Final Exam
Suppose that at 12Z 27 OCT 2016 you board an airplane and fly non-stop directly from Tucson, the southern-most station in Arizona, to Caribou, the northern-most station in Maine. En route, the plane cruises along the 500-mb surface. Flying from Tucson to Caribou, the aircraft's actual cruising altitude ________.
Decreases
Remote sensing of precipitation amounts over the vast areas of tropical oceans is possible with data from the ______ satellite.
GPM
Figure 1 represents a portion of a surface weather map on which are plotted three straight, parallel isobars. Pressure is in mb units, and isobars are uniformly spaced and drawn with a 4-mb interval. ________ pressure is located across the top of the diagram.
Low
An intense thunderstorm thus has a relatively ________ cloud top.
Cold
The next weather system to affect Detroit is likely a cold ________ approaching from central Canada.
Anticyclone
The greatest precipitation amounts in the North and South Carolina area are shown as red shadings within yellow areas. These shadings indicated maximum rainfall totals of ________ inches of precipitation in this twenty-four hour period.
Over 3
Once horizontal motion has begun at this Northern Hemisphere location, the air parcel's path will be deflected to the ________ of its direction of motion.
Right
Dewpoints are likely to be relatively high to the ________ of the cyclone's center.
Southeast
Figure 3 is the surface weather map for 12Z 26 OCT 2016. At map time, an L was shown within the small, closed but elongated 1016-mb isobar, with the lowest pressure of 1012 mb (underlined just to the left of the L), in Iowa. Another local L of 1015 mb was located in northern Texas. From the Iowa Low center, a ________ front extended generally southeastward to southern Kentucky.
Stationary
Across most of the tropical Pacific, the winds were directed generally ________ and were stronger in the central and eastern Pacific.
Toward the West
The pattern of winds in Figure 4 indicates a ________ along the Mississippi River Valley. The flow pattern across the country is meridional.
Trough
The highest wind speeds plotted on the 500-mb map were reported at Reno. Those winds were generally from the south-southwest at about ________ knots (a pennant, two long and one short feathers).
75
One extended period of substantial snowfall at Detroit is more likely if the cyclone takes Track ________.
A
Compare the heights of the 500-mb pressure surface across the southern portion of the U.S. to those along the northern portion on the map. As latitude increases (one moves poleward), the height of the 500-mb surface generally ________.
Decreases
A Chinook wind is most likely to affect the weather of
Denver, Colorado
Knowledge of the location of the jet stream and upper-air winds in general is very important for commercial aviation and can result in fuel savings and shorter flight times. At Figure 4 map time, an airline flight from Little Rock, Arkansas to Seattle, Washington would take ________ time than a flight along the same route from Seattle to Little Rock.
More
By Figure 5 map time, the area of precipitation in the wave cyclone was predominantly located ________.
Narrowly concentrated ahead of the warm front
The wind direction at St. Louis, on the Missouri-Illinois border, was generally from the ________ as would be expected behind the cold front in a wave cyclone.
Northwest
If cumulus clouds (puffy clouds that build vertically) continue to develop to great altitudes, the atmosphere is
Unstable
natural drivers of climate change include all of the following
land use practices
Considering the isotherms and the shading scale for temperature anomalies to the right, the magnitudes in the greatest negative SST anomalies are between ________ Celsius degrees.
-0.5
Refraction or bending of light by atmospheric ice crystals can produce circles about the sun called
haloes
Wind at Charleston was generally from the ________ at about 10 knots.
North
The major uncertainty in the results of global climate models is the net feedback of
clouds
The Coriolis Effect causes objects in the Southern Hemisphere to appear to curve to the ________ as they move freely across Earth's surface.
Left
The frontal symbols in Figure 1 indicated the direction of the movement of the cold front and implied the future motion of the clouds to be ________.
Moving directly toward the mountains which are oriented generally north-south along the coast
The Figure 2 station model for Minneapolis showed the plotted surface wind (Item #14) as generally from the ________.
North-northeast
Portland, Oregon, located just behind the front, had a temperature of 59 °F and dewpoint of 52 °F at map time. Although this surface air was not saturated, the present weather symbol in the station model was two dots signifying ________ was occurring.
Rain
Which one of the following particles has the greatest terminal velocity in still air?
Rain drop
The effect of Earth's rotation on the path of objects moving across its surface is greatest at the poles, and diminishes to zero at the Equator. In summary, the Coriolis Effect causes objects freely moving horizontally over the Earth's surface in the Northern Hemisphere to appear to curve to the ________.
Right
Draw a small arrow from the station circle center at a 90-degree angle to the right of the wind arrow to represent the Coriolis force acting on the wind at Portland. Your Coriolis force arrow is directed generally toward the ________.
South
The bold black arrow along the ocean surface in the convective loop represents the trade winds and points in the direction toward which the prevailing winds are blowing in the equatorial region. As indicated by the arrows, winds during neutral (long-term average) conditions blow toward the ________ along the equator.
West
Based on your response to Item 9, winds near the surface to the north side of the Low center in the North Carolina coastal area ________ be bringing humid air onshore.
Would
The advancing front ________ have provided a lifting mechanism for the air leading to clouds and precipitation.
Would
As the precipitation region of the storm system advances northeastward and reaches Caribou, assuming that temperature remains steady, ________ precipitation would become possible.
cold, frozen
Non-snow precipitation shadings in the bottom panel of Figure 3 ________ occur at Portland, ME.
did
Figure 4 is the 500-mb upper-air map for 12Z 26 OCT 2016, the same time as the Figure 3 surface map. Place a bold "L" on the Figure 4, 500-mb map where the surface 1012-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 you marked, the system would be expected to move generally toward the ________ over the next day.
east
Placing yourself on the map on either of the storm track curves and looking along the direction the storm moved, during the storm's passage, the "cold" side would be to the ________ of the storm track.
left
The lower panel of October 2010 Anomalies shows the Pacific SST anomalies along the Equator being almost all negative, denoted by the dashed lines, with the most negative departures dropping below ________ C°. This relatively cool [compared to the long-term average or Neutral ("Normal") Conditions] water is characteristic of La Niña.
-2
The relative humidity of saturated (cloudy) air is ________.
100%
Most cloudiness associated with a warm front develops over a broad area, often hundreds of kilometers wide, ________ the front. From these clouds, light to moderate precipitation may fall for 12 to 24 hours or longer.
Ahead of
Looking down on a Northern Hemisphere extratropical cyclone, surface winds blow ________ about the center.
Counterclockwise and inward
The Low center ________ generally move as expected from the 500-mb wind directions aloft over the area from Figure 3 to Figure 5.
Did
Lee-wave clouds form ______ of a mountain range.
Downwind
The wind reported at Minneapolis was about 10 knots (one long feather) generally from the ________.
