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Davis Instruments Weather Club
May/June 2008
In This Issue:
WEATHER STATIONS IN ACTION:
Vantage Pro Goes For the Gold
Vantage Pros are being used to keep athletes and spectators weather savvy at the 2008 Olympic Games in Beijing, China. Photo: People's Daily
The 2008 Olympic Games are where the greatest athletes in the world will meet and compete. Our own greatest, the Davis Vantage Pro is not one to be left out! As China prepares for the Games this summer, Vantage Pros are part of the plan to provide very accurate, detailed weather forecasts that will enable athletes to make adjustments for weather variations. Since the games will be held during China’s rainy season, predicting rain and possibly even using seeding techniques to control when it falls, is very important.
Vantage Pros have been installed all over Beijing and other co-host cities to provide athletes with data on the microclimate of their particular venue. During the games, athletes and spectators will have access to almost-real time weather data at kiosks set up throughout Beijing and other venues.
For more on the story, see the story on the
official website of the Beijing 2008 Olympic Games.
Bring us home a medal, Vantage Pro!
Weather Check Quiz Question 1: How do Chinese meteorologists hope to control the weather?
A. By inducing rainfall by seeding clouds with rocket-fired chemicals
B. By accurately predicting rain and using a movable roof over the arena
C. By passing “No Rain On Fridays” legislation
D. By dispersing rain clouds with rocket-fired chemicals
E. By blowing rain clouds away from the area with giant fans
F. By creating underground competition areas
(Click here for answers.)
Oh Canada! Maple Leaf on Mars
Canada's first piece of scientific instrumentation to land on an alien world is: a weather station! The $37 million unit (it's not a Davis system, ours are a little less costly than that) was shipped off to Mars last August on the US’s
Phoenix Mars Lander, and was dropped on the Martian surface on Sunday, May 25.
The station will report temperature, pressure, cloud height, humidity, and wind speed. Scientists are especially interested in cloud measurements because they hope to determine how much ice water is held by the clouds. The overall goal of the mission is to determine if ice exists on Mars and if so, whether the red planet could be, or ever was, habitable.
The station is housed in a shoebox-sized enclosure, with "Canada" and a tiny Maple Leaf on it. (Story:
The Canadian Press) Captain Weatherman Saves the Day with his Tornado Intercept Vehicle
Davis meteorologist and Jedi Knight, Jason Karvelot, in front of his Starship
Amphibious Interstellar Assault Transporter.
Well, our meteorologist doesn’t have superpowers, and the Tornado Intercept Vehicle (or TIV) behind him is not even his. But it is a very cool vehicle and Jason had fun pretending he was driving it toward a twister. The picture was taken in February at the
Storm Chaser Convention in Denver, Colorado. Davis and our reseller, John Utech, of
WeatherLab in Blackwell, Oklahoma were present.
The TIV was built by Storm Chaser Sean Casey over three years starting in 2003, with a total price tag of $80,000. The heavily armored vehicle can hunker down and stretch out its stabilizing legs, allowing the storm chaser to film direct tornado impact. You can learn more about it and see videos on the
Discovery Channel website.
“The Storm Chaser Convention is always fun.” Jason said. “It’s a chance to hang out with real storm chasers, see the latest chasing techniques, and see the latest storm footage from the previous season.”
Weather Check Quiz Question 2: True or False: If a tornado is approaching while you are in a vehicle, it is best to stay in the car. (You better get this right if you live in Tornado Alley, or anywhere in the US in 2008!) (Click here for answers.)
WEATHER 101:
Watching the Clouds for Tornados
Editor's Note: Between the time we prepared this newsletter for emailing and today, this story became, sadly, dated. Over the Memorial Day holiday weekend, tornados hit Colorado, Kansas, Iowa, Minnesota, Wyoming, Oklahoma and even California, bringing the death toll to 110 this year. The unusual tornado that struck Colorado happened to hit the town of Windsor in which a school we profile below is located. See the
CNN story about how 2008 is stacking up to be one of the worst in history.
It looks like we are in for an extraordinarily active tornado season this year in the US. 2008 started out with a tornadic bang when twisters or tornado threats tormented everyone from Ontario to Louisiana, particularly hitting hard at Missouri, Arkansas, Illinois, Wisconsin (recording its first twister since 1967), Mississippi, Alabama, and surrounding areas during the first ten days of the year. In February, there was the “Super Tuesday Tornado Outbreak,” with 84 confirmed tornadoes over the Southern US, especially Memphis and Jackson, Tennessee. This outbreak killed 57 people and injured hundreds.
