CDC 3

1.

1 point

When does the maximum severe activity occur with a major cyclone?

A few hours after sunrise to maximum heating.

Just before and after maximum heating.

From time of maximum heating to a few hours after sunset.

Only during maximum heating.

2.

1 point

Which concept should be considered when trying to determine hail size?

Strength of the convergence aloft.

Strength of the updraft.

Rotation at the base of the storm.

Rotation in the mid-levels of the storm.

3.

1 point

In straight line flow, what quadrants are the main diffluent areas of a jet maximum?

Left & right rear.

Left rear & right front.

Left front & right rear.

Left & right front.

4.

1 point

What do you physically compare the 00-hour forecast with during the initialization step of the verification, initialization and verification (VIV) process?

12-hour forecast.

Analysis.

Previous 12-hour forecast.

24-hour forecast.

5.

1 point

In what tornado-producing airmass do tornadoes most frequently occur in families, with paths that are commonly long and wide?

Type II, Gulf Coast type.

Type IV, Inverted “V” type.

Type I, Great Plains type.

Type III, Pacific Coast type.

6.

1 point

Which zone is not a type of surface convergent zone?

Outflow boundary.

Dry line.

Frontal boundary.

Land breeze front.

7.

1 point

What weather characteristic does the 700 millibars no change line usually line up with?

Low-level jet.

850 millibar warm ridge.

Trough axis.

Surface front.

8.

1 point

What wind speeds do you focus on at the 200 and 30 millibar level for severe weather analysis?

86 knots.

90 knots.

76 knots.

80 knots.

9.

1 point

Which type of airmass has cold air at all levels?

Type III Pacific Coast.

Type II Gulf Coast.

Type I Great Plains.

Type IV Inverted V.

10.

1 point

What parameters are the two most important to analyze at 700 millibars?

Wind maximums and dew point temperatures.

No-change line and wind maximums.

No-change line and dry-air intrusion.

Dew point temperatures and dry-air intrusion.

11.

1 point

What kind of dew-point temperature difference should exist across a dry line?

< 10° C degrees

< 10° F degrees

> 10° C degrees

> 10° F degrees

12.

1 point

What atmospheric event does a negative convective available potential energy indicate?

Decreased cold dry air advection.

Increased warm moist air advection.

Upward vertical motions.

Downward vertical motions.

13.

1 point

Which region is not a primary source for airmasses?

Temperate.

Arctic.

Equatorial.

Tropical.

14.

1 point

Embedded thunderstorms are detected by the Weather Service Radar (WSR)–88D quite well because

the storms move much faster than the surrounding precipitation.

it uses airborne radar technology to seek out these storms.

its 10cm wavelength can see through the stratiform precipitation.

the storms move much slower than the surrounding precipitation.

15.

1 point

Where do multi-cell storms typically regenerate?

Along the gust front.

East of the westernmost cell.

The rear-flank downdraft.

North of the 700mb wind maximum.

16.

1 point

Which type of airmass is tropical in origin and generally warm and moist?

Type III Pacific Coast.

Type IV Inverted V.

Type I Great Plains.

Type II Gulf Coast.

17.

1 point

What does a lifted index (LI) greater than zero indicate?

Instability.

No severe weather - winds too strong.

Severe weather likely, chance of tornadoes.

Stability.

18.

1 point

How many minutes do single-cell storms typically last?

30 to 45.

20 to 40.

30 to 60.

20 to 30.

19.

1 point

Outflow boundaries may be seen on the Weather Service Radar (WSR)–88D even when no clouds are present because

low-level wind shear is usually present with the boundary, making it more visible.

the WSR–88D can detect returns of greater than +18dBZ.

precipitable water is present although it is not visible to the human eye.

a gradient in the refractive index due to density differences that exist with the boundary.

20.

1 point

What does positive vorticity advection indicate?

Divergence or upward vertical motion.

Convergence or upward vertical motion.

Divergence or downward vertical motion.

Convergence or downward vertical motion.

21.

1 point

What factor is evident above the inversion with a Type I airmass?

Rapid drying.

Moisture increase.

Condensation.

Turbulence.

22.

1 point

Which atmospheric occurrence is not a type of lifting mechanism for convection?

Decompression.

Convection.

Oreographic lifting.

Frontal lifting.

23.

1 point

Which decibel (dBZ) value is considered the approximate precipitable/non-precipitable threshold?

+18 dBZ.

–30 dBZ.

–18 dBZ.

+30 dBZ.

24.

1 point

For the Weather Service Radar (WSR)–88D to generate a base reflectivity product, the antenna must complete

at least two complete volume coverage patterns.

one elevation slice.

an entire volume coverage pattern.

one complete 360° circle.

25.

1 point

What initial conditions are models used based upon?

Previously forecasted conditions.

Current weather observations.

Standard atmospheric conditions.

Model of choice conditions.

26.

1 point

Which characteristic is not one of multi-cell thunderstorms?

