I agree with Yewknee- Day. Made.

I agree with Yewknee- Day. Made.

Ok, now that you’ve been properly entertained by that photograph thanks to Yewknee’d, let’s get on with the good stuff.

Rumors have been spreading like wildfire for months that Apple will be releasing a new tablet device that could revolutionize mobile entertainment. According to this article on Financial Times, (via Kottke) it’s looking like the device will be released this fall, just in time for the Holiday shopping season. If this thing is as good as it sounds, Apple’s REALLY gonna cash in, and if it flops, their public image will be severely tarnished. But I have no doubt they will succeed with this in the same way they succeeded with the iPhone, save for that minor pricing debacle when it first came out. It seems to me that this thing will be an iPod Touch on steroids. Having just bought a new Macbook Pro, I sure as hell won’t be able to cough up the cash for one of these, but I can’t wait to go play with them at the Apple Store!

Space Shuttle Endeavour undocked from the ISS today after successfully installing the newest Japanese component. The shuttle is scheduled to land at the Kennedy Space Center this Friday at 10:47am EDT, weather permitting. (Via Space.com)

There’s been a lot of speculation about the possibility of life on Mars and more recently, life on Saturn’s moons Titan and Enceladus, and Jupiter’s moon Europa. But not since the 50’s have we ever thought that life could exist on Venus. People used to think Venus might have a climate somewhat like a tropical paradise, but that notion came to a screeching halt when scientists discovered that its surface is basically a good approximation of hell. Its surface temperature is over 860 degrees Fahrenheit, the atmospheric pressure is 92 times greater than Earth’s and made of mostly CO2 and laden with sulfuric acid clouds. But recent research has shown that it’s possible that microbial life could thrive in conditions found in the upper atmosphere of Venus. We continually discover life in places on Earth once thought to be utterly inhospitable, so it’s no longer such a stretch to imagine life surviving in such extreme environments as are found in Venus’ upper atmosphere. Scientists think that Venus was once much more Earth-like, and even had oceans. But what’s commonly referred to as a “runaway greenhouse effect” took over and caused the planet to heat up enough to boil away all water on the surface and create the hellish environment we see today. It’s possible that primitive life may have emerged during the planet’s more hospitable past and had time to evolve, adapt, and escape to the planet’s outer atmosphere where it could survive. (Via Daily Galaxy)

Quick update on the near-Pavement-reunion last weekend: The Scene’s blog got even more national press- including Rolling Stone’s blog and Stereogum. Wooo!

Apparently Tropicana Pure Premium Orange Juice, which is owned by PepsiCo, is reverting to its old carton design. The new design unveiled in January resulted in a lot of emails and letters from consumers who didn’t like the new look. Thus, they decided to appease the disgruntled customers and go back to the classic design. I personally liked the new typeface, but I agree that the straw-in-orange image was classic, and central to their message of pure, unaltered juice, straight from the fruit. I say return the straw-orange image, but keep the new typeface… but that’s just me. Via NY Times.

Credit: Rod Aydelotte/Waco Tribune-Herald

Credit: Rod Aydelotte/Waco Tribune-Herald

The first fragments of the Texas fireball from last sunday have been found, proving to the doubters that it indeed was NOT fragments from the satellite collision. They’re hoping to find much larger fragments in the near future. The Arizona group of meteorite hunters estimate that the original meteor was about the size of a refrigerator or even a little bigger. It would have to be that big to be seen in the daytime and cause a sonic boom. Very cool!

The whole field of environmental science and protection took a major blow early this morning when NASA’s new Orbiting Carbon Observatory crashed into the ocean near Antarctica. A shield intended to protect the 972-pound spacecraft failed to disengage about 3 minutes after lauch, and caused the overall assembly to fall short of orbit and crash back to earth. This satellite was intended to study CO2 levels in the atmosphere and better understand its natrual cycles. Sad, indeed.

