Here's a great article from LiveScience staff writer Tanys Lewis. It just emphasizes the point that "doing" science not only requires book knowledge, but understanding of the underlying principles as well. Without that understanding, it would be very difficult to make sense of all that memorized book knowledge.
By Tanya Lewis, Staff Writer August 31, 2013
Predicting how strong a storm, whether a hurricane, tornado or
thunderstorm will be is part science and part art — and it wouldn't be possible
without sophisticated measurement and forecasting technology.
To create these forecasts, meteorologists combine observations
from atmospheric sensors, weather balloons, radar, satellites and aircraft
monitoring with complex computer models to predict when a storm will form, where
it will strike and how severe it will be.
Forecasting a storm is a lot like practicing medicine,
said meteorologist Greg Carbin at the National Oceanic and Atmospheric
Administration's (NOAA) Storm Prediction Center (SPC) in Norman,
"You go to the doctor, you tell the doctor your symptoms and the
doctor makes a diagnosis before he makes a prognosis," Carbin told LiveScience.
"We need to diagnose the current state of the atmosphere as best we can before
we can attempt to forecast." [Hurricanes from Above: See Nature's Biggest Storms]
Thunderstorms, hail and tornadoes
The SPC is primarily concerned with forecasting thunderstorms
and tornadoesin the continental United States. At the core of its work is
climatology, the study of climates and how they change. A basic understanding of
how weather works relies on the historical record, Carbin
Here, a radar map showing the thunderstorms and tornadoes hitting the Oklahoma City
metro area on Fr …
"We have a pretty good understanding of the time of year when
parts of the country are at the greatest risk," Carbin said. In the middle and
southern United States, the greatest storm risk occurs in spring and early
summer. At that time, warm, moist air left over from winter cyclones meets winds
from the jet stream, creating high winds, tornadoes and dangerous hail, Carbin
With this knowledge in hand, forecasters can pay close attention
to storm systems at this time of year. Storm prediction starts with measuring
the current weather conditions, such as air temperature, air pressure and wind
speed. Every airport in the country collects this information every five
minutes, Carbin said.
Meteorologists combine these measurements with information from
weather balloons launched to measure conditions at various heights in the
atmosphere and geostationary satellites that sense moisture in the atmosphere
and reveal the locations of clouds.
All of the weather and satellite data is fed into numerical simulations run on supercomputers, which
crunch the numbers and spit out a model of the atmosphere's behavior. Scientists
compare that output with weather observations, and if it’s a good match, they
use the model to make a forecast.
Once a storm is brewing, scientists begin monitoring it using
radar. Radar energy is beamed off the precipitation inside clouds, and the
strength of the reflected signal reveals the density of moisture, snow, hail or
dust in the storm system. The frequency of the signal tells scientists whether
the storm is moving toward the radar source or away from
If the storm is rotating, it could spawn a tornado. Because
tornadoes are relatively small, localized features, meteorologists can't
forecast them more than a few hours in
The eye of Hurricane Earl was clearly visible during a NASA hurricane hunter flight
through the stor …
Hurricanes and storm surge
Hurricanes, by contrast, are much larger, slower-moving weather systems
that form over water, so forecasters have more lead time to predict when they
might hit land.
NOAA's National Hurricane Center (NHC) in Miami uses a variety of tools for forecasting
hurricanes. Some of the most important are the Geostationary Operational
Environmental Satellites(GOES), which monitor the eastern and western portions
of the United States and the bordering regions of the Atlantic and Pacific
oceans. Hurricane forecasters use a method called the Dvorak
technique with the satellite imagery to estimate the intensity
of a tropical storm system.
Once a developing hurricane comes within range of a coast, NOAA
sends in a hurricane hunter aircraft. The aircraft flies straight into the storm
to measure its parameters. "Think of a hurricane hunter as an 'MRI' for the
storm," said NHC spokesman and meteorologist Dennis Feltgen. Inside the storm,
the plane ejects an instrument called a dropsonde, which parachutes down and
relays information about air temperature, humidity, and wind speed and
direction; the instrument later degrades in the
The data gathered by the hurricane hunter goes into computer
models run on computers like those used by the SPC meteorologists.
"We use a number of computer models. No single one is perfect,"
Feltgen told LiveScience. Forecasters integrate the model data with satellite
data, aircraft data and their own experience. "A meteorologist is always looking
for as much data as he or she can get," Feltgen
Predicting storm damage
NOAA's GOES-12 weather satellites captured this image of Hurricane Katrina at Category
5 strength on …
Forecasters use the data to categorize hurricanes on the
Saffir-Simpson Hurricane Wind Scale, a 1 to 5 rating of
sustained wind speed. The scale estimates potential property damage, from 1
("Very dangerous winds will produce some damage") to 5 ("Catastrophic damage
But the greatest threat to life and property from hurricanes is
often from storm surge — a rise in seawater due to a storm — which the
Saffir-Simpson rating doesn't take into account. Hurricane evacuation zones are
based not on wind, but on water, though there's no scale for storm surge,
However, the NHC does have a storm surge unit, and beginning in
2015, it will have a storm surge watch and warning system, separate from the
hurricane watch and warning system.
In June 2012, five months before Hurricane Sandy hit the
Northeast, scientists modeled how storm surge would impact Staten Island,
N.Y. The model matched the actual storm surge from Sandy uncannily
"Computer forecasts have come a long way," Feltgen said. But
ultimately, emergency managers are the ones who use that information to make
decisions about how to prepare for a storm, he said.