In This Issue:

WEATHER STATIONS IN ACTION:

• Vantage Pro Providing UK Hospital with Data
• Vrroom Vrroom, en Español, Vantage Pro2
• There’s Something Wrong With Our Console!

  WEATHER 101:

• March of the Tornadoes
  
  TECH TIPS :
  
• Techie Bob’s Top Call Generators
  
  MAILBAG:
  
• We’re Still Talkin’ Hurricane Season ’05!
• Reviving the “Santana vs. Santa Ana” Discussion
• Just What Causes Storm Surge?
• Spare a Hair for a Fellow Weather Geek?
  
  YOU'RE BRILLIANT!
• Answers to Quiz Questions
  
  
WHO YOU GONNA CALL?
• Davis!
  

WEATHER STATIONS IN ACTION :
Vantage Pro Providing UK Hospital with Data

Andy Overton, of Doncaster, South Yorkshire, UK, has a cabled Vantage Pro that is really earning its keep, both for Andy and his community. Shortly after he put his weather data online and began to publicize his weather site, he was contacted by a hospital, Doncaster Royal Infirmary, which is about 600 yards from his station.

Andy wrote, “They were having some issues with temperature and humidity fluctuations inside the biochemistry laboratories, caused by the hospital's air conditioning system, affecting their instrumentation. They are studying these parameters inside the labs and wanted to compare their readings with outside conditions. They did a search through the Internet and the search engine brought up my station. After a brief exchange of emails to set things up, I will now be supplying daily reductions of maximum and minimum temperature and relative humidity once a month on an Excel spreadsheet to the infirmary to help with their studies.

“I know from reading information on US websites that this sort of cooperation between amateur (weather watchers) and municipal institutions is pretty common in the States but it hasn't been taken up in the UK to any serious degree. I think part of the difference is that US observers seem to be much keener at setting up a website than UK ones and the simple fact is that a website is the easiest way of letting anyone interested know you're out there. There is probably a perception that setting up a site is either difficult (if you do it yourself) or expensive (if you have it done for you), but I wrote all mine using Microsoft Word to create web pages, coupled with the WeatherLink generated AWS display. I'd certainly encourage anyone operating with WeatherLink to create a simple site around this and use the free web space most ISPs give to customers to advertise their station and let people know they've got data. And don't forget, once you've set the site up, to notify one of the popular search engines so that you get added to the search directory as soon as possible.”

We think Andy and his VP should get a Good Citizen Award – maybe a key to the city or free trash pickup?

Weather Check Quiz Question 1: You go out in your back garden to watch the crocus just starting to peek through the cold topsoil at 2:30 one gray afternoon. At 3:04 p.m. raindrop hits your head. At 3:19, you are still out there, getting wetter as the rain increases. Your spouse hollers, “Are you crazy? It’s been raining for 15 minutes and you are still standing out there!” You say, “No, dear, it has been raining for at least 24 minutes.” Now said spouse knows you’ve lost it. But, aha, you haven’t. Why not? (Click here for answers.)

Vrroom Vrroom, en Español, Vantage Pro2

Highest ranking, or at least the highest flying, among the high tech gadgets at the command center of the Argentina TC 2000 car race is a Vantage Pro2.

Guillermo Perez, of Mercobras, our Argentinean reseller, sent us this photo taken at the Argentina TC 2000 (or Turismo Competición 2000), one of the most important auto races in Argentina. Overlooking the race track and the “pit wall” is a Mercobras Vantage Pro2. The pit wall is the command center of the race, with 16 flat screens that let you see the view from cameras all around the track. It is from here that drivers get directions and orders.

“On Saturday,” Guillermo wrote, “during the qualifying races, the wind was blowing across the straightaways. But on Sunday, just minutes before the race, the VP2 reported that the wind had shifted 180º. With this information, the pit crews were able to adapt the gear box.”

Thanks to Mercobras, the drivers and pit crews have access to all the local weather data that affects their engines and race strategies. And it just looks so cool up there, doesn’t it?