North-northeast
At upper levels, the wind directions are also related to the contours. That is, especially where winds are relatively fast, the winds are generally ________.
Parallel to the contours
Water in solid or liquid form that falls from clouds to the Earth's surface is known as
Precipitation
Minneapolis was located nearly between the two bold red Ls on the Iowa-Minnesota border and in central Wisconsin. The bold line with a blue triangle and a red semicircle on opposite sides, marked it as a(n) ________ front.
Stationary
Which of the following parameters is not occurring as an indicator of projected climate change?
decreasing atmospheric water vapor content
Larger atmospheric particles such as cloud droplets and aerosols scatter wavelength of sunlight more evenly. This is an example of ______ scattering.
mie
Brighter refraction by plate-like ice crystals at the same elevation as the sun near the 22-degree halo produces
sundaes
Air masses acquire their temperature and moisture properties primarily from the
underlying earth's surface
The location of the greatest negative SST anomalies was centered about ________ longitude.
130 W
The highest surface wind speeds at map time were along the region of strongest horizontal pressure gradient across the upper Plains States. The wind speed at Fargo on the North Dakota-Minnesota border, and Des Moines in central Iowa, was about ________ knots.
15
The shading and isotherms indicate that the warmest waters across the tropical Pacific are located near ________ longitude. [Note, the Pacific east of 180° longitude (generally the International Dateline) has W(est) numbered longitudes while the Pacific west of 180° has E(ast) numbers measured west and east, respectively, from the Prime Meridian.]
160 E
Doppler radar detects only those motions or components of motion that are directly toward or away from the radar. At two locations within the rotating wind pattern no air motion is detected by the Doppler radar beam. At those points, the actual wind blows along paths perpendicular to the radar beam (dashed line). Hence, the Doppler radar senses no Doppler wind speed at these locations. These two locations are sensed by the radar when its beam is in the ________ position. Draw a small circle around each of the dots associated with those two arrows to denote this 0-Doppler wind speed.
3
For the two arrows that are directed partly away from the radar, use the red pencil to make similar half-length red arrows, drawn from the location dots, which are aimed directly away from the radar. These two locations are at the ________ radar beam position.
4
The Figure 3 composite map showed the storm system's low-pressure at 12Z 28 OCT 2016 by the yellow number ________.
4
Note the temperature and dewpoint in the station model at Charleston, on the SC coast. Charleston temperature at map time was ________ °F and the dewpoint was 44 °F. Charleston was just west of the Low's center and stationary front.
47
Acid rain (or snow) occurs when the pH of the precipitation is less than
5.6
The general 300-mb contour pattern at 00Z on 31 OCT exhibited an upper air flow with ________.
All of these features
Two periods of precipitation, more likely to be rain, separated by a short period of relatively warm fair weather at Detroit might occur if the cyclone takes Track ________.
B
As the cyclone center approaches Detroit on either storm track, the air pressure at the city ________.
Falls
At the same time, the air temperature outside the aircraft ________.
Falls
Winter storms are extratropical cyclones that produce
Frozen precipitation
Warm surface water transported by the wind away from the South American coast is replaced by cold water rising from below in a process called upwelling. Upwelling of cold deep water results in relatively ________ SST in the eastern Pacific compared to the western Pacific.
Low
Fronts slope back from the Earth's surface and over ______ dense air.
More
Examine the SST anomaly field in the critical region box you drew, and estimate its average anomaly temperature. The average SST anomaly of the box area shows that the October 2016 tropical Pacific pattern most nearly resembles ________ conditions.
Neutral
Upper-air winds steer low-pressure systems as well as air masses. A surface Low that is centered to the east of a trough axis and west of a ridge axis will be expected to move toward the ________.
Northeast
On the same map, there is evidence of a broad ________ across the region from Montana to New Mexico.
Ridge
The large-scale motions in the atmosphere show a convection cell (convective loop). The bold dark arrows show that air is rising in the stormy weather area of the western Pacific and ________ in the eastern tropical Pacific.
Sinking
Apply the hand-twist model of low pressure systems to each of the storm's 12-hour positions along Track B. Assume that initially the wind at Detroit is blowing from the east. As the storm approaches the wind shifts from the east to the ________.
Southeast
As a general rule of thumb, the greater the altitude of the top of a thunderstorm cloud (cumulonimbus), the more intense the thunderstorm cell. A relatively high thunderstorm top implies vigorous convection and a relatively ________ updraft.
Strong
The three-dimensional extension of the Norwegian cyclone model includes warm and cold air streams called
conveyor belts
In the bottom, non-snow precipitation map, rain is found trending ________ the storm track.
mainly south
Polar amplification is associated with the shrinkage of Arctic sea ice. The ice loss leads to warming and continued ice loss. This ice-albedo feedback is a __________ feedback.
positive
Based on the temperatures in this precipitation region about the Low center and stationary front, the form of the precipitation with the more intense radar echoes was likely ________.
rain
Refraction combined with one or two internal reflections of sunlight by liquid water drops about the antisolar point creates
rainbows
The shading denoting non-snow precipitation (lower panel) was located during this period, more generally to the ________ of the storm track.
south
Another forcing of climatic change involving solar input is the aerosol concentration coming from volcanic activity. It is estimated that the 1992 eruption of Mt. Pinatubo produced a global mean temperature decrease of about ________ degrees Celsius.
2.0
These observed winds and SST in October 2010 generally ________ consistent with the depiction of those of the Figure 3 schematic of beginning portion of Investigation 9B for a La Niña.
Are
The bright satellite shading of high cloud tops moving onto the Northwest coast ________ approximately coincide with the surface map's display of precipitation as shown by the radar shadings.
Did
The reflectivity (left map panel) is related to the intensity of the radar return signal, and hence the rainfall rates, according to the scale along the right margin of the reflectivity display. The yellow and red shadings west of Minneapolis in the reflectivity view were returns from moderate rates of precipitation embedded in the area of generally lighter precipitation denoted by green and blue returns. The precipitation echoes shown by the shadings in the reflectivity display ________ generally cover much of the area surrounding Minneapolis including the radar site.
Did
From one location to another around the mesocyclone, the wind directions are
Different
The green and red radial velocity shadings and the purple areas ________ generally cover the same areas shaded in the reflectivity return display depicted to the left.
Do
According to the precipitation scale, the pink shade covered extensive areas where the weekly total precipitation was at least ________ inches with the isolated white spots receiving 20 inches or more.
10.0
On the Figure 2 map, the lowest height reported at an individual station for a pressure reading of 500-mb was ________ m.
5510
The air flow at Dallas demonstrates that the horizontal pressure gradient, Coriolis and friction forces combine to direct surface air flow around Northern Hemisphere high-pressure centers that is ________ as seen from above, consistent with the hand-twist model of a High.