Weak directional shear in the lower levels.

large hail near downdraft centers.

short-duration tornadoes.

Straight-line or unidirectional profile.

27.

1 point

What action is the final step of the verification, initialization and verification process?

Verify the 00-hour forecast with your current analysis.

Verify the previous 12-hour forecast against the current 00-hour forecast.

Verify the previous 12-hour forecast with the current 12-hour forecast.

Verify the 12-hour forecast with real-time data for the same time.

28.

1 point

Which product is used in the detection and location of rotating thunderstorms and in determining wind field characteristics?

Base reflectivity.

Base radial velocity.

Severe weather probability.

Severe weather analysis.

29.

1 point

Which type of airmass features maritime polar air overrunning continental tropical air between 5,000 and 8,000 feet above the surface?

Type IV Inverted V.

Type II Gulf Coast.

Type III Pacific Coast.

Type I Great Plains.

30.

1 point

Which thunderstorm is not a type of supercell thunderstorm?

Classic.

Moderate precipitation.

Low precipitation.

High precipitation.

31.

1 point

Where is the geographic area known as the “Great Plains” located?

West of the Rocky Mountains.

East of the Appalachian Mountains.

Between the Appalachian Mountains and the Missouri River.

Between the Mississippi River and the Rocky Mountains.

32.

1 point

What number of feet must the freezing level be for most precipitation to reach the surface as snow?

1,000.

1,200.

1,300.

1,100.

33.

1 point

What severe weather synoptic pattern’s airmass is typically Type III?

Type B, frontal.

Type A, dry line.

Type C, overrunning.

Type D, cold core.

34.

1 point

What size hail do classic supercell thunderstorms typically produce?

Golf ball.

Marble.

Baseball.

Softball.

35.

1 point

What weather feature is commonly found south of the center of a low pressure system and is indicated by a relatively cloud-free region?

Warm front.

Dry line.

Cold front.

Dry slot.

36.

1 point

What action is the goal of severe weather analysis?

Determine the rear-flank downdraft wind direction.

Identify the different types of severe thunderstorms.

Identify the preconditions that allow storms to become severe.

Determine the mid-level wind speed and direction.

37.

1 point

The spectrum width product is most effective when

used alone.

displayed in 16 data levels.

used with other products.

overlaid on composite reflectivity.

38.

1 point

Which air mass is cold with surface temperatures ranging from 50

Type II Gulf Coast.

Type III Pacific Coast.

Type IV Inverted V.

Type I Great Plains.

39.

1 point

What does a >+1 on the Showalter stability index suggest?

Moderate instability.

Strong stability.

Strong instability.

Moderate stability.

40.

1 point

How far ahead of a cold front do pre-frontal squall lines form?

25 to 125 nautical miles.

50 to 150 nautical miles.

50 to 150 statute miles.

25 to 125 statute miles.

41.

1 point

Which characteristic is not one of the single-cell thunderstorm?

Weak vertical and horizontal wind shear.

High winds and hail.

Storm motion equal to the mean wind in the lowest 5km to 7km.

Frequent tornadoes.

42.

1 point

When the Doppler zero line has a noticeable S-shaped pattern, winds are considered to be

from 270°.

backing with height.

increasing with height.

veering with height.

43.

1 point

Which quadrant in the jet max should you look for positive vorticity advection?

Right rear.

Right front.

Left front.

Left rear.

44.

1 point

Aside from the Air Force Operational Weather Squadrons (OWS), what agency produces discussions on model output?

Joint Army Air Force Weather Information Network.

National Weather Service.

Air Force Weather Agency.

Air Weather Service.

45.

1 point

Which type of supercell thunderstorm is most commonly found along the dry line of west Texas?

High-precipitation.

Moderate-precipitation.

Classic.

Low-precipitation.

46.

1 point

What weather occurrence does a severe weather threat index of 650 indicate?

Tornadoes nearly always occur.

No severe weather – winds too strong.

Severe thunderstorms and tornadoes likely.

Severe thunderstorms likely, chance of tornadoes.

47.

1 point

What letter or symbol is appended to the label of a modifying airmass that is cooler than the ground below?

Lower case k

Lower case c

Minus symbol.

Plus symbol.

48.

1 point

At which pressure level is strong wind needed for thunderstorms to become severe?

500 millibars.

700 millibars.

300 millibars.

850 millibars.

49.

1 point

What areas do Storm Prediction Center advisory charts outline?

Areas of frequent severe weather occurrence.

Areas of frequent crosswind occurrence.

Areas of expected crosswinds.

Areas of expected severe weather.

50.

1 point

What does the line echo wave pattern (LEWP) signature mean to a forecaster?

Continued thunderstorm development is certain but severe weather is unlikely.

The current state of the atmosphere is much too stable for severe weather development.

A favorable environment exists for severe weather development.

High pressure is forming and the threat of severe weather has ended.