilings of tombs, onto stone tablets and onto scrolls, in what were likely attempts to help the dead navigate the heavens.

These charts were also used to create calendars, predict celestial events such as eclipses and make astrological divinations. 

They helped in early attempts at astronomy.

A particularly interesting such map is a tomb painting dating to 1116 CE. It shows the Great Bear or Ursa Major constellation, depicted as seven red dots connected by lines.

At a distance are nine small discs of varying sizes, believed to indicate the sun, moon and five naked-eye and two invisible planets.

Links :

• GeoGarage blog : The secrets of the Wave Pilots / Hōkūle'a: The dangers of sailing around the world / How sticks and shell charts became a sophisticated system ...  / The greatest maps in history, collected in one fantastic book
  

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Thomas Ruyant