We can’t believe it ourselves, but we’ve already started working on our 2006 Weather Catalog! That means you have to start working on it too, because we love to feature our users in our catalogs. What we need is a photograph of you with your weather station. As the hot new star, Vantage Pro2 is going to get most of the glamour shots. But we like to see other real-life hardworking stations too, especially if they are being used in some unique, fun, or professional setting.

So get out the digital camera and get creative! And even though the sensor suite is usually out there in the snow (or the salt water spray, or in the vineyard) don’t ignore your loyal little console! We love it when you include yourself in the photo. We also love high resolution photos. Remember, the lower the resolution, the smaller the photo will have to be (good to know if you are hoping for a cover shot!).

Send the photo to us via email at news@davisnet.com or mail to Weather Club, Davis Instruments, 3465 Diablo Avenue, Hayward, CA 94545. We won’t be able to return photos. Please include your full name, address, email address, and phone number with your photo. By contributing your photograph, you give us permission to use and publish the photo, so you must be over 21 or have parental permission in writing.

We can’t promise to publish every photo we receive, but if we do use yours in our catalog, we’ll send you a Davis cap or T-shirt!

Gadget Guru Gushes Over Vantage Pro2 and CarChip

Gadget Guru Ron Rosberg recently featured two Davis products on his portion of the “O'Donnell on Technology” radio show on the Bay Area’s ABC KSFO radio. He seems to be truly one of us! (He LOVES the Vantage Pro2, and our Tech Support Team.) Welcome to the club, Ron. You can hear his comments on his Everything Technology website. Click on “Download an Audio Archive (MP3) of this Program,” then scroll down to June 4, 2005, 11:18 a.m. Ron’s comments start at about 33:30.

Beta Testers: Help us Check out WeatherLink 5.6

There’s nothing like a few dedicated WeatherLink users to find our just how we’ve done with a new beta version of WeatherLink. You always give use great feedback!Once again, we’re asking for your help. Download the beta version of WeatherLink 5.6 from our website, and let us know what you think. (The beta version, as well as the free upgrade once it is released, requires an installed WeatherLink version 5.0 or later on the same computer.)

Testing will run through the end of July. Soon after that we hope to have the final version ready for release.

Here’s a preview of the new features in WeatherLink5.6:

• Inside Dew Point and Heat Index in the Browse and Plot windows
• Average and High Wind Speed values over the last 1, 2, 5, and 10 minute intervals in the Summary window
• Improvements to Internet Upload features: Eight Internet upload profiles (up from three); Local proxy settings; Improved FTP error recovery; New HTML tags for the Weather Forecast, Moon Phase, and new Wind values.
• The Wind Chill formula has been modified to give more "intuitive" values between 40 F (4.4 C) and 93 F (33.9 C). In this temperature range, higher wind speeds will result in lower wind chill values using the new formula than using the previous formula. (This only affects the chill value shown in WeatherLink, not values shown on the weather station.)

There are more details are in the Read Me file that comes with the 5.6 beta version. Thanks in advance!

WEATHER 101:

Is That a Front Behind You?

Every morning, our local television weatherman shows us a satellite photograph of California. On many mornings (especially in the winter), he points to a chipper little swirl of clouds over the Pacific and says something like, “We’ve got this cold front moving into Northern California, bringing some showers…” But just what is a cold front? What’s a warm front? And what on earth (or just above it) is an occluded front?

When weather folk talk about a front, they are talking about the meeting of two air masses. The masses are different in that one is cold and dry; the other is warm and wet. (The really important difference in the two air masses is density, but since density is reflection of temperature and humidity, we get the warm and cold differentiation.) With such different qualities, we can’t be surprised that the meeting will not result in a friendly discussion of differences. Instead, one mass will politely ask the other to “move it.”

In the case of our common Pacific cold front, the cold mass is the bigger bully. As it moves toward the warmer air it shoves it up out of the way, like a big snowplow. The warm air rises above the cold front, cooling as it rises. We’ve all heard that warm air “holds” more moisture than cool air. While this isn’t a perfect analogy, it does make it easier to understand why we often see rain falling along the front: the cooler air can’t “hold” as much as it did when it was warmer, so the moisture condenses and falls.

Sometimes the warm mass is the more powerful force, but warm fronts are usually a bit gentler in their dealings with the cooler air mass. The warm air is less dense, so moving a more dense mass takes persistence. Instead of snowplowing the colder air out of the way, the warm air rides gently over the cooler air, forming a gentle up slope. As the warm air rises, it cools, and once again, we usually see precipitation. Warm fronts are the tortoises of air masses: slow and steady. They move along at about half the pace of cold fronts.

