(Roughly) Daily

Posts Tagged ‘meteorology

“We’re not in Kansas anymore”*…

Randy Shoemaker embraces his son Conner, 6, after surviving a deadly tornado that killed at least seven people in Chatsworth, Ga., in April

In March 2019, a violent tornado plowed through eastern Alabama, flattening houses and demolishing mobile homes. Twenty-three people were killed including four children, ages 10, 9, 8 and 6.

Exactly one year later, on March 3, 2020, a tornado gusting at 170 mph ripped through central Tennessee, killing 19 people. Four of the victims were children between the ages of 2 and 7.

The twisters spiraled along the ground for only minutes, but they are the two deadliest natural disasters in the United States since the start of 2019. They received fleeting national attention.

The mortal storms illustrate an alarming trend that is overlooked amid concern about hurricanes, wildfires and floods: Tornadoes are increasingly occurring in the Southeast, where they are twice as deadly as tornadoes elsewhere in the United States…

A shift of tornado activity from the Great Plains to the Southeast has brought heightened danger by concentrating twisters in a far more perilous landscape — one covered by forest that conceals tornadoes and is filled with mobile homes that are easily demolished…

Tornado Alley has moved from the Great Plains to the Southeast: “Migrating tornadoes are the nation’s deadliest disasters.”

* Dorothy, The Wizard of Oz


As we contemplate the consequences of climate change, we might recall that it was on this date in 1896 that the Cedar Keys Hurricane finally disapated. Having passed as a tropical storm through the Lesser Antilles on September 22 (the earliest known activity), it grew to hurricane strength over Cuba, then passed on to Florida, over the Keys. Before being absorbed into another low pressure area, it made its way to southern New York State, where it finally gave out.

Its winds stayed high throughout its journey, and it was prodigiously wet: it left 19.96 inches at Glennville, Georgia, caused flash floods in the Shenandoah Valley, left the White House grounds in a wreck, and downed trees at the Gettysburg Battlefield. It is estimated to have caused 130 deaths and $1.5 million in damage (in 1896 dollars, which would be about $46 million today).

Storm victims pose with damaged houses on Cedar Key


Written by LW

September 30, 2020 at 1:01 am

“You have to be in the right place at the right time. Or the wrong place at the wrong time, depending on your perspective”*…




Hailstones are balls (or spikes, or flattish pancakes) of frozen precipitation that measure at least 0.2 inches across, according to the National Oceanic and Atmospheric Administration’s Severe Storms Laboratory. Several other types of smaller frozen precipitation are known as “ice pellets,” reports the National Snow & Ice Data Center, and may take the form of graupel (soft balls of water droplets clinging to a snow crystal and looking like Styrofoam) or sleet (essentially icy raindrops). In the sky, either of these can serve as an “embryo,” the little nucleus around which a hailstone can grow. The longer a fledgling hailstone stays lofted in a thunderstorm’s fierce updraft, the bigger it gets. Beyond that minimum 0.2-inch threshold, there are a few finer distinctions between hailstones, thrown around by researchers and sometimes forecasters at the National Weather Service. “Severe” hail has a maximum dimension of one inch or more, “significantly severe” stones are larger than two inches, and “giant” hail is bigger than four inches.

“Giant” sounds pretty big, but this crop of researchers didn’t think it seemed quite big enough. A hailstone of more than four inches is “certainly very large,” says Matthew Kumjian, a meteorologist at Penn State University and lead author of the paper. But, he adds, while stones of that size are rare, “they are not exceptional.” Hailstones bigger than four inches are reported 30 to 40 times a year in the United States alone, he says. Stones larger than six inches, though, are few and far between. Kumjian’s co-author, graduate student Rachel Gutierrez, combed through reports and found about 10 confirmed instances in the last 10 or 15 years, mostly in the U.S. (There were a handful of unconfirmed reports in Australia, Africa, and Asia, but photos or official measurements were missing.)

