WEATHER 101:

ABCs of Hurricane Season ‘06

With Florence threatening to become the only the second hurricane of the Atlantic season at e-press time (Ernesto was the first, and then only for a day), and John leaving Baja Mexico battered but standing, we find ourselves knocking wood that the Northern Hemisphere hurricane season seems so far to be more growl than bite. The fact that we are only on “F” at the half-way point of Atlantic hurricane season is something to celebrate. (For comparison, last year at this time we were already at 15 named storms in the Atlantic!)

But we know that we still have months of hurricane season to go through. One of our favorite hurricane-related sites is on Jan Null's (of Golden Gate Weather Services) hurricane page. Jan has nicely concentrated a list of resources that will keep you abreast of Florence’s activities, as well as Gordon’s, Helene’s, Isaac’s…(stopping here to knock wood, again…)

Weather Check Quiz Question 2: “Knock on wood” has a meteorological origin: it comes from the mistaken belief that touching a tree will protect one from a lightning strike that hits the tree. True or False? (Click here for answers.)

September is National Preparedness Month

Midway through the Atlantic Hurricane Season and the anniversary of the September 11 terrorist attack, September is a good month to remind us that preparing for a disaster – natural or otherwise – is an important responsibility. The Department of Homeland Security, along with many national and local organizations, have joined forces to support National Preparedness Month.

Weather watchers are all too aware of the power and destructive force of the weather. Many Davis weather station owners participate in the Citizen Weather Observer Program (CWOP), which among other goals, make the data from these stations available for weather services and homeland security. (Our WeatherLink software is designed to make to enhance participation in CWOP.) In honor of National Preparedness Month, we encourage to you get information, make a plan, and assemble a disaster kit. (For how-to's, see FEMA’s “Are You Ready?” publication.)

When that’s all done, why not become part of the possible solution and make your Vantage Pro2 (or Vantage Pro, or Weather Monitor II) data part of CWOP?

Weather Check Quiz Question 3: Here’s a great question we wish we could take credit for. But we found it on the Tornado FAQ website of Roger Edwards, of the NOAA Storm Prediction Center.” Was tornado forecasting once banned in the U.S.?” (Click here for answers.)

Californians Under Pressure During a Heat Wave?

Peter Challingsworth, of San Mateo, California sent us a great question for the Weather 101 section. “I have a question that's been bothering me for a few years now. I've often noticed during the summer that weather reports tend to talk about “a ridge of high pressure over Northern California’ to explain a bout of good, or hot, weather. However, in such conditions my Vantage Pro insists on telling me that the pressure is low, not high at all (at this moment it's 89.9 deg outside, and the pressure is 29.65in). What am I missing here?”

We called in our very own expert, Jason Karvelot, Davis’ in-house meteorologist to give us the explanation. Here’s what he had to say:

Mostly, we tend to associate low pressure with stormy, rainy weather. But intense heat can also cause low pressure.

During the late spring, summer and early fall, hot temperatures usually prevail in the central valley. There is a lot of rising warm air rising that creates less air at the surface, and thus lower pressure. This lower pressure generally forms an axis or "trough" along the center of California.

If strong high pressure builds over the western U.S., it can push this "heat" low or trough toward the coast or even offshore if it is strong enough. As a result, the barometric pressure typically drops at the surface during a heat wave in the Bay Area.

Heat lows or thermal lows, as meteorologists call them, are very shallow. They do not extend very far up into the atmosphere. As you go up in the atmosphere, the low actually transforms into a high. Typically, when they talk about high pressure on the TV, they are talking about high pressure in the upper atmosphere. This high pressure is a result of the jet stream forming a "ridge," and resultant counter-clockwise circulation, which induces sinking or compressing air to its south. Thus, our heat wave.

Just as "ridging" of the jet stream pushes the thermal trough toward the coast, when it dips far enough south, it also affects the thermal trough. The jet stream will force the cool, marine air so far inland, that there is little temperature difference between the coast and inland. Thus, it completely dissipates this thermal through. This is more common in late fall, winter, and early spring.

