New Tornado Alley

We all know that severe weather, especially tornadoes, are a threat to the Southeast every year, and it can occur in any month. However, what many of us were taught as children, and even as adults, as to where the most tornadoes, and also the largest, occur has changed, and it may surprise you. 

The "traditional" Tornado Alley stretches from Texas all the way up to South Dakota. Dixie Alley is the not quite as bad, but still important "mini" Tornado Alley. However, in the last 40 years those maps changed ... a lot! 

 

A new study done by the University of Alabama at Huntsville, and published by the American Meteorological Society shows that very little of the original Tornado Alley is still a part of the NEW Tornado Alley.

 

The study focused specifically on F2 strength tornadoes or higher. Because those are the ones that cause the most damage along with injuries and fatalities. They also looked at how long the tornado stayed on the ground, because the longer it does, the more damage it causes. The research found that Deep South tornadoes typically have longer paths than those in the Great Plains because they actually travel at a faster rate.

The study only did the last 40 years. It started in 1973, after the Fujita scale was first implemented, but stopped in 2010. They took out 2011 for fear the super outbreak would skew the results. But that's what makes this even more interesting. Even WITHOUT the super outbreak of 2011,when the Southeast was anihilated by over 300 tornadoes, the new tornado map never changed.

So why is this important? Very little research money is coming to the Southeast at this point to study tornadoes. It's all funneled into the Great Plains. So as Tornado Alley begins to shift, perhaps that research money needs to shift as well.

Sources: AMS, University of Alabama-Huntsville

 

Typhoon Man-Yi Hits Japan

Typhoon Man-yi made landfall in Japan on Monday, but days later it is still wreaking havoc by compromising recovery at the Fukushima Nuclear plant. The storm had winds around 162kph (about 100mph—the equivalent to a category 2 hurricane). Three people so far have been confirmed dead, with five others still missing.

Typhoon Man-Yi as seen from space     Courtesy: NASA Goddard

Over 4,000 homes are flooded, with 200 classified as destroyed, mainly due to strong winds or landslides.  Many boats were ripped from their docks or untied, and were seen floating down the Katsura River. One boat crashed into a bridge along the river in the town of Kyoto. Authorities had advised over 300,000 homes to evacuate due to the unprecedented rains and landslides.

Workers at the Fukushima nuclear plant were pumping out water from areas near tanks storing radioactive water. According to the plant’s spokesman, some leaks are believed to have seeped into groundwater, although it was unknown exactly how much water was released.  

Destroyed home in Kumagaya, Japan      Courtesy: AP Photos

 

Many people also crowded the airports as more than 600 flights were canceled Monday and Tuesday due to the typhoon. The weather is expected to improve over the next few days, allowing for flights to resume normal schedules, and hopefully allow for things to go back to normal. 

Cars underwater in Obama, Japan      Courtesy: AP Photos

 

It's A Bird, It's A Plane, It's....A Jellyfish???

For everyone in Seattle last Tuesday, August 6th, they were enjoying another beautiful, sunny, warm day. However, there were a few unique clouds that interrupted that peaceful day, and had locals wondering what on Earth might be in the sky. "Mini-cyclone" clouds, "Jellyfish" clouds, or "Ice cream cone" clouds as they are often referred to, because of their shape, made a rare appearance in Washington. Their technical term is actually "Fall Streaks", which are a form of virga.

Courtesy: Dale Jordan in Washington

Courtesy: Brian Lutz in Washington

Virga, is rain from a cloud, but that rain never actually makes it to the ground because it evaporates too quickly. Fall streaks are similar, but instead of being in the form of rain, they are ice crystals. As those ice crystals "fall" from the cloud they change directly from a solid to a gas state, or sublimination.

Notice in the picture below that there is one line of "jellyfish" clouds in the western section of the state near Seattle, and another in the eastern section of the state.

As to the reason why they formed on what would have otherwise been a completely clear day: something called a line of deformation. When you have two low pressures, flanking an area on each side, they tug and pull on the area in between. For that area in between that "tugging and pulling" created lower pressures overhead, and that creates the higher level clouds (usually filled with ice crystals).

This isn't the first place to see these strange clouds. Last year similar clouds popped up in Iowa. Thankfully, I think we can all rest soundly knowing that these are not part of an alien invasion or conspiracy theory :)


Courtesy: Danny Murphy in Iowa

 Sources: KOMO News, Atmospheric Optics, KWWL-TV

Tornado Can't Destroy This Home!