Clockwise and outward
The shorter thin blue arrow represents the ________ force, which is acting at a right angle and to the right of the direction of motion.
Coriolis
The upper air station model also gives the air temperature at 500 mb. The plotted station data show that, as latitude increases (i.e. moving poleward), the general decline of 500-mb temperatures are accompanied by a(n) ________ in the altitude of the 500-mb surface.
Decreases
Bright white shadings in the infrared image ________ align east of and along the location of the cold front in the Northwest in Figure 1.
Did
Ascending unsaturated (clear) air ________, cooling at about 10 Celsius degrees per 1000 meters of ascent (5.5 Fahrenheit degrees per 1000 feet).
Expands
Because these are surface winds, another force acting on the air in the direction opposite to the air flow, was the local ________ force. At map time, this force at Portland was acting generally toward the west.
Friction
The surface wind direction from the Minneapolis station model, was ________ the arrow you drew on the radial Velocity display of Figure 3 indicating the low-level wind direction.
Generally consistent with
Radar shadings indicate where the NWS national network of Doppler radars was detecting precipitation. The intensities of the echoes according to the scale at the left edge of the map were related to precipitation rates. From the map display, precipitation was broadly located generally: ________.
In both of these (in a curved band to either side of the coastal cold front & widely spread in eastern Washington and Oregon, Idaho and western Montana)
It is the presence of the frictional force added to the pressure gradient force and the Coriolis Effect that causes air to spiral ________ in surface-map Lows and outward in Highs.
Inward
On the Figure 3 weather map segment, consider an air parcel at rest at Point A. An initial horizontal pressure gradient force ________ acting on the parcel.
Is
The horizontal pressure gradient force is the primary determiner of wind speed. The higher wind speeds reported in the ________ U.S. were associated with stronger pressure gradients.
Northeastern
The moving air parcel follows the dashed curved path shown on the map. The thick black arrow at Point B shows the parcel's direction of motion at that location. At that instant, the longer thin red arrow represents the ________ force.
Pressure Gradient
In the radial Velocity display, the area of greatest radial wind components flowing away from the radar site (brighter red shading) is located generally to the ________ of the radar site.
Southwest
Orient the cards in the "cross" position as shown in the drawing (iii). Place your pencil point at X. With the cards motionless, carefully draw a line on the loose card (B) along the cut-edge and directly away from you. The line you drew represents a path that is ________.
Straight
You actually moved the pencil point along a path that was both straight and curved at the same time! This is possible because motion is measured relative to a frame of reference. In this investigation, there are two different frames of reference; one fixed and the other rotating. When the pencil-point motion was observed relative to the fixed card (A) and its cut-edge, its path was ________.
Straight
________ Along the radar beam, when in position 3, the Doppler wind speed is zero.
T
In this example, the actual winds circulating around the mesocyclone all have the same speed, as shown by arrows whose lengths are ________.
The same
Where there is an abundance of hygroscopic nuclei in the atmosphere, clouds are likely to develop at relative humidities ______ 100%.
Under
At least some of the water (in the liquid or solid form) falling from a cloud vaporizes as it passes through ______ air below the cloud base. If the water completely vaporizes before reaching the Earth's surface, the shaft of falling liquid or ice particles is known as virga.
Unsaturated
On the 500-mb map, the plotted report for Little Rock, in central Arkansas, shows that, at the 500-mb pressure level over the station, the temperature was ________ °C.
-12
A mass of cold, dry air is ________ a mass of warm, humid air. Consequently, warmer (lighter) air is often forced to rise above the sloping frontal surface overlying colder (denser) air.
Denser than
The 500-mb map also shows that, where contour lines are relatively close, such as across the northeastern U.S., wind speeds are relatively ________ compared to where contour lines are more widely spaced. This principle corresponds to the similar relationship between the spacing of isobars and wind speeds on surface maps.
High
Figure 3 shows atmospheric and oceanic conditions during La Niña. At times the tropical Pacific experiences trade winds stronger than neutral conditions with SST lower than usual in the eastern tropical Pacific and higher than usual in the western tropical Pacific. Because stronger trade winds produce stronger surface currents during La Niña, the warm water is pushed westward and colder water wells up to cause below-average SST in the eastern tropical Pacific. It also follows that SST in the western tropical Pacific must be ________ than during a typical El Niño episode
Higher
In the radial Velocity display on the right, the area of radial wind components flowing toward the radar site (brighter green shading) is located generally to the ________ of the radar site.
North
Precipitation was also scattered ________.
Over the western Great Lakes ahead of a cold front & southeast of Florida associated with a tropical disturbance
The warm sector of a mature midlatitude cyclone, where air temperatures and dew-points are relatively high, is usually located to the ______ of the center of the system.
Southeast
Another broad band of cloudiness stretched from northern Minnesota northeastward into the Canadian Province of Ontario. This band was in alignment generally north of the storm system's ________ front.
Warm
Changes in surface air pressure, areas of large-scale convection, and upper air flow patterns as shown in Figures 2 and 3 alter the planetary wind circulation and affect the weather elsewhere in the world. Figure 4 shows some weather patterns that have been statistically associated with El Niño conditions. This figure shows that during our Northern Hemisphere winter when El Niño is taking place, the southeastern states are usually ________ than normal. Figure 5 shows some weather patterns linked to La Niña conditions
Wetter and cooler
Earth's energy input of solar radiation varies as seen in sunspot cycles. Greater numbers of sunspots correlate with _________ amounts of solar output.
greater
Precipitation, as represented by the radar echo shadings on the map, had yellow and scattered red hues of moderate to heavier rainfall rates. The precipitation in the several-state area encompassing this particular wave cyclone was located generally ________.
in both of these locations
The specific track of an extratropical cyclone's low-pressure center across Earth's surface is largely determined by large-scale horizontal winds blowing ________.
in the middles and upper troposphere
During changing climatic conditions, temperature variations depend on latitude. Polar amplification is the __________ in magnitude of temperature change with increasing latitude.
increase
Surface wind speeds over most of the coterminous U.S. were generally less than those at several stations from the Dakotas to Nebraska, which reported a speed with one long feather denoting ________ knots.
10
From the 300-mb station models, the highest wind speed plotted on the Figure 7 map was two pennants at Reno, NV, Boise, ID, and Green Bay, WI, indicating ________ knots.
100
The SST anomalies in the eastern Pacific were positive, with the greatest values being more than ________ C°. SST anomalies along the equator were all positive. The location, degree, extent, and duration of the warm SST anomalies are what define the El Niño situation.