While precipitation is common with the passage of all fronts, the different “styles” of warm and cold fronts results in different precipitation patterns. With a cold front, the upward movement of warmer air is more dramatic. Deep clouds form, and intense bands of showers and thunderstorms result. We see high winds, tornados, and snow storms when a cold front moves through an area. But often the drama is short-lived, with showers lasting minutes or hours. In the case of a warm front, the gentler rise of warm air results in more prolonged but less dramatic rain and snow well ahead of the front. (Since the upslope is gradual, moisture is condensing high above the cold air where we are.) The precipitation may last for hours or days, and if thunderstorms result, there may be an extended period of thunderstorm activity.

Once a front moves through an area, we usually see very different weather from either before or during the front’s passage. When that cold front hits, we can expect to get doused with some showers. Afterward, the wind direction will change, temperatures will be cooler, pressure will rise, visibility will improve, and the dew point will drop. After a warm front passes, we can expect a shift in wind direction, warmer temperatures, pressure rising a bit then falling, clear skies, and a rising dew point.

On a weather map, cold fronts are shown as blue lines with solid blue triangles pointed in the direction of the front’s movement. Warm fronts are shown as red lines with solid red half circles in the direction of the front’s movement. Meteorologist know where to draw these lines by looking for sharp temperature changes over short distances, shifts in wind direction, pressure changes, changes in dew point (which reflects the air’s moisture content), and cloud and rain patterns.

Sometimes in the war of air masses, nobody wins the struggle to dominate and a stationary front results (on the map it’s red half circles pointing one way, alternating with blue triangles pointing the other way) with weather much like that of a warm front. And sometimes, just when the slow and steady warm front thinks it’s got it made, a faster moving cold front catches up with it and overtakes it. The result is an occluded front (on the map, a purple line with alternating purple triangles and half circles, facing the same direction).

Weather Check Quiz Question 1: There’s another strange line you might see on a weather map: red with open half circles. It’s not a warm or cold front. What is it? (Click here for answers.)

What’s that we hear? Sounds like, “Good morning, starshine!” You don’t hear it? Maybe you’re just not old enough to truly appreciate this story!

Matthew Pace must be an old soul. He has aptly blended one of the best things from his generation – the Vantage Pro – with one of the best from a past generation: a fully restored 1969 Volkswagen bus!

Matthew, a college student majoring in Meteorology/Climatology in a transfer program to Arizona State University, is extremely active in the weather community. “In addition to my own research projects, I also share weather information with the National Weather Service in Phoenix (as a Sky Warn Spotter) and NOAA (CWOP). Besides working at the college, I also maintain the campus weather station. For three years I volunteered in creating and sponsoring a Weather Club for children in a local school district. We discussed a different type of weather phenomena at each meeting, and did a simple hands-on project that related to that particular subject (i.e. rain gauge, cloud mobile, anemometer, etc.).”

Matthew, we say let the sunshine in, because this is the time of the season, na na na, hey hey. Sing along while you check out Matthew's Weatherbus website.

Weather Check Quiz Question 2: 1969 was a good year for VW's and a good (depending on how you define “good”) year for extreme weather. What US weather event happened in 1969? (Click here for answers.)

EXTREME WEATHER STATION CONTEST:

Mike’s Vantage Pro Takes First Prize for Highest

Cap, your way-up-high weather station has been out-elevated. Mike Roark’s Vantage Pro, near Fairplay, CO, sits almost 2,000 feet higher than Cap Wenzler’s Keystone, CO, Vantage Pro2. Mike’s station elevation: 11,040 feet (3,365 meters). (Pause for applause.)

Mike sent a photo of the station. Unfortunately, he got so distracted by the beautiful setting he almost cropped the poor VP completely out of the photo. You can just barely see it there on the left.

Mike’s station uploads data to NOAA every 30 minutes.

Next time you see Mike (you’ll recognize him by his Davis cap), ask for an autograph from the First Ever Winner of the Davis Extreme Weather Station contest!

This Month’s Challenge: The OLDEST Davis Weather Station

Davis has been making weather stations for about 25 years. Occasionally we get a call from someone whose original Davis Digitar station has finally given up the ghost. As we drag them kicking and screaming into the wireless age, we have to admire their excellent taste in weather stations. Have you got an ancient Digitar still working? Maybe a nice antique Weather Monitor or Perception? If so, take its portrait and send us a copy (news@davisnet.com.) The owner of the oldest, still functioning, Davis weather station will join Mike in the Extreme Weather Station Hall of Fame.

Try to get us the photo by July 15.

TECH TIPS:

Keeping Your Station Mummified-Lizard-Tail Free

G. David Thayer of Sarasota, FL, sent our Tech Team a Tech Tip of his own.

“I had a rather strange problem with the Fan-Aspirated Vantage Pro I bought last October," he wrote. "About the end of December my fan stopped running. I was sure I was going to have to send it back and kept putting off doing anything about it. Finally, I decided to bite the bullet and took the darn thing apart. I discovered what looked like a little twig caught at the end of one of the fan blades. When I pulled it off, the fan began running.