(Do we know who to ask, or what?) Thanks Jason and Peter!

Weather Check Quiz Question 4: Mountain climbers often carry oxygen when they climb high peaks. At sea level, the air we breathe is about 20% oxygen. Does the composition of the air change? If not, why is 20% enough down here, but not up there? (Click here for answers.)

TECH TIPS:

Bugs Bugging You?

Our weather stations are very well built, and humans aren’t the only beings who appreciate their sturdy, weather-resistant, “nooks-and-crannies-style” design. Spiders, wasps, bees, beetles, and all variety of winged, crawling, multi-legged critters see you installing a Vantage Pro2 and the Bug Gazette headlines shout: “New Condo Available! First Come, First Served and/or Eaten.”

Summer and fall are the hot months for letters like the one we got from Dick Jubinville, of Cherry Valley, Massachusetts, who wrote to tell us that April and May 2006 saw the records broken for the most total rainfall in those two months in Massachusetts, since records were kept, dating back to the late 1800's.

“Things were registering fine on my Davis Vantage Pro until one day in May when it was raining ‘cats and dogs’. I told my wife, ‘something is wrong up back at the weather station, we should be showing much more rainfall.’ So I set out with a step ladder in one hand, an umbrella in the other, and a piece of 18 gauge stainless steel wire in my teeth. Could it be that those pesky mud wasps tried to make another nest in the rain gauge? My answer came in a fleeting moment. As soon as the wire was inserted into the cone to the bottom, water came spraying out of the weather station sides drowning me on the ladder, and the sounds of tick, tick, tick, as the measuring bucket went crazy filling and tipping repeatedly. Upon returning to the console, I saw it now registered the proper (at least I think I didn't lose any rain ) amount of rainfall since the blockage. It looks like I will need to do maintenance more frequently in the summer months!!! I think I will add a ladder to the 4x4 post. At least I will have another hand free with no ladder to carry.”

Or this one from “Mr. Clean,” Mike Snyder of Lake Huron, Michigan:

“I am the proud owner of a Vantage Pro2. I love the equipment and so do all the spiders and Japanese beetles along the shores of Lake Huron. What can I do to beat the spiders and beetles back? All the literature that came with my unit says ‘don't use bug spray.’ I'm losing the battle of the webs. The little critters have even disabled my rain gage. I'm sure others have this problem and tried spray and that's why Davis warned about using it. After a complete cleaning I'm temporarily back in operation.”

Mr. Clean and Wire-In-The-Teeth Dick, you’re on the right track. The best way to deal with bugs (or whatever) is to clean your rain collector regularly. (Which explains why your anemometer came with a nice long cable – you can mount it way up high and mount the rain collector mounted where it is accessible.)

Spraying bug spray, or any other chemical, is not recommended. Our engineering guys have expended a whole lot of their super-duper brain cells to design a plastic that is slick and strong, and there is no predicting the effect of specific chemicals on that plastic. (Yes, we’ve seen our fantastic plastic etched badly by bug sprays!) It is even more important when it comes to the tipping bucket assembly under the cone. The surface of the “teeter totter” is engineered to be extremely sensitive and slick so that no droplet of water can hold on. A scratch in that surface will affect your accuracy. (So, Dick, about that wire…)

But there are a few other tricks. First, make sure you’ve installed grommets on the holes of your system. The grommets do a good job of keeping big bugs – like bees – outside looking in. You can email or call our Tech Support team and they’ll be glad to send you a set of grommets.

The rain collector is designed to meet the high standards of the WMO, so any “fooling” with it could affect that accuracy. However, if you are a home hobbyist for whom absolute accuracy is not as important as a Saturday without “clean rain collector” on your to-do list, you might be interested in the solutions a few of our users have told us about. One is to drop a half a moth ball in the rain collector. This should be done only if you can do it safely – moth balls must be kept away from pets and children so should not be used if any small and/or furry family members could get to it. Another user suggests dropping a plastic open mesh type dish scrubber in the collector. This one will no doubt affect your accuracy, because it will hold some water that will not fall into the tipping bucket. But the fine plastic threads of the scrubber will increase the surface area and prevent bugs, leaves, and bird droppings from blocking the cone. Both of these solutions will sit down in the cone low enough that water can’t bounce off and out.

