tag:blogger.com,1999:blog-88859979320377977612024-03-13T07:09:00.900-07:00WeatherMeasureHands-On WeatherJean Bergerothttp://www.blogger.com/profile/17954875340341381622noreply@blogger.comBlogger12125tag:blogger.com,1999:blog-8885997932037797761.post-52382119671232366502007-08-29T12:00:00.001-07:002023-07-12T10:51:34.167-07:00Oregon Scientific Weather Radio RecallSome radios could fail to receive National Weather Service alert signals in certain areas of the country. In the event of severe weather, this failure could put a consumer’s life and property at risk.<br /><br />The recall involves the following models sold from December 2005 through June 2007:<br />• All Hazards Portable Weather Alert Radio (WR103NX)<br />• Portable Public Alert Radio (WR108)<br />• Public Alert Weather Station (WRB308)<br />• John Deere Public Alert Weather Station (WRB308J)<br /><br />Contact Oregon Scientific for information on how to receive a free replacement radio.Unknownnoreply@blogger.com7tag:blogger.com,1999:blog-8885997932037797761.post-31606565400406399412007-05-24T15:56:00.000-07:002010-05-04T09:42:43.203-07:00Weather Sayings of the Old Sailors<a href="http://www.novalynx.com/images/old-blog-images/weather-sayings-lg.jpg"><img style="width: 400px;" alt="Weather Sayings of the Old Sailors" src="http://www.novalynx.com/images/old-blog-images/weather-sayings.jpg" border="0" /></a><br /><br />• Dew indicates a good day ahead; a dry morning is sign of showers.<br />• Distant shores loom up "nearer" before rain because of thinning of the air.<br />• Large halo around the moon indicates cirrus cloudform and warm front rain.<br />• A veering wind is sign of fair weather; backing wind means rain.<br />• Falling barometer indicates nearing "low" area, with winds and rain.<br />• Rain is most frequent at the turn of the tide (if air is humid).<br />• Rainbow to windward, rain ahead. Rainbow to leeward, rains end.<br />• Higher the clouds, finer the weather. Lowering ceilings foretell a rain.<br />• Smoke that curls downward and lingers, means a nearing storm.<br />• Thinning air is harder to fly in. Birds "sit it out" before a storm.<br />• Sky full of webby cirrus foretells disturbance and rain's on its way.<br />• Lightning from the west or northwest will reach you; from south or southeast will pass.<br /><br />Illustrations by <a href="http://www.ericsloane.com/">Eric Sloane</a>.Clark Adamshttp://www.blogger.com/profile/16800772175552175375noreply@blogger.com0tag:blogger.com,1999:blog-8885997932037797761.post-41529279101465201832007-05-04T14:37:00.001-07:002023-07-12T10:48:11.783-07:00Finding True North<span style="FONT-WEIGHT: bold">Hints about orienting a wind vane to TRUE NORTH for accurate wind direction measurements</span><br /><br />No matter how precise your electronic wind vane is, if the zero point of the wind vane's base is not oriented to north the readings will be in error.<br /><br />There are some easy ways to find north. Once it gets dark look up into the sky and find the north star. When you have done that you are looking in the direction of true north.<br /><br />Another aid can be our streets and roads. Many city streets are laid out in a north-south grid pattern. Just line the zero point of the anemometer so it points parallel to the north-south running streets.<br /><br />The use of a compass to locate true north requires a little extra work. Magnet compass needles point to the magnetic north pole which is not at the same place as the geographic north pole. A correction must be applied to convert the magnetic north direction to the true north direction. The magnitude of the correction depends on where you are located. The following URL will take you to a U.S. government site that takes you through some very simple steps to convert magnetic compass readings to true direction readings for your location: <a href="https://www.ngdc.noaa.gov/geomag/declination.shtml">https://www.ngdc.noaa.gov/geomag/declination.shtml</a><br /><br />Once you have successfully aligned the anemometer to true north, your wind direction readings will report true wind directions within the limit of the errors of the anemometer.Clark Adamshttp://www.blogger.com/profile/16800772175552175375noreply@blogger.com0tag:blogger.com,1999:blog-8885997932037797761.post-27005095302492759972007-04-24T09:12:00.000-07:002010-05-04T10:01:41.600-07:00Why is it so windy in Reno?