3.0
Recall that the heights at which the radiosondes detected 500-mb of pressure are reported in the upper right position of the upper-air station models on the map. Also, the heights are plotted in tens of meters, so that a "0" needs to be placed to the right of the plotted digits for the actual height. The height of the 500-mb pressure level plotted at Reno, in western Nevada, was ________ meters above sea level.
5580
Rawinsonde data for Green Bay at 00Z 31 OCT 2016 (not shown), indicated that the highest wind speeds were 126 knots found at 243 millibars. This indicated the maximum-speed core of the jet stream over Green Bay was ________ the altitude shown on the 300-mb map.
Above
Figure 6 is the 500-mb constant-pressure map for Sunday evening, 00Z 31 OCT 2016, the same time as the Figure 5 surface map. The mid-tropospheric flow pattern shown by the contour lines on the 500-mb map, displayed ________.
All of these features
The wind directions in the eastern Pacific were generally from the southeast. In the western Pacific, south of the Equator (between about 160° E and 180°), winds were generally light with most blowing from the west. Compare these observed winds and SST with the depiction of the Figure 2 schematic of an El Niño, where surface winds are the horizontal black arrows and the SST are color coded. The observations and the schematic model generally ________ consistent. (For larger views of these images, see http://www.pmel.noaa.gov/tao/elnino/nino_normal.html )
Are
Wind directions at station models near isobar lines across the country were generally seen to flow ________. This is best defined with the circulation around the Great Lakes High.
At angles across isobars
Also compare the temperatures for Caribou, Wallops Island, and Miami. (Wallops' plot is obscured but was reported as -16.3 °C.) As you recall from Investigation 5B, the relation of column temperatures to heights of pressure surfaces was examined using conceptual "pressure blocks." The 500-mb temperature, reflective of the temperature of the column beneath that level, was lowest at ________.
Caribou
Using the 500-mb station values as well as the contour pattern, compare the reported station heights at Caribou, in northern Maine; Wallops Island, Virginia on the Chesapeake Bay; and Miami, in southern Florida. The 500-mb height was lowest over ________.
Caribou
As was seen at the 500-mb constant-pressure level in Investigation 8B, higher wind speeds at 300 mb are also located where the spacings of height contours are generally relatively ________. Furthermore, the relationship is consistent with that on surface weather maps between wind speeds and the spacings of isobars.
Closer together
A broad, bright, white arc curling between Wisconsin and east-central Texas is composed of clouds producing precipitation at image time. The arc of clouds across this portion of the country forms the band spread ahead of and along the wave cyclone's ________ front.
Cold
As a cyclone advances, the system typically progresses through a life cycle. As a cyclone develops, the central pressure of the system ________ and surface winds strengthen. At maturity, clouds cover a broad area about the low center and associated precipitation is widespread.
Cold
Considering the wind shifts and frontal positions at Detroit as the cyclone passes through the region along Track A, the city is on the relatively ________ side of the system.
Cold
In the Northern Hemisphere, when the polar-front jet stream is south of a locality, the weather at that location is relatively ________.
Cold
The Northern Hemisphere's upper-air westerlies flowing through topographical troughs exhibit counterclockwise (cyclonic) curvature as seen from above. As shown in Figure 1, the trough axis line divides the trough into two roughly symmetrical sectors. Note that west of the trough axis, winds are from the northwest (a cold weather direction) and east of the trough line, winds are from the southwest (a warm weather direction). We conclude that winds west of a trough axis favor ________ air advection while winds east of a trough line favor warm air advection.
Cold
Compare the temperature and dewpoint at St. Louis, with those at Lexington. The air to the west of (behind) the cold front was ________.
Cooler and less humid
Whenever air pressure changes over distance, a force will move air from where the pressure is relatively high to where pressure is relatively low. The trade winds blow from east to the west because from east to west the surface air pressure ________.
Decreases
Cold air advection occurs to the ______ of the center of a Northern Hemisphere polar high.
East
With the passage of a cold front, the air temperature usually falls and the dewpoint usually ________.
Falls
Within a thunderstorm cell, the temperature ________ with increasing altitude primarily because of the expansion of rising air within the cloud.
Falls
Santa Ana winds are hot dry winds of southern California produced by adiabatic compression from higher elevation desert areas to the northeast. Santa Ana winds especially exacerbate the ______ situation.
Fire Weather
The dewpoint at Nassau indicated air with relatively ________ concentrations of water vapor was offshore along the stationary front as compared to location on the landward side of the stationary front. (A guide is that an increase of 18 F° in dewpoint indicates about a doubling of water vapor concentration in air.)
High
Compare the temperature and dewpoint at Oklahoma City, in central OK, with those at North Platte, in western Nebraska. The air was ________ to the west of (behind) the cold front.
Higher
In coastal areas, a sea (or lake) breeze is likely to develop if regional winds are weak and the surface air pressure is slightly ______ over the water body than over the adjacent land.
Higher
In response to changes in the air pressure pattern across the tropical Pacific, the trade winds weaken (and wind directions can reverse, especially in the western Pacific as shown by the bold dark arrows). No longer being pushed toward and piled up in the western Pacific, the warm surface water reverses flow direction. As shown by the surface currents arrows, the surface water during El Niño flows toward the east. As evident in the appropriate sea surface temperature shading, this causes SST in the eastern tropical Pacific to be ________ than during neutral conditions.
Higher
Rainfall in the tropical Pacific is also related to SST patterns. There are reasons for this relationship. The higher the SST, the greater the rate of evaporation of seawater and the more vigorous the atmospheric convection. Consequently, during neutral conditions, rainfall is greatest in the western tropical Pacific where SST are ________.
Highest
Such relatively small areas of those precipitation values would likely be associated with ________.
Local strong thunderstorms
On average, one would expect temperatures at similar latitudes to be similar. Zonal wind patterns, as in Figure 3, would exhibit this relationship. However, given the wind pattern of Figure 4, at 12Z on 21 OCT 2016, surface air temperatures in the central plains states of Missouri and Illinois are likely to be ________ than surface temperatures over California and Nevada.
Lower
Consider the following stations located on the 500-mb map: Albuquerque in north-central New Mexico, Pittsburgh in western Pennsylvania, Jackson in central Mississippi, and Medford in southwest Oregon. Examining those stations' data shows this reporting station data are from ________. Current rawinsonde reports of upper air data can be found from the Upper Air section, "Upper Air Data - Text" on the RealTime Weather Portal.
Medford, OR
When the upper-air flow pattern is zonal, the source region for much of the air over the coterminous U.S. is the Pacific Ocean. On the other hand, when the upper-air flow pattern is meridional, the source regions for air masses over the lower 48 states are Canada (where winds are from the northwest) or Mexico or the Gulf of Mexico (where winds are from the southwest). Hence, from west to east across the lower 48 states, temperatures are likely to be more variable with a ________ flow pattern.