There’s Something Wrong With Our Console!

Just as we are going to e-press, we happened to glance at the Vantage Pro2 console and noticed something, well, wrong with it.

We looked again, and yes, there was something just very out of place.

What? It’s cold and rainy, yes, and a little breezy, and some clouds, and … that’s when we saw that strange little icon between the cloudy icon and moon phase, looks kind of like a flower? No! It’s a snowflake! That’s something this little console has never displayed!!

(We can just see all you Midwesterners and East Coasters shaking your heads. Oh well, we have to get our weather excitement where we can.)

It’s no mistake! The weatherman is predicting snow all the way down to sea level – a very rare (last time it happened: February 5, 1976), and very exciting event around here.

Weather Check Quiz Question 2: How can the Vantage Pro2 forecast snow when it is 46º outside? (Click here for answers.)

We love March, with the coming of spring and longer days, and, uh oh, the start of tornado season! Tornadoes can form anytime, and anywhere, but here in the US we can expect to see reports of damage from tornadoes through August. And there is no such thing as a non-dangerous tornado.

Tornadoes are defined as “an intense, rotating column of air that protrudes from a cumuliform cloud in the shape of a funnel or a rope whose circulation is present on the ground. But the most important quality of tornadoes is their lack of predictability.” (From Meteorology Today, by C. Donald Ahrens.)

While most are a few hundred feet in diameter, some are just a few feet and some are a mile across. Most travel a few miles at 20 to 45 mph (32 to 72 kph), and last just a few minutes. But some monsters have traveled hundreds of miles over many hours, and have spun across the landscape at over 80 mph (125 kph). One of the twisters in a memorable tornado outbreak that hit Texas, Kansas, and Oklahoma on May 3, 1999, had wind speeds of more than 315 mph (510 kph).

And their worst quality: they are hard to predict, as we all know, with enough time to warn those in the path.

A typical tornado is the homely offspring of a thunderstorm, and one big thunderstorm can produce a whole litter of tornadoes. In the US, dangerous tornado-producing thunderstorms tend to form in the springtime when warm wet air pushes cold and dry air northward. When storm watchers see rotating clouds at the base of a storm, they know they are witnessing the birth of a tornado.

A tornado watch is called when tornadoes are likely to form within a few hours, and a tornado warning is issued when trained spotters see – either visually or on radar – a tornado. At this point, all one can do is take shelter.

In the US, we can expect to see more than 1000 tornadoes this year. Damage to homes, especially mobile homes, will certainly occur, but the warning system has been very successful in preventing a rise in the number of deaths caused by tornadoes over the last 50 years, despite a very large increase in population.

With a hurricane season like the last one, we can only hope Mother Nature gives us a break on this tornado season. But as we go to e-press, with March still young, tornadoes have already ripped into Mississippi, which has had more than enough weather in the past months, and ripped across Illinois, Kansas, Texas and Missouri leaving at least 10 people dead. Hold on to your hats.

While everyone hates the damage tornadoes can do, it is hard to argue that twisters are the ultimate adrenaline fix for storm watchers. The urge to get close to one has been the undoing of many a would-be student of severe weather. On FEMA’s Tornadoes for Kids website, we found a story about a scary tornado in South Carolina written by future weather buff Brandon, age 10.

Our favorite part was this: “Me, I have always had a fascination with weather, especially tornadoes. I had mixed feelings of joy, since I always wanted to see one up close, and fear, because I didn't want to die or be sucked up and fly in the air.” Oh, Brandon, we know just what you mean.

Note: Here in the United States, we’re famous for having the most tornadoes, but we certainly don’t have them all. In Europe, the leader in tornado creation is the UK, with about an estimated 50 a year, and Holland, with about 35. When you consider the land size of these countries, that’s a whole lot of tornadoes. A good resource in the UK is the Tornado and Storm Research and Organisation

Bonus Tornadic Factoid: “Ask Marilyn,” a column produced by Parade Magazine, includes questions from readers. We enjoyed coming across this question and answer in the January “Ask Marilyn” column. We figured you’d get a kick out of it, too!