<a href="http://www.novalynx.com/images/old-blog-images/windy-large.jpg"><img src="http://www.novalynx.com/images/old-blog-images/windy.jpg" alt="" border="0" width="400" /></a><br /><br />Here is an interesting illustration from the Reno Gazette-Journal that explains why very high winds frequently blow in the valleys just to the east of the Sierra Nevada. The predominant wind blows from west to east over the Sierra Nevada and high winds aloft, associated with storms, spill down the lee side of the mountain range following the terrain. These winds of 50 mph or greater spill out onto the valley floors. Winds in the Washoe Valley south of Reno are frequently of sufficient strength to over turn large semi trucks and trailers. The drawing shows how this effect works. This kind of down slope gusting is not unique to the Sierra Nevada. Those of you who live along the Front Range of the Rocky Mountains are familiar with the same effect.Clark Adamshttp://www.blogger.com/profile/16800772175552175375noreply@blogger.com0tag:blogger.com,1999:blog-8885997932037797761.post-42787532451680694542007-04-13T16:30:00.000-07:002007-04-17T16:09:19.535-07:00Wind Direction Potentiometer Configuration<strong>360° Format</strong>: For years a 360° potentiometer has been the standard for measuring wind direction. Because the resistance element of the potentiometer is roughly 358°, there is a "dead area" or "slot" of approximately 2°. This opening in the pot is customarily oriented to the north. The 360° format is extremely well suited to applications where a display indicator is used, either alone or with analog recording instrumentation. Its disadvantage is that when the wind is from the north readings will vary between maximum to minimum output as the wiper in the pot goes back and forth across the slot, thereby causing a pen trace across the full width of an E-A recorder or presenting numerous other complications for computer data logging.<br /><br /><strong>540° Format</strong>: In recent years, a new configuration has been used quite successfully. Two potentiometers are joined together with wipers in the pots 180° from each other, thus providing a 540° uninterrupted display. This convention of dual potentiometers has greatly minimized the problems encountered in 360° displays. The signal conditioning provides automatic switching between the two pots.Clark Adamshttp://www.blogger.com/profile/16800772175552175375noreply@blogger.com0tag:blogger.com,1999:blog-8885997932037797761.post-64182077930346852662007-04-06T13:54:00.000-07:002010-05-04T10:02:33.157-07:00Algae Control in Evaporation Pans<a href="http://www.novalynx.com/images/old-blog-images/evap-pan-algae-lg.jpg"><img style="WIDTH: 400px; CURSOR: hand" alt="evaporation pan" src="http://www.novalynx.com/images/old-blog-images/evap-pan-algae.jpg" border="0" /></a><br /><div><br />An evaporation pan must be cleaned frequently to keep it free from sediment, algae, and oil films. Any of these contaminants will materially affect the rate of evaporation.<br /><br />The growth of algae can be discouraged by adding a small amount of copper sulfate to the water. (Approx 5-10 mg of copper sulfate per liter of water.) A standard Class A pan filled to 8 inches would require about 1/2 teaspoon of copper sulfate granules.<br /><br />If algae is already present, it must be removed first by thoroughly cleaning the pan. Dry granules added directly into the pan will sink to the bottom and may not dissolve completely. If you have this problem, the granules can be dissolved in water before being added to the pan or placed in a burlap bag and dragged around the pan until dissolved.<br /><br />It's not necessary to add additional copper sulfate each time you add water to the pan. The copper sulfate doesn't evaporate with the water but remains in the pan.<br /><br />Copper sulfate is corrosive and can be toxic to animals and fish, so it must be handled with care and disposed of properly. Copper sulfate can be purchased at feed and agricultural supply stores, garden centers, and pet supply stores.