Too often we expect Mother Nature to respect the homes that we have built, when in reality we should be respecting Mother Nature and building our homes around her capabilities instead. We can’t force people to stop building homes along beaches where hurricanes or erosion could destroy them, nor can we expect people whose whole livelihoods are in Oklahoma and Kansas to just pack up and leave everything in the chance that a tornado might hit there. So the solution may be to build homes that can evade Mother Nature’s cruelest abilities. One company is doing just that.

Ten Design Company in Hong Kong has created a prototype home modeled off of the survival mentality of a turtle. The home is constructed of  simple hydraulic levers which push the home in and out of the ground, when the home’s outer shell detects high velocity winds associated with thunderstorms and especially tornadoes. For decades people have been building their homes up, either on stilts or columns in the hopes that water and/or air would flow underneath them, not affecting the main structure of the home. The problem with this is that people often forget the flying debris that may be associated with that tornado, or the surge that could be associated with that tropical system. Both of those elements are great examples of how going under ground, could be the best option.

The home is not tornado-proof per-say, but rather tornado-evading, since it is instead dodging the weather rather than trying to go against it. The homes are built with a series of solar cells and layers of Kevlar to be able to allow the home maximum natural light, while also keeping it safe from the day-to-day elements. They are also looking into putting carbon nanotubes on the shell of the home to absorb some pollution turning it directly into fuel for the home to power the hydraulics, but this would be something that would likely not have on the initial homes to keep costs down.

As soon as warning sirerns would go off, the sensors on the home would activate, and entire neighborhoods of these homes can be collapsed in mere seconds. After the home has been lowered into the ground, a water tight seal on the roof is locked, making the structure water and wind proof.

10 is currently developing a prototype with a group of ship builders in the US and Africa. The company’s hope is to get a prototype built in the mid-western U.S. to be able to test it in real-life weather scenarios. They would like to take that prototype house to a state fair somewhere in the mid-west to be able to show what it can do, to the people that would likely fit the company’s intended audience.

 

Source:  10 Design Company

Less Pollution = More Rain?

For most people living in the southeastern section of the U.S., many probably feel like they live in Seattle or the Amazon Rainforest instead thanks to the non-stop rain. Well, they can thank the Clean Air Act for that…..sort of.

Back in 1970 the Clean Air Act was passed. This initiative focused on reducing airborne pollutants that posed a threat to human health. Jeremy Diem, a climatologist at Georgia State University performed research looking at 18 National Weather Service co-op weather stations and noticed that Atlanta’s average annual rainfall increased by 10 percent in the decade following the new Clean Air Act. He studied specifically the summer months during the years of 1948 to 2009.

"It suddenly just changed dramatically in the '70s. It wasn't a gradual change. It was pretty abrupt," explains Jeremy Diem, a climatologist at Georgia State University who performed the research. But not everyone agrees. "Other people said we had a recession and that caused less fuel to be consumed," Diem said, although he does agree that that was also probably a factor.

Diem explains that having a lot of pollution in the air can lead to clouds being “less efficient”. In general, any water molecule can create a cloud, but you need specific types of water molecules to make a cloud drop rain. Standard clouds form from small particles that are almost perfectly uniform in both particle and water vapor size. This is especially the case when a lot of pollution is factored into the clouds. However, in order for the cloud to create falling rain, the particles must be of various sizes.

"You don't want tons of little ones, which is what Atlanta had in the '50s and '60s," Diem said.

How does he know that? Well, the first 5 years after the Clean Air Act was passed, the recorded emissions of particles with diameters of 10 micrometers or less decreased by about 40 percent nationwide, that according to the Environmental Protection Agency.

Diem took his research one step further. He used the results he got from looking at the weather stations in rural areas to predict what the rainfall values would be at some of the urban and suburban locations. What the results showed was that rainfall in the urban areas was greatly suppressed before the Clean Air Act. How much so? The urban/suburban areas had rainfall totals of about 1.6 inches less in the 1950 and 60s (when air pollution peaked). In the 1970s those summer rainfall levels went back to the normal 11.8 inches. Starting in the 1980s the numbers started to become more consistent, and remained that way all the way through 2009 (the last year that was studied).

