Submit a link Features Reviews Podcasts Video Forums More ▾

Rare "snonado" captured on Lake Superior

According to the Weather Channel, there are only six known photographs of winter waterspouts in existence. Then, last week, Jordan Detters captured a good minute and a half of video, showing winter waterspouts dancing along the waves of Lake Superior near Knife River, Minnesota.

While water spouts are relatively common in warm months, producing one in the winter requires a pretty specific set of meteorological circumstances, writes Minnesota Public Radio's chief meteorologist Paul Huttner. Thus, the dearth of images. In fact, for one to form at all you need a temperature difference between the water and the air of 19 degrees C.

Read the rest

Word of the day: Haboob

Fun to say. Less than fun to experience. Haboobs are dust storms known for their distinctive wall-like appearance. Think the ice wall from Game of Thrones, but made of dirt, and heading right for you at speeds as high as 60 miles per hour.

The word is Arabic, but haboobs can happen all over the world. In fact, one of them hit eastern Washington state last weekend.

Image: Hey, Haboob... You suck., a Creative Commons Attribution No-Derivative-Works (2.0) image from nickbastian's photostream

Beautiful video of a supercell thunderstorm

It took photographer Mike Oblinski four years of traveling to Plains States to capture this fantastic time lapse footage of a supercell thunderstorm near Booker, Texas.

Supercells are a type of thunderstorm, specifically the type that contains a rotating mass of rising air called a mesocyclone. These are the storms that form tornadoes (although Oblinski says this one did not). Watching the video, I just kept thinking about the title of that Flannery O'Connor story: Everything that rises must converge.

The timelapse was shot on a Canon 5D Mark II with a Rokinon 14mm 2.8 lens. It's broken up into four parts. One thing to note early on in the first part is the way the rain is coming down on the right and actually being sucked back into the rotation. Amazing.

A few miles south is where part two picks up. And I didn't realize how fast it was moving south, so part three is just me panning the camera to the left. During that third part you can see dust along the cornfield being pulled into the storm as well...part of the strong inflow. The final part is when the storm had started dying out and we shot lightning as it passed over us.

Video Link

The Meteorology of Little House on the Prairie

If you read The Long Winter, Laura Ingalls Wilder's novel about narrowly avoiding starving to death during a ferocious winter on the South Dakota prairie, then you'll remember how the trains stopped running because of the snowfall. In fact, that's a big part of why Laura and her family were so hungry — their harvest had been lean and the train carried the supplies they were dependent upon.

I'd never had a real clear idea of what "the train can't get through" really meant, not being totally clear on how to adjust snow-clearing expectations from today back to the 1880s. But, as it turns out, when the train company said they couldn't get the trains through, they were not messing around. The above image, from the Minnesota Historical Society, shows you the kind of snowfall we're talking about. That picture was taken in southern Minnesota, during the same winter — 1880-1881 — that nearly killed Laura Ingalls Wilder. Please note the dude standing on top of the train. He really gives you the overwhelming sense of scale.

Last year, Barbara Mayes-Boustead, a meteorologist with the National Weather Service, actually looked at the records we have for temperatures and snowfall from that winter, most of which come from military forts and major cities miles away from the small town of DeSmet, where Laura Ingalls Wilder lived. Mayes-Boustead found that the story in the book matches up reasonably accurately with actual data.

She's got a series of short audio commentaries on the winter of 1880-1881 and how it plays out in the Little House books, including a really fascinating one about the climate patterns and probably created those many months of blizzards. By looking at weather patterns from the time and at the climate systems we associate with weather like that today, Mayes-Boustead says that we can probably blame the Long Winter on a combination of a strong negative North Atlantic Oscillation — a pattern in the jet stream that sucks icy air from the Arctic down into the Midwestern US — and an El Nino year — which tends to make that same region of the county wetter than usual.

Listen to all of Barbara Mayes-Boustead's recorded presentations

The wild rivers above California

Atmospheric rivers are meteorological phenomenon that we humans only discovered in 1998 and which supply about 30-to-50 percent of California's annual precipitation. In the NOAA satellite image above, the atmospheric river is visible as a thin yellow arm, reaching out from the Pacific to touch California. Or, more evocatively, reaching out to slap California silly with a gushing downpour.

An atmospheric river is a narrow conveyor belt of vapor about a mile high that extends thousands of miles from out at sea and can carry as much water as 15 Mississippi Rivers. It strikes as a series of storms that arrive for days or weeks on end. Each storm can dump inches of rain or feet of snow.

The real scare, however, is that truly massive atmospheric rivers that cause catastrophic flooding seem to hit the state about once every 200 years, according to evidence recently pieced together (and described in the article noted above). The last megaflood was in 1861; rains arrived for 43 days, obliterating Sacramento and bankrupting the state.

As you might guess, climate change is also involved. Evidence suggests that warming global temperatures could increase the frequency of atmospheric rivers. That, combined with the 200-year event expected soon and the fact we're learning so much much more about these storms, means that you should expect to hear the phrase "atmospheric river" more often.

Scientific American has two interesting stories on the phenomenon right now. The first, which I quote from above, is a blog post by Mark Fischetti. The second is a much longer feature story that gets into the forces that cause these storms and the climate change connection.

What makes wind?

It can be a nice breeze, or a destructive storm, but either way wind is just moving air. And moving air is just moving molecules.

In an explainer for kids that's actually pretty helpful for grown-ups, too, Matt Shipman reminds us that the air around us isn't totally weightless. It weighs something, because molecules all weigh something:

They don't weigh very much (you couldn't put one on your bathroom scale), but their weight adds up, because there are a LOT of molecules in the air that makes up our atmosphere. All of that air is actually pretty heavy, so the air at the bottom of the atmosphere (like the air just above the ground) is getting pressed on by all of the air above it. That pressure pushes the air molecules at the bottom of the atmosphere a lot closer together than the air molecules at the top of the atmosphere.

