Term
1. Aside from the Air Force Operational Weather Squadrons (OWS), what agency produces discussions on model output?
A. Joint Army Air Force Weather Information Network..
B. Air Force Weather Agency.
C. National Weather Service.
D. Air Weather Service. |
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Definition
| C. National Weather Service. |
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Term
2.What areas do Storm Prediction Center advisory charts outline?
A. Areas of expected crosswinds.
B. Areas of expected severe weather.
C. Areas of frequent crosswind occurrence.
D. Areas of frequent severe weather occurrence. |
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Definition
| B. Areas of expected severe weather. |
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Term
3.What do you physically compare the 00-hour forecast with during the initialization step of the verification, initialization and verification (VIV) process?
A. Analysis
B. 12-hour forecast.
C. 24-hour forecast.
D. Previous 12-hour forecast. |
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Definition
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Term
4.What action is the final step of the verification, initialization and verification process?
A. Verify the 00-hour forecast with your current analysis.
B. Verify the 12-hour forecast with real-time data for the same time.
C. Verify the previous 12-hour forecast with the current 12-hour forecast.
D. Verify the previous 12-hour forecast against the current 00-hour forecast. |
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Definition
| B. Verify the 12-hour forecast with real-time data for the same time. |
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Term
5.What initial conditions are models used based upon?
A. Standard atmospheric conditions.
B. Previously forecasted conditions.
C. Current weather observations.
D. Model of choice conditions. |
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Definition
| C. Current weather observations. |
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Term
6.What action is the goal of severe weather analysis?
A. Identify the preconditions that allow storms to become severe.
B. Identify the different types of severe thunderstorms.
C. Determine the rear-flank downdraft wind direction.
D. Determine the mid-level wind speed and direction. |
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Definition
| A. Identify the preconditions that allow storms to become severe. |
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Term
7.How many minutes do single-cell storms typically last?
A. 20 to 30.
B. 20 to 40.
C. 30 to 45.
D. 30 to 60. |
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Definition
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Term
8.Which characteristic is not one of the single-cell thunderstorm?
A. Storm motion equal to the mean wind in the lowest 5km to 7km.
B. Weak vertical and horizontal wind shear.
C. High winds and hail.
D. Frequent tornadoes. |
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Definition
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Term
9.Where do multi-cell storms typically regenerate?
A. Along the gust front.
B. The rear-flank downdraft.
C. East of the westernmost cell.
D. North of the 700mb wind maximum. |
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Definition
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Term
10.Which characteristic is not one of multi-cell thunderstorms?
A. Weak directional shear in the lower levels.
B. Straight-line or unidirectional profile.
C. large hail near downdraft centers.
D. short-duration tornadoes. |
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Definition
| A. Weak directional shear in the lower levels. |
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Term
11.Which thunderstorm is not a type of supercell thunderstorm?
A. Classic.
B. High precipitation.
C. Low precipitation.
D. Moderate precipitation. |
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Definition
| D. Moderate precipitation. |
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Term
12.What size hail do classic supercell thunderstorms typically produce?
A. Marble.
B. Softball.
C. Golf ball.
D. Baseball. |
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Definition
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Term
13.Which type of supercell thunderstorm is most commonly found along the dry line of west Texas?
A. Moderate-precipitation.
B. High-precipitation.
C. Low-precipitation.
D. Classic. |
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Definition
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Term
14.Which region is not a primary source for airmasses?
A. Arctic.
B. Tropical.
C. Equatorial.
D. Temperate. |
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Definition
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Term
15.What letter or symbol is appended to the label of a modifying airmass that is cooler than the ground below?
A. Plus symbol.
B. Lower case c.
C. Lower case k.
D. Minus symbol. |
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Definition
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Term
16.Where is the geographic area known as the "Great Plains" located?