</div>Bill Begghttp://www.blogger.com/profile/12887785248900464473noreply@blogger.com0tag:blogger.com,1999:blog-8885997932037797761.post-79292966409605359202007-03-30T16:30:00.001-07:002018-04-25T12:20:15.231-07:00Anticipating Severe Weather<a href="http://www.weather.gov/nwr/"><img style="margin: 0pt 0pt 10px 10px; float: right;" src="https://www.novalynx.com/images/old-blog-images/noaa-weather-radio.jpg" alt="NOAA Weather Radio" border="0" /></a><a href="https://www.weather.gov/nwr/">NOAA Weather Radio All Hazards</a> is a nationwide network of radio stations broadcasting continuous weather information directly from a nearby National Weather Service office. NWR broadcasts weather warnings, watches, and forecasts, and other hazard information, 24 hours a day. It is provided as a public service by the National Oceanic and Atmospheric Administration, part of the Department of Commerce, and includes more than 940 transmitters, covering all 50 states, adjacent coastal waters, Puerto Rico, the U.S. Virgin Islands, and the U.S. Pacific Territories.<br /><br /><a href="https://www.weather.gov/skywarn/">Skywarn</a> is the spotter training program developed and sponsored by the National Weather Service. In areas where tornadoes and other severe weather is a frequent concern, the NWS recruits volunteers, trains them in storm identification and spotting procedures, and subsequently accepts the spotter's reports during episodes of severe weather.<br /><br /><a href="https://www.weather.gov/stormready/">StormReady</a> - Some 90% of all presidentially declared disasters are weather related, leading to around 500 deaths per year and nearly $14 billion in damage. StormReady helps arm America's communities with the communication and safety skills needed to save lives and property.Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-8885997932037797761.post-9708778369147365562007-03-23T16:02:00.000-07:002009-03-18T09:06:08.765-07:00Power Budget CalculationsThe power budget is an analysis of how much power a data collection site requires. The analysis is required to determine how long a data recorder or a remote telemetry unit (RTU) will operate from a battery of a given capacity (amp-hours) without recharging and what size solar panel (or charging source) should be used to sustain the battery.<br /><br />A power budget is determined by calculating how much time a data recorder or RTU spends in each of its operating modes and then summing the power used in each mode.<br /><br />You can see an example of a <a href="http://www.novalynx.com/reference-power-budget.html">power budget calculation</a> here.Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-8885997932037797761.post-12326543866897055012007-03-15T16:10:00.000-07:002018-01-16T10:43:43.896-08:00What Is a Wind Rose?The wind rose is the time honored method of graphically presenting the wind conditions, direction and speed, over a period of time at a specific location. To create a wind rose, average wind direction and wind speed values are logged at a site, at short intervals, over a period of time, e.g. 1 week, 1 month, or longer. The collected wind data is then sorted by wind direction so that the percentage of time that the wind was blowing from each direction can be determined. Typically the wind direction data is sorted into twelve equal arc segments, 30° each segment, in preparation for plotting a circular graph in which the radius of each of the twelve segments represents the percentage of time that the wind blew from each of the twelve 30° direction segments. Wind speed data can be superimposed on each direction segment to indicate, for example, the average wind speed when the wind was blowing from that segment's direction and the maximum wind speed during the logging period. A good example of a wind rose application is shown at the following URL <a href="http://www.wcc.nrcs.usda.gov/climate/windrose.html">http://www.wcc.nrcs.usda.gov/climate/windrose.html</a>.<br /><br />The information provided by the wind rose can be applied to many and varied situations. Sailors use wind rose information taken from the "Pilot Charts" by the U.S. Naval Oceanographic Office to get average winds for each ocean for each month of the year to help the create optimal sailing routes between ports. Architects do, or should, use wind rose information for the siting of buildings and stadiums. If wind rose data had been collected and used prior to the construction of San Francisco's famous windy Candlestick Park, the stadium could have been placed a few hundred yards to the north where it would have been protected from the prevailing westerly wind. Windpower "farms" do extensive wind rose type studies prior to erecting their wind turbines. Thus the wind rose is a simple information display technique that has a multitude of uses.