And things aren’t improving. Ask Missouri and Mississippi, which have had more than 100 twisters each this year. Alabama, Arkansas, and Georgia are right behind with over 80 each. The EF4 tornado that killed 12 in Arkansas in February left the longest recorded damage track in the state’s history. The twister that tore downtown Atlanta to shreds in March killed two and did $150 million in damage. As of May 18, there have been 868 tornados and 100 tornado deaths in the US. The National Weather Service Storm Prediction Center in Norman, Oklahoma must feel pretty safe in predicting that this year will meet or beat 2004, which finished with 1,819 tornados.
Tornados are a fact of weather life across the center of our nation. The death, injury and destruction they cause are a constant reminder that weather watching is not the pursuit of mild-mannered, overly-controlled, introspective types. While most weather data is benign and predictable, the subtleties, trends, and visual clues that foreshadow such intense and immediate events as tornados are where the art of weather watching comes in.
Weather watchers in Tornado Alley are very good at seeing indicators in cloud formations. What they are looking for is tall, dense cumulonimbus clouds. Cumulonimbus clouds form along cold fronts, rising mushroom-shaped above lower cumulous clouds. They can then grow into the classic warning cloud for strong winds, thunderstorms and tornados: the anvil cloud, or cumulonimbus incus. This “King of Clouds” is a huge, mountainous, water logged formation, topped by a crown that looks much like a blacksmith’s anvil. When a weather watcher sees that “thunderhead,” he or she knows a full fledged thunderstorm is on the way.
Cumulonimbus clouds form during periods of atmospheric instability and convective updrafts. As the cloud grows upward, it finally reaches the troposphere where temperatures stop dropping and start to increase with altitude. The troposphere clamps a virtual lid on the cloud, causing the tell-tale spread of the anvil.
Cumulonimbus clouds sometimes form pendulous blobs that reach downward from the underside of the cloud. The cumulonimbus mammatus always indicates severe weather. As for tornado prediction, mammatus formations mean a very vigorous thunderstorm – perfect for tornado breeding.
But weather watchers know that a tornado is not a cloud, it is a wind. They form in the updraft of a thunderstorm, while rain and hail form in the downdraft. That means tornados form in the “backside” of thunder storms. If you are in the path of a tornado, you will probably not be able to see it until it is very close. But if you are following the storm or behind it, you may see a wall cloud, which is a small cloud rotating slowly at the back edge of the thunder storm. This is an ominous sighting, because while not all wall clouds spawn tornados, they would all like to! There is a good labeled picture of a tornado-spawning thundercloud on
Discovery.com.
Wildweather
also has a lot of good information.
So while looking at your Vantage Pro2 console is a good idea, if you live in Tornado Alley in 2008, don’t forget to go outside and look up every so often too.
Weather Check Quiz Question 3: True or False: A waterspout is a tornado that draws water upward into its funnel.
(Click here for answers.)
TECH TIPS :
Top FAQs on Weather Support Page
We’ve got a great Tech Support team, but sometimes a solution to a common problem is even closer than a phone call away. One place is the
FAQ pages on our support pages. (Click support on the Davis homepage, then weather support. FAQ’s are grouped by product.)
Here’s the number one FAQ for Vantage Pro2:
“While testing my new system I see that the transmitter’s green light is flashing every 2.5 seconds but I cannot receive anything on my console that is a few feet away.”
Tech Support’s answer:
“Be sure to wait for a few minutes. Our new hopping radio technology can take a bit longer to first acquire a signal. If you have waited for more than five minutes and the console and transmitter are very close to each other, remove the white plastic cover from the center of the transmitter board and see if there are two jumpers attached to the board. If so, remove them and repower your transmitter board by plugging a power adapter (not connected to AC power) into the jack on the transmitter board for one minute. This will reset the board after you have removed the jumpers.”
If you can’t find the answer to your question here, feel free to call our amazing, (they just know everything!) Tech Support team at 510-732-7814.
MAILBAG:
Dew Point and Overnight Low Temperature
Californian Ray Froess liked the idea of using his Vantage Pro2 dew point indicator to predict overnight lows and asked for more details. Here’s how it works:
Look at your dew point in the afternoon - really the later the better, but before dark. Provided no frontal passages are expected overnight, and the afternoon humidity is above 50%, it is a good rule of thumb that it will not get colder than that temperature tonight. The later you check, the more accurate your prediction will be.