“I thought, Problem solved! Ha! Little did I know. That evening I found the fan was no longer running. Now, I had noticed some anoles playing around the radiation shield (anoles are little lizards, aka American chameleons, that are ubiquitous around here). I began to suspect they had something do to with the problem. The next day I took the thing apart again, and guess what? I found an anole tail stuck at the end of one of the fan blades. A soon as I pulled it out, the fan began running again. I now believe the first "twig" was a mummified anole tail. (Like most lizards, anoles can lose a tail and carry on without it--they just grow a new one.)

“I also had a problem with wasps. I found two nests. One was under the plate that holds the solar panel and the other was in between two of the radiation shields. My solution to both problems was to make a ‘bag’ out of mosquito netting (okay, it was my wife who made the thing!), which we put around the whole radiation shield. The netting has the same gauge as regular screening (about 200 to the square inch), and with the fan there still should be plenty of ventilation. The netting keeps both the anoles and the wasps out. I thought your readers might want to know about this solution in case one of them has a similar problem with their Vantage Pro.

“Incidentally, the sun down here in Sarasota is brutal! I got the fan running again at 2:00 p.m. in the afternoon (standard time; 3:00 p.m. daylight time). The sun was shining brightly and the wind was averaging 1 mph with gusts in the 4 to 6 mph range. Within 20 minutes of starting the fan, the indicated ambient temperature dropped 7 degrees--from 87.5° to 80.3°! That's spectacular in my book.”

Weather Check Quiz Question 3: When a lizard loses its tail, it’s no big deal because it will just grow back, right? (Click here for answers.)

John Norman (West Paterson, NJ), cloud watcher extraordinaire and Vantage Pro2 owner, has kind of freaked himself out.

“I had just finished watching some more Memorial Day dedications to our troops,” John wrote, “and decided to check in on my weather site. I saved this shot from my weather cam. I'm totally freaked. Tell me you don't see three soldiers here. To top if off, the conditions are a ‘few clouds’ I just had to share these: something special on such a special day!”

Hmmm. We see one thing very clearly: a weather watcher who loves his country and deeply appreciates all the brave men and women who gave their lives for it. We’re certainly with you on that one, John.

(As for the astral soldiers, the one by Abraham Lincoln is really clear, but the one next to the unicorn is a bit iffy. Actually, the more we look at it the clearer the helmeted soldier looking at the top of lighthouse becomes. Now we’re getting kind of freaked out…)

John’s website is well worth checking out. It’s full of interesting stuff and has an awesome virtual Vantage Pro2 console!

Real or Not: You Be the Judge!

Karl Williamson noted that in the last issue, “you mention the ‘Coriolis force.’ Later you say it is an ‘apparent force.’ What that means is that it isn't a true force. For that reason, many prefer to call it the ‘Coriolis effect.’ Someone who isn't familiar with this could be confused by your text.”

Karl’s absolutely right, but we will hold our ground on this one.

First, only brilliant, difficult to confuse folks read this newsletter. Second, because it IS a force, but a force that physicists refer to as a “fictitious force.” Centrifugal force is also “fictitious,” but tell your salad spinner that. Some extra deep thinkers even say that gravity is a fictitious force, but that won’t be much comfort when the ‘chute fails to open. Our point is that whether it is “real” or “fictitious,” the air is forced into movement, just like the water is forced off the lettuce and the parachuter is forced into the unyielding embrace of Mother Earth.

But we believe in free speech around here so “Coriolis effect” is cool with us, too. Thanks, Karl!

Human and Vantage Pro: What a Team!

Marjorie Suedekum got a kick out of our article about looking, as with eyes, at the weather instead of relying on instruments because it aptly applies to a project that she is working on.

“In July of 1998,” Marjorie wrote, “there was a storm uphill from Fort Collins, Colorado. Weather radar saw the storm but did not predict how much water there was in it. There was major flooding in part of Fort Collins and 12 people died. From that the Community Collaborative Rain and Hail Study (CoCoRaHs) was born.

“CoCoRaHs began in Fort Collins and has now spread to Kansas, Wyoming, Nebraska, New Mexico and part of Texas. Volunteers read the precipitation daily and report to Colorado State University (CSU) in Fort Collins. Intense rain, hail or snow is reported immediately and is sent to the weather service.

“As I work, I am frequently not at home when it rains, but my Davis Vantage pro tells me when it rained and how much, amongst other information of course. I find this to be a great advantage over having the four inch rain gauge only.”

So, we think Marjorie would say that observing the weather works best when a very smart human shares the task with a very smart weather station!

