Tomorrow – December 2nd – is National SKYWARN® Recognition Day!!
So, just what is SKYWARN® ?
SKYWARN® is a National Weather Service (NWS) volunteer program with between 350,000 and 400,000 trained severe weather spotters. The main responsibility of a SKYWARN® spotter is to identify and describe severe local weather and storms. Unlike storm chasers, they generally stay in one place until it is necessary for them to move. The spotter is the “eyes and ears in the field” for the NWS.
In 1999, the NWS and the American Radio Relay League (ARRL) created SKYWARN® Recognition Day to recognize and honor “. . . the contributions that SKYWARN® volunteers make to the NWS mission, the protection of life and property. . .”
Think you would be interested in becoming a SKYWARN® volunteer? Training includes learning about basic severe weather structure and development, how to report, and basic severe weather safety. Training is free and typically lasts about 2 hours. Volunteers include police, EMTs, dispatchers, fire fighters, individuals affiliated with hospitals, schools, nursing homes – and concerned private citizens! You can attend training at any NWS office facility, no matter where you live! Check SKYWARN training for information and find the SKYWARN® program in your area! Attend a training course near you, register as a spotter, and help keep your community safe!
Thank you to all the spotters out there who volunteer their time to help the NWS with the updated, real-time weather information!
Mogil, H. Michael. 2007. Extreme weather :understanding the science of hurricanes, tornadoes, floods, heat waves, snow storms, global warming and other atmospheric disturbances. New York, N.Y. : black Dog & Leventhal Publishers. Engineering Library QC981 .M65 2007
It’s hard to pay attention to the science behind hurricanes when people’s lives are on the line and everyone is waiting to see what will really happen. Now that Harvey and Irma have done their worst, here are a few facts and interesting tidbits about hurricanes . . . information that will stand you in good stead when the next one approaches. And there will be a next one. After all, the Atlantic hurricane season last through November 30.
How does a hurricane form? Briefly, hurricanes develop from smaller, but strong, thunderstorms which develop in tropical waters. If several thunderstorms cluster together and become stronger they can become a tropical depression. (A tropical depression has a relatively low air pressure and wind speeds between 23 and 38 mph circling around the center). If the wind speeds increase above 38 mph it is called a tropical storm and given a name (we’ll look at naming a little later). A tropical storm could last for days while moving across the ocean – fizzling out or possibly reaching shore. If winds intensify and reach 74 mph, the storm becomes a hurricane. (The speed of 74 mph was first calculated by Sir Francis Beaufort in 1805…)
Now, about those categories. The graphic on the left may be humorous – but it is accurate (at least as far as the facts go, not sure about the cats…Notice I’m refraining from saying anything about ‘cat’egories…). A category 1 (winds between 74-95 mph) will produce some damage (roofs, siding, gutters, trees, and the possibility of power outages lasting several days). Category 2 (96-110 mph) will cause extensive damage (major roof damage, trees snapped and uprooted, and near total power outage which could last weeks). Devastating damage will occur with a category 3 (111-129 mph) hurricane (homes will sustain major damage, many trees will be uprooted blocking roads, water and electrical outages could last weeks). Catastrophic damage will occur with a category 4 (130-156 mph) hurricane (homes suffer severe damage, most trees will be uprooted or snapped, power poles will come down, residential areas will become isolated and most areas will uninhabitable for weeks or months). Category 5 (157 mph and higher) damage is catastrophic (most homes destroyed, residential areas isolated, water and electrical outages will last months and most of the area will be uninhabitable for months or longer). This is only the damage from the winds and doesn’t include the flooding from the rain and storm surges.
So, where does the data come from? Data on individual hurricanes is gathered using satellites and radar – but that data isn’t as complete as when hurricane hunters are also collecting data. Yes, there really are Hurricane Hunters who fly through the eye of the hurricanes on purpose! Specially equipped National Oceanic and Atmospheric Administration (NOAA) aircraft play an integral role in hurricane forecasting. Instruments on board are continually transmitting measurements of pressure, humidity, temperature and wind direction – all which help give scientists and forecasters real-time access to the storm information. And these Hurricane Hunters make the run through the eye of the storm over and over again during an 8-10 hour shift!
So what’s the deal with naming the hurricanes? It’s pretty simple – human names are easier to remember than meteorological numbers. If there is more than one hurricane at a time (like now) there is much less chance for confusion when referring to the storms. There are six lists of names, which are used in rotation. One list is used one year, then the next list the following year, etc. Names on the list are alphabetical with one name for each letter (with the exception of the letters Q, U, X, Y and Z, which have no names associated with them). This system of relying on names from these lists began in 1953, and was begun by the National Hurricane Center. These lists are now maintained and updated by an international committee of the World Meteorologic Association.
