NWSlogoIt’s been quite a while since I posted much of anything weather-related, but now is as good a time as any! Our middle TN National Weather Service office started a Facebook page a while back, and I’ve been loving the hell out of it. Let’s face it, the weather service has always had a bit of an image problem. I’d be willing to bet that when most people think of the NWS, they think of a boring office with a bunch of crotchety old dudes staring at weather maps & computer screens. But in reality, the meteorologists are dedicated and passionate scientists who truly love what they do, and they enjoy talking about weather on a more conversational level, too! That’s exactly what their Facebook page is for, and it’s filled with tons of interesting factoids, tidbits, and more humanized/conversational information about the forecast. The forecasters are on there quite often, and are very good about responding to comments or questions posted. They also just closed submissions on a summer weather photo contest, and you can browse through the album and vote on your favorites. The photo with the most likes as of June 20th will be declared the winner. So check out their Facebook page and Like it. Even if you’re not as big of a weather nerd as I am, I promise you will learn something interesting if you Like the page and follow their posts!

Speaking of weather, I’m looking forward to the very favorable forecast for this year’s Bonnaroo! I will be there taking photos for the Scene as I have for the last 5 years, and thus I’m issuing my yearly Bonnaroo posting disclaimer: *This will be my last post before Bonnaroo, and posting will resume sometime early next week.* Be sure to follow our coverage and photos over at the Nashville Cream! Also, my girlfriend Lauren will be there with me blogging about the new & improved food options on her blog Old Red Boots, so follow her coverage to see the festival through the eyes of a foodie. But back to the weather- while it’d be nearly impossible to beat last year’s utterly euphoric Bonnaroo weather, this year’s forecast looks very good. Thursday is a little iffy as there’s currently a 30% chance of showers & storms, and the Storm Prediction Center has Manchester right on the edge of their ‘Slight Risk’ area for severe weather in their convective outlook. BUT, that activity should be pretty scattered/isolated so the risk is still pretty low. Friday & Saturday are damn-near perfect, however- sunny skies with mid to upper 80s for highs and low to mid 60s for lows- very similar to last year! That temperature span also suggests lower humidity! Sunday will be a little hotter with highs in the upper 80s and Sunday night brings back a 20% chance of showers. Overall, you really couldn’t ask for a better Bonnaroo weather forecast. See you here next week!

*I was going to create diagrams to go along with this post but I just don’t have time today. You’ll have to envision it in your mind’s eye. 

*For more on winter weather in general, check out my reeeeeally old post about winter weather in the south

I will go out on a limb and say that weather-wise, the past 5 days or so have been just about the ugliest, most depressing string of days Nashville and middle TN have seen in quite a while. This is all due to a rather interesting weather scenario across the whole nation. I will attempt to concisely explain the factors involved, and hopefully you’ll also see why these types of storms are so incredibly hard to forecast.

First of all, last weekend (Jan. 11th & 12th) were unseasonably warm and also very rainy, especially Saturday. This was due to a large upper level “cutoff” low pressure system that parked itself right over the southwestern U.S. Because this system was in the upper levels of the atmosphere (about 18,000-30,000 ft) where the main branches of the jet stream exist, it controlled on a broad scale which airmasses were influencing which parts of the nation. The big trough of low pressure stubbornly sat spinning over the western 1/2 of the U.S. for several days, causing the jet stream to dig southward over the west, then shoot northeastward over the midwest and on into the northeast. The southern branch of the jet stream was allowed to surge northward and pump lots of warm moist air from the Gulf and northern Mexico up across the southeast and even into the northeast U.S., bringing the soaking rain and warm temps we had over the weekend. Meanwhile, the northern branch of the jet stream was doing just the opposite, pumping dry frigid air from Canada down over the western and southwestern U.S.

Finally on Sunday Jan. 13th, the huge upper-level low pressure pushed eastward across the nation, and thus the cold arctic air across the west pushed eastward along with it, creating a very sharp cold front at the surface that moved across Nashville that afternoon. You may remember that the temp was a balmy 65F or so Sun. morning, and around 3:30pm it plummeted 15-20 degrees over the course of about 2 hours.

