• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

Card Range To Study



Play button


Play button




Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

175 Cards in this Set

  • Front
  • Back
1. (001) How often do you accomplish a Skew-T?
Every 12 hours.
2. (001) Why does the isobar spacing on a Skew-T increase from the bottom to the top of the chart?
Accounts for the decrease in density of the atmosphere with height.
3. What is RH dependent on?
Temperature and water vapor content.
4. (001) The saturation mixing-ratio lines represent
the amount of water vapor necessary to saturate a volume of air at a given temperature and
5. (001) Which equation shows how saturation vapor pressure (es) is related to saturation mixing ratio
Ws = 622es
6. (002) Potential temperature is the temperature an air sample would have if its pressure were
increased to
1,000 mb in a dry adiabatic process.
7. (002) The wet-bulb potential temperature θw is the Tw a parcel of air would have if it were brought
moist adiabatically to the 1,000 mb level.
8. (003) A parcel of air that is lifted and returns to its original position is in what state of stability?
Absolutely stable.
9. (003) A parcel of air that is lifted and continues to rise after the lifting is stopped is in what state of
Absolutely unstable.
10. (004) A parcel of lifted air will cool dry adiabatically until condensation occurs. The level at
which this occurs is called the
lifted condensation level.
11. (005) What is the convective condensation level?
Theoretical level where condensation in an ascending parcel is reached because of convection
12. (005) One way to obtain the CCLp is to locate the point at which the mixing ratio line (on a
Skew-T) crosses the
temperature curve of the sounding.
13. (005) A second method for finding the CCLml was developed to give increased accuracy in
severe weather forecasting.
14. (006) The mixing condensation level is the
lowest height in a layer, mixed by turbulence, at which saturation occurs after complete mixing
of the layer.
15. (006) To determine the mixing condensation level, you must first determine the
top of the mixing level.
16. (007) Convective temperature is the temperature that surface air must reach to initiate convective
currents that will
extend high enough for the air to become saturated.
17. (008) To obtain the LFC, find the point at which the moist adiabat crosses the
temperature curve of the sounding.
18. (009) In an inversion, the temperature
increases with an increase in height indicating a negative lapse rate.
19. (009) A subsidence inversion is formed by
the adiabatic warming of sinking air and the dew point decreases rapidly at the base of the
20. (010) What is the potential for thunderstorms with a convective available potential energy
(CAPE) of 2250J/kg?
21. (011) Use Total Totals carefully when there
are inversions with available moisture below 850 mb.
22. (011) What would be the likely coverage and intensity of thunderstorms with a cross total of 30
and a vertical total of 23?
Scattered severe
23. (012) Tornado occurrences are grouped in SWEAT index values of
24. (013) The use of K-index values is primarily applicable to the prediction of
air-mass thunderstorms.
25. (014) The SSI is the algebraic difference between the temperature of the air at
the 500 mb level and the temperature that a sample of air at the 850 mb level would be if it
were lifted to the 500 mb level.
26. (014) What would an SSI of –8 indicate?
27. (015) The season of maximum hail occurrences coincides with
the season of maximum thunderstorms.
What is the cloud depth ratio if the CCL is at 740 mb, the freezing level at 600 mb, and the
equilibrium level at 230 mb?
CCL- FL= 1ST #
CCL-EL = 2ND #
29. (016) What is the cloud depth ratio if the CCL is at 770 millibars (mb), the freezing level at 550
mb, and the equilibrium level at 270 mb?
30. (017) What is the first step in determining the size of hail?
Determine the CCL
31. (017) What is considered the optimum WBZ height for hail?
8,000 feet.
32. (018) In using the T1 method of forecasting maximum wind gusts, the warmest point on the
inversion is used to determine the T1 if surface convection does not dissipate the inversion and if
that warmest point is within
150 to 200 mb of the surface.
33. (018) What preconditions must exist that would make the T2 method over-forecast the speed of
the maximum gusts?
The thunderstorm must pass over the forecast point and moderate to heavy rain must occur.
34. (019) What are the names of the three different types of conveyer belts?
Warm, cold, and dry air.
35. (019) A veering wind in the vertical suggests
36. (020) When forecasting turbulence in convective clouds below 9,000 feet what determines the
severity of the turbulence?
The temperature difference between the moist adiabat and the free air temperature.
37. (020) When forecasting turbulence in convective clouds above 9,000 feet, where is the central
portion of the most turbulent area?
Where the maximum temperature difference between the moist adiabat and the free-air
temperature is.
38. (021) In severe weather forecasting, when is the best time period to forecast a Skew-T sounding?
for maximum heating.
39. (021) What element at 700 mb is most favorable for air mass destabilization?
Dry air advection.
40. (022) The wind at the gradient level is 30 kts, what can you expect at the surface due to the
frictional force?
15 kts
41. (022) The Coriolis Force is
zero at the equator and maximum at the poles.
42. (023) In the northern hemisphere, if you stand with the wind to your back and turn 30 degrees
there’s a low to your left and a high to your right.
43. (024) Variations from climatological winds are often the result of
migratory systems.
44. (025) Geostrophic winds are unsuitable for
long-term forecasting.
45. (025) Geostrophic winds may overestimate the true wind when a low-pressure center is within
200 miles.
46. (026) With a gradient wind of 36 kts, what would you forecast for a mean surface wind speed?
47. (027) When the air is subsiding and diverging horizontally where do highs tend to move?
Toward the center of isallobaric highs.