“I am tired of being attacked by my shower curtain liner! Why does it always blow inward when I shower? —Debbie Tuell, Fullerton, Calif.

“This pressing question was studied exhaustively by David Schmidt, an assistant professor in the mechanical and industrial engineering department at the University of Massachusetts at Amherst, maybe when he ran out of stuff to do at work. Using specially designed software, he simulated a room-temperature shower running for 30 seconds—long enough for the curtain to envelop you in that unwanted embrace. Schmidt learned that the spray generates a vortex like a mini-tornado, with a center of low pressure that sucks the shower curtain toward that region. The buoyancy of warm air in the average shower adds to the effect.”

We were curious to find out more, so we found David’s own discussion of the phenomenon. Read it yourself and you’ll see why they call him "Professor!"

Weather Check Quiz Question 3: Do tornadoes always rotate cyclonically (i.e., counterclockwise in the northern hemisphere and clockwise south of the equator)? (Click here for answers.)

TECH TIPS:

Techie Bob’s Top Call Generators

We recently went right to the source and asked one of our exalted Tech Gurus, Bob, what the most common “call generator” was. He had a nice quick answer, and then another!

First, according to Bob, is a problem experienced by a new weather station owner who has just installed his station and finds that while everything else seems to be working fine, he is not getting any wind data. The frustrated caller can look out the window and see his wind cups spinning merrily, yet the number in the middle of his compass rose on the console remains stubbornly at “0”.

Bob says that this is usually a very quick fix.

“I tell them to go outside and loosen the wind cup assembly using the Allen wrench (.05) we provided in the station kit and then push the wind cups up on the shaft again. Continue to push up on the cups and tighten the set screw at the same time. They say, ‘I already did that!’ and I say, ‘Humor me and try it one more time.’ My caller almost always comes back and tells me, ‘It’s working!’

The wind cup assembly needs to be firmly in place, but still free moving. The caller may need to remove the wind cups and reinstall them, which can be a bother if the station has been installed on a roof or high pole. “Whenever I set up an ISS (Integrated Sensor Suite), before I climb up on the roof, I always spin the cups (and tip the tipping bucket, and move the wind vane) to make sure the console is receiving data. You just have to remember to clear the data from your console so that your history will be accurate.”

We could truly relate to the second call generator Bob told us about: no rain data. We recently found ourselves in a downpour while visiting in Alabama. The rain was sweeping down like it almost never does here in the balmy Bay Area, but the newly installed Vantage Pro2 console was reporting no rainfall at all! Knowing the accuracy of Davis weather stations, we actually experienced a moment of doubting our eyes and ears! (Of course, it turns out the problem was that the ISS had been blown off its temporary mounting -- not jet-lag induced storm hallucinations!)

Bob says this problem is usually caused by one of two problems. If the station has just been installed, he asks the caller if she is sure she removed the plastic cables that secure the tipping bucket during shipment.

“Oops,” is often the embarrassed response.

If it is a station that has been reporting rainfall and suddenly stops or reports obviously too little or too much rain, Bob suggests that the owner see if anything is blocking the rainfall.

“Usually the caller finds something simple like a leaf over the hole in the bottom of the rain collector, or something not so simple, like a hornet nest hanging off the tipping bucket assembly.” Keeping the rain collector clean should be part of annual maintenance, Bob reminds the caller -- and all of us!

If the customer is getting the “too much rain” scenario, Bob suggests he check the tipping mechanism to see if it is in a position so that neither of the cups is resting on its standoff screw.

Bob, like the rest of his Tech Support colleagues, is endlessly patient and loves talking to weather station owners.

“I’ve always been a teacher,” he told us. “I really enjoy explaining things to people, and I always get a big kick out of solving a problem for a caller.”

Need Bob’s (or another equally enchanting Tech Support team member’s) number? It’s (510) 732-7814, Monday - Friday, 7 a.m. to 5:30 p.m. Pacific Time, or you can use email, support@davisnet.com.