A. West of the Rocky Mountains.
B. East of the Appalachian Mountains.
C. Between the Mississippi River and the Rocky Mountains.
D. Between the Appalachian Mountains and the Missouri River. |
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Definition
| C. Between the Mississippi River and the Rocky Mountains. |
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Term
17.In what tornado-producing airmass do tornadoes most frequently occur in families, with paths that are commonly long and wide?
A. Type II, Gulf Coast type.
B. Type I, Great Plains type.
C. Type III, Pacific Coast type.
D. Type IV, Inverted “V” type. |
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Definition
| B. Type I, Great Plains type. |
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Term
18.What factor is evident above the inversion with a Type I airmass?
A. Moisture increase.
B. Rapid drying.
C. Condensation.
D. Turbulence. |
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Definition
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Term
19.Which type of airmass is tropical in origin and generally warm and moist?
A. Type I Great Plains.
B. Type II Gulf Coast.
C. Type III Pacific Coast.
D. Type IV Inverted V. |
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Definition
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Term
20.Which type of airmass has cold air at all levels?
A. Type I Great Plains.
B. Type II Gulf Coast.
C. Type III Pacific Coast.
D. Type IV Inverted V. |
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Definition
| C. Type III Pacific Coast. |
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Term
21.Which air mass is cold with surface temperatures ranging from 50°F to 68°F, the relative humidity commonly exceeding 70 percent at all levels up to at least 500mb, and average windspeeds of 15 knots at 850mb and 50 knots at 500mb?
A. Type II Gulf Coast.
B. Type I Great Plains.
C. Type III Pacific Coast.
D. Type IV Inverted V. |
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Definition
| C. Type III Pacific Coast. |
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Term
22.Which type of airmass features maritime polar air overrunning continental tropical air between 5,000 and 8,000 feet above the surface?
A. Type II Gulf Coast.
B. Type I Great Plains.
C. Type IV Inverted V.
D. Type III Pacific Coast. |
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Definition
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Term
23.What kind of dew-point temperature difference should exist across a dry line?
A. < 10° F degrees.
B. > 10°F degrees.
C. < 10°C degrees.
D. > 10°C degrees. |
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Definition
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Term
24.What severe weather synoptic pattern’s airmass is typically Type III?
A. Type C, overrunning.
B. Type D, cold core.
C. Type A, dry line.
D. Type B, frontal. |
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Definition
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Term
25.When does the maximum severe activity occur with a major cyclone?
A. A few hours after sunrise to maximum heating.
B. From time of maximum heating to a few hours after sunset.
C. Just before and after maximum heating.
D. Only during maximum heating. |
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Definition
| B. From time of maximum heating to a few hours after sunset. |
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Term
26.What wind speeds do you focus on at the 200 and 30 millibar level for severe weather analysis?
A. 76 knots
B. 80 knots.
C. 86 knots.
D. 90 knots. |
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Definition
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Term
27.In straight line flow, what quadrants are the main diffluent areas of a jet maximum?
A. Left & right rear.
B. Left & right front.
C. Left front & right rear.
D. Left rear & right front. |
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Definition
| C. Left front & right rear. |
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Term
28.Which quadrant in the jet max should you look for positive vorticity advection?
A. Left rear.
B. Right rear.
C. Left front.
D. Right front. |
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Definition
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Term
29.At which pressure level is strong wind needed for thunderstorms to become severe?
A. 300 millibars.
B. 500 millibars.
C. 700 millibars.
D. 850 millibars. |
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Definition
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Term
30.What does positive vorticity advection indicate?
A. Divergence or upward vertical motion.
B. Convergence or upward vertical motion.
C. Divergence or downward vertical motion.
D. Convergence or downward vertical motion. |
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Definition
| A. Divergence or upward vertical motion. |
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Term
31.What parameters are the two most important to analyze at 700 millibars?