It’s Not Just Bugs

Our Tech Support team got a call from an owner who told us that her rain collector has been blocked by a new one for us: bat guano. The bats are apparently hanging out inside the rain collector, but do a good job of vacating any time our friend tries to catch them in the act. We hope they are just dropping by to enjoy an appetizer of a few spiders and Japanese beetles before heading out to eat a zillion mosquitoes. (Mr. Clean, maybe you need a new winged pet?)

But sometimes it’s something much nicer than a creepy-crawly or guano of any sort.

Francois Bergeret, of France, got a bit suspicious when his rain collector suddenly started reporting “tons” or rain – with not a cloud in the sky. He peered up at the rain collector, mounted about 10 meters up on his ham radio antenna (see story above about the anemometer separately from the rain collector, Francois!), and could see what looked like twigs sticking out of the cone! Then, suddenly, a little bird head with dark little eyes was peering back at him.

“So, I take my camera and go to climb into my tower.” Francois wrote. “And what was my surprise: A nice dove flying away, afraid by my visit, and two eggs into a nest, just in the rain collector. Also, little spines of pine trees are in the collector hole, pushing the cups near to the horizontal position, leaving the circuit of my weather station permanently shorted.

“As I am not a monster, I have let this future family remain, and simply disconnected my rain collector, waiting for when the nest will be given up during the cold season. As we have no rain during the hot season it is not a great problem.”

Too cute! (Francois, you’re a softie!)

Weather Quiz Question 5: In California, scientists studying the ground nests of a bird called the Horned Lark discovered that these guys are really little, feathered meteorologists who truly understand their microclimate. What did they discover?
A. The nests were completely waterproof and able to withstand regular flash flooding to rim level for several days at a time.
B. Nest building occurred only in the weeks that preceded a 10-day or greater spell of clear weather, indicating a very high level of forecasting ability.
C. The nests were all oriented so that they were shaded during the hottest part of the day, and well ventilated, yet protected from cool evening winds.(Click here for answers.)

Tech Tip Footnote: AC and/or Batteries?

Jim Sebring, of Lake Wales, Fl (site of hurricanes Charley, Frances, and Jeanne in 2004) made a point we should have in our last issue’s Tech Tips, about getting a blank screen.

“My Vantage Pro allows me to have the C cell batteries installed and the AC power adaptor operating at the same time. I never get a blank screen on my wireless system.”

You’re right, Jim. BUT our Tech Guys might offer this warning: if your house is hit by lightning, having the AC plugged in could “fry" the whole system. Your Vantage Pro or Vantage Pro2 console should last a nice long time on batteries alone. On the other hand AC power allows you to use the backlight more freely. So consider your area’s propensity for lightning storms in deciding whether or not to use AC power.

MAILBAG:

Why Your Own Weather Station? Noelene Explains

Noelene James-Mitts, of Laughlin, Nevada wrote (on July 28 at 3:15 p.m. with an outside temperature of 113ºF [45ºC], humidity, of 11%, and total annual rain 1.98 inches [50.3 mm]), to tell us that she saw an article in Smart Computing that was quite enthusiastic about the Vantage Pro2. However, Noelene being a weather buff had a bone to pick with the author, who clearly, isn’t, and therefore doesn’t get it. She wrote to tell him this:

“My husband and I enjoyed your article on the Davis Weather station. However, you fell just a little short in telling what the weather station can do. We here in Laughlin, Nevada have one subject that always comes up in conversation during the summer months and that is the heat along with the humidity or lack of. With temperatures ranging from the mid 90’s (mid 30s C)at night to 118ºF ++ (48ºC) in the day, we like to keep track and then there is the ever present wind that always blows here.