And, because the air at the top of the atmosphere is pushing down on the air at the bottom of the atmosphere, the air molecules at the bottom REALLY want to spread out. So if there is an area where the air molecules are under high pressure (with a lot of weight pushing down), the air will spread out into areas that are under lower pressure (with less weight pushing down).

Read the full story at Carolina Parent

Image: wind, katarinahissen, a Creative Commons Attribution Share-Alike (2.0) image from mararie's photostream

Radar imaging of Hurricane Sandy reveals the power in its core

The images above — prepared by NASA hurricane researcher Owen Kelly — were taken on Sunday, before Hurricane Sandy made landfall on the United States' Northeast coast. They're made from radar data collected by the Tropical Rainfall Measuring Mission (TRMM) satellite, and they show a feature of this storm that helps explain why it's caused much more destruction than you might expect from a Category 1 hurricane.

In the right-hand image, showing a close-up of the storm's eye, you can see a feature labeled "eyewall". Those are vertical cloud walls that surround the eye, and they're the spot with the strongest winds in the whole storm.

Placed in context, the TRMM-observed properties of Hurricane Sandy’s eyewall are evidence of remarkable vigor. Most hurricanes only have well-formed and compact eyewalls at category 3 strength or higher. Sandy was not only barely a category 1 hurricane, but Sandy was also experiencing strong wind shear, Sandy was going over ocean typically too cold to form hurricanes, and Sandy had been limping along as a marginal hurricane for several days.

That eyewall, says NASA and New Scientist, is the result of Sandy's Frankenstorm nature. Despite all the factors that should have made this storm weak, it represented the merging of several storm systems. Because of that, Sandy was stronger than a Category 1 storm normally is.

Read the full story on this at NASA and New Scientist

Via Michael Marshall

When geology meets meteorology

Dust from the Sahara desert could leave Sweden soaked in red "blood rain" this weekend. (Via Kevin Zelnio)

Goodbye "Snowmageddon XIX", hello "Gandolf"

The Weather Channel has decided to begin naming winter storms the way we already name tropical storms. But while tropical storm nomenclature is an organized and official process, carried out by a branch of the United Nations, winter storms will be named apparently at the whim of The Weather Channel. The result: Not only can we move past calling every blizzard either Snowmageddon or Snowpocalypse, but we also get to hear news anchors discuss the damage caused by Winter Storm Gandolf. (Please note that this is Gandolf, not Gandalf. The former is a character in The Well at the World's End, an 1896 fantasy novel. The latter is probably tied up in intellectual property restrictions.) Maggie

Prospecting for wind

Before the Lights Go Out
is Maggie’s new book about how our current energy systems work, and how we’ll have to change them in the future.

Read the rest

Time-lapse video of lab-grown snowflakes

Back in December, researchers at Caltech posted a research paper to arXiv that attempts to explain why the shape and structure of snowflakes change significantly depending on relatively small shifts in temperature.

In order to study this, they had to grow snowflakes in laboratory conditions. It was not an easy thing to figure out how to do. On his Snowcrystals page, physicist Kenneth G. Libbrecht show you how it's done.

There are many ways to grow snowflakes, but my favorite starts with something called a vapor diffusion chamber. This is essentially nothing more than an insulated box that is kept cold on the bottom (say -40C) and hot on the top (say +40C). A source of water is placed at the top, and water vapor diffuses down through the box, producing supersaturated air. The cold, supersatured air at the center of the chamber is ideal for growing ice crystals.

While working with this diffusion chamber, we rediscovered a wonderful technique for growing synthetic snow crystals that was first published in 1963 by meteorologist Basil Mason and collaborators [1]. One starts by putting a wire into the diffusion chamber from below, so that small ice crystals begin growing on the wire's tip. Then apply a high voltage to the wire, say +2000 volts, and voila -- slender ice needles begin growing from the wire.

Video Link

Lubbock, Texas dust storm similar to Dust Bowl-era events

Whenever you see a dust cloud, there's an almost instinctual reflex to start talking about The Grapes of Wrath. It's natural. But it's often misplaced. Your average cloud of dirt is less apocalyptic than the dust storms that ripped across the Central Plains of the United States during the 1930s. They can also have different underlying causes.

But the dust storm that hit Lubbock, Texas, earlier this week can legitimately be called Dust Bowl-esque, according to the National Weather Service. That's the Lubbock storm on the right in the image above ... and a 1930s dust storm on the left.

A storm system passing out of the Rockies into the southern plains sent a cold front racing south through the Texas Panhandle and across the South Plains and Rolling Plains late Monday afternoon and evening. Ahead of the front, temperatures were unusually warm, with highs mainly in the upper 80s to lower 90s, and even 96 degrees out at Aspermont. Temperatures dropped quickly behind the front. The high at Amarillo was only 72 degrees. As the front moved south, more and more dirt was lofted by the front until a well-defined "Haboob" (an Arabic term for intense dust storm) developed along the front.

The intense dust storm drew some comparisons to the Dust Bowl years of the 1930s. The likeness may not be so farfetched as the region is mired in an exceptional drought, as was the case back in the Dirty Thirties. In fact, 2011 is on pace to shatter the record for the driest year in recorded history for both Lubbock and Childress. In addition, like many of the iconic pictures of rolling dust storms in the 30s, the haboob on the 17th was also caused by a strong cold front.

You are now free to correct anyone who accuses of hyperbole when describing the Lubbock dust storm.

Via Christine Gorman