A. No-change line and dry-air intrusion.
B. No-change line and wind maximums.
C. Dew point temperatures and dry-air intrusion.
D. Wind maximums and dew point temperatures. |
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Definition
| A. No-change line and dry-air intrusion. |
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Term
32.What weather characteristic does the 700 millibars no change line usually line up with?
A. Trough axis.
B. Surface front.
C. Low-level jet.
D. 850 millibar warm ridge. |
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Definition
| D. 850 millibar warm ridge. |
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Term
33.Which zone is not a type of surface convergent zone?
A. Dry line.
B. Frontal boundary.
C. Land breeze front.
D. Outflow boundary. |
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Definition
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Term
34.How far ahead of a cold front do pre-frontal squall lines form?
A. 25 to 125 statute miles.
B. 50 to 150 statute miles.
C. 25 to 125 nautical miles.
D. 50 to 150 nautical miles. |
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Definition
| D. 50 to 150 nautical miles. |
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Term
35.What does a >+1 on the Showalter stability index suggest?
A. Strong stability.
B. Strong instability.
C. Moderate stability.
D. Moderate instability. |
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Definition
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Term
36. What does a lifted index (LI) greater than zero indicate?
A. Stability.
B. Instability.
C. No severe weather - winds too strong.
D. Severe weather likely, chance of tornadoes. |
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Definition
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Term
37. What weather occurrence does a severe weather threat index of 650 indicate?
A. Severe thunderstorms likely, chance of tornadoes.
B. Severe thunderstorms and tornadoes likely.
C. No severe weather – winds too strong.
D. Tornadoes nearly always occur. |
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Definition
| D. Tornadoes nearly always occur. |
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Term
38.What atmospheric event does a negative convective available potential energy indicate?
A. Increased warm moist air advection.
B. Decreased cold dry air advection.
C. Downward vertical motions.
D. Upward vertical motions. |
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Definition
| C. Downward vertical motions. |
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Term
39.What weather feature is commonly found south of the center of a low pressure system and is indicated by a relatively cloud-free region?
A. Warm front.
B. Cold front.
C. Dry line.
D. Dry slot. |
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Definition
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Term
40.Which atmospheric occurrence is not a type of lifting mechanism for convection?
A. Convection.
B. Frontal lifting.
C. Decompression.
D. Orographic lifting. |
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Definition
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Term
41. What number of feet must the freezing level be for most precipitation to reach the surface as snow?
A. 1,000.
B. 1,100.
C. 1,200.
D. 1,300. |
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Definition
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Term
42.For the Weather Service Radar (WSR)–88D to generate a base reflectivity product, the antenna must complete
A. one elevation slice.
B. one complete 360° circle.
C. an entire volume coverage pattern.
D. at least two complete volume coverage patterns. |
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Definition
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Term
43.Which decibel (dBZ) value is considered the approximate precipitable/non-precipitable threshold?
A. –30 dBZ.
B. –18 dBZ.
C. +18 dBZ.
D. +30 dBZ. |
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Definition
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Term
44.What does the line echo wave pattern (LEWP) signature mean to a forecaster?
A. A favorable environment exists for severe weather development.
B. High pressure is forming and the threat of severe weather has ended.
C. Continued thunderstorm development is certain but severe weather is unlikely.
D. The current state of the atmosphere is much too stable for severe weather development. |
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Definition
| A. A favorable environment exists for severe weather development. |
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Term
45.Embedded thunderstorms are detected by the Weather Service Radar (WSR)–88D quite well because
A. it uses airborne radar technology to seek out these storms.
B. the storms move much faster than the surrounding precipitation.
C. its 10cm wavelength can see through the stratiform precipitation.
D. the storms move much slower than the surrounding precipitation. |
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Definition
| C. its 10cm wavelength can see through the stratiform precipitation. |
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Term
46.Outflow boundaries may be seen on the Weather Service Radar (WSR)–88D even when no clouds are present because
A. the WSR–88D can detect returns of greater than +18dBZ.
B. precipitable water is present although it is not visible to the human eye.
C. low-level wind shear is usually present with the boundary, making it more visible.
D. a gradient in the refractive index due to density differences that exist with the boundary. |
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Definition
| D. a gradient in the refractive index due to density differences that exist with the boundary. |
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Term
47.Which product is used in the detection and location of rotating thunderstorms and in determining wind field characteristics?