“You said ‘Of course, no matter how intriguing this kind of product seems, it’s worth remembering that between cable TV and the Internet, immediate weather information is everywhere.’ Because we are far enough away from a major city, the weather reports are not the same for us as say Las Vegas (100 miles [160 km] away), so having a local weather station gives more accurate local information.

“One thing you did not mention is the fact that you can use WeatherLink to set up a web site so that others can see what the conditions are in a very localized area. During the last hurricane season we clicked on to several Davis Weather station links in Florida, Louisiana, Georgia and others to follow the storms. We had better information than some of the news stations thanks to these private internet connected weather stations.”

Well said, Noelene! We couldn’t have done it better.

(When the kids in Laughlin sign yearbooks with “Stay cool,” they aren’t talking about popularity, are they?)

Puerto Vallarta Gets Dampened

Our discussion of record rain rates brought in a few comments from bedraggled readers. Angela, who’s Health Environmonitor presides over the weather in Puerto Vallarta, Mexico, wrote to tell us that it recorded a record rainfall. “On July 20. 2006 at 8:33pm, I recorded high rain rate of 36 inches per hour (914 mm/hr). I believe it. I was wading home in it and had to stop under a balcony until it subsided a little. Total rainfall for about 2 1/2hours of rain was 4.67 inches (118.6 mm).”

(Why is it just so much more fun to see those numbers than to just slog through the storm and know it’s raining very hard? It’s a mystery.)

Hurricane Stamps of Approval

Jeff Cooper, of Tampa, Florida sent us some nice fan mail after he moved to Tampa from Coral Springs.

“After boarding up the house in Coral Springs last year, I was too tired to take my well mounted tripod off my roof. We had both sides of the Hurricane Wilma pass through and my tripod held up fantastic through 120 mph (190 km/h) winds. I had $25,000 in damage, but the tripod and station made it. Can’t tell you how impressed I was. It looked like a war zone, but we were safe and the station made it. The only loss was the drain filter from the rain collector to keep debris out. (FYI: Another neighbor had a Davis station with a wall mount on the side of their house which made it through the storm as well. Says quite a bit for Davis I must say!!!!”

Scott vanNederijnen, of Metairie, Louisiana, keeps storm testing his Vantage Pros!

“Instead of repairing my three-year-old Vantage Pro that has weathered many storms, I have just ordered my Vantage Pro2. But I thought you might like to know how the original did during Hurricane Katrina. When I got back in town on September 15th after Hurricane Katrina I didn't know what to expect, but attached is a picture of what I found:

“For the record my station measured the following on 8/29/2005 in Metairie LA: Max Wind, 85 mph (85 km/h); Min Pressure, 956 mb (28.23 inches); Rain Rate, 9.29 in/hr (236 mm/hr); Day Rain,13.45" (341.6 mm).

We’re amassing quite a collection of Hurricane Approvals! (But we have enough, really.)

Bridges Bridge Because They Have…What?

Frank Masters, Jr., of Harrisburg, Pennsylvania, puts “P.E.” after his name, and not for no good reason. We guess that means Physical Engineer, and therefore he knows that the things that hold up a bridge are “not columns!” as we blithely stated in our last issue.

“They are PIERS! Columns are used in buildings,” says Frank, P.E.

(And newspapers?) Thank you, Frank.

Toni and Her City Bees

We’ve always nurtured a quiet little dream: to smear our morning toast with sweet, golden honey produced by our own little bee hive. And until now, we’ve felt pretty safely assured that the dream wouldn’t ever be more than that because we live in the city, where you don’t keep bees…right? But then we heard from Toni, who is posting her Washington, D.C. weather data on our Weather World ‘Round page. And guess what she does, right in her own urban backyard: she’s a beekeeper! She even has a City Bee Blog, with her Davis ticker running across it.