Diem’s research will be published in the August 2013 edition of the Journal of Atmospheric Science, although he says he isn’t finished. He would like to continue the study in other cities such as Minneapolis, Cincinnati, Dallas, Oklahoma City, and a few others.

For more on the EPA’s Clean Air Act click here.

Sources: Live Science, National Geographic, Southern Environmental Law Center, EPA

Ice Required For Icewine!

Seems like a obvious concept right? You have to have ice in order to make icewine? Well, the strange thing is, counterfeiters are using a loophole to get into the icewine business, but Canada is striking back!

Some white wine producers have been adding artificial sweeteners to simulate icewine's very sugary taste. Other companies have been picking the grapes early and then freezing them inside of buildings. Doing so helps minimize a loss of the crops due to rot. However, by picking the grapes early and freezing them inside a building, and not naturally on the vine, this can cause the grape to to have inconsistent or incomplete fermentation.

"[These companies] can produce a fine wine, but that should not be allowed to be called icewine," explains Dan Paszkowski, the head of the Canadian Vinters Association.

Canada is hoping that by implementing new federal standards requiring that "the grapes must be naturally frozen on the vine", it will help prevent fraudsters. The Canadian province of Ontario already has these same rules, but now the changes will be mandated across the country effective January 1, 2014. 

So what exactly is icewine? Icewine is a very unique, yet risky to make, dessert wine. Weather plays a vital role in the making of icewine. In fact, it has to be grown in a very cool climate because the grapes cannot be harvested until the temperature has fallen to below 18°F (-8°C) in Canada, or below 19°F (-7°C) in Germany. In Canada specifically, the first hard freeze may not occur until after Christmas. Once the grapes have met that hard freeze point, the harvesters only have but a few hours to pick the grapes off the vine. Canada and Germany are the worlds top two producers of icewine, but other countries such as Denmark, Czech Republic, Sweden, Austria, Slovakia, United States (specifically in the Michigan, Washington, and Colorado), and China are also producers. It's the last of those countries that is causing the majority of the counterfeit problems.

Icewine has become rapidly popular in China, but not all of it is regulated, and that opens the door to counterfeits galore.

"It's very difficult to regulate greed," emphasizes Paszkowski. "We've identified counterfiet icewines even in five-star restaurants and hotels."

Sources: Reuters, Vancouver Sun, Lancette Arts Journal, The Telegraph, Niagara Wine Trail

 

 

First High Risk of 2013

The first High Risk for 2013 was issued today, and it stretched from eastern Iowa to northwestern Ohio.  That puts a total of 12 million people in the risk area for severe weather such as straigh-line wind damage and tornadoes.

The bullseye of this high risk is right over Chicago. In fact, this is the first high risk tat has been issued for Chicago since May 30, 2004, and only the third since 2000. The Storm Prediction Center issues these categories on a daily basis based off of the current/forecasted weather, and they have three categories: Slight, Moderate,and High. High risks are extremely rare, and are only issued prior to large outbreaks of severe weather.

So what do the different risk levels mean? Below is what the SPC uses to define their outlook categories:

 

Slight, moderate, and high risks represent progressively larger threat for organized severe storm episodes. These risks and their graphical labels (Slight, Moderate, High) are based directly on the numerical probabilities of severe weather that we provide with every outlook. The probability values represent the chance of severe weather within about 25 miles of a point, which is about the size of a major metropolitan area. Though severe storms tend to receive a large amount of media coverage, severe weather is uncommon at any one location. Your chance of getting a tornado on any random day are very small, climatologically speaking. Put in that context, even a 10% chance of a tornado within 25 miles of a point means a much bigger threat than usual, and should be taken seriously. Think of how often tornadoes normally happen close to you on any given day, and those small-looking probabilities start to seem large by comparison!

For a complete list of all the Risk Outlooks, Tornado Watches (formerly called “tornado forecasts”), you can use this link here.

This is a link to all of the times the SPC has issued a High Risk Day, use this link here. Notice that the only month that has never had a High Risk issued was September. Also, the last time a High Risk was never issued once during the year was back in 2000.

Sources: SPC, NOAA, NWS-Chicago

2013 Behind The Hurricane Name

Even though hurricane season technically started last Saturday, the tropics are just now starting to get going. Tropical Storm Andrea was just named late this afternoon. Every year I have always pulled up the list of the hurricane names for the Atlantic Ocean, and tried to determine what strength they will be and where they might hit based off of the names alone. There is nothing scientific about this process. Simply some fun.

Atlantic Names:

Andrea—this would be cheating if I answered this one, because it has already formed.
Barry--makes me think of Barry Manilow. Smooth and gentle. This one will be a Category 1.
Chantal--I worked with a Chantal, and she was the nicest lady ever. This will be a tropical storm
Dorian--this to be the first Cat 5 of the season, but will downgrade to Cat 2 when it hits Florida
Erin--this one sounds sweet and innocent, but will end up as a Category 4.
Fernand--the Bull? Just like in the book, he will be huge in size, but gentle. Only tropical storm.
Gabrielle--Gabrielle in ’89 killed 9 people, despite never making landfall. This one will be Cat 3
Humberto--this one will hit Cuba and fall apart. Category 2.
Ingrid--sounds exotic, but it will do damage. Category 3.
Jerry--Seinfeld. This one will be funny. It will have a crazy track, but not do much damage. Cat 1
Karen--Typhoon Karen did massive damage to Phillipines ('60) and Guam ('62). This year Cat 3
Lorenzo--I feel this one will be large, but will get lost and stay out in Atlantic Ocean only.
Melissa--I know too many Melissa’s. This is a no win forecast for this one :)
Nestor--this name just confuses me, so the storm will too. Erratic path, but benign. Category 1.
Olga--I think this will be the last named storm of season, and it goes out with a bang, Cat 4.
Pablo--we won't get this far down the list, but if we did, tropical storm.
Rebekah--we won’t get this far down the list, but if we did, Cat 2
Sebastien--crab from Little Mermaid anyone? Very tiny, but a fighter. Small sized Category 3.
Tanya--we won’t get this far down the list, but if we did, Cat 1
Van--I picture this to be big, like a real van, but not do much. Tropical storm.
Wendy--all I think about is the Wendy’s girl with red pigtails. Too sweet: tropical storm at best.

Hurricane Ivan     courtesy: NOAA

Where Are All the Tornadoes?

So far this month, we have a preliminary tornado count of only 14. According to Dr. Greg Forbes, meteorologist at The Weather Channel, that number should be around 96. That’s the number we normally see for the first ten days of May (when looking at data for the last 10 years). 

 It’s not just May either. When you look back to March and April, those months were also way below normal. April 2013 only had 73 tornadoes, but we average 234. Prior to that, in March of 2013, we had a near record low month! The average for March is 98, and we only had 17, making it the 5^th lowest count for March on record!

There is even better news…..according to Harold Brooks, a research meteorologist from the National Severe Storms Laboratory, from May 2012 through April 2013 there were only 7 tornado deaths in the U.S., which is the fewest number of fatalities in a 12 month period since September 1899-August 1900 when there were only 5 fatalities. 

In Iowa specifically, they are close to breaking the longest stretch in history without a reported tornado: 354 days. That’s right; the last time a tornado was reported in Iowa was back on May 24^th, 2012. The record is 355 days, which means tomorrow they would tie it, and Wednesday they would break the record. The current record of 355 days was set between May 5, 1955 and April 26^th, 1956. The thing you have to note here is that back in 1955-1956, tornadoes were not as widely reported as they are now. There may have actually been one during that stretch, but if it happened in a field, or did not cause damage, it may not have been reported. That is much different now, so for the record to possibly be broken in this day of technology, it’s very impressive. 

With just 2 tornadoes in May 2013 through today (both rated EF0 in FL). The first 6 days in May of this year only had 2 tornadoes, which makes it the fourth-quietest for those days since 1950. And note, those 2 tornadoes were in Florida, and only received an EF0 rating, the lowest on the scale.

Number   Year

  0           1970

  0           1962

  1           1952

  2           **2013 **

  2           2011

  3           1951

  5           1986

  5           1966

  7           1957

Sources: NSSL, The Weather Channel, NOAA, Associated Press, SPC, Iowa Environmental Mesonet, Twitter

First American Tornado Chaser

When you hear “Ben Franklin” you likely think of a politician, an author, inventor, and a scientist, just to name a few. Even though Franklin technically had no background or education in weather, he made many advancements in the field of meteorology, including determining the general directions in which storms travel, how temperature affects electric conductivity, how volcanic eruptions affect climate, weather pertaining to oceanography, and we all know about his infamous “discovery of electricity” when he flew a kite into a lightning storm.