On your Vantage Pro2 or Vantage Pro console, push 2nd and DEW so the dew point is displayed. Use the directional buttons to get the graph symbol on the dew point. Then press GRAPH. The daily min/max dew point will show below the graph. You can use the left button to go back to yesterday afternoon (the date and time appear at the top of the screen as you go back) and see what the dew point was, then push DONE. Use the directional buttons to get the graph symbol on outside temp, then push GRAPH, and use the directional buttons to go back and find the lowest temp overnight. This is just a rule of thumb - but it is interesting to see how often the two temperatures are very close, and that the outside temp almost never goes lower than the afternoon dew point.
Ray wasn’t just asking though, as he understands the principles quite well and offered us this explanation of what is going on with dew point and low overnight temperature.
“I'd explain the relationship as follows. The dew point is the temperature at which humidity is 100%. If the air temperature goes below it, the water vapor it contains must condense. This phase change, vapor to liquid, takes much more energy. See
Hyperphysics where they show a graph. You'll see that changing water to vapor (steam) takes 539 cal/gram during which the temperature doesn't change. Notice on the left that in its liquid state it only takes 1 cal/gram to change it one degree.
“So what happens at night is the heat stored in the air is radiated (lost) and the air temperature drops. But once it hits the dew point, the temperature stays constant until enough energy is lost to convert the vapor to liquid. Then the air temperature continues to drop.
“Your statement that the humidity must be above 50% isn't a hard and fast requirement. It just means that there's plenty of water vapor that has to be converted to liquid.
“The reverse happens when it rains or even more when it snows. You'll notice that the air temperature plateaus as the energy is released when the water vapor changes phase to liquid. This phase change is the principal used in refrigeration.”
(But Michael Fox, of Chino, California, outsmarted us both, Ray, when he noticed that we said the humidity has to be below 50% in the original newsletter story. Oops, wrong direction. Arrggggg!)
Key Buoy Cooks with Rachel
We know all our readers are weather fans, and many of you may be unaware that Davis Instruments also manufactures a line of marine accessories, as well as a line of automotive products. Since boaters are usually quite interested in the weather, many of our customers are interested in both product lines!
So when one of our marine products made an appearance on the Rachel Ray show, we thought you’d get a kick out of seeing your weather station’s fun little cousin,
Key Buoy, in action. Click
here to see the video.
Vantage Pro2s Make the News
Sunny Jerry and his Vantage Pro2 Cover the Weather in Rhode Island
Photo courtesy of Warren Times-Gazette
Jerry La Roche and his trusty sidekick, Vantage Pro2, are famous for their daily online and email weather reports in their hometown of Warren, Rhode Island. Featured in a story in the
East Bay Beacon (Warren Times-Gazette), Jerry is known for his weather expertise and his "sunny disposition." (What a great combination!) Jerry met up with a hurricane named Carol when he was a teenager and was smitten with a passion for the weather. Now his neighbors, the local television station, and the rest of us, get the benefit of his weather reporting. His website,
www.weatherfun.com
is an educational resource as well as a place to post and blog about the weather.
What we like best about Jerry, besides his weather station, is the pride he takes in the name bestowed upon him by his fellow weather watchers: "Official Weather Nut."
Sixth Grade Meteorologists in Colorado
Editor’s Note: Windsor, Colorado was hit by a tornado on Thursday, May 22. One person died and almost 600 homes were destroyed or damaged. We were relieved to see that no schools or students were mentioned in the news stories. We know the school staff is concentrating on getting their school back in order and in helping their community recover, but we hope that they will let us know how he young meteorologists and their weather station and are doing.
Ms. Winfrey is breeding the next generation of enthusiastic weather buffs in her classroom at Windsor Middle School in Windsor, Colorado. They've installed a high tech system based on a Vantage Pro2, with weather cam, and students are having a great time collecting data and keeping their school and community up to date on the latest weather with their
weather website.
Their story was covered by The Windsor Beacon.
Weather Check Quiz Question 4: Here’s one for all you weather dudes and dudettes, from 12 to Granddad. What is the difference between "partly sunny" and "partly cloudy"?
(We borrowed this question from Steve Sistek’s KOMO TV, Seattle, who has a list of great quiz questions on
Steve’s Weather FAQ page!) (Click here for answers.)
Sunset Over Hawaii, or Maybe That’s Hayward
 One of our resident IT genii, Norm, took this photo of the spectacular sunset over our Hayward, California, home. (Poor Norm, as you can see, sometimes he works very late!