Weather Check Quiz Question 6: If we wanted to set up just a nice little hive in our backyard (shhh, don’t tell our neighbors) how many new “pets” would we be adding to our household? (Click here for answers.)

Ken Needs Canadian GDD Information?

Ken Drimmie, of Saskatchewan, wonders if any of our readers out there can help him find Growing Degree Day information for crop maturation (such as hard red spring wheat, barley, oats, canola, flax) for crops grown on the Canadian prairies. He’d be interested in GDDs for insect (such as grasshopper) development, too. He’s checked with his local University Agriculture department, as well as his federal and provincial agriculture departments with no luck.

We’re offering the UC Davis insect model page, but he needs more on specific crops as well.

Any Canadian growers out there with a good resource for Ken can send him a much appreciated email!

YOU'RE BRILLIANT!:

Question 1: False. In the winter, the urban heat island effect makes air pollution even worse. “Inversion layers form as a result of radiative cooling on clear, calm winter nights. Ascending air currents created by warm urban areas are trapped under the inversion layers, forming mixed layers (dust domes) that exacerbate air pollution.” From “Measures to Mitigate Urban Heat Islands,” by Yoshika Yamamoto, in the Quarterly Review of Science & Technology Trends, January 2006. (Back to stories.)

Question 2: No way, Jose. While most notions about bringing good luck are equally inane and ineffective, getting under a tree during a lightning storm will definitely not bring you luck, or at least not good luck. The phrase probably comes from the pre-Christian association of wood and trees with good spirits. Or it might be that knocking might deafen the Devil (or mischievous wood sprites) to your bragging words, or if you’re Irish, that it’s a way to thank the leprechauns. We also like this version, from the Morris Dictionary of Word and Phrase Origins: “A Jewish version says it originated during the Spanish Inquisition under Torquemada during the 1490s. During that time Jews were in flight and since temples and synagogues were built of wood, they evolved a code to use in knocking on doors to gain admission. Since this resulted in lives being saved, it became commonplace to `knock on wood' for good luck.” (Back to stories.)

Question 3: “Yes. Before 1950, at various stages of development of the Weather Bureau, the use of the word ‘tornado’ in forecasts was at times strongly discouraged and at other times forbidden, because of a fear that predicting tornadoes may cause panic. This was in an era when very little was known about tornadoes compared to today, by both scientists and the public at large. Tornadoes were, for most, dark and mysterious menaces of unfathomable power, fast-striking monsters from the sky capable of sudden and unpredictable acts of death and devastation. As the weather patterns which led to major tornado events became better documented and researched, the mystery behind predicting them began to clear -- a process which still is far from complete, of course. In 1950, the Weather Bureau revoked the ban on mentioning tornadoes in forecasts.” From Tornado FAQ by Roger Edwards, of the NOAA Storm Prediction Center. (Back to stories.)

Question 4: It’s not the percentage of oxygen that goes down – it’s the total amount of air! At sea level, the atmospheric pressure is higher because of all that air stacked up above us. As altitude increases, the amount of atmosphere above decreases, and so does the pressure. Up on a mountain top, or in an unpressurized airplane cabin, the lower pressure means there are fewer molecules of all gases – including oxygen -- in the air. (Back to stories.)

Question 5: C. The scientists noticed that the larks’ nests were typically built next to and north of objects such as a tuft of grass or a rock and with a “significant northern bias in orientation angle and were 49% shaded in the early afternoon, the hottest part of the day. A northern orientation ensured maximal shading by the grass tuft to the sought, may protect nests from cool evening winds, and provides increased daytime ventilation of the nest through exposure to prevailing winds.” From a study by Hartman and Oring (2003), on Eastern Kentucky University’s Ornithology page. (Back to stories.)

Question 6: A typical small hive includes about 20,000 individuals. Of those, one would be a queen, about 200 would be drones and the other 19 ,799 to 200,000 would be workers. (Note: We’re currently reassessing the bee keeping fantasy.) Check out Ross Koning’s “The Biology of the Honeybee, Apis Mellifera” webpage. (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, 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!


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