48. (028) What is the header for satellite-derived winds in the Northern Hemisphere?
*****TWXNXX KWBC*****
TWXSXX KWBC this one in southern hemisphere
49. (029) What begins to develop 3–4 hours after sunrise and peaks in the afternoon?
Sea breeze.
50. (029) These winds start when strong winds aloft flow perpendicular to a mountain range.
Foehn wind.
51. (030) What’s the first step in calculating crosswind component values?
Determine the difference in degrees between the runway headings and the actual wind
52. (031) When does low-level wind shear normally terminate below 5,000 feet with a warm front?
At frontal passage.
53. (031) When does low-level wind shear normally terminate below 5,000 feet with a cold front?
Until the depth of the cold air reaches the gradient level.
54. (032) When, where, and during what season would you most likely find a low-level jet?
4 A.M., Kansas City during summer.
look for answers, US central plains in summer in early
55. (032) The most likely place to find a low-level jet is
650–1500 feet AGL.
56. (033) In relation to the jet stream, you forecast the strongest turbulence
on the cold air side
57. (034) With confluent jets, CAT is normally seen when the spatial difference is
5 degrees
58. (034) When cyclogenesis occurs, where would you forecast CAT?
near the jet stream core NNE of the surface low development.
59. (035) When the wind component is 38 knots perpendicular to a mountain, approximately how far
will a mountain wave extend?
150 NM. (2-20)
60. (036) Which type of turbulence is experienced when an aircraft encounters vortices from another
61. (036) What is the best product to use to forecast wake turbulence?
Is not forecasted.
62. (037) For what percentage of the time is moderate or stronger turbulence present when water
vapor image darkening persists over an area for 3 hours or more?
63. (038) What intensity of turbulence has been associated with spectrum width values of 8–11 knots
64. (038) What intensity of turbulence has been associated with spectrum width values of 12 knots
(kts) or higher?
65. (039) Most icing tends to occur at temperatures between
0 and –20C.
66. (040) What are the three types of icing?
Rime, clear, mixed.
67. (040) What type ice appears as a thin smooth surface or as rivulets, steaks, or bumps?
68. (041) What type aircraft tend to be more susceptible because they fly at lower altitudes and slower
69. (041) What type of icing would you forecast that is not hazardous unless encountered for one hour
or more?
70. (042) What type of clouds would produce extensive areas of icing potential?
71. (042) Icing rarely occurs in this type of clouds.
72. (043) Ice formation is most common in what aircraft system?
Air induction.
73. (044) What reports do you use to verify icing forecasts?
74. (045) CAA is identified on the Base Velocity Product on the WSR–88D by what looks like a
backward S.
75. (046) What spectral channels on GOES–8 and GOES–9 are useful in spotting potential icing
1, 2 and 4.
76) 1. (201) For the development of severe thunderstorms, what is the optimum height above the terrain
of the wet-bulb-zero?
********************START OF VOLUME 2******************* 8000ft
77) 2. (201) The conditions necessary for the development of tornadoes, severe thunderstorms, and their
associated destructive phenomena are a conditionally
*UNSTABLE* atmosphere,*LARGE* quantities of moisture, *STRONG* mid-level winds, surface-based lifting
mechanism, and a favorable WBZ.
78) 3. (202) What kind of thunderstorm is the closest to the three-stage non-severe thunderstorm?
Air mass.
79) 4. (202) Squall line thunderstorms form ahead of
*INACTIVE* cold fronts in unstable, moist air.
80) 5. (202) What air masses are separated by a dryline?
mT and cT.
81) 6. (203) Thunderstorms that appear to move to the right of the mid-level winds are called
discrete propagation.
82) 7. (203) Which of the following is associated with the gust front?
The forward flank downdraft.
83) 8. (204) How many types of supercell thunderstorms are there?
84) 9. (204) What supercell thunderstorm occurs mostly along the dryline?
Low precipitation.
85) 10. (205) At what surface pressure does the more destructive family-type tornado outbreaks occur?
1005 mb.
86) 11. (205) The occurrence of hail is rare when the wet bulb zero height is below
5,000 feet or above 11,000 feet.
87) 12. (206) Pronounced veering of how many degrees or greater between the low-level and mid-level
winds is highly productive for severe storms?
30 degrees
88) 13. (206) About 80 percent of storms occurred with a level of free convection between
640 and 850 mb
89) 14. (207) A type of destructive summertime mesoscale system associated with northwest flow
outbreaks is known as a
90) 15. (208) What is the depth of warm air needed to melt snow as it falls?
750 to 1,500 feet
91) 16. (209) What product should be used to forecast the end of snow showers?
LAWC (local area work chart)
92) 17. (210) When does the most significant lake-effect snow occur?
Late fall and winter.
93) 18. (211) For heavy snow, the 700 mb dew point should be warmer than what range?
–10 to –5 °C.
94) 19. (212) On what is snow accumulation dependent?
rate and duration
95) 20. (213) What is the most common predictor for precipitation type?
96) 21. (214) Which indicator is a heavy rain signature?
Train echoes.
97) 22. (215) What is another name for the Foehn wind?
98) 23. (215) Where does the air reach its lowest temperature in a Foehn wind?
At the mountain crest.
99) 24. (216) Which wavelength is best for the detection of small water droplets?
3 cm.
100) 25. (216) The two related factors that attenuation of radar waves depend on are the size and
composition of the particle encountered by these waves and the emitted radio waves’
101) 26. (217) If a radar transmits a pulse for 3 microseconds (μsec), it would produce a pulse length of
900 meters (length is 3 times the number of μsec)
102) 27. (217) What decides the minimum range of the radar?
Pulse length.
103) 28. (217) Another term for second-trip echoes is
range folding.
104) 29. (218) How does the beam width vary with the wavelength; how does it vary with the diameter of
the antenna?
Directly: inversely

