Published Tuesday, July 2,,  2002 in the San Jose Mercury News
Weather Corner

No degree necessary for forecasts


Special to the Mercury News
 
Singer Bob Dylan said, ``You don't need a weatherman to know which way the wind blows,'' and in fact, you don't even need a degree to call yourself a meteorologist.

This will likely come as a surprise to most people -- including nearly 80 percent of respondents to my recent Weather User Survey who thought that there are requirements to use the title. About 40 percent of the 256 respondents thought a bachelor of science degree is required, while 12 percent thought certification was needed from the American Meteorological Society, 2 percent thought some kind of license was needed, 2 percent said more than five years of experience was needed and 24 percent thought that all of the above were required.

In fact, there are no requirements by any government agency for using the moniker ``meteorologist.'' This has prompted debate in meteorological circles for decades. It is also somewhat surprising in a society that requires a license or certification to be an accountant, engineer, to cut hair or even do someone's nails.

But if someone wants to go on radio, television or the Internet and call themselves a meteorologist, they can.

As far as broadcast meteorologists go, a case can be made that it may be better to have good communication skills than a formal degree -- if the facts are not conveyed effectively, the message gets lost. Some of those who deliver the weather forecast over the airwaves have a producer with meteorological training.

My opinion is that a minimum of a bachelor's degree in meteorology or atmospheric science should be required.

Complete results from the Weather User Survey can be found at http://ggweather.com/survey.htm.

Q Why are weather forecasts from sites on the Internet, including the National Oceanic and Atmospheric Administration site, many times different? Mike Wedel - Nevada City

A The biggest problem with Internet weather forecasts is that most of them rely on various computer models of the atmosphere and are never looked at by a human who might know the local microclimates. I personally like the forecasts on the IPS Meteostar site because the program that generates the forecasts looks at both the computer model output and the local forecasts from the National Weather Service. I have a link to getting a seven-day forecast from this site on my Web site at http://ggweather.com/links.html.

Q Why is the ocean temperature SOOOO cold along our coast? Scott Archer - Stanford

A The cool water along the northern and central California coast is a key component of our summer climate. Technically known as ``upwelling,'' it's the result of the interaction of atmospheric pressure, ocean currents and the geography of California.

In brief, the persistent northwest winds along the coast this time of year parallel the coast and interact with the top layers of the ocean. Although the winds are pushing the ocean water toward the south, the rotation of Earth causes the surface water to deflect toward the west -- away from the coast. This curving motion, called the Coriolis effect, affects ocean currents as well as winds. Its effects are greatest in the uppermost layer of the ocean but can be felt a couple hundred feet below the surface. As this surface water is pushed offshore, colder waters from the ocean's depths replace it. Along the west coast of North America, this phenomenon is greatest between San Francisco and the Oregon state line.

Q You recently talked about pressure readings taken at 18,000 feet. How many pressure data points are gathered in the United States at this altitude? How many times per day? And how are air pressure measurements obtained at 18,000 feet? If it is by radio telemetry balloons, that must get very expensive because of the need for lots of data points, and balloons are not recovered. I might guess that commercial jet airliners report pressure readings, but they do not cruise at that altitude. Curtis Panasuk - San Carlos

A Vertical measurements of the atmosphere are taken with instruments called radiosondes, instruments sent aloft on weather balloons twice a day at noon and midnight Greenwich Mean Time, which is 4 a.m. and 4 p.m. Pacific Standard Time.

There are about 900 stations worldwide, and 90 of these sites are in the United States. The instruments and battery weigh about 24 ounces and cost about $75 each. Tiny, very low-power radio transmitters send back temperature, humidity and pressure data from the surface up to above 80,000 feet.

At this altitude, the balloon bursts and the instruments drift slowly to the ground under a small parachute. In the United States, about one-third of them are recovered, refurbished and relaunched. The data that is gathered is used to construct a three-dimensional picture of the atmosphere that is then used as a starting point for computer forecast models.

Some aircraft weather data is also gathered to supplement the radiosondes, but it is often available only along specific routes and at specific altitudes.


Jan Null, founder of Golden Gate Weather Services, 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. Please indicate in your e-mail what city you live in.