The researchers suspect that there are probably more of these spectacularly sized hailstones dropping down across the country, but they’re likely going unnoticed. When measuring hail, time is of the essence: Hailstones vanish fairly quickly, especially in hot or humid conditions, or if they shatter on impact; even large ones with cushioned falls might be overlooked. The most severe hailstorms in the United States are in the Great Plains, Kumjian says, where people are spread fairly far apart…

They’re huge; they’re rare; and they’re melting all the time: “The Slippery Problem of Measuring Enormous Hunks of Hail.”

* Matthew Kumjian, a meteorologist at Penn State University, on measuring hailstones


As we check the weather, we might recall that it was on this date in 1883 that the volcano on the Indonesian island of Krakatoa began to release huge plumes of steam and ash. Roughly three months later, on August 27, it erupted in earnest– with a sound so loud that it circled the earth four times.  (As big as the explosion was, it was not the biggest in history: experts suggest that Santorini’s eruption in 1628 BCE was three times as powerful.)

300px-Krakatoa_eruption_lithograph source


Written by LW

May 20, 2020 at 1:01 am

“Simplicity is the ultimate sophistication”*…



Selectric I Typewriter, 1961 aluminum, steel, molded plastic.


The Cooper Hewitt, Smithsonian Design Museum’s diverse collection, spanning thirty centuries of historic and contemporary design, includes the world’s coolest office, a large snail shell, snakes, a dragon and four bearded men, a cone propped up on a bench, a pair of colorful hands, a mysterious tv and a perpetual calendar.

The selection above is from the Digital Collection, which one can browse in full here… or just dive into the collection in full.

* Frequently attributed to Leonardo da Vinci, but likely first used by Clare Boothe Luce in her 1931 novel Stuffed Shirts


As we let form follow function, we might recall that it was on this date in 1875 that the first “weather map” ran in a newspaper (The Times, London).  It was the creation of polymath Sir Francis Galton, an explorer and anthropologist who was also a statistician and meteorologist.

The map was not a forecast, but a representation of the conditions of the previous day. This is known as a synoptic chart, meaning that it shows a summary of the weather situation. Readers could make their own predictions based on the information it provided.

Galton’s chart differs from the modern version only in minor details. It shows the temperature for each region, with dotted lines marking the boundaries of areas of different barometric pressures. It also describes the state of the sky in each land region, with terms such as “dull” or “cloud,” or the sea condition – “smooth” or “slight swell”… [source]

weather source




Written by LW

April 1, 2020 at 1:01 am

“Most of us spend too much time on the last twenty-four hours and too little on the last six thousand years”*…


Willard infographic

“Willard’s Chronographer of American History” (1845) by Emma Willard — David Rumsey Map Collection


In the 21st-century, infographics are everywhere. In the classroom, in the newspaper, in government reports, these concise visual representations of complicated information have changed the way we imagine our world.  Susan Schulten explores the pioneering work of Emma Willard (1787–1870), a leading feminist educator whose innovative maps of time laid the groundwork for the charts and graphics of today…

Willard’s remarkable story– and more glorious examples of her work– at “Emma Willard’s Maps of Time.”

* Will Durant


As we picture it all, we might recall that it was on this date in 1870 that Congress authorized the formation of the U.S. weather service (later named the Weather Bureau; later still, the National Weather Service), and placed it under the direction of the Army Signal Corps.  Cleveland Abbe,  who had started the first private weather reporting and warning service (in Cincinnati) and had been issuing weather reports or bulletins since September, 1869, was the only person in the country at the time who was experienced in drawing weather maps from telegraphic reports and forecasting from them.  He became the weather service’s inaugural chief scientist– effectively its founding head– in January, 1871.  The first U.S. meteorologist, he is known as the “father of the U.S. Weather Bureau,” where he systemized observation, trained personnel, and established scientific methods.  He went on to become one of the 33 founders of the National Geographic Society.