Winter weather in the south

December 12, 2008

So I’m sure if you’re from the Nashville area you know how ridiculous people around here can be when even a flurry of snow is mentioned in the weather forecast. If you’ve been paying much attention in the past couple of days, you’ll also know that Mississippi (yes, Mississippi!) got a pretty significant snowfall recently…. even 2-4 inches in some areas across central Miss. That’s absolutely unheard of in the south! If you know me, you’ll also know that I’m a weather nerd- I follow the forecasts and even chase storms when the opportunity arises. Often times I hear people talking about how crazy winter weather is in Nashville, and how we never get any snow (some people like it that way, some don’t), and how the forecast is never right. I thought this would be a good time to do a little post explaining a few things about why winter weather can be such a roller-coaster sometimes, and why it’s so difficult to accurately forecast winter weather in the south.

Basically, the location of TN, especially its latitude, causes it to always be influenced by air masses created in other areas. During the winter, the jet stream is essentially split into two branches, a southern branch that resides over northern Mexico and the Gulf, and the northern branch that resides over the northern US states and Canada. (Sometimes it can actually split into 3 branches, but for simplicity’s sake let’s leave it at 2.) TN’s latitude causes it to be right in the zone where those two branches can sometimes come together, and with them comes air masses created in their respective areas. The southern branch can sometimes bring northward a warm, moist airmass from the Gulf, and the northern branch can sometimes bring southward cold, dry airmasses created over Cananda. In order to have snow you have to have A) cold air- freezing or below- and B) moisture/clouds. Because of our location relative to the track of winter storms, we rarely ever see moisture and cold air at the same time. Most often we see the moisture in the form of rain as the system/front approaches, and then the cold air comes in after the system has passed, and taken the moisture away with it. I’ve made some diagrams to help illustrate what I’m talking about. To understand these you need to know a few basic things about weather- high pressure (blue H)=calm, clear weather and has clockwise circulation around it, and low pressure (red L)=cloudy, rainy/snowy weather and counter-clockwise circulation. The blue line with teeth is a cold front, which means that to the west (left) of it is a cold airmass advancing eastward. The red line with round humps is a warm front, which means that to the south of it is warm air advancing northward. In this first diagram I’ve made, you will see the typical scenario for a winter storm in the south. You can see that the rain is in the moist sector to the south and east of the low pressure system. The cold doesn’t make it to those areas because it’s being pulled down from the west of the system, behind the cold front. Because that cold air mass originated over land (Canada), it’s fairly dry, and if you’re to the south of the low, once the cold front passes the moisture is gone. It’s only in that northwest quadrant of the system that moisture gets pulled around and mixed with the cold air, creating snow. Most of these storm systems track a little too far north or south (this diagram has it going too north) and there either isn’t enough cold air in place over the northern plains, or the warm moist air simply rides up over the cold air (we’ll talk about that in a minute). Click on the image to show the full size diagram.
winterweathermap-usualstorm

So what happens when the warm air is pulled up and then rides over the cold air? Ice. Normally this happens right along the warm front, in the northeast quadrant of the storm. The warm air is lighter and rises (we all learned that in elementary school) and creates a wedge. The precipitation starts as snow way up in the clouds, then melts when it gets to that layer of warmer air, then the rain drops re-freeze when they get closer to the ground where the colder air sits. This is called sleet. If the layer of colder air is really shallow, the rain may not freeze until it touches a surface. It will then freeze and form a glaze of ice on everything. This is called freezing rain. Another diagram to illustrate: (click to enlarge)
icestorm

Finally, this last diagram will show you what the “ideal” scenario for a heavy snowfall event in Nashville/middle TN would look like. Unfortunately if you’re a snow-lover like me, this doesn’t happen very often because the low has to track in JUST the right place for it to happen. There also has to be a very strong, very cold airmass parked over the northern plains, waiting to plunge down to the southeast. The southern branch of the jetstream also must be very active and the low pressure must be very strong- strong enough that you have full 360 degree circulation (called a “closed low”). The exact track of the low makes all the difference. It has to track just to the southeast of us so that we are in that “sweet spot” of heavy snow just to the north and west of the low. The perfect Nashville snowstorm: (click to enlarge)
winterweathermap-idealstorm

Essentially this is the great “Blizzard of ’93,” except its track is shifted slightly to the west of that storm. Ok, now that we’ve all had a full nerd-gasm, hopefully you now have a better understanding of why Nashville’s winter weather can be rather fickle and difficult to forecast. Back to the normal posting tomorrow.