Meridional
Apply the hand-twist model of low pressure systems to the cyclone's position at 12-hour intervals along Track A. Assume that before the storm's arrival the wind at Detroit is blowing from the east. As the cyclone approaches the wind shifts from the east to the ________.
Northeast
To the northeast of the center of a mature midlatitude cyclone, surface winds are likely to blow from the
Northeast
Portland, Maine, in the radar shading reported a temperature of 49 °F with the current weather condition of three dots signifying ________ occurring. (For present weather symbols, see the RealTime Weather Portal, Extra's section, Surface Station Model.)
Rain
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 ________.
Rise
Strong trade winds also cause the warm surface waters to pile up in the western tropical Pacific so that the sea surface in the western Pacific is somewhat higher than in the eastern Pacific. Transport of surface waters to the west also causes the thermocline (the transition zone between warm surface water and cold deep water shown by the blue layer in the ocean side view) to be ________ in the eastern tropical Pacific than in the western Pacific.
Shallower
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
With passage of the warm front, surface winds shift direction from the east to the ________.
Southeast or south
Examine Figure 1, the neutral (long-term average or normal) conditions in the tropical Pacific Ocean from about Borneo in the western Pacific Ocean to the west coast of South America (greatly exaggerated in the vertical scale). The scene depicts the ocean surface with atmosphere above and a cross-section of the ocean below. Fair weather appears in the eastern tropical Pacific (near 80 degrees W) while the cloud diagram implies that ________ weather prevails in the western Pacific (near 120 degrees E).
Stormy
Radar reflectivity shadings of red splotches showed that some precipitation intensities associated with the precipitation area across southeastern North Carolina were relatively ________.
Strong
________ The red shaded area depicts air motions away from the radar.
T
By Figure 5 map time, the wave cyclone had developed more. The Low pressure center was located in northern Ohio. Although the central pressure had not changed (1012 mb underlined just above the L), _________ isobars closely and completely encircled the L indicating the existence of a stronger horizontal pressure gradient.
Two
Considering the wind shifts at Detroit as the cyclone's center passes through Michigan along Track B, Detroit is positioned to experience weather related to the relatively ________ side of the system.
Warm
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 ________ air advection.
Warm
Figure 2 is the surface weather map for 12Z 28 OCT 2016. This map follows the Figure 5 of Investigation 10A by twenty-four hours. At this Figure 2 time, the storm system had developed in its life-cycle by undergoing the occlusion process. The original low-pressure center of the storm had weakened and moved into southeastern Canada. At the Figure 2 time, the lowest pressure center of the storm was 1007 mb located over Boston, Massachusetts. Precipitation, as shown by radar echoes, ________ occurring to the north of the main L at Boston.
Was
Figure 2 is the forecast map issued at 2 AM EDT, Wednesday, 24 October 2012, 39 hours after the Figure 1 advisory. The Figure 1 forecast position for the Figure 2 time was approximately 17 N 77.5 W. Compare this forecast position with the Figure 2 storm center location stated in the legend portion of the map. The Wednesday forecast longitude position was quite near the Figure 2 value; the forecast latitude position ________ within a degree of the Figure 2 value.
Was not
Compare Figures 1 and 2. From the location and intensity of these precipitation amounts on Figure 2, we can conclude that thunderstorms ________ occurring in areas of red radar echoes on Figure 1 at that map time.
Were likely
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 ________.
West or Northwest
As a component of the planetary-scale upper-air westerlies and similar to the winds at 500 mb, the polar-front jet stream steers low pressure systems. Hence, middle latitude storms generally move from ________.
West to East
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 ________ than that associated with a warm front.
Wider
These relative positions of the respective precipitation types in this actual storm ________ generally consistent with the model presented in Figure 1.
are
Sea level rise is a major concern of the changing climate. The global variation in ocean volumes results from
both ice amounts and ocean temperatures
The wind pattern in the several state area around the Low exhibited a generally ________ flow as expected.
counterclockwise and inward
Changing climate conditions must involve imbalances of the global energy budget. Radiation processes in the Earth system strive to create global radiative
equilibrium
Fluids, including air, do not readily mix if their densities are different. The boundaries between neighboring air masses of different densities are called ______. Differences in air-mass density are due to differences in temperature and/or humidity.
fronts
The contour pattern of the 500-mb map has ________.
generally straight west-east flow across the central U.S.
Milankovitch determined that Earth's orbital parameters had varying cycles that could combine to change solar input and influence the
ice sheet expansion/contractions
Climates of the past two million years have been generally cooler than previously and featured the development of huge
ice sheets
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 ________, and clouds typically form.
increases
The areas that experienced snow were therefore located to the ________ of the storm track.
mainly south
The broad pattern of current SST anomalies, in general, across the tropical equatorial Pacific region (from 5° north and south), shows values that were: ________.
negative over the eastern two-thirds of the region and positive over the western third
The shading denoting snow precipitation (upper panel) was located during this period generally to the ________ of the storm track.
north
Blue wavelengths of sunlight are preferentially scattered by gas molecules in the atmosphere to give the sky its color. This is an example of ______ scattering.
rayleigh
Looking along the storm track curve on the non-snow precipitation map, during the storm's passage, the "warm" side would be generally to the ________ of the track.
right
The wind direction at Lexington, KY, as also at Nashville, TN, was generally from the ________ as would be expected in the "warm sector," between the warm and cold fronts in a wave cyclone.
southwest
Air masses are distinguished from one another on the basis of
temperature and humidity
The anomalous winds along the equator across the tropical Pacific were generally ________ across the tropical Pacific.
very light and of varying direction
Assuming the temperature at Portland remains steady, ________ precipitation would likely continue there.
warm, liquid
As an air mass migrates from its source region, it begins to modify. Air mass modification is more rapid when the air mass flows over a surface (land or water body) that is ______ than the lowest layer of the air mass.
warmer
The wind direction at Charleston ________ consistent with the wind flow of the hand-twist model around a Low center.
was
This position ________ consistent with the position of the storm's low-pressure center on the Figure 2 surface weather map.
was
The lowest 500-mb heights are generally associated with the ________ latitude stations. These upper air features result from cooler temperatures in the air column between 500 mb and the surface.
Highest
which statement is correct?
Climate sets the boundary condition for weather
Using the cyclone's Track B frontal positions in Oklahoma as a guide, pencil in the associated cold front and warm front at 12-hour intervals. Follow the same guidelines you employed in drawing Track A frontal positions. With Track B, residents of Detroit ________ experience the passage of fronts.
Do
Using Track A frontal positions shown in Texas as the starting point, pencil in the cyclone's estimated cold and warm frontal positions at 12-hour intervals along its predicted path. Draw the fronts from the low-pressure center at each location. For simplicity, draw the warm front in essentially the same position relative to the low pressure center and gradually rotate the cold front until it is oriented roughly north/south 24 hours after its Texas position. With Track A, residents of Detroit ________ experience the passage of fronts.