Cleveland Abbe



“It’s tough to make predictions, especially about the future”*…




As astrophysicist Mario Livo recounts in Brilliant Blunders, in April 1900, the eminent physicist Lord Kelvin proclaimed that our understanding of the cosmos was complete except for two “clouds”—minor details still to be worked out. Those clouds had to do with radiation emissions and with the speed of light… and they pointed the way to two major revolutions in physics: quantum mechanics and the theory of relativity.  Prediction is hard; ironically, it’s especially hard for experts attempting foresight in their own fields…

The idea for the most important study ever conducted of expert predictions was sparked in 1984, at a meeting of a National Research Council committee on American-Soviet relations. The psychologist and political scientist Philip E. Tetlock was 30 years old, by far the most junior committee member. He listened intently as other members discussed Soviet intentions and American policies. Renowned experts delivered authoritative predictions, and Tetlock was struck by how many perfectly contradicted one another and were impervious to counterarguments.

Tetlock decided to put expert political and economic predictions to the test. With the Cold War in full swing, he collected forecasts from 284 highly educated experts who averaged more than 12 years of experience in their specialties. To ensure that the predictions were concrete, experts had to give specific probabilities of future events. Tetlock had to collect enough predictions that he could separate lucky and unlucky streaks from true skill. The project lasted 20 years, and comprised 82,361 probability estimates about the future.

The result: The experts were, by and large, horrific forecasters. Their areas of specialty, years of experience, and (for some) access to classified information made no difference. They were bad at short-term forecasting and bad at long-term forecasting. They were bad at forecasting in every domain. When experts declared that future events were impossible or nearly impossible, 15 percent of them occurred nonetheless. When they declared events to be a sure thing, more than one-quarter of them failed to transpire. As the Danish proverb warns, “It is difficult to make predictions, especially about the future.”…

One subgroup of scholars, however, did manage to see more of what was coming… they were not vested in a single discipline. They took from each argument and integrated apparently contradictory worldviews…

The integrators outperformed their colleagues in pretty much every way, but especially trounced them on long-term predictions. Eventually, Tetlock bestowed nicknames (borrowed from the philosopher Isaiah Berlin) on the experts he’d observed: The highly specialized hedgehogs knew “one big thing,” while the integrator foxes knew “many little things.”…

Credentialed authorities are comically bad at predicting the future. But reliable– at least more reliable– forecasting is possible: “The Peculiar Blindness of Experts.”

See Tetlock discuss his findings at a Long Now Seminar.  Read Berlin’s riff on Archilochus, “The Hedgehog and the Fox,” here.

* Yogi Berra


As we ponder prediction, we might send complicating birthday greetings to Edward Norton Lorenz; he was born on this date in 1917.  A mathematician who turned to meteorology during World War II, he established the theoretical basis of weather and climate predictability, as well as the basis for computer-aided atmospheric physics and meteorology.

But he is probably better remembered as the founder of modern chaos theory, a branch of mathematics focusing on the behavior of dynamical systems that are highly sensitive to initial conditions… and thus practically impossible to predict in detail with certainty.

In 1961, Lorenz was using a simple digital computer, a Royal McBee LGP-30, to simulate weather patterns by modeling 12 variables, representing things like temperature and wind speed. He wanted to see a sequence of data again, and to save time he started the simulation in the middle of its course. He did this by entering a printout of the data that corresponded to conditions in the middle of the original simulation. To his surprise, the weather that the machine began to predict was completely different from the previous calculation. The culprit: a rounded decimal number on the computer printout. The computer worked with 6-digit precision, but the printout rounded variables off to a 3-digit number, so a value like 0.506127 printed as 0.506. This difference is tiny, and the consensus at the time would have been that it should have no practical effect. However, Lorenz discovered that small changes in initial conditions produced large changes in long-term outcome. His work on the topic culminated in the publication of his 1963 paper “Deterministic Nonperiodic Flow” in Journal of the Atmospheric Sciences, and with it, the foundation of chaos theory…

His description of the butterfly effect, the idea that small changes can have large consequences, followed in 1969.

lorenz source


%d bloggers like this: