Refer to Figure 1 and what you have learned so far in this course when responding to the following:

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Sharyl Hubbard
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1 Refer to Figure 1 and what you have learned so far in this course when responding to the following: 1.Looking down on a Northern Hemisphere extratropical cyclone, surface winds blow [(clockwise and outward)(counterclockwise and inward)] about the center. [ ]clockwise and outward [ ]counterclockwise and inward 2.The specific track of an extratropical cyclone s low-pressure center across Earth s surface is largely determined by large-scale horizontal winds blowing [(near Earth s surface)(in the middle and upper troposphere)]. [ ]near Earth s surface [ ]in the middle and upper troposphere 3.As a cyclone advances, the system typically progresses through a life cycle. As a cyclone develops, the central pressure of the system [(rises)(falls)] and surface winds strengthen. At maturity, clouds cover a broad area about the low center and associated precipitation is widespread. [ ]rises [ ]falls 4.In the extratropical cyclone s warm sector (the area between the warm front and the advancing cold front), surface winds are likely to be producing [(cold)(warm)] air advection. [ ]warm 5.To the north and west of the center of an extratropical cyclone, surface winds are likely to be producing [(cold)(warm)] air advection. [ ]warm 6.Dewpoints are likely to be relatively high to the [(southeast)(northwest)] of the cyclone s center. [ ]southeast west 7.As the cyclone progresses across Earth s surface, the cold and warm fronts rotate about the center of low pressure. The motion of the storm system has similarities to that of a flying Frisbee, that is, a Frisbee spins as it sails through the air (simultaneously exhibiting rotational and translational motions). Typically, the cold front rotates about the center of the low faster than the warm front. Consequently, the extent of the warm sector occupied by relatively warm and humid air at the surface [(shrinks)(increases)]. [ ]shrinks [ ]increases

2 8.Eventually the cold front catches up with and merges with the warm front forming an occluded front. At this stage in the life cycle of an extratropical cyclone (known as occlusion), the storm often begins to weaken as the central air pressure begins to [(fall)(rise)]. [ ]fall [ ]rise 9.With the passage of a warm front, the air temperature usually rises and the dewpoint usually [(rises)(falls)]. [ ]rises [ ]falls 10.With the passage of a cold front, the air temperature usually falls and the dewpoint usually [(rises)(falls)]. [ ]rises [ ]falls 11.A shift in wind direction usually accompanies the passage of a front. With passage of the cold front, surface winds shift direction from the south to the [(southeast or east)(west or northwest)]. [ ]southeast or east [ ]west or northwest 12.With passage of the warm front, surface winds shift direction from the east to the [(southeast or south)(west or northwest)]. [ ]southeast or south [ ]west or northwest 13.Ahead of a surface warm front, warm and humid air rides up and over a wedge of cooler air (a process known as overrunning.) As the ascending warm air expands and cools, its relative humidity [(increases)(decreases)], and clouds typically form. [ ]increases [ ]decreases 14.Most cloudiness associated with a warm front develops over a broad area, often hundreds of kilometers wide, [(ahead of)(behind)] the front. From these clouds, light to moderate precipitation may fall for 12 to 24 hours or longer. [ ]ahead of [ ]behind 15.As a cold air mass advances and a warm air mass retreats, the colder, denser air forces the warmer, lighter air to ascend either along or just ahead of the cold front. Uplift of warm air triggers cloud development and perhaps showery precipitation. In some instances, uplift is so vigorous that thunderstorms develop. Typically, the band of clouds and precipitation associated with a cold front is [(narrower)(wider)] than that associated with a warm front.