While trying to see an eclipse, Franklin realized, accidentally, that in North America large storms tended to move from southwest to northeast. The reason this was a shocker, and that nobody else in the colonies seemed to notice, was because in Europe this isn’t always the case. Many storms can actually come from the Northwest.

One of Franklins lesser known titles was “tornado-chaser”. It all started after a series of waterspouts in Italy back in 1749. Waterspouts are not uncommon there, but one in particular did something that the others had not done before…it came onshore.

Many of the residents of this badly damaged Italian coastal town became paranoid, thinking this was the end of the world, and that surely the apocalypse was near. In order to calm fears, the Pope ordered a very well-known natural philosopher, Father Ruder Boscovich, to investigate, and print his results in a book. In his book were details of the trail of ruin, interviews with survivors and eyewitnesses, and also extensive research in the Vatican Library on similar meteorological events.

Franklin began receiving copies of Father Boscovich’s book. Many colleagues started asking Franklin what his thoughts were, so he started his own investigation. Never having personally seen one himself, he researched travelers’ tales, historical documents, and the diaries of officers and sailors on ships who had witnessed them firsthand. As he read through all these papers, he quickly realized that the common theory that waterspouts were made out of water, not air, could not possibly be true. The sheer weight of the water would not allow for a force to either raise or sustain such a large body of it in midair. But the big question remained....if it wasn’t water, why did it look like it was? After more research, Franklin came to the conclusion that it only appeared to be made of water because of fog that was condensing around the waterspout.

After all of this came to light, Franklin’s biggest “discovery” was that if the waterspout truly was made out of air rather than water, then the long-held belief that waterspouts only remained over water was false. In theory, if all they are made of is air, then they should be just as likely to happen over land as they would be to happen over water. Finding the evidence to prove this however, wasn’t quite as easy.

He found the best piece of information through a published piece out of the Yorkshire countryside in England. It described in detail what it looked like, and described the minor damage to village rooftops. What caused them? Why did some last longer than others? Could they occur anywhere, or just certain parts of the world? These are the questions that plagued Franklin for quite some time.

Sensing Franklin’s frustration, a colleague, Colonel Tasker invited Franklin and his son William to stay with him at his home in the countryside of Maryland. On their way was a dusty, winding road winding, and all of a sudden someone noticed a tight little column of air: a newly forming “tornado”. I put that word in quotes because back then they were not called tornadoes. They were referred to as landspouts or whirlwinds most frequently.

Franklin wrote in his research that it resembled a sugar-loaf funnel, with an odd, irregular bob and swerve like a spinning top. It swayed across the hillside and began to come right at them. At that point everyone but Franklin started to head backwards away from the funnel. Franklin later said he couldn’t help himself; he just had to get closer. Just as he began to chase the funnel it turned and changed course into the woods. Franklin decided to follow it further into the woods, but noticed the wind was getting louder. As he got closer he noticed the funnel was picking up everything in sight: leaves, branches, etc. He also noted that the whirlwind was bending and snapping trees as though they were mere twigs. At this point Franklin decided he best stay put for his own safety. Moments later the funnel just dissolved into nothing as it moved into an old tobacco field.

While he never officially used the word “tornado” in any of his research, he certainly was the first real “tornado chaser”.

Sources: NWS, Daily Beast, PBS, Britanica (first photo), Weatherwise Magazine (second photo--the first known photo of a tornado)

Lunar Dust Predicts Flooding?

After major cities like Atlanta, Nashville, and Dallas just to name a few, have experienced major flooding events in the last few years, forecasters are looking for anything that may provide better flood notice. Thanks to NASA, meteorologists may get just that.

John Lane, a Kennedy Space Center physicist, has spent much of his career trying to preserve the historic lunar landing sites, but stumbled on something very interesting. Apparently measuring lunar dust is no different than measuring rain.



courtesy: NASA

Lane used a laser to measure exactly how much lunar dust a rocket ship would displace as it landed on the surface. (This is key for NASA because the Apollo landing sites are considered sacred, so future moon landings would have to be precise as to prevent any damage to the historical sites.)