A. Base reflectivity.
B. Base radial velocity.
C. Severe weather analysis.
D. Severe weather probability. |
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Definition
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Term
48.When the Doppler zero line has a noticeable S-shaped pattern, winds are considered to be
A. from 270°.
B. veering with height.
C. backing with height.
D. increasing with height. |
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Definition
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Term
49.Which concept should be considered when trying to determine hail size?
A. Strength of the updraft.
B. Rotation at the base of the storm.
C. Strength of the convergence aloft.
D. Rotation in the mid-levels of the storm. |
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Definition
| A. Strength of the updraft. |
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Term
50.The spectrum width product is most effective when
A. used alone.
B. used with other products.
C. displayed in 16 data levels.
D. overlaid on composite reflectivity. |
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Definition
| B. used with other products. |
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Term
51.Which statement is not a use of the composite reflectivity product?
A. It is the first step in identifying significant weather features.
B. It can be used as a quick check on the overall reflectivity pattern.
C. It can be used to show the 3-D structure of the reflectivity pattern.
D. It provides an instant snapshot of the most important reflectivity features. |
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Definition
| C. It can be used to show the 3-D structure of the reflectivity pattern. |
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Term
52.The melting level is displayed on the composite reflectivity product as a
A. straight line of higher reflectivities.
B. circular pattern of higher reflectivities.
C. series of ellipses centered over each snow shower.
D. series of spots that show ice forming on the radome. |
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Definition
| B. circular pattern of higher reflectivities. |
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Term
53.Vertically integrated liquid (VIL) algorithms display VIL values for storms based on
A. water droplet size converted to liquid water content.
B. water droplet size converted to water vapor values.
C. reflectivity data converted to liquid water content.
D. reflectivity data converted to water vapor values. |
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Definition
| C. reflectivity data converted to liquid water content. |
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Term
54. A strongly tilted storm may cause what kind of vertically integrated liquid values to be displayed?
A. Taller.
B. Lower.
C. Higher.
D. Shorter. |
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Definition
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Term
55.The echo tops product is based on data from what other product?
A. Base velocity.
B. Spectrum width.
C. Base reflectivity.
D. Vertically integrated liquid. |
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Definition
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Term
56.The echo tops product is very useful in
A. identifying bounded weak echo regions.
B. assessing the possibility of hail damage.
C. showing the presence of vertical tilt within a storm.
D. depicting the true cloud tops within 124 nautical miles. |
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Definition
| C. showing the presence of vertical tilt within a storm. |
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Term
57.The storm total precipitation product provides continuously updated information on precipitation accumulations within how many nautical miles of the radar?
A. 120.
B. 124.
C. 200.
D. 240. |
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Definition
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Term
58.A limitation of the storm total precipitation product is that it
A. has trouble with large-scale features.
B. has trouble with small-scale features.
C. gives us a limited post storm analysis.
D. displays total precipitation accumulations. |
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Definition
| B. has trouble with small-scale features. |
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Term
59.What is an advantage that the user selectable precipitation product provides over the storm total and three-hour precipitation products?
A. Data is presented in 16 levels.
B. A product is available every volume scan.
C. Gaps of precipitation will not affect amounts.
D. Accumulation amounts are available for a 124 nautical miles area. |
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Definition
| C. Gaps of precipitation will not affect amounts. |
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Term
60.How many hours is the database for the user selectable precipitation product limited to?