Do not
The cold front extending from the low-pressure center was advancing generally toward the ________.
East
Draw a thin, straight line about 1 cm long from the center of the Portland station circle in the direction toward lowest pressure that is perpendicular to the 996-mb isobar just north of the Portland station circle. Add an arrowhead to form an arrow pointing toward lowest pressure. The arrow you just drew represents the direction of the ________ force acting on the air at Portland.
Horizontal pressure gradient
Cloud droplets can cool to temperatures well below 0 °C (32 °F) without freezing. When these so-called supercooled droplets coexist with ice crystals in the same cloud, the ______ grow in size. This is the basis of the Bergeron-Findeisen process that is responsible for the formation of most precipitation.
Ice crystals
The warmer air rising above the frontal surface expands and cools as it ascends, and its relative humidity ________. If saturation is achieved, clouds develop and from those clouds, rain or snow may fall.
Increases
Next, focus on Dallas in northeastern Texas. Conditions at Dallas were influenced by the southeastern High. Again, draw an arrow from the station circle in the direction the air is flowing at Dallas. The plotted pressure at Dallas was "195" (1019.5 mb) with a wind speed of about 10 kt. Dallas' pressure gradient force (perpendicular to the 1020-mb isobar) was acting in a direction generally toward the ________.
Northwest
A relationship exists between the orientation of height contours and wind direction on 500-mb maps, especially at higher wind speeds. As seen in Figure 2 across the Washington State to Idaho area of the U.S., wind directions are generally ________ to nearby height contour lines. This is because the frictional forces acting on moving air at and near Earth's surface diminish rapidly with height and are essentially absent in determining middle and upper atmosphere motions.
Parallel
The Northern Hemisphere's upper-air westerlies flowing through topographical ridges exhibit clockwise (anticyclonic) curvature as seen from above. As shown in Figure 1, the ridge axis line divides the ridge into two roughly symmetrical sectors. Note that west of the ridge axis, winds are from the southwest (a warm weather direction) and east of the ridge axis, winds are from the northwest (a cold weather direction). We can conclude that winds to the west of a ridge axis favor ________ air advection while winds to the east of a ridge axis favor cold air advection.
Warm
Also compare the temperatures and dewpoints at Nashville, TN, with those of Lexington, KY, stations separated by the stationary front. The air to the south of the stationary front was ________ water vapor content.
Warmer and had higher
Compare the temperature and dewpoint at Lexington, with those at New York City. The air to the south of (behind) the warm front was ________.
Warmer and more humid
Survey the map for wind speeds of 70 knots or more. Using this arbitrary wind speed threshold to define the existence of a jet stream, we can therefore conclude that there ________ evidence of a jet stream on the Figure 7, 300-mb constant-pressure map curving across the U.S.
Was
The large white, open arrows provide surface ocean current information. The surface current arrows indicate that during neutral conditions, surface water flows towards the ________ driven by the prevailing winds.
West
The wind at Little Rock was generally from the west-southwest at about________ knots. [Note: When winds of 50 knots or greater are reported, a pennant is used on the station's wind shaft for a 50-kt increment along with the appropriate number of long and short "feathers."]
10
The top view of Figure 8, December 2015 Means, displays the average SST and surface winds. The sea surface temperatures across the region ranged from about 25 °C as the "coolest," in the southeast corner, to about 30.5 °C as the "warmest," just south of the Equator. These highest SST were located at about ________ longitude in the tropical Pacific.
180
The IPCC AR5 report estimated that Northern Hemisphere Arctic Ocean sea ice cover may be gone in summers by about
2050
Caribou, in northern Maine, was reporting a temperature of ________ °F.
32
The lifetime of a greenhouse gas is defined by the time a given amount of the gas is reduced to ________ of what was introduced to the atmosphere.
37%
Recalling that the heights plotted at individual stations on 500-mb maps are in tens of meters (place a 0 to the right of the three plotted digits), the coded height at Little Rock ("585") indicated 500 mb occurred at ________ meters above sea level.
5850
Figure 7 is the 300-mb constant-pressure map for 00Z 31 OCT 2016, the same time as the surface and 500-mb maps. The 300-mb pressure level occurs in the upper troposphere. The 300-mb station model heights are also plotted in tens of meters. The height of the 300-mb pressure level at Reno, NV, was ________ meters above sea level.
9240
Wind directions at stations near isobars were generally oriented ________ to their nearby isobars. These wind patterns were a result of the combination of horizontal forces acting on air near the surface, including the horizontal pressure gradient, Coriolis, and friction forces.
At an angle
Also from the Iowa Low, a ________ front stretched generally southwestward curving into northern Texas. The 1016-mb isobar enclosed an extended area of lower pressure, a trough, which contained the two Low centers and that front.
Colder
Colored areas on the top of the block diagram portion of the figure denote sea surface temperatures (SST) during neutral conditions. The red colored area in the western Pacific denotes the highest SST. These highest SST occur under ________ in the tropical Pacific. This SST pattern is caused by relatively strong trade winds pushing sun-warmed surface water westward, as indicated by the direction of surface current arrows.
Considerable cloudiness
Now examine Figure 9. These are the tropical Pacific average SST and wind conditions for October 2010, the last strong La Niña. For October 2010, the sea-surface temperatures along the Equator in the eastern Pacific were near 20 °C, several degrees ________ than those of the same area during the El Niño in December 2015. The winds across the entire Pacific area (Means) were generally blowing from east toward west at that time. The warmest waters were found in the extreme western Pacific.
Cooler
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 ________. It is the circulation and rising motions of low-pressure systems that leads to the "comma" shape of cloudiness frequently seen in satellite images.
Counterclockwise
Viewed from above, cold and warm fronts in the Northern Hemisphere rotate ______ around centers of low pressure, with cold fronts typically advancing more rapidly than warm fronts.
Counterclockwise
Comparing the heights of the 300-mb pressure surface generally across the southern portion of the U.S. to those along the northern portion on the map, as latitude increases (one moves poleward), the height of the 300-mb surface generally ________. This pattern is the same as that found at 500 mb.
Decreases
In response to changes in surface currents, sea surface heights in the eastern tropical Pacific are higher than during neutral conditions. At the same time, the arrival of the warmer water in the east causes the surface warm-water layer to thicken. Evidence of this is the ________ depth of the thermocline to the east compared with neutral conditions.
Deeper
The 500-mb wind directions often provide guidance on storm movements. The 500-mb wind directions over the Mid-Atlantic region indicate the storm center seen on the Figure 5 surface map off New Jersey would generally move toward the ________ over the next day or so.