That same laser also has the ability to detect tiny particles, smaller than most raindrops. That is key, because if forecasters can see how large or small the raindrops are within a cloud, they can better predict rainfall rates. If the rates are high, then the chances of flooding are also high.

Lane does not have a degree in meteorology, nor does he even have any meteorology experience, but that didn’t stop him from realizing the connection to flood forecasting.



courtesy: NASA

Robert Molleda, a meteorologist at the National Weather Service in Miami, Florida is very excited about the possibilities of using the lasers to make more accurate computer model forecasting.

"If you can accurately determine the size of a raindrop, you can find the relationship between the amount of rain and rainfall rates [considering current weather radar has a hard time estimating the size of raindrops]," Molleda said.



courtesy: National Geographic

The best part..... putting these lasers into widespread usage is not expensive because the lasers cost less than $100.

Sources: Sun Sentinel, NWS, NASA, National Geographic

New Weather Satellite Coming!

The University of California at Berkeley has been given a $200 million grant by NASA to build a satellite. This new satellite will be made to determine how Earth’s weather affects extreme “space weather” (the weather at the edge of our atmosphere and the edge of space). Why would that be important? Just about everything we use in our daily lives anymore involves a cell phone, GPS, satellite communication, or radio communications. Well, some space weather can actually disrupt those satellites (GPS, cell phones, etc.) and radio communications.

The new satellite will be called the Ionospheric Connection Explorer (ICON), and UC Berkeley will be responsible for the design, construction, and operations of the project. Since this can’t be done overnight, the launch is not expected to occur until some time in 2017. Once launched, it will be sent to orbit around 345 miles above the Earth’s surface in the ionosphere. Why the ionosphere specifically? There are many layers of the atmosphere, and one of the highest levels is the ionosphere, ranging from around 50 miles to 370 miles in altitude. It can encompass parts of the mesosphere, thermosphere, and even the exosphere, but it is not the same exact thing as those. What makes the ionosphere unique is that it is ionized by the sun radiation to create constantly moving streams of charged particles. The ionosphere is basically a container of electrons and electrically charged molecules surrounding the Earth. Those charged molecules are what can disrupt GPS, cell phone service, radio communications, etc.

But ICON won’t just be studying weather in space, but it will also be trying to see how that weather affects our weather here on Earth too, and vice versa.

“Ten years ago, we had no idea that the ionosphere was affected and structured by storms in the lower atmosphere,” said the project’s principal investigator, Thomas Immel, a senior fellow at the Space Sciences Laboratory. “We proposed ICON in response to this new realization.”

The below image shows a bright red wall of plasma, not to be confused with the aurora lights, which are lower in altitude, where Earth and the ionosphere meet. Despite the fact that it looks computer rendered, this is actually a real picture taken by an astronaut aboard the International Space Station.

UC Berkeley will use ICON to try to make a connection between storms that occur near Earth’s surface and space-weather storms, which may allow for better prediction of space weather events. Not only does this help with our communications satellites, but it also could help with the safety of commercial airliners, which today cannot rely solely on GPS satellites to fly and land because sometimes the satellites can send distorted signals thanks to charged-particle storms in the ionosphere.

“We know that the solar wind plays a big role in the ionosphere, but most of the time the sun is relatively quiet, and our space environment still varies quite a bit,” he said. “We think that variability is coming from weather on our own planet, which can be very powerful.”

Sources: NASA, UC-Berkeley, Stanford

Sandy Retired From Storm Names

We all remember the images that came out of "Superstorm Sandy" last year. They were incredible, even unbelieveable at times.

Sandy caused at least 150 fatalities, with over 70 of them being in the Northeast alone. That is the highest number of fatalities from a tropical storm to happen outside of the southeastern states since Hurricane Agnes over 40 years ago. Sandy was the costliest storm system, only behind Hurricane Katrina, with an estimated $50 billion in damages.

Because of these statistics, the name Sandy will be retired from the list of Atlantic Ocean list. The National Hurricane Center has been using that list since 1954. The names are on cycles, and get re-used every six years, which means a new name, Sara, will replace the Sandy's slot in 2018.

Properties that lacked the protection of robust sand dunes. Courtesy: NASA

The surprise??? Isaac will not be retired. Despite the fact that the storm ravaged Louisiana on the anniversary of Katrina with over $2 billion in damages, 34 fatalities, and caused millions of power outages, the World Metoeorological Organization (the committee who makes these decisions), decided it wasn't enough to retire the name.