This means we can get a narrower beam width by either
choosing a shorter wavelength or by building a larger antenna.
105) 30. (218) The ability of the radar to distinguish between two targets at the same range but at different
directions from the radar is called
bearing resolution.
106) 31. (218) The ability of the radar to differentiate between two closely spaced targets at the same range
and bearing but at different elevations depends on
beam width.
107) 32. (218) Range resolution depends on
pulse length.

The shortest distance between two targets must be more
than one-half the pulse length in order for the echoes to appear separate on the display.
108) 33. (219) Superrefraction affects the radar’s displayed height values by making displayed height
over estimated

The beam is lower than it's supposed to be. So upon stiking a target the sysetm will display the height on your screen higher than the target actually is. (Over estimated)
109) 34. (219) An unusual straightening of the radar beam upward best defines
110) 35. (219) Subrefraction affects the radar’s displayed height values by making display height values
111) 36. (220) When using weather radar to measure the intensity of precipitation, the presence of both
liquid and frozen scatterers may
decrease the accuracy of the measurement because the radar equation does not handle mixed
112) 37. (220) Computation of the equivalent reflectivity factor (Ze) depends on
average returned power, range to target, and a set of known factors called the “radar constant.”
113) 38. (220) What will the 2.2nm (resolution) reflectivity product display be, when the values of the four
consecutive 0.54nm data bins are 23, 24, 30, and 26?