<br /><br /><a href="http://www.novalynx.com/reference-wind-rose.html">More wind rose links</a>Clark Adamshttp://www.blogger.com/profile/16800772175552175375noreply@blogger.com0tag:blogger.com,1999:blog-8885997932037797761.post-9380864432449486532007-02-28T20:28:00.000-08:002007-09-20T22:03:19.295-07:00Weather Station HandbookWe recently scanned and posted our copy of the <a style="FONT-STYLE: italic" href="http://www.novalynx.com/manuals/nfes-2140.html">Weather Station Handbook--An Interagency Guide for Wildland Managers</a>, published by the National Wildfire Coordinating Group in 1990. While some sections are outdated, it contains a lot of still useful information about setting up and maintaining a weather station.Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-8885997932037797761.post-39118560258451113642007-02-22T08:35:00.000-08:002016-12-01T08:45:20.802-08:00Finding your Latitude and Altitude for Barometer Corrections<b>Online Resources</b><br />
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<a href="http://nationalmap.gov/">The National Map Viewer</a> offers free access to the US Geoglogical Survey's topographic base map data. US Topo maps are available for free web download from the <a href="http://store.usgs.gov/">USGS Store</a>.<br />
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<a href="http://earth.google.com/">Google Earth</a> is free for personal use. You can find your latitude, longitude (not needed for barometer corrections), and ground elevation by entering the address or place name, then zooming in on detailed satellite photos and maps.<br />
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<b>Paper Maps</b><br />
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You can get your latitude coordinate and ground elevation from many local maps of your area. The most detailed is usually the US Geological Survey 7.5 minute, 1:24,000-scale quadrangle series topo maps, available from local outfitter stores, some bookstores, your local BLM or Forest Service office, and from the <a href="http://store.usgs.gov/">USGS Online Store</a>. Some public libraries may have topo maps available.<br />
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To find your ground elevation, look at the wavy never-ending lines on either side of your location. They are lines of constant elevation called <em>contour lines</em>. Find some with numbers inserted in them. The number is the elevation of that line. In the United States they are mostly in feet, the <em>contour interval</em> between them may be 10 feet or more, and every fifth perhaps every 50‑foot contour line may be in bold. You may interpolate your ground elevation between the elevations of the contour lines on either side of your location.<br />
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<a href="http://geology.isu.edu/wapi/geostac/Field_Exercise/topomaps/index.htm">Introduction to Topographic Maps</a>, a tutorial from the GeoSpatial Training and Analysis Cooperative, offers detailed information on understanding and using topo maps.<br />
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<b>GPS</b><br />
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Commercial GPS (Global Positioning System) devices have typical latitude errors of 10–15 meters which is good enough for the relatively small gravity correction, however the GPS typical elevation errors are much too large for barometry where errors ideally should not exceed one foot.<br />
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<a href="http://novalynx.com/reference/find-latitude/">Read more</a> . . .Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-8885997932037797761.post-82578486833550768892007-02-14T15:55:00.000-08:002007-03-08T16:33:57.114-08:00Rejoining a Separated Thermometer ColumnA separated column is one in which portions of the mercury or alcohol become separated from the main column. Column separation is common in thermometers, particularly after transit or other situations producing excessive jarring. In alcohol thermometers, column separations may appear as small bubbles. They can be caused by a distillation tendency during warm weather; alcohol vapor condenses in the upper portion of the bore. Column separation may entrap the minimum thermometer index rod.<br /><br />Separated columns can usually be reunited by one of the following methods: tapping, applying centrifugal force, and heating. <a href="http://www.novalynx.com/reference-rejoining.html">We explain the procedures here</a>.Unknownnoreply@blogger.com0