A. 24
B. 30
C. 36
D. 48 |
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Definition
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Term
61 The maximum number of hours that the user selectable precipitation product can be generated for is
A. 12.
B. 24.
C. 30.
D. 36. |
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Definition
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Term
62 What number of nautical miles is the optimum effective range of the mesocyclone detection algorithm?
A. 32.
B. 65.
C. 124.
D. 240. |
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Definition
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Term
63 Why is tornadic vortex signature detection beyond 55 nautical miles difficult?
A. Beam broadening.
B. Beam wander.
C. Scintillation.
D. Ducting. |
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Definition
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Term
64 The inputs to the velocity azimuth display algorithm are
A. base reflectivity and spectrum width.
B. mean radial velocity and spectrum width.
C. mean radial velocity and base reflectivity.
D. mean radial velocity and velocity cross section. |
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Definition
| C. mean radial velocity and base reflectivity. |
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Term
65 The velocity azimuth display winds profile provides
A. an alphanumeric list of wind velocities by height.
B. a graphic display of wind velocity at one azimuth.
C. a graphic display of wind velocities at various ranges.
D. a time-height profile of wind velocity at a pre-determined range. |
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Definition
| D. a time-height profile of wind velocity at a pre-determined range. |
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Term
66 Data thresholds for the vertical winds profile can be changed
A. by unit control panel.
B. by radar data acquisition.
C. on the principal user processor.
D. on the radar product generator. |
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Definition
| A. by unit control panel. |
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Term
The velocity azimuth display wind profile displays
A. the radial component of the wind.
B. the true wind speed and direction.
C. only the component of the wind perpendicular to the beam.
D. radial winds, provided the root mean square is less than four meters per second. |
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Definition
| B. the true wind speed and direction. |
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Term
68 The maximum number of vertical wind profiles that can be displayed on a single velocity azimuth display winds profile is .
A. 9
B. 10
C. 11
D. 12 |
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Definition
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Term
69 The velocity azimuth display wind profile (VWP) can detect features such as
A. wind shifts and jet streams.
B. inversions and microbursts.
C. convergence and divergence.
D. thermal winds and forecasted time of a wind shift. |
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Definition
| A. wind shifts and jet streams. |
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Term
70 If the velocity azimuth display (VAD) algorithm finds no difference between the zero velocity line and the zeroth harmonic, then the offset is zero, and the wind field is
A. uniform.
B. divergent.
C. convergent.
D. not determinable. |
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Definition
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Term
71 The color-coded root mean square of the displayed velocity azimuth display winds is related to what characteristic of the winds?
A. Strength
B. Altitude.
C. Direction.
D. Reliability. |
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Definition
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Term
72 The storm relative mean radial velocity map and storm relative mean radial velocity region product depends on what algorithm?