The 2.2-nm resolution product displays the maximum of four consecutive 0.54-nm data values and like
the 1.1nm product, does no averaging
114) 39. (221) The factor that allows a Doppler radar to remember the frequency of transmitted energy for
later comparison to returning energy is
115) 40. (222) The actual wind speed is determined if the flow of wind is
parallel to the radar beam axis.
116) 41. (222) By convention, velocities toward the radar are expressed as
negative numbers.
117) 42. (223) What limits velocity detection in a Doppler radar?

As soon as we pass the 1/2 wavelength limit or 180°, the determination of velocity becomes ambiguous—the
radar may not display the true velocity.
118) 43. (223) The basic assumption of the velocity dealiasing technique is that
velocity should not dramatically change over a small linear distance.
119) 44. (224) What kinds of pulse repetition frequencies are required for high velocity measurements and
long ranges?
High PRFs are required for high velocity measurements, and low PRFs are required for long
120) 45. (225) What is the Doppler spectrum?
the distribution of power received by the radar at each frequency within the sample volume.
121) 46. (225) The spectral slope of the Doppler spectrum of a large thunderstorm with hail appears
broad and flat
the spectrum for these targets has much more
area under the curve than other targets since the particles are larger and reflect more power back to
the radar.
122) 47. (226) What would cause widespread low spectrum width values with isolated areas of unusually
higher values?
Embedded convection.
123) 48. (226) Widespread low spectrum width values with isolated areas of higher values is most likely
indicative of
embedded storms.
124) 49. (227) For the WSR–88D to generate a base reflectivity product, the antenna must complete
one elevation slice.
125) 50. (227) Where is the ideal location to look for a hook echo signature?
In the right rear quadrant of the trailing half of the storm.
126) 51. (227) Embedded thunderstorms are detected by the WSR–88D quite well because
its 10cm wavelength can see through the stratiform precipitation that tends to hide the storms
on 5cm radars.
127) 52. (227) Outflow boundaries may be seen on the WSR–88D even when no clouds are present
a gradient in the refractive index due to density differences will exist with the boundary
128) 53. (228) Which product is used in the detection and location of rotating thunderstorms and in
determining wind field characteristics?
Base mean radial velocity
129) 54. (228) When the Doppler zero line has a noticeable forward S-shaped pattern, winds are
considered to be

*Forward* "S" veering with height
*BACKWARD* "S" BACKING with height.
130) 55. (228) When the radar detects pure cyclonic rotation, how is the Doppler zero line oriented
parallel to the viewing direction.
131) 56. (229) Why is the spectrum width product useful for the early detection of thunderstorm
The detection of high spectrum widths may be indicative of currents present in a convective
132) 57. (230) Data collected for generation of the composite reflectivity product is derived from
all elevation slices.
133) 58. (230) The melting level is displayed on the composite reflectivity product as a
circular pattern of higher reflectivities.
134) 59. (231) Which procedure is a primary use for the layered composite reflectivity maximum product?
Quickly identifying stronger storms and areas with a greater potential for convection.
135) 60. (231) Which condition indicates an intense updraft and strong likelihood for severe weather on
the layered composite reflectivity product?
Strong reflectivity values (>50 dBZ) in the high altitude layer
136) 61. (232) Identify the three processing regions of the layered composite reflectivity maximum (LRM)
anomalous propagation removed (APR) algorithm.
Omit all, accept if, and reject if.
137) 62. (233) As the strength of the updraft in a storm increases, what would you expect the vertically
integrated liquid values to do?
138) 63. (233) Vertically integrated liquid algorithms display VIL values for storms based on
reflectivity data converted to liquid water content.
139) 64. (234) Although severe weather probability is calculated using vertically integrated liquid,
occasionally VIL values will drop dramatically while SWP values change little or not at all. What
does this indicate?
Storm tilt.
140) 65. (234) Limitations that influence the vertically integrated liquid algorithm’s processing also affect the calculation of what other product?
Severe weather probability product.
141) 66. (235) The echo tops product is based on data from what other product?
Base reflectivity.
142) 67. (235) The echo tops product is very useful in
showing the presence of vertical tilt within a storm.
143) 68. (236) Which product is best used to determine the accuracy of WSR–88D precipitation products?
Hybrid scan reflectivity.
144) 69. (237) The storm total precipitation product provides continuously updated information on
precipitation accumulations within how many nautical miles of the radar?
145) 70. (237) A limitation of the STP product is that it
has trouble with *SMALL*-scale features.
146) 71. (238) Which information is included in the table that accompanies the user selectable precipitation
The total number of hours used to build the product.
147) 72. (238) How long is the database for the user selectable precipitation product?
30 hours.
148) 73. (238) The maximum number of hours that the user selectable precipitation product can be
generated for is
149) 74. (239) The 2-D processor searches for cyclonic shear by identifying
pattern vectors
150) 75. (239) Once the mesocyclone algorithm identifies all pattern vectors, it attempts to consolidate
them to form
3-D features
151) 76. (239) No-data gaps are most prevalent in
152) 77. (240) The tornado detection algorithm analyzes base velocity data to detect regions of strong,
localized, cyclonic shear.
153) 78. (240) The graphic symbol for a tornadic vortex signature is a
red-filled, inverted, isosceles triangle
154) 79. (240) The maximum shear associated with a tornadic vortex signature must be at least
36m/s (≅ 72 knots) anywhere in the circulation

