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Viewed from above in the Northern Hemisphere, surface winds surrounding a high pressure system blow
a)clockwise and inward
b)clockwise and outward
c)counterclockwise and inward
d)counterclockwise and outward
clockwise and outward
Usually, ______ weather is associated with a high pressure system and ______ weather is associated with a low pressure system.
Usually highs are accompanied by fair weather and hence are described as fair-weather systems. Most lows produce cloudy, rainy or snowy weather and are often described as stormy-weather systems.
The cold, snowy side of a winter cyclone is usually to the ______ of the storm track.
a)west and north
b)east and south
d)none of the above are correct
west and north
Weather on the left side (west and north) of an extratropical cyclone's track (path) tends to be relatively cold, whereas weather on the right (east and south) of the cyclone's track tends to be relatively warm. For this reason, winter snows are most likely to the west and north of the path of a low-pressure system.
A front is a narrow zone of transition between air masses that differ in
c)temperature and/or humidity.
d)None of the above is correct.
temperature and/or humidity
Fronts form where contrasting air masses meet, and the associated air movements often give rise to cloudiness and precipitation.
A measure of the actual concentration of the water vapor component of air compared to the concentration of water vapor at saturation:
Relative humidity is always expressed as a percentage. Because the saturation concentration varies with air temperature so too does the relative humidity. On most days, the relative humidity is highest during the coldest time of day (around sunrise) and lowest during the warmest time of day (early to mid-afternoon).
Wind direction is always specified for the direction ______ the wind blows.
According to the meteorological tradition, wind direction is the compass direction from which the wind blows. As a general rule, at middle latitudes a wind shift from east to northeast to north to northwest is accompanied by falling air temperatures. On the other hand, a wind shift from east to southeast to south usually brings warmer weather. Over a broad area about the center of a high-pressure system calm air or light winds prevail. Wind speed tends to increase markedly as a cold front passes a location and winds are particularly strong and gusty in the vicinity of thunderstorms.
The band of clouds and precipitation associated with a warm front is _______ the band of clouds and precipitation produced by a cold front.
c)about the same width as
- Most cloudiness and precipitation associated with a warm front occur over a broad band, often hundreds of kilometers wide, in advance of where the front intersects Earth's surface. Widespread precipitation ahead of a warm front generally is light to moderate in intensity and may persist at a particular location from 12 to 24 hours or longer.
- Most cloudiness and precipitation associated with a cold front occur as a narrow band along or just ahead of where the front intersects Earth's surface. Although precipitation often is showery and may last from a few minutes to a few hours, its intensity can be very heavy.
A weather ______ is issued by the National Weather Service when hazardous weather is imminent or actually taking place.
A type of satellite image that is available and useful both night and day:
The intensity of a weather radar echo ______ with an increase in the rate of rainfall.
c)does not change
The relflected signal is displayed as blotches (radar echoes) on a television-type screen with a superimposed map of the region surrounding the radar. The heavier the precipitation, the more intense is the echo. Echo intensity is calibrated on a color scale so that light green indicates light rain whereas dark red signals heavy rain or hail.
_______ is defined as the state of the atmosphere at some place and time described in terms of such variables as temperature and cloud cover.
Cyclones that travel from west to east along the Canadian border usually produce ______ precipitation compared to cyclones that track northeastward along the U.S. Atlantic coast.
c)about the same amount of
Lows that track across the northern United States or southern Canada are more distant from sources of moisture and usually produce less rain or snowfall than lows that track further south (such as lows that travel out of eastern Colorado and move along the Gulf Coast or up the Eastern Seaboard).
Surface temperatures associated with polar air masses are
a)about the same in winter and summer.
b)colder in winter than summer.
c)warmer in winter than summer.
colder in winter than summer
In response to regular seasonal changes in the duration and intensity of sunlight, polar air masses are much colder in winter and milder in summer.
Tropical storms and hurricanes impact the U.S. East and Gulf Coasts primarily
b)during tornado season.
c)from August through October.
August through October
On an infrared satellite image, _______clouds appear bright white.