WEATHER CORNER

How to give the gift of forecasting

BY JAN NULL
Special to the Mercury News 

Q. I am considering whether to buy a home weather station to measure temperature, wind and rainfall. I would like to be able to download this information into a computer for year-to-year comparisons. Any suggestions on types and models of home weather stations? Phil Nielsen - 
Los Gatos

A.  That's a timely question with the holidays just around the corner. So, in this column and the next, we'll discuss not only home weather stations but also a variety of gift ideas for the weather enthusiast. Today, lets look at items that generally cost less than $100. In my next column, we'll
examine some of the more costly tools (and toys) of the trade, including weather stations.

First, if you are considering a weather instrument, give some thought to where you will put it. The accuracy of any instrument is only as good as its location. Temperature readings need to be taken in the shade and away from heat-emitting objects such as vents and south-facing walls.

Of the four most common weather elements -- temperature, barometric pressure, humidity and rainfall -- only the pressure reading can be taken inside. The others must be taken directly outside, or data from remote sensors can be transferred inside. The wind and rain gauges must be away from obstructions, which could bias their readings.

Also keep in mind the limited local availability of many weather products. There are a few weather-related items in local nature and specialty stores, but I have found the best selections are either on the Web or in weather product catalogs. 

The following companies have such catalogs: Edmund Scientific, (800) 728-6999 or
http://www.edmundscientific.com/scientifics/scientifics.cfm , Northeast Discount Weather Catalog, (781) 331-3795 or www.discountweather.com/ , Weather Affects, (800) 317-3666 or http://www.weatheraffects.com/ and Wind & Weather, (800) 922-9463 or www.windandweather.com/ . A couple of excellent online-only catalog sites are http://www.oregonscientific.com/home.html and http://www.weathershop.com/ . The latter even offers free batteries with your purchase. Most of the items discussed here are available at several of these companies.

Temperature is easiest to measure, and there is a plethora of thermometers available. A basic electronic indoor/outdoor thermometer will cost about $25; about $35 for a model that will remember the highest and lowest reading of the day.

Many thermometers are paired with a hygrometer that will measure the humidity, although most of these units will tell you only the relative humidity inside.

In addition to the electronic thermometers, there are some very classy brass and wood models.

Many people are fascinated by rain and want to know how much has fallen in their back yards. Again, you have a wide variety of choices, ranging from plastic cylinders that do an excellent job to pretty cool digital models. 

There's a downside to most of these rain gauges, however. It's often raining just when you want to check them. The solution? A remote wireless rain gauge lets you monitor the precipitation by 0.04-inch increments. I particularly like the Cable Free Long Range Rain Gauge from Oregon Scientific that has a 300-foot range and sells for only $80. 

If you don't want to measure the weather yourself, but want up-to-date weather information, you can buy an NOAA Weather Radio. These VHF receivers get direct broadcasts from the National Weather Service ( http://nws.mbay.net/nwr.html ) with the latest weather and forecasts around the region. They range from basic portable models for about $20 to radios that turn on automatically when there is a warning or alert. The most sophisticated models are programmable to alert you to
emergency conditions in your specific location. Prices start about $70.

Local bookstores and most catalogs offer some really nice weather books. An excellent book with great graphics is Jack Williams' ``USA Today Weather Book'' (Vintage Press, second edition, $20), which is geared for all levels of meteorological interest.  A really nice series of books geared for more sophisticated weather aficionados comes from Chaston Scientific, (816) 628-4770, and includes ``Weather Basics,'' ``Weather Maps'' and ``Hurricanes.'' For younger meteorologists and teachers, check out the excellent line of products from How the Weather Works (http://www.weatherworks.com/ ), including weather flash cards, books and posters. Cloud charts and weather calendars also are available.

Weatherwise magazine ( http://www.weatherwise.org/ ), published six times a year, is extremely well written and graphically pleasing and should appeal even to those with the most casual interest in meteorology. 

For the really technically savvy, there is a wide variety of weather-related computer software. Some programs allow you to download automatically the latest meteorological data from the Internet to create your own weather maps or satellite images. If you want to track a hurricane as it
approaches Florida, a number of programs will gather the data, display the forecast and graphically plot the path of the storm. 

A comprehensive list of weather software is available from the University of Michigan (http://cirrus.sprl.umich.edu/wxnet/software.html ).

Jan Null, founder of Golden Gate Weather Services, is a retired lead forecaster with the National Weather Service. Send questions to him c/o Weather Corner, San Jose Mercury News, 750 Ridder Park Drive, San Jose, Calif. 95190. You also can telephone questions at (510) 657-2246, fax them to (510) 315-3015 or e-mail them to weathercorner@ggweather.com. Please indicate in your e-mail where you live.