Hurricane Katrina from space

So why retire the names in the first place? If I said to you that my parents survived Hurricane Katrina, do you think about the storm that annihilated the Gulf Coast in 2005, or the storm that hit Cuba and the Bahamas back in 1981? Exactly. Nobody remembers the Katrina from 1981, but everyone remembers the one from 2005. When a storm name becomes tied to a very large, memorable event, a decision is made to retire it, so there is no confusion recalling events. other big names to be retired are Hugo, Andrew, Opal, Ivan, Wilma, and Irene to name a few. Note: Allison is the only name on the retired list that never made it to hurricane status. During its entire life, Allison was only a tropical storm with maximum winds of 60mph. Most of the damage from Allison did not come from the wind, but rather the rain. Allison's track made a complete 360, causing Houston to take a double dose of heavy downpours.

 

Sources: NOAA, NCSU, The Times, Scientific American, NHC

4/7/13 Record Cold March

For those living along the western coast of the U.S. March was an overall warm month. Several cities in Washington, Nevada, and California broke record high temperatures; some, several days in a row. However, for the people who live in the southeastern states, they were bundling up, and wondering when Spring was going to arrive.

So why the extreme cold for the Southeast? Much of the blame can be attributed to a strongly negative Arctic Oscillation. The Arctic Oscillation basically determines how the warm and cold weather patterns get distributed. When you have atmospheric pressure changes at both the polar and middle latitudes, that pattern usually allows for colder air to come farther southward than it normally would in springtime.

So just how cold was it? Atlanta had it’s 17^th coldest March on record with an average temperature of 49.1°F. That means March was colder than both December (51.1ºF) and January (49.9ºF)!  Another strange anomally; Birmingham, Alabama had its 10^th coldest March on record at 49.7°F, but just last year, they had their WARMEST March on record at 65.5°F. What a difference a year makes! Here are some other cities that felt the chill:

Huntsville, Alabama had its 10^th coldest at 47.4°F

Knoxville, Tennessee had its 6^th coldest at 44.0°F

Macon, Georgia had its 7^th coldest March at 50.7°F

Tuscaloosa, Alabama had its 4^th coldest March at 51.5°F

Charlotte, North Carolina had its 8^th coldest March at 46.1°F

 

Sometimes it is hard to imagine that 50°F is cold, so lets put it into perspective. First, this is March, not January we’re talking about. With that in mind, at times Raleigh, North Carolina felt more like Philadelphia for much of March;  Asheville, North Caorlina felt more like New York City; and Atlanta felt more like Washington D.C. Would you like to see how your city fared? This link here will let you see what your city's temperatures were comparable to.

Sources: NWS, NOAA, SERCC

4/4/13 Record Low Count for March Tornadoes

It was a very cold March for many areas across the country. Charlotte, NC had their coldest March on record, and cities like Atlanta, Nashville, and Birmingham were not far behind. However, although many complained of the cold, there is one benefit to having it: it kept tornadoes away. That’s right. The last March we had fewer tornadoes was almost 50 years ago when we had 8 tornadoes, back in 1969.

So far, based off of preliminary data, there were only 17 tornadoes throughout the entire U.S. in the month of March. Based off of that data, this makes it the 5^th lowest March on record.

The strange thing is that last March, in 2012, we had quite the opposite. With 154 tornadoes that month, it was almost double the average.  So why such a drastic change from last year to this year? That is a two part answer. First is the jet stream. Second is the cold temperatures across much of the eastern half of the country in March.

Normally, this time of year, the jet stream creates a trough, or dip, that comes from out of the western section of the country and into the central and southeastern states (think Texas to Oklahoma to Tennessee to Florida). However, the opposite has occurred for much of March this year. That allowed for a lot of those bitter cold temperatures that many folks in the southeast felt. That cold air dominated, and blocked any of the warm air from entering (you need both to create that unstable air needed for severe weather). Cold air also has a hard time supporting moist air, so the humidity was also not a factor last month.

The one thing to note is while March may have been relatively quiet, that doesn’t mean April and May will be the same!

Tornado path and strength from Glascock county, Georgia

Damage at Magnolia Baptist Church in Glascock county, Georgia

Sources: SPC, NOAA, Weather.com