WEATHER CORNER

Commercial Web Sites Deliver Zoned Weather Data

BY JAN NULL
Special to the Mercury News

In your last column you mentioned some of the university and government weather Web sites. What are you favorite commercial weather Web sites and what are their strengths and weaknesses?

There are hundreds of commercial weather sites, but we'll look at seven of the most popular ones.

Just about every search engine or news page has a button for ``weather,'' and there are numerous small, dedicated weather sites. However, there are only a dozen private sources plus the National Weather Service providing the data for the vast majority of these pages. Consequently, although you may see identical forecasts, other features on these pages may make them your favorite source. Most of the sites also allow a person to register to be e-mailed the latest local forecast or advisory.

All of the sites here have the capability to search for weather reports by city or ZIP code, the latter being useful for your local forecast but not great if you are going to Disney World and don't know the ZIP code for Orlando. And the resolution of the forecasts is only on the city scale at best, so you would not get a different forecast for a ZIP code near the San Jose International Airport than for Almaden Valley.

In a brief, very unscientific survey, at the end of each listing I have included the forecast for San Jose made last Wednesday for Friday, Aug. 11. Note the forecast high temperatures range from 74 to 85 degrees -- a fairly wide spread for the relatively benign conditions last week. The actual conditions Friday in San Jose were a high temperature of 90 and a low of 54.

Most of the sites also have the current local weather conditions, such as temperature, wind and humidity. However, weather reports are not taken in every city, so the current weather you get for Los Gatos may actually be from the San Jose airport. And data is not always updated in a timely
manner.

Here are seven popular sites:

Accuweather (http://www.accuweather.com) is one of the largest private weather companies in the United States. Located in Pennsylvania, Accuweather's claim to fame is its forecasts for the media, primarily east of the Rockies. This weather Web site is very comprehensive and has a pretty straightforward format. One of its main strengths is the excellent radar imagery, which is updated about every 15 minutes for individual radar sites including the Bay Area radar on Mount Umunhum. If you have a fast Internet connection (cable, DSL or T-1), there is a very nice streaming video weather feature. (San Jose high 78, low 58, mostly sunny.)

The weather page from news giant CNN (http://www.cnn.com/WEATHER) is pretty basic but fairly responsive. As would be expected, the sidebar stories above weather events are very well-done. It doesn't have a lot of bells and whistles, but CNN has good international coverage and satellite pictures. (San Jose high 78, low 58, mostly sunny.)

Earthwatch (http://www.earthwatch.com) recently added daily forecasts to its suite of 3-D satellite and radar imagery. Despite the fact that the original imagery is only two-dimensional, the pictures have a very appealing three-dimensional perspective. Earthwatch's products are pretty minimalist but get the job done. However, I have noted some serious flaws in their automated forecasts. (San Jose high 75, low 56, sunny.)

Intellicast (http://www.intellicast.com) is the weather Web site from Weather Services Inc. (WSI), which has made its mark on the Internet marketplace with the first widely available weather radar data. This continues to be Intellicast's forte with not only timely radar imagery but also a very attractive presentation. The forecasts are pretty basic. Whenever there's a major weather event like a hurricane, the site can get very slow. (San Jose high 80, low 60, mostly sunny.)

The Weather Channel (http://www.weather.com) is the big gorilla on the weather Web site block, taking advantage of the name recognition from cable television and also its easy-to-remember Internet address. Because of the site's media background, much of the content has the look and feel
of the television presentation. This is particularly reflected in the very good coverage the Weather Channel does on national weather news stories. (San Jose high 85, low 58, mostly sunny.)

Weather Underground (http://www.wunderground.com) is a funny name for a weather company because weather occurs above the ground. It is a spinoff from the University of Michigan Meteorology Department. In general, it repackages National Weather Service products, but it does a nice job of displaying current weather conditions as well as almanac information such as sunrise, sunset and phases of the moon. There also is a really nice astronomy page that shows the night sky in your ZIP code. (San Jose high 85, low 58, morning low clouds, otherwise sunny.)

The Yahoo weather page (http://weather.yahoo.com) is produced by Sunnyvale-based Weathernews Inc., which also does weather pages for dozens of other sites. The local forecasts are a mix of original and National Weather Service data. The site also has extensive worldwide forecasts. A section called Storm Center highlights ongoing severe weather events such as hurricanes. (San Jose high 81, low 61, mostly sunny.)

Jan Null, founder of Golden Gate Weather Services and Adjunct Professor at San Francisco State University, is a retired lead forecaster with the National Weather Service. Send questions to him c/o WeatherCorner, 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.