East
Cold surface water cools the air above it, which leads to increases in the surface air pressure. Warm surface water adds heat and water vapor to the atmosphere, lowering the surface air pressure. These air-sea interactions result in tropical surface air pressure being highest in the ________ tropical Pacific.
Eastern
Figure 2 shows atmospheric and oceanic conditions during El Niño. Compared to Figure 1 (neutral or long-term average conditions), the area of stormy weather during El Niño has moved ________. While no two El Niño episodes are exactly alike, all of them exhibit most of the characteristics shown in the El Niño schematic of Figure 2. With the onset of El Niño, tropical surface air pressure patterns change. Compare El Niño conditions in the western and central tropical Pacific with the neutral conditions of Figure 1. During neutral conditions, surface air pressure in the central Pacific is higher (accompanied by fair weather) than to the west. During El Niño, the surface air pressure to the west is higher than in the central Pacific. This reversal in the atmospheric pressure pattern, called the Southern Oscillation, was first studied in an attempt to explain monsoon failure and drought in India.
Eastward
For a weather radar operating in the reflectivity mode, the strongest echoes are produced by
Hail
On a visible satellite image, a large thunderstorm can appear as a bright white blotch, or cluster. The brightness of the blotch indicates that the cloud top has a relatively ________ albedo for visible solar radiation.
High
Comparing the wind speeds in a general west-east band across the middle of the country for the 500-mb level with the surface winds at those same locations at 00Z 26 OCT 2016, shows that, as altitude in the atmosphere increases, wind speeds generally ________. This relationship results in part from the absence of friction in the middle and upper atmosphere.
Increase
The NOAA Climate Prediction Center (CPC) ENSO description of Pacific conditions and their forecast can be found at http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.html . The CPC discussion and SST and wind anomalies of Figure 7 suggest the approach of ________ conditions. For the past few months, near-normal temperatures had covered most of the equatorial Pacific. The forecast suggested that the current cool conditions seen in Figure 7 may reach La Niña levels during fall 2016 and likely persist through winter of 2016-17. This expectation comes from a consensus of the ocean-atmosphere indicators and ENSO numerical models.
La Nina
Fundamental to the formation of the polar-front jet stream within the westerlies is the physical property that warm air is less dense than cold air when both are at the same pressure. Air pressure drops ________ rapidly with increasing altitude in cold air than in warm air.
More
Compare the 500-mb and 300-mb wind flows. The pattern of wind directions also shows that the winds generally flow ________. This directional relationship is particularly evident at higher wind speeds.
Parallel to the contour lines
As the cyclone center moves away from Detroit, the air pressure at the city ________.
Rises
With the passage of a warm front, the air temperature usually rises and the dewpoint usually ________.
Rises
Compare the temperatures across the Virginia to Georgia region from Figure 3 to Figure 5 maps. The advancement of the Low and its warm sector caused residents of the Mid-Atlantic and Southeast regions of the country to see ________ temperatures over the period.
Rising
Indications that a cold front has passed through your location could include the following: falling air temperature, falling dewpoint, ______ air pressure, and a wind shift from south to the west.
Rising
The location of the reports ________ likely related to the passing low-pressure area.
Was
The major in earth's climate system because of it's capacity heat is the
ocean
This non-snow precipitation ________ consistent with the present weather symbol on Figure 2 reported at Portland, ME.
was
Two arrows on the column circle are along the direction of the radar beam, one directly toward the radar and one directly away. These two locations are sensed when the radar beam is at the ________ positions. Because these arrows are oriented directly away from or directly toward the radar site along the beam direction, the radar will sense the full wind speed, away or toward, respectively.
5 and 1
At map time, the low-pressure center of the storm system stretched across the center of the country from Kansas to south of Lake Superior. The general wind circulation about the extended low-pressure area marked by the innermost, 996-mb isobar, as suggested by the hand-twist model and consistent with wind arrows in the several-state region on Image 1, was ________.
Counterclockwise and inward
Considering the Portland conditions as part of the circulation about the northeastern Low, the horizontal pressure gradient, Coriolis and friction forces combine to direct surface air flow around Northern Hemisphere low-pressure centers that is ________ as seen from above, consistent with the hand-twist model of a Low.
Counterclockwise and inward
Point D shows the effect of friction on moving air. The force of friction, represented by the small green arrow drawn from Point D, always acts opposite to the direction of motion and slows the moving object. The slowing causes the Coriolis Effect to decrease. As shown by the thick arrow at Point D, the direction of airflow changes and air flows obliquely across isobars towards ________ pressure.
Lower
Draw a short (about 1 cm) arrow perpendicular to your 0-Doppler wind speed boundary line through the Minneapolis radar site (black dot). Place an arrowhead on the end in the red area to indicate the Doppler-detected wind direction at the station. The direction of your arrow, signifying the wind direction in the lower layers of the atmosphere sensed by the radar signal, is generally from the ________.
North-northeast
This force acting on the wind flow at Portland was directed generally toward the ________.
North-northeast
Radar shadings along and to the north of the frontal boundary from the Great Lakes to southwestern Minnesota ________ show that precipitation was scattered in the Minneapolis area.
Did
The greatest precipitation amounts are shown as several white specks within purple blobs in Washington, Oregon and northern California. These shadings of the heaviest precipitation ________ generally occur where precipitation had been indicated by radar echoes in Figure 1 and bright white cloud tops of Figure 2. While the surface map is a single time, the conditions depicted in Figure 3 were representative of the several days where multiple storm systems passed across the same area.
Did
The intense red shadings of heavy precipitation ________ generally extend along the coast and midway north-south through Washington and Oregon where mountainous terrain existed.
Did
In the atmosphere, cloud condensation nuclei are ______ abundant than ice-forming nuclei.
More
Focus on the other four wind arrow locations shown around the mesocyclone along the radar beam positions 2 and 4. These printed arrows are neither directly toward or away, nor perpendicular to the radar beam direction. Where the radar beam direction and the actual wind arrow make an angle other than 0 or 90 degrees, Doppler radar senses only the component of the total motion that is directly toward or away from the radar. For the two arrows that are directed partly toward the radar, use the green pencil to draw approximately half-length green arrows, from the location dots, that are aimed directly toward the radar along the dashed beam direction. These two locations are at the ________ radar beam position.
2
As a general rule-of-thumb, on average, 13 inches of snow will melt down to 1 inch of liquid water. Therefore, a 33-inch snowfall will produce approximately ______ inches of liquid.
2.5
Solid lines on the 500-mb map join locations where the 500-mb pressure level is at the same altitude. These lines, called contours of height, are drawn here at intervals of 60 m. The coded height values on the map are in tens of meters. On the map, contour values are labeled in whole meters. The highest reported 500-mb height at any individual station on the Figure 2 map was ________ m.