Weather Check Quiz Question 5: What does the fact that there are lots of dark oranges and reds in this photo mean?
(Click here for answers.)
YOU'RE BRILLIANT!:
Answers to Quiz Questions
Question 1: A & D. China has been successful in seeding and diffusing rainclouds using liquid nitrogen or silver iodide fired into clouds by rockets. They hope to do the same thing this year to keep athletes and spectators dry during the games. Seeding clouds, although controversial, has been tried often – but meteorologists say it is very difficult to tell how effective it is because it is impossible to know how much rain would have fallen if the seeding hadn’t been done. In China, the hope is that rain can be induced during non-competition hours which will clean the air of pollution. Later, raindrops will not form as easily because there will be fewer particles, or nuclei, on which to form. The other way is to disperse rainclouds with chemicals. However, according to ABC News, William Brune of Penn State University meteorology department said the process is technically feasible, but he remains skeptical about its effectiveness. "What this process is trying to do is distribute the water among the cloud to make it hard for the water molecules to come together to make rain drops," he said. "It is very hard to prove you've actually done anything at all, and there isn't any indisputable evidence that this actually works." (Back to stories.)
Question 2: Unless you are in the TIV, FALSE!!!! According to a recent
AP story, “nearly half the 21 people killed by a tornado that smashed Oklahoma and Missouri over the weekend [of May 10] died in cars, troubling experts who say vehicles are among the worst places to be in a twister.” If you are driving when a severe storm warning is issued, seek shelter at a permanent structure, like a restaurant. If you can’t find a permanent structure, get out of the car and take shelter in a low-lying place like a ditch, where you can duck and cover. (Back to stories.)
Question 3: False. This is kind of a trick question, but you are getting harder and harder to stump, so we’re resorting to wording tactics. While a waterspout may be a tornado that has moved or formed over a body of water, the water is not drawn up into the funnel. The funnel is fast-moving air, just like on land. But when the funnel contacts the surface of the water, it creates swirling spray several meters off the water. It makes the waterspout look like it is a solid tube of water spinning up into the cloud. (Back to stories.)
Question 4:
Question 4: “This is [also] a trick question. There really isn't much of a difference. They all mean the sky is part clear, and part cloudy. It just gives us a larger vocabulary to work with. Although most of the time, we'll tend to use it as a bit of psychological factor. If the forecast is improving (as in, rain event is just ending and we'll clear up a bit), we'll usually go partly sunny. If the forecast is deteriorating (as in, it's sunny now, but rain moving in tomorrow), we might say mostly cloudy as the condition during the increasing clouds. We tend to save 'partly cloudy' for nighttime, since we can't use partly sunny.” (Back to stories.)
Question 5: Unfortunately, those pretty colors tend to indicate that our air over Hayward is not so clean. Fine particles in the air, like smog, tend to scatter the yellow waves away, leaving more red and orange. If you have ever been near a big wildfire when the air is loaded with particulates, you might have seen an all-red sun. Or if you were anywhere near Mt. Pinatubo in 1991 or El Chichon in 1982, you might remember some spectacular sunsets, thanks to volcanic ash.
(Back to stories.)
WHO YOU GONNA CALL?
Davis!
Each month after the E-News goes out, we receive messages back. Sometimes the messages are in response to a story we shared; other times they are a request for help of some kind. We read all the emails, answer those we can, and pass the rest on to the appropriate departments.We think you should know, though, that if you're interested in the fastest possible reply, news@davisnet.com may not be the best place to send your message. Questions about how things work should be addressed to tech support directly at support@davisnet.com. For general information about the products contact sales@davisnet.com. To request a catalog, you’ll find links for catalog requests on our web site at www.davisnet.com/contact/catalog.asp.
Please continue to send your comments, weather URL's, and story suggestions to news@davisnet.com. We look forward to getting your comments and any responses you have to the Davis E-News. Member participation is what keeps the Davis E-News alive and kicking.
Well, that’s it for this edition. You’ll be hearing from us again next month!
The Davis Weather Club E-Newsletter is published by Davis Instruments.
© 2008 Davis Instruments Corp. All rights reserved.
Vantage Pro2, Vantage Pro2 Plus, Vantage Pro, Vantage Pro Plus, Weather Monitor, Weather Wizard, WeatherLink, Weather Envoy, and Perception are trademarks of Davis Instruments Corp.
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