Ask the E-News Readers

Stuart Muench, of Lexington, MA, has been having some fun with his collection of weather data that includes almost every ten minutes of the last five years. Poring over his graphs, he began to pay attention to what he calls “sudden temperature drops.” He analyzed the data and can explain most of what he observed, but he’s still got a question, and he knew just who to ask – you!

“In mid to late afternoon with clear skies,” Stuart notes, “we often get a temperature drop of 5º to 10ºF over an hour, which would be 1º to 2ºF in 10 minutes. But with a ‘sudden temperature drop,’ the drop is 3º to 6º degrees in 10 minutes (sometimes in 5 minutes) and it can occur any time of day. Also, these temperature drops are accompanied by a sudden shift in wind direction and speed, and a sharp pressure rise. Those who have studied meteorology will recognize these changes as characteristic of cold front passages that were described some 80 years ago by Norwegian scientists and investigated in detail by Professor Sanders (and others) from the 1950's onward.

“However, in some cases my sudden drops were clearly caused by outflow from thunderstorms and in others a sea breeze was involved (though we are some 12 miles inland from the Boston shore). This leaves the potential cold fronts occurring about once every month or two from October through April (our active weather season). During this period, weather analyses by National Weather Service as well as TV forecasters show cold fronts moving through New England once or twice a week, but why should only about one in ten of these produce a sudden temperature drop while the others only produce gradual temperature falls and gradual wind and pressure changes, when looking at ten-minute interval data? I would be interested in hearing of similar experiences of other Davis Club members who have data loggers.”

Chance of Rain 60%; Chance of Understanding Forecast, 3%

Bill Clancey of Portola Valley, CA, has an interesting way to look at the issue of rain probability that we discussed in our last two issues. In our April issue we said that when a weatherman predicts a 60% chance of rain, it means that “there is a 60% chance that any random place in the forecast area, such as your home, will receive measurable rainfall.”

In our May issue, reader Ken Koenitzer said that in Florida, “the chance of rain is used to express how much of the area will see rain.”

But Bill asserts that the two descriptions given below are equivalent.

“Here's the visualization,” Bill Wrote. “I imagine a billboard of which 60% has been shaded (‘how much of the area will see rain’). Now blindfolded, throw a dart at the billboard. The probability that the randomly selected point is in the shaded area is 60% (‘any random place in the forecast area will receive measurable rainfall’).”

That sounds way too reasonable to us, Bill. But somehow, we’re still not sure. Maybe if we find a giant dart sticking out of our front yard, we’ll get it.

Weather Check Quiz Question 4: Maybe it’s just us, but it seems that our beloved Earthquake State of California has lately been vying for a name change: the Earthquake and Tornado State. We’ve seen several twisters here in Northern California over the last six months. According to Jan Null of Golden Gate Weather Service, how many tornadoes have been recorded in California since 1950 (to 2004)?
a. 14
b. 76
c. 108
d. 303
e. 754

Extra Credit: In w hich state(s) has there never been a recorded tornado? (Click here for answers.)

YOU'RE BRILLIANT!:

Question 1: That symbol shows the location of a dryline, which is a narrow boundary between air masses that have generally the same temperature, but very different moisture contents. Dew point temperature may drop as much as 16ºF (9ºC) per km from one side of the dryline to the other. Drylines don’t usually cause unstable weather, but they are considered trigger mechanisms for unstable weather such as thunderstorms and even cyclones. If you are a Texan, Oklahoman, or Kansan weather watcher, you are probably pretty familiar with drylines!

Question 2: Her name was Camille, and she slammed into the gulf coast in August of 1969. She was the US's second strongest 20th century hurricane. For a look back at Hurricane Camille, check out this USA Today story.

Question 3: Wrong. It will grow back, but tell the lizard it’s no big deal and he’ll roll his beady little eyes at you. Lizards “shed” their tails only when they are in dire need of escape from a predator (or a fan, apparently). Although this trick often allows the injured animal to escape alive, the next few months of tail-less existence can be very difficult. The lizard’s locomotion, including its ability to escape other predators will be impaired. Growth rates, reproduction, and activity levels can also be affected, and the “new” tail will probably not be as “good” as the original in terms of color, strength and size. For more on this topic, especially as it relates to skinks, see a scientific paper by zoologists D.G. Chapple and R. Swain.

Question 4: D. 303 tornadoes have hit California since 1950. Only two have been F3, and none have been deadly (although there have been 85 injuries). For everything you ever want to know about California tornadoes, check out Jan’s California Tornado Statistics webpage.

Extra Credit: Trick question! Tornadoes have occurred in every state in the US.

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, 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.

If you would like to receive the Weather Club e-newsletter via email every month, sign up now.