or 25m/s (≅ 72 knots) at the base of the circulation
155) 80. (241) The velocity azimuth display winds profile provides
a time-height profile of wind velocity at a predetermined range.
156) 81. (241) The maximum number of vertical wind profiles that can be displayed on a single velocity
azimuth display winds profile is
157) 82. (241) The color-coded root mean square of the displayed velocity azimuth display winds is related
to what characteristic of the winds?
158) 83. (241) If the velocity azimuth display algorithm finds no difference between the zero velocity line
and the zeroth harmonic, then the offset is zero, and the wind field is
159) 84. (242) The SRM/SRR (storm relative mean radial velocity product/storm relative mean radial
velocity (region) product) depends on what algorithm?
Storm tracking.
160) 85. (243) Which resolution is the severe weather analysis reflectivity product available in?
0.54nm by 1°.
161) 86. (244) The velocity cross section is limited to
162) 87. (244) Resolution of cross-section products
remain constant.
163) 88. (245) Which algorithm is the output of the storm cell segments algorithm directly sent to?
Storm cell centroids.
164) 89. (246) The SCIT algorithm can track how many individual storm cells?
165) 90. (246) What determines the length of a forecast made by the storm position forecast algorithm?
Accuracy of previous volume scan’s forecast.
166) 91. (246) The storm track information product algorithm provides data on
past, present, and future positions of thunderstorms.
167) 92. (247) The three estimates that the hail detection algorithm provides are probability of
hail, probability of severe hail, and MAXIMUM EXPECTED HAIL SIZE
168) 93. (247) The probability of severe hail algorithm will look for hail
>3/4 inch.
169) 94. (248) Which product provides information on cell-based vertically integrated liquid, height of
maximum reflectivity, and maximum reflectivity in the cell?
Storm structure product.
170) 95. (248) What information does the cell trends product provide the forecaster?
Status of supercells and the potential for microbursts.

By tracking the increase or decrease of storm tops, maximum reflectivity values, and cell-based VIL, you’ll have a better idea of what to expect from storms in the area. You can also determine the status of supercells and the potential for microbursts. After a weather event occurs, the cell trends display may be used for post-storm analysis.
171) 96. (249) As reflectivity gradients become stronger and more evident in the lower levels of a
thunderstorm, what should you be looking for?
Usually, as the storm becomes stronger and potentially more deadly, this gradient becomes more andmore evident and may eventually exhibit the classic hook shape.
172) 97. (250) What is a 3-dimensional region in a storm that rotates and is closely correlated with severe
173) 98. (251) What should you use Spectrum Width products with?
Velocity and reflectivity.
174) 99. (252) Who developed the WSR88-D Product/Phenomena matrix?
Air Weather Service

It was developed, and verified, by Air Weather Service forecasters at the WSR–88D Operational Support Facility at Norman, Oklahoma during the Operational Test & Evaluation of the radar.
175) 100. (253) What is the best product to use to isolate storms associated with heavy snow showers?
Vertically integrated liquid.