5910
The observed wind direction at Dallas was ________ to the pressure gradient force.
At an angle
Therefore, the air below the 500-mb region of lowest heights in Figure 2 must be ________ than the air below the surrounding higher 500-mb surfaces.
Colder
The overall circulation pattern of surface winds about the extended low-pressure center from South Dakota to northern Texas as seen from above was generally ________. This pattern was a result of the combination of forces including friction at Earth's surface.
Counterclockwise and inward
Clouds (and perhaps precipitation) can develop in the ascending branch of a convection current, along a front, and up the windward slopes of a mountain range. The ascending branch of a convective current may produce an upwardly billowing cloud known as a ________ cloud. For a review of cloud types and their development, see Chapter 7 of the AMS Weather Studies textbook.
Cumulus
Now investigate how rotation affects the path of your pencil line. Again, begin with the cards in the "cross" position and your pencil point at X. As you slowly pull the lower left tab of the loose card (B) towards you, slowly move your pencil point away from you along the cut-edge while drawing its path on (B). The loose card is rotating counterclockwise as you do this. The line you drew is
Curved
When the pencil motion was measured relative to the rotating card (B), its path was ________. This apparent deflection of motion from a straight line in a rotating system is called the Coriolis Effect for Gaspard Gustave de Coriolis (1792-1843), who first explained it mathematically. Because Earth is a rotating system, objects moving freely across its surface exhibit curved paths, except at the equator. This includes air parcels moving horizontally.
Curved
Now imagine yourself far above the South Pole and looking down on the Earth below. Again, think of the loose card (B) as being part of the Earth's surface and that X represents the South Pole. From this perspective, Earth appears to rotate clockwise. Rotate the loose card clockwise by pulling on the lower-right tab as you draw a line along the cut edge. You can observe that as the pencil point moves along the cut-edge and away from the X, it draws a path on the rotating card that ________.
Curves to the left
Now imagine yourself far above the North Pole and looking down on the Earth below. Think of the loose card (B) as being part of Earth's surface and that X represents the North Pole. From this perspective, Earth appears to rotate counterclockwise. You can observe the pencil point's motion relative to the Earth's surface (B). You see that as the pencil point moves along the cut-edge and away from the X, it draws a path on the rotating surface that ________.
Curves to the right
Portland, in southern Maine, was under the influence of the northeastern Low. The wind at Portland, where the pressure was "969," meaning 996.9 mb, showed the air was moving generally toward the ________ at about 15 knots. The wind shaft is plotted crossing New Hampshire and has one long and one short feather. (It may help to extend the wind arrow through the station circle in the direction the air is flowing and add an arrowhead.)
East
Draw an arrow from the station circle center at a 90-degree angle to the right of the wind arrow to represent the Coriolis force acting on the wind at Dallas. The Coriolis force at Dallas was directed generally toward the ________.
East-northeast
The greatest wind speeds as evidenced by the Base Velocity speed shading scale were ________ the reported surface wind speed.
Greater than
Contour lines on constant-pressure upper-air maps separate regions that have higher altitudes from those areas that have lower altitudes than the value of that contour line. In Figure 2, the area to the south of the 5880-m contour across the Southwest U.S. is where 500-mb altitudes are among the ________ on the map. Conversely, on the same map, the area north of the 5520-m contour line in northern Maine and eastern Canada is a region where 500-mb altitudes are the lowest.
Highest
The 500-mb map and other constant-pressure upper-air maps are actually topographic maps that give form or shape to imaginary surfaces on which the air pressure is everywhere the same. That is, the contour pattern reveals the "hills" and "valleys" of the constant-pressure surface. The contour pattern of the Figure 2 map indicates that, in general, the 500-mb surface (the surface where the air pressure is everywhere 500 mb) is at a ________ altitude in southern Canada than in the southern U.S.
Lower
The diagram shows a pattern of air pressure changing over distance. Assuming that the atmosphere is initially calm, the only force acting horizontally on a parcel of air represented on the diagram at Point A is a pressure gradient force. Draw an arrow about a centimeter in length starting at Point A and aimed directly towards the top of the diagram that depicts the direction the pressure gradient force would act. Your arrow shows the pressure gradient force acting directly towards ________ pressure. This force is directed perpendicular to the isobar lines. The horizontal pressure gradient has given rise to a force that causes the air parcel at A to begin moving in the direction towards which the force is acting.
Lowest
The spacing of isobars on the map correlates to the strength of the horizontal pressure gradient with closer isobar spacings associated with stronger gradients. Compare the pressure gradients inferred by the isobar spacings in the northeastern Low and across the southeastern High. The stronger horizontal pressure gradients were located in the ________ U.S. Another relatively strong horizontal pressure gradient can be found in the northwest corner of the map area.
Northeastern
As the air parcel speeds up, the Coriolis Effect increases and the parcel's motion continues to be deflected to its right. This continues until the parcel reaches Point C where the magnitude of the Coriolis Effect finally equals that of the pressure gradient force (which continues to act toward lowest pressure). At Point C the Coriolis Effect will be acting directly opposite to the pressure gradient force. The two forces are then in balance. From Point C and onward, the air parcel will flow ________ to the isobars. This flow is known as the geostrophic wind.
Parallel
Print a copy of Figure 3 for analysis purposes. Draw a straight line about 2 cm in length centered on the radar site aligned along the 0-Doppler wind speed boundary. This "zero-speed" situation occurs where the radar beam is ________ to the actual wind flow and there is no wind motion component directly towards or away from the radar.
Perpendicular
Overnight radiational cooling of clear air may cause temperatures to reach saturation with stable conditions to form ______ fog.
Radiation
Freezing rain (or drizzle) occurs when falling water drops are ______; thus, drops partially freeze when they strike cold surfaces.
Supercooled
________ The green shaded area depicts air motions toward the radar.
T
________The green arrows are directed toward the radar.
T
The wave pattern of most of the contour lines on the Figure 2 map consists of topographic ridges and troughs, that is, elongated crests and depressions, respectively. A ________ appears on the Figure 2 map over the region from the Great Lakes to Mississippi.
Trough
The water droplets and ice crystals that make up clouds are always falling relative to the air, yet the clouds themselves may not be falling relative to the Earth's surface. This happens because clouds are most likely to be located where ______ prevail.
Updrafts
The friction force at Dallas was toward the general direction of ________.
West-northeast
Prevailing winds blow from west to east across most of North America. Winds that blow onshore from the Pacific Ocean are forced up the windward slopes of the Cascade Mountain Range in the Pacific Northwest. Hence, the heaviest precipitation falls on the ________ slopes of the Cascades.
Western
The movement of the frontal system and the direction of travel in relation to the orientation of the mountains ________ combine to enhance the lifting of the humid air.
Would