3 [ ]narrower [ ]wider 16.Around the low-pressure system, the visible image shows a broad white, comma shaped swirl of clouds. Consistent with the hand-twist model of a Low, an animation would show this swirl to be rotating [(clockwise)(counterclockwise)]. It is the circulation and rising motions of low-pressure systems that leads to the comma shape of cloudiness frequently seen in satellite images. [ ]clockwise [ ]counterclockwise 17.A broad, bright, white arc curling between Indiana and Florida is composed of clouds producing widespread precipitation at image time. The arc of clouds across this portion of the country forms the band spread ahead of the wave cyclone s [(cold)(stationary)] front. [ ]stationary 19. Figure 3 is the surface weather map for 12Z 10 NOV At map time, a wintry storm system was crossing the country with a low-pressure center in central Nebraska. The L was shown within the small closed 992-mb isobar with the lowest pressure of 990 mb (underlined just to the right above the L). From that Low center, a [(cold)(warm)(stationary)] front extended generally eastward to Lake Michigan, where the frontal boundary essentially took on stationary and then cold front identities as it extended into eastern Canada. [ ]warm [ ]stationary 20.Also from the Nebraska Low, a [(cold)(warm)(stationary)] front stretched generally westward across Wyoming before becoming stationary along the Rockies to the northwest. An extension of the isobar curves to the south of the Low center is marked by an orange dashed line or trough mainly showing a change of wind directions. [ ]warm [ ]stationary 21.The wind pattern in the several state area around the Low center exhibited a generally [(clockwise and outward)(counterclockwise and inward)] flow as expected. [ ]clockwise and outward [ ]counterclockwise and inward 22.The wind directions at Rapid City, SD, and Glasgow, in northeastern Montana, were generally from the [(south)(west)(north)(east)] as would be expected following the cold front in a wave

4 [ ]south [ ]west 23.The wind directions at Kansas City, and St. Louis, MO, were generally from the [(south)(west)(north)(east)] as could be expected in the warm sector, between the warm and cold fronts in a wave cyclone. [ ]south [ ]west 24.Compare the temperature at Denver with that at Casper, WY. The air was [(warmer)(colder)] to the north of (behind) the cold front. This region had a marked contrast in temperature, and the dewpoints differed as well. [ ]warmer er 25.Compare the temperatures and dewpoints at Kansas City, MO, and Minneapolis, MN. The air was [(warmer and had greater)(cooler and had lower)] water vapor content to the south of (behind) the warm front. [ ]warmer and had greater [ ]cooler and had lower 26.Precipitation, as represented by the radar echo shadings on the map, had widespread green hues. These precipitation areas were located generally [(north of the Low and warm front) (in the warm sector between the warm and cold fronts)(ahead the cold front)]. of the Low and warm front [ ]in the warm sector between the warm and cold fronts [ ]ahead of the cold front 27.Based on the temperatures and visible station weather symbols in this precipitation region, the form of the precipitation with the more intense radar echoes was probably [(rain)(snow)(drizzle)]. [ ]rain [ ]snow [ ]drizzle 28.Behind the cold front accompanying this storm system, there were [(0)(1)(3)(5)] isobars between the southern and northern borders of eastern Wyoming. This pressure pattern indicated a strong horizontal pressure gradient and probable strong winds over that area. [ ]0 [ ]1

5 [ ]3 [ ]5 29.Figure 4 is the 500-mb upper-air map for 12Z 10 NOV 2014, the same time as the Figure 3 surface map. Mentally place a bold L on the Figure 4, 500-mb map where the surface 990-mb Low center of Figure 3 was shown. Wind directions at 500 mb over surface weather features are often a good indicator of the movements of those systems over the next day or so. Based on the wind directions at 500 mb as inferred by the station plots and contour lines over the area of the surface storm center, the system would be expected to move generally toward the [(east)(north)(west)(south)] over the next day. [ ]west [ ]south 30.Now look back to the Figure 3 surface map. Based on the frontal symbols, the cold front stretching from Nebraska to Wyoming would be expected to move generally toward the [(south)(east)(north)]. [ ]south 31.The warm front, as expected from the symbols, would likely move a little toward the [(east)(north)(west)(south)] over the same period. [ ]west [ ]south 32.The expected continuing advancement of the cold front and the Low would likely cause residents of the center portion of the country to see [(rapidly rising)(small changes in)(rapidly falling)] temperatures over the next day or so. [ ]rapidly rising [ ]small changes in [ ]rapidly falling

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9 Figure 4:

1. Which weather map symbol is associated with extremely low air pressure? A) B) C) D) 2. The diagram below represents a weather instrument.

1. Which weather map symbol is associated with extremely low air pressure? 2. The diagram below represents a weather instrument. Which weather variable was this instrument designed to measure? A) air pressure