The origins of the modern naming system may be traced back to a 19th century Australian meteorologist named Clement Wragge (known as Wet Wragge….). He started out using letters of the alphabet and then switched to using popular female names in the South Pacific. It is also said that he sometimes named hurricanes after politicians who were not supportive of his work …
In the 1960s women began to speak out about the inequality of gender-specific names. Finally, in 1979, male name’s were introduced and they now alternate with female names. The first hurricane with a male name was “Bob” and he hit the Gulf Coast on July 11, 1979. The names of hurricanes which are particularly destructive and deadly are retired – Irene, Katrina, Sandy, and Matthew are recent examples. It is expected that the names Harvey and Irma will be retired after this year.
Or perhaps you’d like to create your own hurricane playlist? There are a number of possible songs – Ridin’ the Storm Out (REO Speedwagon), Riders on the Storm (The Doors), Like a Hurricane (Neil Young), and so many more.
Wherever you are – please be safe! Listen to the forecasters and officials in your area. The category meme, the movies and the playlist might make light of hurricanes, but they are dangerous, destructive, and can be deadly.
Hapij, Adam W., editor. 2011. Multidisciplinary assessment of critical facility response to natural disasters : the case of Hurricane Katrina. Reston, VA : American Society of Engineers.Engineering Library TH1096 .M85 2011
NOAA Hurricane Hunters. May 19, 2017. Office of Marine & Aviation Operations. NOAA.
Volcovici, Valerie and Brian Thevenot. Sept. 1, 2017. After bungling Katrina, Hurricane Harvey is a big test for FEMA – and tens of thousands of Americans are counting on federal help.Business Insider : Politics.
We haven’t had a lot of ice and snow here in Eastern Iowa,
but winter isn’t over yet!
When we think of those big trucks with the plows, clearing and de-icing our roads, we often call them “sand trucks.” But there is much more than simply sand in those trucks. You know the white stains you get on your shoes and the hem of your pants? Those stains are the result of the salt which is also used for de-icing roads and walkways.
Road salt lowers the freezing point of water, which thaws the ice and allows vehicle tires to reach the pavement for traction. Salt does make winter driving safer, but also leads to corrosion on vehicles – both cars and the road maintenance trucks. The rust and corrosion occurs on the underside of the vehicles making it hard to detect. It is recommended that consumers use car washes – with an under carriage spray – on a regular basis.
A road maintenance truck is made of many different components – not just steel, but many softer metals that can be found in the wiring and other places on the truck. More and more liquid de-icers are being used and they more easily penetrate the nooks and crannies of the truck’s underside, causing more corrosion. There are several methods which are used to minimize the corrosion – coatings, additives, and cleansing techniques. Another option is to do nothing, and accept the lessened equipment lifetime.
The chemicals that are used in the sand and salt mixture are formulated for different temperatures and types of snow.
The effectiveness of a de-icer is measured by the range of temperature in which it provides de-icing in a reasonable length of time. So, after the truck goes by, how long do you need to wait before the roads are safer to travel? Generally that time-frame is about 15-20 minutes.
Different chemicals have differing temperatures at which they are most effective. Calcium Chloride is effective at the lowest temperature, as seen below.
Calcium Chloride (-25o F)
Magnesium Chloride (5o F)
Sodium Acetate (5o F)
Calcium Magnesium Acetate (5oF)
Potassium Chloride (12o F)
Urea (15o F)
Sodium Chloride (20-22o F)
Various Blends (usually 20-22o F)
Here’s an interesting fact: in the United States and Canada, more salt is used on snow and ice than with cooking! Every year, nearly 140 pounds of salt per person are applied to roadways in the US alone. That amounts to over 20 million tons of salt. And that doesn’t include the use of salt on sidewalks, walkways or parking lots!
We sometimes hear the words “snow and ice control.” How is it possible to “control” snow and ice? Interestingly enough, there is a “heat island” effect around major metropolitan areas. The heat that is emitted by those major cities can modify the climate enough that the amount of snowfall is reduced or rain (or freezing rain) falls instead of snow. You’ve heard of covered bridges? They were – and are – built to protect bridges from snow and ice. Ever wonder why bridges are more slippery than the roadways? Both the roadway and the underside of bridges are exposed to the cold, making them more susceptible to ice – those covered bridges protect the top, making the bridges that much safer!
