Coming of age: Forecasting weather

By Mark McLaughlin · 

120414-SierraStories

The winter season is nearly upon us and everyone is studying the tea leaves to determine what our weather has in store for us.

Similar to last year, NOAA’s Climate Prediction Center has forecast warmer than normal temperatures in the West, with below average in the southeast. The precipitation forecast, based on a weak El Niño event that may or may not form, is calling for wetter than normal conditions in the southern tier of states (including southern California) with drier than average conditions in the Pacific Northwest.

As is often the case during weak El Niño conditions, the Tahoe regional forecast is in the equal chances category, meaning we have an equal chance for above, near or below average precipitation this winter. In other words, without a strong ENSO (El Niño/Southern Oscillation) signal in the Pacific Ocean, scientists have little to help them make a seasonal outlook that is more than just an educated guess.

Considering that 2014 was the third least snowiest winter since 1879, and 2013 was the fifth least, an average or wetter than normal season in 2015 would help mitigate severe drought conditions in California. In fact, NOAA is predicting at least a 2 in 3 chance that winter precipitation will be near or above normal throughout the state, but don’t bet the mortgage just yet. Like most winters, we’ll just have to wait and see how this season plays out.

If you have ever wondered why forecasting the weather more than a week out is such a challenge, consider this statement posted by the Raytheon Company at a 1963 weather symposium: “Take a large, almost round, rotating sphere 8,000 miles in diameter. Surround it with a murky viscous atmosphere of gases mixed with water vapor. Tilt it back and forth with respect to a source of heat and light. Freeze it at the ends and toast it in the middle. Fill most of its surface with liquid that constantly feeds vapor into that atmosphere. Then try to predict the conditions of that atmosphere over one small area 50 miles square for a period of one to three days in advance.”

Modern meteorologists post five-day weather forecasts that are quite accurate, but these extended prognostications are often subject to significant change and revision. Even with the National Weather Service’s modern arsenal of sophisticated radar systems, satellites, computers, and extensive land and sea observation network, today’s forecasters still find predicting the weather a challenge.

Americans have always been fascinated by weather. Colonial-era weather observers included President George Washington, who kept a diary in which he noted the weather every day up until his death. Thomas Jefferson bought his first thermometer while writing the Declaration of Independence, and purchased his first barometer a few days following the signing of the document.

Most famous of all is the legendary American scientist, Benjamin Franklin, who is credited with theorizing that storms have a rotating motion and generally travel in an easterly direction in the northern hemisphere. Without the aid of the telegraph and simultaneous observations to confirm it, his idea was little more than speculation, but it was one of those intuitive observations that mark true scientific genius. As a nation of farmers, mariners, merchants and tourists, Americans have a long history of involvement when it comes to studying the country’s ever-changing weather.

In the first half of the 19th Century, a typical observer, equipped with a thermometer, wind vane and rain gage, recorded only the surface weather conditions, took measurements at irregular hours and communicated the results by mail. With the introduction of the telegraph system in 1845, East Coast academic organizations such as the Franklin Institute and the Smithsonian Institute began gathering daily information from volunteers in an effort to develop a more sophisticated system of weather observation. The collected data resulted in the creation of weather maps and charts showing recent storm tracks and other practical information.

Although most basic meteorological instruments had existed for many years, it was the telegraph that was largely responsible for the advancement of operational meteorology during the 19th Century. Around 1850, the Smithsonian Institute began supplying calibrated instruments to weather observers, and, for the first time, incorporated observations of high altitude air movement at mountain stations and by balloonists.

By 1860, there were 500 stations (nearly all east of the Mississippi River) furnishing daily weather reports. The system proved invaluable in the dissemination of weather alerts and marine forecasts that primarily benefited mariners on the Great Lakes, and residents and shippers in the Gulf of Mexico and along the Eastern Seaboard. Unfortunately, farmers, ranchers and residents in the Far West were on their own when it came to anticipating stormy weather.

In 1870, President Ulysses S. Grant authorized the Secretary of War to require weather observations at military stations, and to utilize the telegraph to post storm warnings. Thus was born the nation’s first government-funded, national weather service and federal storm warning system. That year, the first systematized, synchronous weather observations taken in the U.S. were made by 24 graduates of the first Signal Service class of trained meteorologists. An act of Congress in 1872 extended the service throughout the United States.

By 1879, the Signal Service was distributing a synoptic weather map that comprised the entire country showing various stations from Maine to San Francisco, with arrows, lines and signs indicating expected direction and force of wind, weather and rainfall. These weather maps were produced on a regular basis and published in newspapers around the country.

Despite the advances in data collection and networking by telegraph, in the first years of operation Signal Service forecasts and storm warnings were looked upon by the press and the average citizen more as experiments than as serious statements. Over time, however, farmers, mariners and ranchers realized that storm warnings helped them prepare for dangerous weather, which ultimately saved lives, crops, livestock and money.

Atmospheric science in the United States has progressed from the era of amateur, isolated diarists before 1800, to the 19th Century period of emerging forecasting systems when trained observers were linked together by telegraph, to the 21st Century where meteorology is recognized today as a professional scientific discipline that incorporates the integration and application of state-of-the-art technologies in space and on Earth. Despite all these advances, long-range seasonal weather forecasting is a science still in its infancy.

Tahoe historian Mark McLaughlin is a nationally published author and professional speaker. His award-winning books are available at local stores or at thestormking.com. You may reach him at [email protected] Check out Mark’s blog at tahoenuggets.com.

 

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Mark McLaughlin
Mark is an award-winning, nationally published author, historian and professional speaker with seven books and more than 800 articles in print. A prolific writer, Mark has received the Nevada State Press award five times. He is a popular lecturer and experienced field trip leader who has lived at North Lake Tahoe since 1978. He teaches Sierra Nevada history using entertaining stories, slide shows and informative tours. He has been a frequent guest on National Public Radio and has appeared as an expert consultant on CNN, The History Channel and The Weather Channel, as well as many historical documentaries.