What is transportation forecasting?

Most people are probably familiar with this specialty in forecasting, which helps warn car drivers and truckers that road conditions could be hazardous. It also helps prepare local governments to clear streets and freeways, spray road salt or sand, and have law enforcement and emergency personnel ready for emergencies. On the business level, weather forecasts can warn shipping companies, for instance, not to ship perishable products in unrefrigerated or unheated trucks. Shipments by rail also need to be ready for unfavorable weather conditions. Some larger companies rely on private forecasting firms to provide them with timely advisories.

Can meteorologists predict tornadoes?

It is difficult to nearly impossible to predict where and whether or not a tornado will strike. All forecasters can do is warn people when conditions are right for tornadoes to form, or, if one is sighted, to tell people to take shelter. Meteorologists look for tornadic thunderstorms that have strong indications of wind shear, lift, moisture, and instability. No one type of weather pattern leads to tornado formation, which greatly complicates forecasting efforts. To aid in their predictions, meteorologists use all sorts of technology, including weather balloons, Doppler radar, satellites, data from weather stations, lightning strike plots, and computer modeling.

A Coast Guard aircraft drops a hurricane warning announcement down to a sponge fishing boat off the coast of Florida in 1938. (NOAA)

A Coast Guard aircraft drops a hurricane warning announcement down to a sponge fishing boat off the coast of Florida in 1938. (NOAA)

Can you see a tornado using Doppler radar?

No. Doppler radar can tell meteorologists if conditions within a storm are favorable for tornadoes—such as strong winds and cloud rotation—but it can't actually see a tornado.

Who were the first people to successfully forecast a tornado?

U.S. Army officers Ernest Fawbush and Robert Miller were the first to correctly predict a tornado would form on March 25, 1948. Recognizing that weather patterns in central Oklahoma were very similar to those that had occurred a few days earlier when a tornado hit Tinker Air Force Base, Fawbush and Miller told their superiors and a decision was made to warn residents about the possible threat. A tornado again hit the Tinker base a few hours later.

What is numerical weather prediction?

Numerical weather prediction—or numerical forecasting—is the science that believes that weather forecasting is possible if one has a thorough knowledge of the

Why was tornado forecasting once banned in the United States?

Concerns that warning people about possible tornado formation would panic residents led the Weather Bureau to ban such forecasting off and on in the 1940s. As meteorology improved and tornadoes became somewhat less terrifying in their ability to appear suddenly, the ban was lifted in 1950.

laws of physics and also knows the current state of the weather. Proposed by a group of Norwegian scientists collectively known as the Bergen School, the idea was that air behaves much like a fluid, and that it therefore adheres to the hydrodynamical equations that liquids like water do. Knowing the current state of the weather is vital, and so numerical forecasting relies heavily on having detailed weather reports from multiple locations before predictions can be made. Once this is available, mathematical formulas are applied to the weather's current state based on the principles of thermodynamics, the Boyle's law, Newtonian physics, and so on.

Who first proposed the approach of numerical weather prediction?

Vilhelm Bjerknes (1862-1951), a Norwegian physicist and meteorologist, was the author of the first formal studies on weather forecasting. He was also famous for his seminal 1921 book, On the Dynamics of the Circular Vortex with Applications to the Atmosphere and to Atmospheric Vortex and Wave Motion, which proposed the fundamental ideas behind numerical weather prediction in 1904. The theory was picked up again in 1922 by English mathematician and meteorologist Lewis F. Richardson (1881-1953). The mathematics behind Bjerknes's theory appealed to Richardson, but the calculations necessary to come up with the predictions, in a time before the invention of the computer, were formidable. Richardson estimated it would take a coordinated effort of about 26,000 people using calculators to figure out the math fast enough for the numerical method to work. Trying to do some preliminary calculations himself, Richardson's early attempts at weather predictions were far off the mark. His misunderstanding of some of Bjerknes's numerical methods led him to come up with estimates on air pressure that were far too high. Because of Richardson's failure, numerical weather prediction was abandoned until the 1940s.

What happened in the 1940s and 1950s that gave hope to the science of numerical weather prediction?

Hungarian-American mathematician John von Neumann (1903-1957) devised a forerunner of the modern computer that could make the rapid calculations needed to predict the weather using the numerical forecasting method. Next, Princeton University meteorologist Jule Charney (1917-1981), having studied Richardson's earlier failure, wrote revised formulas in 1946 that could be used for weather prediction with the help of von Neumann's computer. With this background foundation in place, in 1950 the first successful weather forecast using the numerical method was completed in April, 1950, by the ENIAC computer at Maryland's Aberdeen Proving Ground. An ongoing weather forecast service was then begun in 1955, using an IBM computer funded by the National Weather Service, and the U.S. Navy and Air Force.

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