Sand, salt and chemicals are the common ways to de-ice roadways. However, there are some new methods that are gaining traction (see what I did there?). You may have heard that beet juice and brine – cheese brine – are being used to de-ice roadways. A company in Indiana is distributing a sugar beet molasses-based product that is mixed with rock salt. The mixture helps rock salt melt ice below the 15o limit. We know from our pancake and waffle experiences that syrup and molasses are very sticky. That is actually an advantage – that stickiness helps prevent the rock salt from bouncing off roadways as cars drive past.
And, cheese brine? Wisconsin (the “cheese state”) is turning to cheese brine to help with icy roads – it helps keep roads from freezing. Cheese brine is a farm waste product so the Wisconsin DOT often gets the brine for free. The downside is there are environmental concerns about effects on rivers and lakes if significant amounts were to enter the waterways. Another downside is, well, there’s an odor…
Of course roads aren’t the only things that need to be de-iced. A patent for “Method and device for de-icing trains” was granted in 2013. A patent for “deicer composition” created for “melting ice on and defrosting a surface such as a windshield of a car” was granted in 1963. And a patent for “De-icing of aircraft” was granted in 2008.
Want a little help clearing your sidewalks and driveways, check out the Autonomous Snowplow Competition!
In case an autonomous snow plow isn’t in your future, there are now a number of different types of snow shovels, snow blowers, and ecological- and pet-friendly de-icers for your driveways and walkways.
Keep a safe distance from road maintenance vehicles, watch for ice and snow on uncleared roadways and be sure to clear your driveway and walkways – in other words – be safe this winter!
Nixon, Wilfrid A. 2009. Investigation of materials for the reduction and prevention of corrosion on highway maintenance equipment. Iowa City, IA : IIHR-Hydroscience and Engineering, University of Iowa. Engineering Library TE233 .N59 2009
Qiu, Lin and Nixon, Wilfrid A. Performance measurement for highway winter maintenance operations. 2009. Iowa City, IA : IIHR-Hydroscience and Engineering, University of Iowa. Engineering Library TE220.5 .Q228 2009
Don’t miss the trees turning those gorgeous colors!
The days are shorter and cooler and the trees are changing colors. Beautiful deep reds, oranges, and vibrant yellows…. So, how does that happen, and why in the fall?
Trees that change color are called deciduous (which means it sheds leaves annually) or broad-leaf trees, which have, obviously, broad leaves with a relatively large surface area. Leaves have two purposes – to convert carbon dioxide to oxygen (thank a tree for our fresh air!) and also to convert sunlight into energy for the tree. The large surface area helps the leaves gather more sunlight and therefore, more energy. The leaves “breathe in” carbon dioxide and “exhale” oxygen (for more information about this process check Plant Biochemistry by Florence K. Gleason with Raymond Chollet).
Leaves actually have several other pigments, besides green, which are always present – red, yellow, orange and even purple (beets, carrots, cherries!). The leaves on trees (and many plants) have so much green pigment, however, that the other colors aren’t visible – until fall, that is! The green pigment comes from chlorophyll which is used in photosynthesis (the complex process by which carbon dioxide and water are converted into carbohydrates by using the energy from the sun). The carbohydrates that are formed are then stored in the branches, roots, and buds of the trees.
We all know that, in the fall, days get shorter and cooler and the nights get longer – and cooler! Broadleaf trees are sensitive to sunlight – they need the sunlight to transform the chlorophyll. When there is less sunlight, the leaves make less chlorophyll, which means the trees become less green and the other pigments begin to become visible. Different types of trees have differing amounts of pigment – for example, trees with more anthocynins (the pigment responsible for the red and purple hues) will be more red than those with less. Temperature, sunlight, and soil moisture also influence the quality of the fall colors. A spring and summer with ample moisture followed by a dry, cool, and sunny autumn will produce the brightest fall colors.
Why do leaves fall? Without chlorophyll to help them make energy, they are no longer needed. The energy that they have produced is stored in the tree. The other pigments also eventually break down – when there is even less light, or if they are frozen. The only pigment that then remains is brown (tannins), and at that point the leaves drop off. The tree then lives through the winter on the energy that it has stored. When the days begin to get longer and warmer, the tree grows new leaves and the process begins all over again.
(Why don’t coniferous trees – evergreens, firs, etc. – change color and drop their needles? Briefly, needles are smaller, more watertight, more wind resistant and are able to photosynthesize all year long. Since needles have a reduced surface area, they are harder to destroy – and less tasty for insects!).
For a short, easy-to-understand, explanation of why leaves change color in the fall, watch this SciShow Kids video!
Here are resources where you can find more information!