That was part 1 of this crazy chain of events. Now for part 2:

After that initial surge eastward, the upper-level low pressure trough stalled out yet again, leaving that sharp cold front draped roughly along the spine of the southern Appalachians. The cold airmass wedged down at the surface (we all remember from basic science that cold air sinks and warm air rises, right?) but after it stalled out, the southern jet stream was still active. Monday & Tuesday of this week we had a battle between the southern flow of warm Gulf moisture and the stubborn cold airmass that surged eastward Sunday. The warm moist air has been sliding up and over the heavy cold air at the surface and thus we’ve had sleet and freezing rain across the whole middle TN area as the two forces have been at a stalemate. Temps in the mid-levels of the atmosphere have been steadily 6-10 degrees warmer than at the surface. This is an old diagram I made showing a simplified version of how that looks as a cross-section:


Judging exactly where that freezing line will be on the surface is nearly impossible. Thus, forecasts for this type of weather are rarely accurate on a local scale. Last night, the Nashville metro area got lucky in that the freezing line at the surface ended up being just to the west of us- the temp held at about 33 or 34 degrees. This large trough is finally going to push further eastward tomorrow, as yet another piece of Gulf moisture and energy combines with a surface-level low pressure system moving east out of Texas. That will bring the possibility of significant snow and ice to east TN, southern VA, and western NC. Nashville will be spared any precipitation from that system, though, and most of the southeast is forecast to remain firmly in the grips of that arctic airmass for at least another week or so, so keep your heavy coats handy.

First of all allow me to direct you to my girlfriend’s blog, and her post about Hurricane Sandy. In short, her parents live a few blocks from the bay on Long Island, and her childhood home flooded with about 2 feet of water last night. So if you’re the praying type, keep her family in your prayers. If you’re the thinking type, keep them in your thoughts.

I discovered this jaw-dropping, mesmerizing US wind map this morning via Discovery News. This fascinating animation is created by streaming realtime wind speed and direction data from the National Digital Forecast Database and feeding it into software that then generates the animation, graphing out the wind as lines across a map of the U.S. The image at the top of this post is a screenshot of the remnants of Sandy. When you visit it, be sure to click on the map and zoom in on the center of circulation. Get really close- it’s truly mesmerizing. Things like this have always fueled my fascination with weather.

And what would any major event, good or bad, be without some sort of meme coming from it? Please direct your browser toward the hilarity of NYC Mayor Bloomberg’s sign interpreter Lydia Calas. I was watching the weather channel last night when this address was airing live, and her face, coupled with Bloomberg’s pathetic attempt at Spanish, provided us some much-needed comic relief in the midst of all the bad news. Literally within minutes of that airing, there was a joke “Miguel Bloombito” twitter account created. I recommend following…

A combination of technical problems and gusty winds caused Feliz Baumgartner’s record-breaking 23-mile supersonic skydive attempt to be aborted just as the balloon was being inflated today. They had a good window of calm winds to work with, but weren’t able to get the balloon off before a gust of wind came along and blew parts of the partially inflated balloon onto the ground. This is a dicey situation, because the balloon material is so delicate and folded so meticulously that once it’s been unfolded, it cannot be deflated and used again. As far as I can gather from what was said during live webcast, they only have one backup balloon. Since this is the largest balloon of its type ever made or used, it’s REALLY expensive, so they really have to get it right on the next attempt.

The air at the surface, and for roughly the first 1,000 feet off the ground, must be absolutely still for the launch to happen safely. Even a little bit of crosswind can take the balloon off course, dragging the capsule across the ground or smashing it into anything nearby, just as NASA learned first-hand a few years ago during this failed balloon launch in Australia.

What could possibly be more awesome than a TORNADO MADE OF FIRE?!? Not much. This is a spectacular natural phenomenon that occurs in wildfires. It’s the same atmospheric process that causes dust devils- the difference here is that the strong updraft is from the heat of the fire, so it’s much more intense than a normal dust devil. The hot air rises rapidly and the surrounding winds happen to be flowing into the updraft at just the right angles so that the rising column of air gets a twist. From there the law of conservation of angular momentum takes over and the vortex becomes self-sustaining. This one was captured recently in Australia.

