Relative humidity (RH): - Answers 1) RH=(VP/SVP) * 100% where SVP is the saturation vapour pressure,
which depends solely on temperature.
2) RH=(MR/SMR) * 100% where SMR is the saturation vapour mixing ratio, which depends on
temperature and pressure.
Depending on local topography, the maximum range of broadcasts of the NOAA weather radio is about
____________ kilometers. - Answers 65
Viewed from above in the Northern Hemisphere, surface winds blow ___________ about the center of a
low pressure system. - Answers counterclockwise and inward
Weather systems usually cross the United States in - Answers Several days
Weather systems in the mid-latitudes of the Earth generally move in the direction towards the - Answers
East
Air pressure can be thought of as - Answers Weight of the overlaying air
Weather radar monitors the movement of - Answers Precipitation
Viewed from above in the Northern Hemisphere, surface winds in a high pressure system blow -
Answers clockwise and outward.
As a general rule, lows that track from west to east across southern Canada produce ___________
precipitation compared to lows that track along the Gulf of Mexico coast. - Answers Less
Usually, the day's minimum temperature occurs - Answers Around sunrise
Meteorologists use water vapor satellite imagery to - Answers track the movement of water vapor at
higher altitudes of the atmosphere.
A cloud in contact with the Earth's surface is known as - Answers Fog
Wispy-appearing clouds that occur at high altitudes are composed of mostly - Answers Tiny ice crystals
What sources of current weather information are available to the public? - Answers The public may
obtain weather reports, maps, and forecasts via NOAA Weather Radio, local television or radio, The
Weather Channel or other cable-TV weather reports, newspapers, and telephone weather services.
Distinguish between the weather that usually accompanies a high (anticyclone) and a low (cyclone). -
Answers Fair weather usually but not always accompanies a high (anticyclone) and stormy weather
usually but not always accompanies a low (cyclone).
, What determines the temperature and humidity characteristics of an air mass? - Answers The
temperature and humidity characteristics of an air mass are determined by the properties of the surface
over which an air mass forms or travels. For example, an air mass that develops over a warm sea
becomes warm and humid.
Distinguish among stationary, warm, and cold fronts in terms of their typical movements. - Answers All
types of fronts are narrow zones of transition between air masses that differ in temperature and/or
humidity. A stationary front does not move or moves very little. With a warm front, colder air retreats
while warmer air advances. At the same pressure, warm air is less dense than cold air so warmer air
advances by gliding up and over the retreating colder air. With a cold front, colder air advances while
warmer air retreats. The advancing colder air forces the warmer air upward.
Compare the cloudiness and precipitation pattern usually associated with a warm front with that
associated with a cold front. - Answers Cloudiness and precipitation associated with a warm front
typically spreads over a much broader area (ahead of the surface warm front) than the cloudiness and
precipitation triggered by a cold front. Also, warm frontal precipitation tends to be steady over a longer
time period (12-24 hrs) whereas cold frontal precipitation tends to be showery.
What is the main advantage of an infrared satellite image versus a visible satellite image for weather
surveillance? - Answers Infrared satellite images can be obtained 24-hrs a day whereas visible satellite
images are possible only during daylight hours.
How is it possible for satellite sensors to observe continuously the same area of Earth? - Answers A
geostationary satellite orbits Earth at the same rate as the planet rotates on its axis so that the satellite
is always positioned above the same spot on Earth's surface (the subsatellite point) and its sensors
always observe the same portion of the planet.
Describe the capabilities of weather radar in the surveillance of weather systems. - Answers Operating in
the reflectivity mode, weather radar locates and tracks the movement of areas of precipitation. Based
on the intensity of the reflected signal (echo), weather radar distinguishes the intensity of precipitation.
Operating in the velocity (Doppler) mode, weather radar monitors the movement of targets
(precipitation, dust) directly toward or away from the radar unit. In this way, weather radar can monitor
the circulation within thunderstorms and provide early warning of the development of severe weather
(e.g., tornadoes).
Explain the fibrous appearance of high thin clouds. - Answers High thin clouds (e.g., cirrus) are
composed of tiny ice crystals that give those clouds a fibrous or wispy appearance.
Compare fog to other clouds. - Answers Fog is a low cloud that is in contact with the Earth's surface.
How and why have technological advances of the 20th century improved weather observation
and forecasting? - Answers Technological advances of the 20th century included development of new
instruments (e.g., radiosonde, radar, satellite sensors) that provide more complete and accurate
representation of the state of the atmosphere (weather), which in turn makes it possible to more