Weather Quiz Question 4: Does the size of the rain collector matter to the accuracy of the data? (Click here for answers.)

MAILBAG:

We’re Still Talkin’ Hurricane Season ’05!

Harry Longo III has been running a Wireless Vantage Pro2 Plus with 24-Hr Fan Aspirated Radiation Shield weather station for almost a year now, and says he has “been constantly impressed with the unit and its operation since installation.”

Which is saying quite a bit, since that year was most of 2005, and he put the poor little thing in his yard in Lantana, FL, right in the middle of the eye of October’s Hurricane Wilma. His data is pretty fun to look at – he has stacked graphs that show the dramatic dip in pressure to 953.2 hPa, the change in wind direction, the increasing winds and the sudden calm followed by more winds, etc., so the storm’s effects are well illustrated. Check out his Wilma data and his ongoing daily weather data.

Reviving the “Santana vs. Santa Ana” Discussion

Barbara Bonnin, of Tucson, AZ found our site and past e-newsletter discussions on the proper name for the dry and dangerous southern California winds. As a longtime resident of the area, it spurred her memory.

“Our paper in Tucson has a question regarding the use of Santa Ana vs. Santana for the hot, dry winds coming from the east. The paper’s resident weather reporter gave your website as a source for the best information. As a native San Diegan, I remember them called Santa Ana winds in the ‘30s and ‘40s. Sometime in the mid ‘50s or so Santana winds suddenly came into use by a television reporter, perhaps someone new to the San Diego area. It persisted for a few years by some, but Santa Ana wind was used by most people, and gradually Santana disappeared. Since moving to Tucson a year ago the name I have heard here is Santa Anas.”

Barbara’s memory seems to jibe with those of our other readers, who say even though the winds certainly seem inspired by Satan, they are still the Santa Anas. The Journal of the San Diego Historical Society has a good article summing up all the discussion.

Weather Quiz Question 5: This kind of wind goes by many aliases. Which of these does not apply to winds like the Santa Anas? (You can pick two!) A. Katabatic
B. Etesian
C. Chinook
D. Mistral
E. Foehn
F. Maria
(Click here for answers.)

Just What Causes Storm Surge?

Chris Corey, of Milford, MA, took up Pete Engels’ challenge to come up with an authoritative answer to the primary cause of storm surge: pressure or wind? Chris did some research and found, like we did, that the pros agree that both are factors, along with the contour of the ocean floor and depth. He sent along quite a few links to back up his opinion, including the NOAA, the Australian Government Bureau of Meteorology, the BBC Weather Website, and Answers.com.

Chris told us he thinks the most interesting fact came from the BBC website describing the effect of pressure drop on sea levels: “If pressure decreases by one millibar, the sea level rises by one centimetre. While this doesn't sound like much, across the whole sea this can represent a significant volume of water."

Thanks, Chris. (How’s that, Pete?)

Spare a Hair for a Fellow Weather Geek?

Dave Benson, of St. Louis, MO, is a true Weather Geek. Not only does he love watching the weather, he even loves weather equipment!

“It sure hurts to see all of those proud Davis stations twisted by hurricanes and such,” Dave wrote. “It made me think about how long stations can last when they are not subjected to the wrath of mighty Momma Nature. My Weather Monitor II is going on eight years old and is still in fine shape.”

Dave has a sort of old weather gadget museum, mostly barometers – and as curator, he needs your help!

“I like to get a neglected piece of weather history and breathe new life into it, restoring it to its original glory. Which brings me to my question. I recently acquired an antique barometer/hygrometer combo dated 1930. It's no replacement for my WMII, but it is an intriguing glimpse into the history of our shared hobby. I wonder how our weather enthusiast counterparts from the 1930's would react to a Vantage Pro2?!

“The barometer works great but the hair hygrometer needs some Rogaine! It seems that someone twisted the adjusting screw a bit too much and snapped the fine hair inside. I am more than willing to do a repair on it, and I actually have access to plenty of hair (another story). But I'm looking for someone who can tell me just where the new hair should go. I thought your incredibly intelligent and resourceful readers might be able to offer some help to a fellow weather geek in need.”