Also from the department of TOTALLY AWESOME: Warp Drives (like the ones they used in Star Trek) may actually be much closer to reality than ever thought. NASA physicist Dr. Harold White has recently done some tweaking of the theoretical design of the famous Alcubierre Warp Drive, originally proposed in 1994 by physicist Miguel Alcubierre. The original design, while theoretically possible, was completely impractical because it required more energy than a human mind can comprehend. But with Dr. White’s tweaks, the amount of energy required to run this thing suddenly became more plausible. Essentially the ship would be able to travel much faster than light, without actually traveling faster than light. It does this by literally compressing a region of space-time ahead of it and expanding a region behind it. The ship itself is in a bubble in which it never breaks the speed of light relative to the space-time it’s in. Think of it like surfing a wave of space-time. Granted, the amount of energy require to run the Warp Drive is still roughly equivalent to 1.5 million Hiroshima bombs, but with a little antimatter (about 500 kilograms) that number is not out of reach. The problem is that the idea hasn’t been tested in real life. So Dr. White and his team are currently attempting to actually warp space-time on a microscopic scale in their lab. Take a moment to digest that. Right now, we are attempting to warp space-time in a lab. It doesn’t get much more awesome than that. For more info on how the drive actually works check out this article on Extreme Tech or this article on Discovery News.

Scientific eye candy

July 24, 2012

Two pieces of eye candy for your viewing pleasure today:

Over the past 40 years the US Geological Survey and NASA have teamed up on the LANDSAT mission, a series of imaging satellites that have taken some breathtaking photos of our planet. They recently posted a series of images and got the public to vote on the top 5. Those 5 can be seen in the video below, and the full gallery can be seen on the USGS website.

Secondly, I came across this set of amazing weather photos by photographer Camille Seaman last week. Feast your eyes on these simultaneously gorgeous and terrifying views of storm clouds over the great plains.

(Credit: Camille Seaman) Click through to view the full gallery.

This is some scary shit.

We have some crazy weather headed our way in middle TN (see above graphic!) so A Few Good Shows is super quick today. GO:


Vitalic Noise presents CRAVE at TAVERN in midtown: I will be DJing along with resident DJs Losici and Dali Drama. FREE, 21+ 10pm

Chancellor Warhol, Sam & Tre, Gummy Soul, and Ducko McFli @ 12th & Porter. 9pm $10

Cheap Time, Leather Nightmare, King Karl, Psychic Hotline @ The Other Basement. 8pm $???


Dr. Dog w/ Purling Hiss and PUJOL @ War Memorial Auditorium. 8pm $20

Bass Drum of Death, Cy Barkley & the Way Outsiders, Thelma & The Sleaze @The End. 9pm $10

Scale Model, A Secret Policeman’s Ball, You Blew It!, and Direct Effect @ Springwater. 10pm $5



  • Good design can be defined different ways, but it almost always means organizing and presenting information in an engaging and/or innovative manner. The Weather Wheel created by Bard Edlund is an outstanding example of this, and I dare you to not stare at it for at least 10 minutes. (Hint: the size of the blue dots changes to represent how much rain the given city recieves, the orange circle’s intensity represents temperature, and the speed at which the arrow passes by the city represents how much wind it gets.) Via Kottke.org
  • Cinemagraphs are photographs in which one small part of the image is animated to create continuous motion. This new technique creates surreal and sometimes slightly creepy images the blur the line between video and still photography. The technique is being pioneered by photographers Jamie Beck and Kevin Burg. Fascinating.


It may take many more days before NWS survey teams can finish their assessment of the damage from the April 27th tornado outbreak, but being the weather nerd that I am, I want to go ahead and share a collection of links where you can find preliminary reports on the tracks and intensities of some of the many twisters that touched down. Note that there is at least one EF-5 (the highest intensity with winds over 200 mph) tornado confirmed, and there could be more upgraded to that status as more damaged is inspected. NWS Memphis survey– covering parts of northern Mississippi. NWS Jackson, MS survey. NWS Hunstville, AL survey. NWS Morristown, TN survey. And finally, this graphic from the NWS Birmingham, AL survey. The most complete graphic I’ve seen:

So that’s the bad. Please make a donation to the American Red Cross or any other legitimate organization providing relief for those devastated by this natural disaster. Now for some good things to lighten the mood.

I will call the news of Osama bin Laden’s assassination good, but I certainly will never rejoice the death of any human being. While I am relieved somewhat, and do feel that justice has been done, I’m quite certain that the assassination itself as well as the celebrations will only give the rest of al-Qaeda even more reason to attack the US and its allies.

In even better and much much much lighter news, Moustache May has begun its final year of activity. I participated back in 2008 and am doing so again this year. Due to some very important meetings happening last week at my work, I was unable to start my stache until Friday, so I’m basically starting with a clean slate. Right now I look utterly creepy but hopefully we’ll get past that stage very soon as it fills in.

I came across this absolutely amazing new music video for the Supermen Lovers’ track “Take A Chance” and decided that it was the best thing to end this post with. Enjoy. (Via Too Many Sebastians)

So I’m thinking that some Fridays I’m gonna steal NPR’s “Science Friday” idea and write a post debunking some popular myths. Not gonna happen every Friday, but I’m gonna make a pointed effort to do it somewhat often.