A. Reflectivity.
B. Storm series.
C. Mesocyclone.
D. Storm-tracking. |
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Definition
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Term
73 Resolution of cross-section products
A. vary depending on the product requested.
B. vary with the height of the phenomena.
C. vary with range from the radar data acquisition site.
D. remain constant. |
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Definition
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Term
74 In clear-air mode, the reflectivity cross-section is used to determine
A. hail spikes.
B. the freezing level.
C. bounded weak echo regions.
D. the extent of mid-level overhang. |
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Definition
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Term
75 The range of a velocity cross-section is limited to
A. 32 nautical miles (nm).
B. 64 nm.
C. 124 nm.
D. 240 nm. |
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Definition
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Term
76 Which data collection limitation of the reflectivity cross-section product causes reduced values at long ranges?
A. Range folding.
B. Velocity aliasing.
C. Beam broadening.
D. Decreased pulse length. |
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Definition
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Term
77 A velocity cross-section limitation causing small features at long distances to go undetected is
A. beam broadening.
B. product resolution.
C. aliased velocity data.
D. lack of height continuity. |
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Definition
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Term
78 What is an important thing to keep in mind when requesting a velocity cross-section?
A. Storm motion.
B. The orientation of the storm.
C. Where the reflectivity cross-section was cut.
D. It must be either parallel, or perpendicular to, a radial. |
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Definition
| D. It must be either parallel, or perpendicular to, a radial. |
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Term
79 The storm cell centroid algorithm performs best when
A. solid lines of thunderstorms are present.
B. a mesoscale convective complex is present.
C. embedded multicell thunderstorms are present.
D. isolated, well-defined thunderstorms are present. |
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Definition
| D. isolated, well-defined thunderstorms are present. |
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Term
80 The storm track information product algorithm provides data on
A. past positions of thunderstorms.
B. forecasted positions of severe thunderstorms.
C. past and present positions of severe thunderstorms.
D. past, present, and future positions of thunderstorms. |
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Definition
| D. past, present, and future positions of thunderstorms. |
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Term
81 What determines the length of a forecast made by the storm position forecast algorithm?
A. Storm’s cell based vertically integrated liquid.
B. Accuracy of previous volume scan’s forecast.
C. Storm’s current speed of movement.
D. Size of storm cell centroid. |
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Definition
| B. Accuracy of previous volume scan’s forecast. |
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Term
82 The most important product used in defining storm segments is
A. hail.
B. storm tracking.
C. spectrum width.
D. base reflectivity. |
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Definition
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Term
83 Which statement best defines a storm cell segment?
A. That portion of a severe thunderstorm that is directly below the anvil top.
B. That portion of a storm that exceeds the maximum reflectivity thresholds.
C. The smallest portion of a vertically stacked thunderstorm that exceeds maximum reflectivity thresholds.
D. Contiguous sample volumes along a radial that are greater than or equal to specific reflectivity thresholds. |
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Definition
| D. Contiguous sample volumes along a radial that are greater than or equal to specific reflectivity thresholds. |
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Term
84 The three estimates the hail detection algorithm provides are probability of
A. hail, possibility of severe hail, and forecast hail size.
B. severe hail, maximum hail size expected, and possibility of hail.
C. hail, probability of severe hail, and maximum expected hail size.
D. large hail (>3/4 inch), probability of severe hail, and forecast hail size. |
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Definition
| C. hail, probability of severe hail, and maximum expected hail size. |
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Term
85 The probability of severe hail algorithm will look for hail greater than
A. 1/4 inch.
B. 1/2 inch.
C. 3/4 inch.
D. 1 inch. |
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Definition
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Term
86 What information needs to be routinely updated to increase the hail detection algorithm’s performance?
A. Height of the wet bulb zero value.
B. Mean sea level altitudes for 0°C and –20°C.
C. Mean sea level altitudes for 0°C and –10°C.
D. Wind speeds for 10,000 feet above ground level. |
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Definition
| B. Mean sea level altitudes for 0°C and –20°C. |
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Term
87 Which product provides information on cell-based vertically integrated liquid, height of maximum reflectivity, and maximum reflectivity in the cell?
A. Cell trends.
B. Storm structure product.
C. Storm tracking information product.
D. Storm cell identification and tracking algorithm attribute table. |
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Definition
| B. Storm structure product. |
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Term
88 What information does the cell trends product provide the forecaster?
A. Forecast of life cycle for convective development.
B. Status of supercells and the potential for microbursts.
C. Status of microbursts and potential for overshooting tops.
D. Forecast for maximum reflectivity values and cell-based vertically integrated liquid. |
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Definition
| D. Forecast for maximum reflectivity values and cell-based vertically integrated liquid. |
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Term
89 What agency developed the Weather Service Radar (WSR) 88–D product/phenomena matrix?
A. National Oceanic and Atmospheric Administration.
B. National Weather Service.
C. Air Weather Service.
D. United States Navy. |
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Definition
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Term
90 What product is best used to isolate storms associated with heavy snow showers?
A. Velocity.
B. Reflectivity.
C. Vertically integrated liquid.
D. Severe weather probability. |
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Definition
| C. Vertically integrated liquid. |
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