If you can help this fellow weather geek, send him an email at www.afftonweather.com.

Weather Quiz Question 6: A hair? How in the world can a hair help measure humidity? And what kind of hair?

YOU'RE BRILLIANT!:

Question 1: Because that silly spouse is thinking that it starts to rain when the first raindrops hit the ground. But you, being a weather genius, know that raindrops start falling within the clouds before they hit the ground. Even without considering updrafts, a rain drop falling from the middle of a cloud 20,000 feet thick would take longer than nine minutes to reach the ground. If you only had your own radar as well as your weather station you would be able to see exactly when it starts to rain! Then that spouse would be impressed, indeed. (Back to stories.)

Question 2: Because it’s predicting the temperature will drop overnight. It’s also looking at the humidity, which is relatively low. When a snowflake falls from the colder air above into the warmer layer of air it will begin to melt. The water on the snowflake and the relatively low humidity in the air will cause the snowflake to evaporatively cool back below freezing (32ºF, 0ºC), allowing it to survive as it falls to the ground through warmer air. (Back to stories.)

Question 3: No, but anticyclonically rotating tornadoes are very rare. According to Roger Edwards of the Storm Prediction Center’s Online Tornado FAQ page, “Anticyclonic tornadoes (clockwise-spinning in the northern hemisphere) have been observed, usually in the form of waterspouts, non-supercell land tornadoes, or anticyclonic whirls around the rim of a supercell's mesocyclone. There have been several documented cases of cyclonic and anticyclonic tornadoes under the same thunderstorm at the same time. Anticyclonically rotating supercells with tornadoes are extremely rare; but one struck near Sunnyvale, CA, in 1998.” (Back to stories)

Question 4: Yessiree, Bob, as Bob would say. Our rain collectors are carefully designed with the cone’s dimensions – mouth diameter, interior slope, hole diameter, cone height – exactly engineered to create a proper “tip” of the tipping bucket. That is why our Tech Team gets so nervous when users cover or screen the mouth of the cone to prevent leaves, bird droppings, and other debris from entering. Anything that blocks any rainfall skews the data. So resist that urge! (Back to stories.)

Question 5: Not B., Etesian. (“A refreshing northerly summer wind of the Mediterranean, especially over the Aegean Sea.”) Also not F. Maria, which you better not have chosen! (“A fictional wind popularized in ‘Paint Your Wagon’ (Lerner and Lowe, 1951) and by the Kingston Trio (1959), whose name may have originated with the 1941 book ‘Storm’ by George R. Stewart.”) Definitions are from the About.com page on wind names. (Back to stories.)

Question 6: We have a friend who had relatively normal hair here in the San Francisco Bay Area who moved to the humid south. When he sent us a photo of himself, we were delighted to find that he actually had very BIG hair. That’s because, as every woman knows, humidity makes your hair do bad things, as in have a bad hair day. Technically, hair gets longer as humidity increases. In terms of glamour, if your hair is curly, it frizzes. If it is straight, it goes limp. A couple of hundred years ago, a Swiss physicist named Horace Bénédict de Saussure built a device to measure the humidity in the air by measuring the change in a human hair. The best kind of hair to use: human, thick, blond, long, and taken with permission of owner.

You can build a hair hygrometer yourself! Check out these links from the Exploratorium, Franklin Institute Online , and Queen’s University in Kingston, Ontario, Canada.

Here’s a bonus factoid, just ‘cuz we like you, from the Queen’s University website: “Fir cones (e.g. cone from Douglas fir tree) are natural hygrometers. When a fir cone is closed and smooth, it indicates wet weather. When the cone opens and sticks out in all directions, there's a drying trend.”

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, such as how much cable comes with a station contact sales@davisnet.com. To request a catalog, you’ll find links for catalog requests on our web site at http://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 E-News. Member participation is what keeps the E-News alive and kicking.

Well, that’s it for this edition. You’ll be hearing from us again next month!


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.