Today we’ll tackle the myth about water spinning in opposite directions down the drain in the northern and southern hemispheres. This is simply not true at all. While large-scale weather systems do indeed follow this pattern due to a phenomenon called the Coriolis Effect, water going down a drain does not. Minute things such as imperfections in the angle at which a basin was installed, inconsistencies in the surface or shape of the basin, and any residual motion in the water itself are what determine the direction the water rotates when drained. Once the water begins to drain, the conservation of angular momentum takes over and any hint of rotational motion in the water, whether clockwise or counter-clockwise, gets amplified as it moves toward the drain, creating a vortex. This is the same law of physics that causes tornadoes and dust devils to behave the way they do. The classic explanation for this concept is the spinning ice skater. As he/she moves her limbs closer to their body the conservation of angular momentum forces their rotational speed to increase. They can then move their limbs further away and they will slow down again. So no, no matter what you’ve heard, water does NOT always drain counter-clockwise in the northern hemisphere and clockwise in the southern. That being said, experiments have been done that show the Coriolis Effect can be seen in draining water IF AND ONLY IF all other forces are completely removed. A large and absolutely perfect cylinder-shaped container with one very small hole exactly in the center was filled with water and allowed to sit untouched for 24 hours to allow any residual motion in the water to die out. The container was perfectly balanced with extreme precision. The plug in the hole was then carefully removed and the water did eventually start rotating counter-clockwise, and continued to do so when the experiment was repeated. BUT clearly this only happens in extremely controlled conditions. In your sink or toilet, a myriad of other forces are orders of magnitude stronger and completely overwhelm the minute effect of the Earth’s rotation. Snopes has a decent debunking of this myth as well.

Tornadoes are different. I was asked about this yesterday, in the wake of the massive tornado outbreak on Wednesday. The Coriolis Effect does influence the direction tornadoes spin, but in a more indirect way. There have, in fact, been clockwise (anticyclonic) tornadoes documented in many cases in the U.S. There have even been a few storms that dropped multiple tornadoes, both cyclonic and anticyclonic, at the SAME TIME. As I said earlier, the Coriolis Effect is what causes large-scale weather systems such as hurricanes, low pressure systems, and high pressure systems to rotate the way they do. Low pressure systems and hurricanes always rotate counter-clockwise in the northern hemisphere and clockwise in the southern. The opposite is true for high pressure (clear weather) systems. The storms which produces tornadoes are always associated with a large-scale low pressure system. The Coriolis Effect determines the rotation of that large-scale system, which in turn has an indirect influence on the structure of the supercell thunderstorms which spawn tornadoes. Tornadoes are far, far more common in the U.S. than anywhere else in the world, and because the warm moist air which “feeds” these storms at the surface is moving in from the southeast, and the cooler, drier air aloft is moving in from the northwest, that setup naturally lends itself to counter-clockwise rotation, hence most but not all tornadoes in the U.S. spin counter-clockwise. This illustration from NOAA’s National Severe Storms Laboratory shows the inner workings of a tornadic storm quite well:

The U.S. Department of Energy’s Office of Science Education has a website called NEWTON, with a forum of sorts called “ask a scientist.” This very question regarding the rotation of tornadoes was asked, and I found this particular response quite helpful:

At least the great majority of tornadoes rotate counterclockwise (as do all low-pressure systems) in the northern hemisphere, and clockwise in the southern hemisphere, for the reason (coriolis force) given by Eric Peterson in response #1. But occasionally, it would seem, northern hemisphere tornadoes do rotate clockwise: S. Flora’s book “Tornadoes of the United States” cites an 1890 article in the American Meteorological Journal. Its author, a J.P. Finley, states that, of 550 American tornadoes he studied, 29 were deemed to have rotated clockwise. I have not been able to find any “modern” study of this question. But I believe it could be true. The region of swirling air that contracts to become the tornado is not itself large enough in extent to have its rotation dictated by the coriolis force; rather, it “inherits” this tendency from the great masses of air whose movement sets the stage for the storms and any associated tornadoes. If the study cited is correct and representative, on occasion the direction of rotation is set by some other factor, perhaps the topography in the area where the tornado forms, for example.

So there you have it. I won’t have as much time every week to write up a post this in-depth, so don’t expect this every Friday, but I’ll do my best.