Beck. Charles B. An introduction to plant structure and development : plant anatomy for the twenty-first century. Cambridge, UK ; New York : Cambridge University Press. Engineering Library QK641 .B38 2010
Their team of storm chasers, competing against a better-funded team, are trying to create a device meant to be released into a tornado. The plot is a dramatized view of research projects like Verification of the Origins of Rotation in Tornadoes (VORTEX) of the National Oceanic and Atmospheric Administration (NOAA). The device used in the movie, named “Dorothy,” is copied from “TOTO” (TOtable Tornado Observatory)- the real device used in the 1980s by the National Severe Storms Laboratory (NSSL). Dorothy (i.e. TOTO) was an instrument designed to be placed in the path of a tornado, and then sucked up into the tornado. When TOTO was sucked into the tornado, sensors would be released and these sensors would measure, among other things, pressure and humidity. Unfortunately, TOTO was too light and fell over when it was sideswiped by the edge of tornado. It was later deployed as a portable weather station to measure thunderstorm gust fronts and non-tornadic mesocyclones.
VORTEX was designed to answer questions about the causes of tornado formation. It documented the entire life cycle of a tornado from beginning to end, for the 1st time in history. VORTEX2 has many more instruments than the original VORTEX and is now mobile. Currently, in 2016, NSSL researchers are embarking on VORTEX Southeast. With this research, scientists seek to understand the environmental forces in the southeastern United States – studying the intensity, structure, and path of tornadoes in the region.
What does it take to be a storm chaser? Anyone can become a storm chaser – there are no procedures, certifications or permits required unless you want to become a SKYWARN® spotter.
SKYWARN®is a National Weather Service (NWS) volunteer program with between 350,000 and 400,000 trained severe weather spotters. The main responsibility of a SKYWARN® spotter is to identify and describe severe local weather and storms. They are different than chasers, usually staying in one place to observe, until it is necessary for them to move. Their training includes learning about basic severe weather structure and development, how to report, and basic severe weather safety. If you are interested in becoming a SKYWARN® volunteer, training is free and typically lasts about 2 hours. Check SKYWARN training for information and find the closest SKYWARN® program in Iowa!
Storm chasing is an expensive as a hobby – mainly because it involves a lot of travel. The term “chaser” refers to the careful forecasting and tracking of storms and then going to those storms to make observations. Many chasers have to drive or fly to “tornado alley,” stay in hotels, and can drive over 500 miles in a single chase day, all of those expenses add up to be pretty costly
If you do decide you want to venture out on your own to watch a storm, you must be very careful – not only because of the storm, but also because of the other chasers in the vicinity. Often amateur storm chasers will park in the middle of a road to watch and photograph the approaching storm. Parking in the middle of the road makes it nearly impossible for vehicles to leave the potential danger zone and they are often in the way of the trained and seasoned storm chasers. In some locations it has been reported that as many as 100 amateur storm chasers may all converge in an area where the chance for tornadoes is high.
Storm chasing is dangerous – even for the seasoned chasers. In May, 2013, 3 chasers and 1 civilian were killed by tornadoes near El Reno, OK. Local resident, Richard Henderson, was killed when he decided to follow that storm. Tim Samaras (a chaser and a meteorologist), his son Paul Samaras, and Carl Young were experienced, seasoned chasers and considered to be the safest storm chasers at the time. Tim founded and headed the Tactical Weather-Instrumental Sampling in/near Tornadoes EXperiment (TWISTEX). The TWISTEX vehicle in which the three were chasing was struck by a violent wedge tornado with winds up to 295 mph.
If you are intrigued by the idea, but don’t feel up to chasing on your own, you can actually be a “tornado tourist.” A 10-day, professional storm chasing tour (sometimes called “tornado safaris”), typically costs between $2000 and $3000. That includes lodging and fuel costs…
Both Bill Paxton and Helen Hunt were temporarily blinded by bright electronic lamps used to get the exposure right for the dark, stormy sky. They also both had to have hepatitis shots after filming in an unsanitary ditch.
Twister(1996 film). Produced by Steven Spielberg’s Amblin Entertainment.
Horvitz, Leslie Alan. 2007. The essential book of weather lore : time-tested weather wisdom and why the weatherman isn’t always right. Pleasantville, NY : Reader’s Digest Association. Engineering Library QC995.4 .H665 2007
Mogil, H. Michael. 2007. Extreme weather : understanding the science of hurricanes, tornadoes, floods, heat waves, snow storms, global warming and other atmospheric disturbances. New York, NY : Black Dog & Leventhal Publishers : Distributed by Workman Pub. Co. Engineering Library QC981 .M65 2007